数控技术课程毕业设计外文文献翻译、中英文翻译、外文翻译
机械类数控外文翻译外文文献英文文献数控.doc
Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was developed in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.However ,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is 4he curve . Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this represented giant step forward in the control of machine tools . However ,there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium . It was common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigors of shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goes down , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connectDigital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP’s for certain fields like motor-control or modems ,and general high-performance DSP’s that can perform broad ranges of processingtasks. Development kits an` software are also available , and there are companies making software development tools for DSP’s that allows the programmer to implement complex processing algorithms using simple “drag ‘n’ drop” methodologies.DSP’s more or less fall into t wo categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose” register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP’s behave more like common general-purpose CPU’s ,with register-files.There are thousands of different DSP’s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA’s provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits, linearity , speed, filter characteristics and other things.The TMS320 family DQP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (D[Ps) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The’ F/C240 is a number of the’C2000DSP platform , and is optimized for control applications. The’C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications:--- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the ‘C24x devices provides analog designers a digital solution that does not sacrifice the precision and performance of their system performance can be enhanced through the use of advanced control algorithms for techniquessuch as adaptive control , Kalman filtering , and state control. The ‘C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwired solutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purp ose‘C2xx generation ,source code compatible with the’C2x generation , and upwardly source code compatible with the ‘C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The ‘C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow’s embedded control marke tplace.The TMS320F/C240 is the first standard device introduced in the ‘24x series of DSP controllers. It sets the standard for a single-chip digital motor controller. The ‘240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The ‘240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the ‘240 include:---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climatecontrol---Appliance and HV AC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the ‘240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it’s own compare register, suppo rt the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A humanbeing may be considered to be a control system with many inputs and outputs, capable of carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there may be multitude of feedback loops and element blocks.数控在先进制造技术领域最根本的观念之一是数控（NC）。
数控加工技术概述外文翻译、中英文翻译、外文文献翻译
原文：The digital control process technology is summarized1. digital control programming reaches such developmentThe digital control programming is the segment that be able to obviously bring into play the beneficial result in at the moment CAD/CAPP/CAM's system the most most , such is living to achieve to design the process automation and raise process accuracy and processes the quality and cuts down the product development cycle and so on the respect is brining into play the significant action . Being living possess the greats quantity applications such as aviation industry and auto industry and so on territorys . Since giving birth to the intense demand of practice , wide-ranging research has wholly been carried on to the digital control programming technique in the home and abroad , and acquires the plentiful and substantial fruit . The next reaches such to the digital control programming and develops to act as some to introduce .1.1 basic concept of digital control programmingThe digital control programming is through the spare parts drawings up the full process that obtains the digital control processing program . Its main mission is that the sword spot ( Cutterlocationpoint abbreviate CL's spot ) in the sword is processed away in the calculation .The point of intersection that sword the spot was oridinarily get to the cutting tool axial line against the cutting tool face still will be give out the sword shaft vector in much processs1.2 digital control programming technique development surveyMIT designed one kind of special language that is used in the inflexible spare parts digital control processing program establishments to the program problem in order to resolve in the digital control process , andis called APT ( AutomaticallyProgrammedTool ) in the 50's .Well-developed editions such as after APT time and again develops , takeed shape such as APTII and APTIII ( the stereoscopic cutting action is employd ) and APT ( the algorithm improves , add much coordinates surface processes the programming meritorous service capacity ) and APTAC ( Advancedcontouring ) ( add cuts the database administration system ) and APT/SS ( SculpturedSurface ) ( add engraves the camber processes the programming meritorous service capacity ) and so on .Adoping APT language drawing up digital control order to have easy the refineing of order , and gos away the strongs point such as sword control is agile and so on , and causes the digital control process the programming , and moves upward up yet possess much not suitable points to geometry element .APT through " assemble language " grade to the machine tool order : Adoping language definition spare parts geometry form shape , and is difficult to depict complex geometry form shape , and lack audio-visual quality of geometry ;The certification measure that the figure audio-visual that is short of to spare parts form shape and the cutting tool movement locus displays and the cutting tool locus ;Being difficult to effectively join with CAD's data bank and CAPP's system ;Not to act as easily up the high automation , the integrationizationIn view of the APT's language defect , in 1978 , France attained the system that the large rope airplane corporation starts development gathers assemble three dimensions design , analysis and NC's process integration , and is called in the interest of CATIA .Having ariseed alikely the systems such as EUCLID and NPU/GNCP and so on soon afterwards very quickly , the geometry moldswholly valid settlements of these systems and the spare parts geometry form shape display is designed mutually and mends generates the cutting tool locus , and the problems such as the imitation to go away the sword process displays and certification and so on promoteed CAD and CAM developing to the integration orientation . The approximately idea that system ( CIMS ) and parallel project ( CE ) was manufacture in the calculating machine integration take shape up the 80's gradually on the base that the CAD/CAM's integration being living is approximately attend school . At the moment , and the necessaries that CE developed in order to adapt to CIMS , the digital control programming system to integrationization and intelligentization the development .Being living the integration respect , with the development accords with the STEP ( StandardfortheExchangeofProductModelData ) criterion parameterization feature moldmaking and systematically gives priority to , having carried on the highly effective work of greats quantity at the moment is the home and abroad development heatpointBeing living the intelligentization respect , the work has start only a short while ago , and still awaits that we leave hard2、NCs' cutting tool locus generates the method study developing actualityDigital control programming core work is generateing the cutting tool locus , afterwards by such scattered one-tenth sword spot , places that the handle comes into being the digital control processing program afterwards viaing .The next cutting tool locus comes into being the means and actes as some and introduce2.1 baseding on a little and string , surface and part of the body NC's sword track formation meansCAD's technique moves through the two dimension mapping , andudergo the three dimensions wires frame and camber and the solid modelling generation , now the parameterization feature reacing is always moldded .Is living two dimension mapping together with three dimensions wires frame phase , in case the opening processes , the rough sketch is processed the digital control process is main with spot and string act as drive target , the plane area process and so on .This kind of level that personnel staff was requireed manipulating in the process is taller , complex mutually .Being living camber and the solid modelling generation , entity process had ariseed to based on .The entity process target is an entity ( oridinarily blendes for CSG and BREP express ) , its ( moreover , intersects , falls short of to operate ) but get yield through some fundamental parts of the body habitually after the set operation .The entity is processed not merely usable rough machining and semi precision work to the spare parts , and the great area cuts Yu Liang , and the effectiveness is processed in the raise , but also usable research together with development to digital control baseding on the feature programming system , is the feature process baseEntity process oridinarily possess entity rough sketch process and the entity area and processes two kinds .The entity process realization means slices law ( SLICE ) in the interest of the straturm , in immediate future slices by the process entity in the way of one series of level , afterwards to obtains the intersection comes into being the isometry string dos worthwhile the sword the going away locus .The original slave system needs the angle depart , the digital control process that the ACIS's geometry moldmaking being living achieved thiskind to based on a little on the terrace and the string and surface and entity Feature NC's sword track formation means 2.2 baseding onThe parameterization feature molds to possess the specified development particular period , yet baseds on that feature cutting tool locus formation means research starts only a short while ago .The feature processes to cause digital control programming personnel staff to be out to let drop the step geometry message to those ( in case : Spot , string , surface and entity ) manipulate , but transforing to carry on the digital control programming in the interest of directly to accords with the feature that engineers and technicians are used to , and liftd the programming effectiveness enormouslyW.R.Mail and A.J.Mcleod are living in their research to give out one to based on feature NC's code generating sub system , and this systematic work rule is : Spare parts every one process wholly may be regarded as to adjust to make up the total that the spare parts form shape feature group processed .In immediate future the queen completees spare parts process is not processed that to the feature adjusting entirely form the shape in that way either form shape feature component .But each form shape feature either form shape feature series NC's code may generate voluntarily .The system opened up at the moment merely is applicable to 2.5D's spare parts processThe LeeandChang opened up one kind of raised liberal camber feature cutting tool locus of means autogeneration in the way of fictitious border system .This systematic work rule is : Being living to inlay inner place the raised liberal camber into one the minimal long and square , so raised liberal camber feature is transformd into the hollow feature .Minimal the long and square incorporation against the end product pattern constituteed to be called one kind of indirect produce pattern on the fictitious pattern .That the cutting tool locus formation means separates into completees three paces : ( 1 ) and the cutting action polyhedron feature ;( 2 ) and cuts the liberal camber feature ;( 3 ) and the cutting action intersects the featureJongYunJung researcies baseds on the non- cutting action cutting tool locus formation problem of feature .The article process baseding on the feature locus separates into rough sketch process and processes two types with the inside area , and the definition this two types of process cutting action orientations , attains the aim that the entirety optimizes the cutting tool locus by means of decreasing the cutting action cutting tool locus .Type who talked about these fundamental features gos away sword way and cutting tool selection and process order and so on to main being aimed at of article some kinds of fundamental features ( hollow inner place Kong and step , trough ) , and averting repeatedly going away the sword by means of IP ( InterProgramming ) technique , with the non- cutting action cutting tool locus of optimization .Besides JongYunJong still is living , and his doctor in 1991 researcied tabrication feature extraction and baseds on feature cutting tool and the cutting tool way in the dissertationThe feature process base is an entity process , and surely of course also may think the entity process being more high-quality .Yet feature process distinct entity process , and entity process possess it oneself the limitations .Feature process chiefly possess below difference against entity process :Through approximately attends school says that the feature is the meritorous service capacity key element to make up the spare parts , and the operation that accords with engineers and technicians is used to , by engineers and technicians are know intimately ;The entity is the geometry target on low straturm , and is a geometric object that obtains after a series of Booleans calculation , and does not have whatever meritorous service capacity semantic information ;It frequently is adjusting the once only process of entire spare parts ( entity ) that the entity is processed .Yet in reality the spare parts is not very much probably merely once processed through in the way of the sword , frequently will go through a series of workmans of rough machining and semi precision work and precision work and so on stage , the place of spare parts difference oridinarily will be employd the difference cutting tool and process ;Now and then not only the spare parts will be employd up turning , but also employ up mill .Hence entity process is chiefly used spare parts rough machining and semi precision work .But but the feature on processing through essentially resolved the above-mentioned issue ;Feature process havees even more intellect .May regulate some kinds of settled admittedly process meanss as to the specially designated feature , particularly those have been living , and STEP's criterion the person who regulates the feature still more is such in this way .In case we wholly draw up the specially designated process means to all standards feature , it is you can imagine that spare parts that in thatway sufficiently succeed through the standard feature to those are processed such convenient quality .In case CAPP systematically be able to supply the relevant technology feature , NCP's system may decrease inputing mutually , and havees even more intellect enormously in that way .But these entity process can not achievedFeature process is favour of achieving through comprehensive integration of CAD , CAPP , NCP and CNC's system , and achieves the two-way going from place to place of message , in the interest of CIMS and even parallel project ( CE ) are settleed the well base ;It be helpless that but the entity is processed to theseNC's sword track formation means 2.3 being on active service in several main CAD/CAM's systems is analysedActive duty CAM constitutes reaching the main meritorous service capacityThat at the moment comparatively more mature CAM's system is main with two kinds of shapes achieves CAD/CAM's system integration : Integration CAD/CAM's system ( in case : UGII , Euclid and Pro/ENGINEERs and so on ) and independent relatively CAM's system ( in case : Mastercam and Surfcams and so on ) . Unitary less than the former data format is directly gaind the produce geometric model through CAD's system , but the latter is main gains the produce geometric model by means of the neutral papers through else CAD's systems . However , no matter is what the CAM's system growed the shape , wholly consising of five modules , in immediate future mutually technology parameter input module and cutting tool locus formation module and cutting tool locus compiler module and three dimensions process that dynamic imitation module and afterwards places the processing module . Next merely some famous CAD/CAM's system NC's process meanss are holied discussions .UGII's process means is analysedOridinarily think that UGII is the best in trade circle , and havees representativeness digital control software most .That such havees the distinguishing feature most is the cutting tool locus formation means that such meritorous service capacity is powerful .Consists of turning , milling and string cuts and so on the consummate process means .In it milling chiefly possess the below meritorous service capacity :And PointtoPoint: Completeing the different openings processesAnd PanarMill: Plane is milled .Consising of that the one-way walkes surely , the two-way row are slice , and the hoop is slice along with rough sketch process to await And FixedContour: Admittedly much projectionss are areed processed stably .Dominateeing on being living on the single camber either much camber the removing of cutting tool in the way of the projection means , and that the control cutting tool is removed may be the cutting tool locus that has generateed , a series of either suite stringAnd VariableContour: Variable projection is processedAnd Parameterline: Await that the parameter string is processed .The successive process of single camber either much camber may be adjustAnd ZigZagSurface: Cutting out processAnd RoughtoDepth: Rough machining .The depth is reachd assigning in the rough machining by Mao PiAnd CavityMill: The many stages depth mould cavity processes .Rough machining that particularly is applicable to the male contact with the hollow standardAnd SequentialSurface: The camber occuies simultaneously the workman .In accordance the spare parts and guides that and the thinking of check adjust the removing suppling the largesttest degree control of cutting toolEDSUnigraphics still consists of greats quantity else the respects meritorous service capacitys , and did not enumerate one by one here STRATA's process means is analysedSTRATA is a digital control programming system development environment , and it is establishing ACIS's geometry model building terrace onIt supplys two kinds of programming development environments in the interest of consumer , in immediate future NC's command language interface and the NC's operation C++ storehouse . It may back three to mill , and turning and string cut NC and process , and may back wire frame , camber and the entity geometry model building . Such NC's cutting tool locus formation means is baseding on the physical model . STRATA is baseded on , and what supplys the process means in entity NC's cutting tool locus formation type storehouse consists of : ProfileToolpath: Rough sketch processAreaClearToolpath: The area on plane processesSolidProfileToolpath: The entity rough sketch is processedSolidAreaClearToolpath: The area on entity plane processesSolidFaceToolPath: The entity face processesSolidSliceToolPath: The entity severs process on planeLanguagebasedToolpath: Baseding on , language cutting tool locus generatesElse CAD/CAM software , in case Euclid the person who awaits the NC's meritorous service capacity is each has his strong point , yet suchfundamental substance is almost alike , the not natural difference .2.4 main problem of systematic sword track formation means of active duty CAMIn accordance tradition CAD/CAM's system and CNC's system work means , CAM's system is with directly either the indirect means gains the produce geometry data model through CAD's system ( by means of neutral papers ) . CAM's system is with spot , string , surface in the three dimensions geometrics model and either the entity is the drive target , the cutting tool locus is processed in the formation , and afterwards the shape with the cutting tool locating file viaes the handle is placed , with the NC's code shape supplys to CNC's machine tool , the some respects problems under being living in entire CAD/CAM and the CNC's system operation process to be :CAM systematically can only gain produce low tier of geometry message through CAD's system , and can not seize voluntarily meritorous service capacity and the semantic information of produce geometry shape information and produce higher level .Hence manufacturing engineering master that entire CAM's process have to be living is very experience haves a hand in secondly , and completees mutually by means of the figure .In case : Manufacturing engineering master .The entire system automation degree is leted dropBeing living in the CAM's system generation cutting tool locus , equal also merely embodying low straturm geometry message ( right line and arc geometry locating information ) , along with the a little process control information ( as moving forward ) to rate , main shaft rotation speed and trading sword and so on .Hence , can not obtain the process technology parameter that haves something to do with against generateing the cutting tool locus yetThe produce data between CAM's system every module are not unitied , and the independence is opposite to each other to every module .For instance the cutting tool locating file is merely keep the minutes the cutting tool locus and is not keep the minutes the relevant process technology parameter , the dynamic imitation of three dimensions merely keeps the minutes that the cutting tool locus interference against runs into , but keep the minutes interference and process target and correlation process technology parameter that runs into happen against suchThe CAM systematically is an independence system .Not thering is the unitary produce data model between CAD's system together with the CAM's system , even if being the integrated CAD/CAM's system of integration in , one-way and unity is enjoyed also being only to message in all . CAM systematically can not sufficiently comprehend and complete message utilizing CAD's system to have something to do with the produce , feature message that especially haves something to do with against process , equal CAD's system can not gain the process data message that CAM systematically come into being yet . This is give parallel project implementation to bring the hardship3、digitals control techniques of simulation3.1 calculating machine imitation approximately idea and applicationThe angle through the project is see , and the imitation is the system by means of the test to the system model leave to research in the existing either design .Analysing the complex dynamic target , the imitation is one kind of valid means , may decrease the hazard , cuts down design and manufactures cycle , and practise thrift the investment .Calculating machine imitation is draing support from the calculatingmachine , and utilizes the system model to adjust actually systematically testing the process which researcied .It is swiftly developed in the wake of the calculating machine technique development , and is living in the imitation to passess the more and more significant position .Three foundation maneuveies between the key element that the calculating machine imitation process may be notify by means of the picture 1 are depictd :The model building maneuver is by means of viewing either examination to the actual system , and is living to over look the less important element to reach on the base that examine the variable , and the means in the way of physics either mathematics is depictd , thereby obtains the similar pattern of actual system simplification .The meritorous service with the actual system of the pattern here be able to together with between the parameter ought to have similarity and homologous qualityThe imitation pattern is the mathematical model to the system ( simplifying the pattern ) carries on the specified algorithm handle , and causes such become the appropriate shape ( in case turns into iterative operation pattern by the numerical integration ) afterwards , yet becomes " computation module computational mode " that be able to be receiveed by the calculating machine .The imitation pattern is two simplification patterns to the actual systemThe imitation test is shall system imitation pattern be living the process rund in the calculating machine .The imitation is researching actual system one kind of technique by means of the test , may clarify systematically immanent structure variable and the ambient condition effect by means of the technique of simulationCalculating machine technique of simulation main expressing of development tendency be living two respects : Application territory enlargement and imitation calculating machine intelligentization .The calculating machine technique of simulation not merely is living tradition project technique territory ( respects such as aviation , spaceflight and chemical industry and so on ) subsequent development , but also broadens up community economy and living beings and so on much non- project territorys , moreover , technique such as parallel processing , artificial intelligence , knowledge base and expert system and so on the development is affecing the imitation calculating machine development Digital control process imitation utilizes the calculating machine imitation practice process , being the forceful means to verify digital control processing program dependability and the calculation cutting action process , in order to decrease work attempies surely , and lifts production efficiency3.2 digital control technique of simulation research present situationThe APT process spare parts are completeed near the digital control order program control .In the interest of right quality to guarrantee the digital control order , guard against in process to intervene happenning , and is living in the actual manufacture , and constantly adopts attempting the anxious means to examine with what runs into .Yet this kind of means requiring a lot of labor expense is anticipateed , the cost expansively causes the manufacturing cost move upward , addd produce process time and production cycle .Adoping once more the locus to display the law afterwards , in immediate future in order to mark needle either pencil or writing brush replace the cutting tool , with colouring plank either paper replaces the work imitation cutting tool movement locus two dimension figure ( alsomay display the two dimension semi process locus ) , possess the considerably great limitations .Three dimension and the many-dimensionss as to the work are processed , the cutting action locus that the inspection that the stuff that also possess use easily to cut replaces the work ( in case , paraffin wax , lumber , midified resin and plastic material and so on ) comes is processed .Yet APT and the process field is very important occupied in the attempt .For this reason , people are living always to research replace gradually attempting the anxious calculating machine emulation mode , and is living to attempt to slice that the respects such as environment modeling and imitation calculation and graphic display and so on acquire the significant progress , and develops to raise pattern accurateness and imitation calculation real timeization and improvement real feeling of graphic display and so on orientations at the momentThrough attempies the pattern distinguishing feature sliceeing the environment seeing , NC's cutting action process imitation branch geometry imitation and mechanics imitation at the moment two respects .Geometry imitation is not consider that cutting action parameter and cutting force reach else the physics elements effects , the imitation cutting tool work geometric object movement , and with right quality of certification NC's order .The problem such as it may decrease either remove as a result of the machine tool injury that the program error causes and clamping apparatus damage either the cutting tool rolls over to snap and the spare parts are reported something as worthless and so on ;May decrease moreover through the product design up time manufacturing , and cut down the manufacturing cost .Cutting action process mechanics imitation pertains to the physics imitation category , and its dynamic mechanics property by means of the imitation cutting action process is forecast that the cutting tool breakage and cutting tool vibration and control cuts the parameter , thereby attains to optimize the cutting action process aimThe geometry technique of simulation development is in the wake of geometry model building technique development but development , and consists of that quality graphic display and the ration is intervened verifying two respects .At the moment the means in common use possess the immediate solid modelling law , and the means of figure image space baseding on is requestted the intersection law with the scattered vector3.3 immediate solid modelling lawThis kind of enveloping solid that the means is the work part of the body against the cutting tool movement takes shape is underway that the entity Boolean falls short of operating , and the work part of the body three dimensions patterns are continuously replaceed in the wake of the cutting action processSungurtekin and Velcker opened up a miller simulation system .The three dimensions patterns that ought to systematically adopt CSG's law to keep the minutes Mao Pi utilize some fundamental primitives like cuboid , the cylindrical body and taper part of the body , and the set operation , particularly operating , the area by Mao Pi and a series of cutting tool scannings is keep the minutes , afterwards usies the set difference and operates through Mao Pizhong's order take-offing the scanning area .Traverse when the so-called area by has sweep is cutting the cutting tool to move along some locuss area .Per length of Mao Pixing's shape that NC's code afterwards。
数控技术外文文献翻译
数控技术外文文献翻译(含：英文原文及中文译文)英文原文The development trend of numerical control technology AbstractThe current trends in the development of numerical control technology and equipment in the world and the status quo of the development and industrialization of CNC equipment technology in China are briefly introduced. On this basis, we discuss the development of CNC technology and equipment in China under the new environment of China's accession to the WTO and further opening to the outside world. The importance of improving the level of China's manufacturing informatization and international competitiveness, and put forward some views on the development of China's CNC technology and equipment from both strategic and strategic aspects.The technological level and degree of modernization of the equipment industry determine the level of the entire national economy and the degree of modernization. Numerical control technology and equipment are the development of emerging high-tech industries and cutting-edge industries (such as information technology and its industries, biotechnology and its industries, aviation, aerospace, etc.) (Defense Industry Industry) enabling technology and basic equipment. Marx oncesaid that “the difference between various economic times is no t what is produced but how it is produced and what labor data it is used to produce”. Manufacturing technology and equipment are the most basic production materials for human production activities, and numerical control technology is the core technology of today's advanced manufacturing technologies and equipment. In the manufacturing industry of the world today, CNC technology is widely used to improve manufacturing capabilities and levels, and to improve the adaptability and competitiveness of dynamic markets. In addition, various industrialized countries in the world have also listed numerical control technology and numerical control equipment as strategic materials of the country. They not only take significant measures to develop their own numerical control technologies and their industries, but also have the key technology and equipment of “high-precision” numerical control. Our country adopts a policy of blockade and restriction. In short, the vigorous development of advanced manufacturing technologies centered on numerical control technology has become an important way for all developed countries in the world to accelerate economic development and improve their overall national strength and national status.Numerical control technology is a technology that uses digital information to control mechanical movement and work process. Numerical control equipment is a mechatronic product formed by thepenetration of new technologies represented by numerical control technology into traditional manufacturing industries and emerging manufacturing industries, namely, so-called digital equipment. Its technical scope covers many fields: (1) machinery manufacturing technology; (2) information processing, processing, and transmission technology; (3) automatic control technology; (4) servo drive technology;(5) sensor technology; (6) software Technology and so on. Keywords: CNC technology, machinery manufacturing, information processing, sensors1 Development Trends of Numerical Control TechnologyThe application of numerical control technology has not only brought about revolutionary changes in the traditional manufacturing industry, but also made manufacturing a symbol of industrialization. With the continuous development of numerical control technology and the expansion of application fields, he has made important contributions to the national economy and people's livelihood (IT, automotive The development of light industry, light industry, medical care, etc. is playing an increasingly important role, because the digitalization of the equipment required by these industries is a major trend of modern development. From the current trend of numerical control technology and its equipment development in the world, its main research hotspots are the following aspects [1~4].1.1 New trends in high-speed, high-precision processing technology and equipmentEfficiency and quality are the mainstays of advanced manufacturing technology. High-speed, high-precision machining technology can greatly improve efficiency, improve product quality and grade, shorten production cycle and increase market competitiveness. To this end, the Japanese Advanced Technology Research Institute will list it as one of the five major modern manufacturing technologies. The International Association of Production Engineers (CIRP) has identified it as one of the central research directions for the 21st century.In the passenger car industry, the production cycle of 300,000 vehicles per year is 40 seconds per vehicle, and multi-species processing is one of the key issues that must be addressed for car equipment. In the aviation and aerospace industries, the parts processed by them are mostly thin-walled. With thin ribs, the rigidity is poor, and the material is aluminum or aluminum alloy. These ribs and walls can be processed only when the high cutting speed and cutting force are small. Recently, the method of “hollowing out” large-size aluminum alloy billets has been used to manufacture large parts such as wings and fuselage to replace multiple parts and assembled by numerous rivets, screws, and other coupling methods to obtain strength, stiffness, and reliability of components. improve. All of these require high-speed, high-precision andhigh-flexibility for processing equipment.From the standpoint of EMO2001, the feed rate of high-speed machining centers can reach 80m/min, or even higher, and the airspeed can reach around 100m/min. At present, many automobile plants in the world, including China's Shanghai General Motors Corporation, have adopted a part of the production line consisting of a high-speed machining center to replace the combined machine tools. The HyperMach machine tool feed rate of CINCINNATI, USA is up to 60m/min, the speed is 100m/min, the acceleration is 2g, and the spindle speed has reached 60,000r/min. It takes only 30 minutes to machine a thin-walled aircraft part, and the same part takes 3h for general high-speed milling and 8h for normal milling; the spindle speed and acceleration of the twin-spindle lathe of DMG, Germany, reach 12*!000r/mm respectively. And 1g.In terms of machining accuracy, in the past 10 years, the machining accuracy of ordinary CNC machine tools has increased from 10μm to 5μm, precision machining centers have increased from 3~5μm to 1~1.5μm, and ultra-precision machining precision has begun to enter the nanometer level. (0.01μm).In terms of reliability, the MTBF value of foreign numerical control devices has reached more than 6000 hours, and the MTBF value of the servo system has reached more than 30,000 hours, showing very highreliability.In order to achieve high-speed, high-precision machining, the supporting functional components such as electric spindles and linear motors have been rapidly developed and the application fields have been further expanded.1.2 Rapid development of 5-axis simultaneous machining and compound machiningThe use of 5-axis simultaneous machining of 3D surface parts allows cutting with the best geometry of the tool, resulting in not only a high degree of finish, but also a significant increase in efficiency. It is generally considered that the efficiency of a 5-axis machine tool can be equal to 2 3-axis linkage machines. Especially when using ultra-hard material milling tools such as cubic boron nitride for high-speed milling of hardened steel parts, 5-axis simultaneous machining can be compared with 3-axis linkage. Processing to play a higher efficiency. In the past, due to the complexity of the 5-axis linkage CNC system and the host machine structure, the price was several times higher than that of the 3-axis linkage CNC machine tool, and the programming technology was more difficult, which restricted the development of 5-axis linkage machine tools.At present, due to the emergence of electric spindles, the structure of the composite spindle head that realizes 5-axis simultaneous machining isgreatly simplified, its manufacturing difficulty and cost are greatly reduced, and the price gap of the numerical control system is reduced. As a result, the development of composite spindle head type 5-axis linkage machine tools and compound machine tools (including 5-sided machine tools) has been promoted.At the EMO2001 exhibition, the new 5-axis machine tool of Nippon Machine Tool Co., Ltd. adopts a compound spindle head, which can realize the processing of four vertical planes and processing at any angle, so that 5-sided machining and 5-axis machining can be realized on the same machine tool. It can realize the processing of inclined surface and inverted cone. Germany DMG company exhibited DMUV oution series machining center, which can be processed in five-face machining and five-axis linkage in a single clamping. It can be directly or indirectly controlled by CNC system control or CAD/CAM.1.3 Intelligentization, openness, and networking have become major trends in the development of modern digital control systemsThe 21st century CNC equipment will be a certain intelligent system. The intelligent content is included in all aspects of the CNC system: in order to pursue the processing efficiency and processing quality in the intelligent, such as the process of adaptive control, process parameters automatically Generated; To improve the driving performance and the use of convenient connection intelligent, such as feed-forward control,adaptive calculation of motor parameters, automatic identification load automatic selection model, self-tuning, etc.; simplify the programming, simplify the operation of intelligent, such as smart The automatic programming, intelligent man-machine interface, etc.; as well as the contents of intelligent diagnosis, intelligent monitoring, convenient system diagnosis and maintenance.In order to solve the problems of traditional CNC system closure and industrial application of CNC application software. At present, many countries have conducted research on open numerical control systems such as NGC of the United States, OSACA of the European Community, OSEC of Japan, and ONC of China. The openness of numerical control systems has become the future of CNC systems. The so-called open CNC system is the development of CNC system can be in a unified operating platform, for machine tool manufacturers and end users, by changing, adding or cutting structure objects (CNC function), to form a series, and can be convenient to the user's special The application and technology are integrated into the control system to quickly realize open numerical control systems of different varieties and different grades to form brand-name products with distinctive personality. At present, the architecture specification, communication specification, configuration specification, operation platform, numerical control system function library and numerical control system function software development toolof open CNC system are the core of current research.Networked CNC equipment is a new bright spot in the international well-known machine tool exposition in the past two years. The networking of CNC equipment will greatly satisfy the requirements of information integration for production lines, manufacturing systems, and manufacturing companies. It is also the basic unit for realizing new manufacturing models such as agile manufacturing, virtual enterprise, and global manufacturing. Some famous domestic and foreign CNC machine tools and numerical control system manufacturing companies have introduced relevant new concepts and prototypes in the past two years. For example, at the EMO 2001 exhibition, the “Cyber Production Center” exhibited by Japan's Mazak company Mazak Production Control Center (CPC); Okuma Machine Too l Company, Japan exhibited “ITplaza” (Information Technology Plaza, IT Plaza); Open Manufacturing Environment (Open Manufacturing Environment, OME), exhibited by Siemens, Germany Etc., reflecting the trend of the development of CNC machine tools to the direction of the network.1.4 Emphasizing the Establishment of New Technology Standards and Specifications1.4.1 About Design and Development of CNC SystemsAs mentioned above, the open CNC system has better versatility, flexibility, adaptability, and expandability. The United States, theEuropean Community, and Japan have implemented strategic development plans one after another, and have conducted the open architecture system specification (OMAC). , OSACA, OSEC) research and development, the world's three largest economies in the short term carried out almost the same set of scientific plans and norms, indicating that the arrival of a new revolution in digital technology. In 2000, China began to conduct research and development of the regulatory framework for China's ONC numerical control system.1.4.2 About CNC StandardsCNC standards are a trend in the development of manufacturing informatization. The information exchange in the 50 years since the birth of CNC technology was based on the ISO 6983 standard. That is how the G and M codes describe how to process. The essential feature is the processing-oriented process. Obviously, he has been unable to meet the high speed of modern CNC technology. The need for development. For this purpose, a new CNC system standard ISO14649 (STEP-NC) is being researched and developed internationally. Its purpose is to provide a uniform data model that can describe the entire life cycle of a product without relying on a neutral mechanism of a specific system. , in order to achieve the entire manufacturing process, and even the standardization of product information in various industrial fields. The emergence of STEP-NC may be a revolution in CNC technology. It will have aprofound impact on the development of CNC technology and even the entire manufacturing industry. First, STEP-NC proposes a brand-new manufacturing concept. In the traditional manufacturing concept, NC machining programs are concentrated on a single computer. Under the new standard, NC programs can be distributed on the Internet. This is the direction of open and networked CNC technology. Secondly, STEP-NC CNC system can also greatly reduce the processing drawings (about 75%), processing program preparation time (about 35%) and processing time (about 50%).At present, European and American countries attach great importance to the research of STEP-NC, and Europe has initiated STEP-NC's IMS plan ( Participation in this program comes from 20 CAD/CAM/CAPP/CNC users, vendors and academic institutions in Europe and Japan. STEPTools of the United States is the developer of global manufacturing data exchange software. He has developed a SuperModel for the information exchange of CNC machine tools. Its goal is to describe all machining processes with a unified specification. This new data exchange format has now been validated on prototype prototypes equipped with SIEMENS, FIDIA and European OSACA-NC numerical control systems.2 Basic Estimates of China's CNC Technology and Its Industrial DevelopmentCNC technology in China started in 1958. The development process in the past 50 years can be roughly divided into three stages: the first stage from 1958 to 1979, which is the closed development stage. At this stage, the development of numerical control technology is relatively slow due to the limitations of foreign technology and China's basic conditions. The second stage is the introduction of technology during the “sixth and fifth” periods of the country, the “seventh five-year plan” period, and the “eighth five-year plan period,”and it will be digested and absorbed to initially establish the stage of the national production system. At this stage, due to the reform and opening up and the country’s attention, as well as the improvement of the research and development environment an d the international environment, China’s CNC technology has made great progress in research, development, and localization of products. The third stage is the implementation of industrialization research in the later period of the "Eighth Five-Year Plan" and the "Ninth Five-Year Plan" period of the country, entering the stage of market competition. At this stage, the industrialization of domestically-manufactured CNC equipment has achieved its essenceSexual progress. At the end of the “Ninth Five-Year Plan” period, the domestic market share of domestic CNC machine tools reached 50%, and the number of domestically-manufactured numerical control systems (pervasive models) also reached 10%.Looking at the development process of CNC technology in China in the past 50 years, especially after four five-year plans, the overall results are as follows:a. It lays the foundation for the development of CNC technology and basically masters modern CNC technology. China has now basically mastered the basic technologies from numerical control systems, servo drives, numerical control mainframes, special planes and their accessories. Most of these technologies already have the basis for commercial development. Some technologies have been commercialized and industrialized.b. Initially formed a CNC industrial base. Based on the research results and the commercialization of some technologies, we have established numerical control system production plants such as Huazhong Numerical Control and Aerospace Numerical Control which have mass production capabilities. Lanzhou Electric Machinery Factory, Huazhong Numerical Control and a number of servo systems and servo motor manufacturers, as well as a number of CNC machine manufacturers such as Beijing No. 1 Machine Tool Plant and Jinan No. 1 Machine Tool Plant. These production plants have basically formed China's CNC industrial base.c. Established a basic team of CNC research, development and management talents.Although significant progress has been made in the research, development, and industrialization of numerical control technology, we must also soberly realize that the research and development of high-end numerical control technologies in China, especially the status quo of the technological level of industrialization and the actual needs of China There is a big gap. Although our country's development speed is very fast in the vertical direction, the horizontal ratio (compared with foreign countries) not only has a gap in the level of technology, but also has a gap in the development speed in certain aspects, that is, the gap in the technological level of some highly sophisticated numerical control equipment has expanded. From the international point of view, the estimated level of China's numerical control technology and industrialization is roughly as follows:a. On the technical level, it will be about 10 to 15 years behind the advanced level in foreign countries, and it will be even bigger in terms of sophisticated technology.b. At the industrialization level, the market share is low, the variety coverage is small, and scale production has not yet been established; the specialized production level of functional components and the complete set capacity are low; the appearance quality is relatively poor; the reliability is not high, and the degree of commercialization is insufficient; The domestic CNC system has not established its own brand effect, andthe user's confidence is insufficient.c. On the ability of sustainable development, the research and development and engineering capabilities of pre-competitive numerical control technology are weak; the application of numerical control technology is not strong; the research and formulation of related standard specifications is lagging behind.The main reasons for analyzing the above gaps are as follows:a. Awareness. Insufficient understanding of the arduous, complex and long-term characteristics of the domestic CNC industry process; Insufficient estimates of market irregularities, foreign blockades, killings, and systems; and insufficient analysis of the application level and capabilities of CNC technology in China.b. Systematic aspects. From the point of view of technology, attention has been paid to the issue of CNC industrialization. It has been a time to consider the issue of CNC industrialization from the perspectives of system and industry chain; there is no complete supporting system of high-quality supporting systems, perfect training, and service networks. .c. Mechanisms. Bad mechanisms have led to brain drain, which in turn has restricted technological and technological route innovations and product innovations, and has constrained the effective implementation of planning. It is often planned to be ideal and difficult to implement.d. Technical aspects. Enterprises have little ability to independentlyinnovate in technology, and the engineering ability of core technologies is not strong. The standard of machine tools is backward, the level is low, and the new standard of CNC system is not enough.3 Strategic Thinking on the Development of CNC Technology and Industrialization in China3.1 Strategic ConsiderationsChina is a manufacturing country, and we must try to accept the transfer of the front-end rather than the back-end in the industrial transfer of the world. That is to master the advanced manufacturing core technologies, otherwise, in the new round of international industrial restructuring, China's manufacturing industry will further “empty core”. At the expense of resources, the environment, and the market, we may obtain only the international "processing centers" and "assembly centers" in the world's new economic structure, rather than the status of manufacturing centers that master core technologies. This will seriously affect our country. The development of modern manufacturing.We should pay attention to numerical control technology and industrial issues from the perspective of national security strategy. First of all, we must look at social security because manufacturing industry is the industry with the largest number of employed people in China. Manufacturing industry development can not only improve the people’s living standards, but also ease the country’s The pressure of employmentguarantees social stability. Secondly, from the perspective of national defense security, Western developed countries classify high-precision numerical control products as national strategic materials and implement embargoes and restrictions on China. The “Toshiba Incident” and the “Cox Report” "This is the best illustration.3.2 Development StrategyFrom the perspective of China’s basic national conditions, taking the country’s strategic needs and the market demand of the national economy as the guide, and aiming at improving the comprehensive competitiveness and industrialization le vel of China’s manufacturing equipment industry, we can use systematic methods to choose to dominate the early 21st century in China. The key technologies for the development and upgrade of the manufacturing equipment industry and supporting technologies and supporting technologies for supporting industrialization development are the contents of research and development and the leap-forward development of the manufacturing equipment industry. Emphasizing the market demand as the orientation, that is, taking CNC terminal products as the mainstay, and driving the CNC industry with complete machines (such as large-scale CNC lathes, milling machines, high-speed, high-precision and high-performance CNC machine tools, typical digital machines, key equipment of key industries, etc.). development of. The focus is on the reliability and production scale of CNC systems andrelated functional components (digital servos and motors, high-speed spindle systems and accessories for new equipment, etc.). Without scale, there will be no high-reliability products; without scale, there will be no cheap and competitive products; of course, CNC equipment without scale in China will be difficult to come to the fore. In the research and development of high-precision equipment, we must emphasize the close integration of production, learning, research, and end-users, and aim at “doing, using, and selling off” as a goal, and implement national research on the will of the country to solve the urgent need of the country. . Before the competition, CNC technology emphasizes innovation, emphasizes research and development of technologies and products with independent intellectual property rights, and lays a foundation for the sustainable development of China's CNC industry, equipment manufacturing industry, and even the entire manufacturing industry.中文译文数控技术的发展趋势摘要本文简要介绍了当今世界数控技术及装备发展的趋势及我国数控装备技术发展和产业化的现状, 在此基础上讨论了在我国加入WTO 和对外开放进一步深化的新环境下, 发展我国数控技术及装备、提高我国制造业信息化水平和国际竞争能力的重要性, 并从战略和策略两个层面提出了发展我国数控技术及装备的几点看法。
数控专业毕业设计外文翻译
Conventional Machining ProcessesConventional machining is the group of machining operations that use single- or multi-point tools to remove material in the form of chips. Metal cutting involves removing metal through machining operations. Machining traditionally takes place on lathes, drill presses, and milling machines with the use of various cutting tools. Most machining has very low set-up cost compared with forming, molding, and casting processes. However, machining is much more expensive for high volumes. Machining is necessary where tight tolerances on dimensions and finishes are required.Turning is one of the most common of metal cutting operations. In turning, a workpiece is rotated about its axis as single-point cutting tools are fed into it, shearing away excess material and creating the desired cylindrical surface. Turning can occur on both external and internal surfaces to produce an axially-symmetrical contoured part. Parts ranging from pocket watch components to large diameter marine propeller shafts can be turned on a lathe.Apart from turning, several other operations can also be performed on lathe.Boring and internal turning. Boring and internal turning are performed on the internal surfaces by a boring bar or suitable internal cutting tools. If the initial workpiece is solid, a drilling operation must be performed first. The drilling tool is held in the tailstock, and the latter is then fed against the workpiece. When boring is done in a lathe, the work usually is held in a chuck or on a face plate. Holes may be bored straight, tapered, or to irregular contours. Boring is essentially internal turning while feeding the tool parallel to the rotation axis of the workpiece.Facing is the producing of a flat surface as the result of a tool’s being fed across the end of the rotating workpiece. Unless the work is held on a mandrel, if both ends of the work are to be faced, it must be turned around after the first end is completed and then the facing operation repeated. The cutting speed should be determined from the largest diameter of the surface to be faced.Facing may be done either from the outside inward or from the center outward. In either case, the point of the tool must be set exactly at the height of center of rotation.Because the cutting force tends to push the tool away from the work, it is usually desirable to clamp the carriage to the lathe bed during each facing cut to prevent it from moving slightly and thus producing a surface that is not flat. In the facing of casting or other materials that have a hard surface, the depth of the first cut should be sufficient to penetrate the hard material to avoid excessive tool wear.Parting is the operation by which one section of a workpiece is severed from the remainder by means of cutoff tool. Because cutting tools are quite thin and must have considerable overhang, this process is less accurate and more difficult. The tool should be set exactly at the height of axis of rotation, be kept sharp, have proper clearance angles, and be fed into the workpiece at a proper and uniform feed rate.Threading can be considered as turning since the path to be travelled by the cutting tool is helical. However, there are some major differences between turning and threading. While in turning, the interest is in generating a smooth cylindrical surface, in threading the interest is in cutting a helical thread of a given form and depth which can be calculated from the formulae. There are two basic requirements for thread cutting. An accurately shaped and properly mounted tool is needed because thread cutting is a form-cutting operation. The resulting thread profile is determined by the shape of the tool and its position relative to the workpiece.The second by requirement is that the tool must move longitudinally in a specific relationship to the rotation of workpiece, because this determines the lead of the thread. This requirement is met through the use of the lead screw and the split unit, which provide positive motion of carriage relative to the rotation of spindleLathe bed is foundation of the engine lathe, which heavy, rugged casting is made to support the working parts of the lathe. The size and mass of the bed gives the rigidity necessary for accurate engineering tolerances required in manufacturing. On top of the bed are machined slideways that guide and align the carriage and tailstock, as they are move from one end of the lathe to the other.Headstock is clamped atop the bed at left-hand end of the lathe and contains the motor that drives the spindle whose axis is parallel to the guideways through a series of gears housed within the gearbox. The function of gearbox is to generate a number of different spindle speeds. A spindle gear is mounted on the rear of the spindle to transmit power through the change gears to the feeding box that distributes the power to the lead screw for threading or to the feed rod for turning.The spindle has a through hole extending lengthwise through which bar stocks can be fed if continuous production is used. The hole can hold a plain lathe center by its tapered inner surface and mount a chuck, a face plate or collet by its threaded outer surface.Carriage assembly is actually an H-shaped block that sits across the guideways and in front of lathe bed. The function of the carriage is to carry and move the cuttingtool longitudinally. It can be moved by hand or by power and can be clamped into position with a locking nut. The carriage is composed of the cross slide, compound rest, tool saddle, and apron.The cross slide is mounted on the dovetail guideways on the top of the saddle and it moved back and forth at 90°to the axis of the lathe by the cross slide lead screw. The lead screw can be hand or power activated.The compound rest is mounted on the cross slide and can be swiveled and clamped at any angle in a horizontal plane. The compound is typically used for cutting chamfers or tapers, but must also be used when cutting thread. The compound rest can only be fed by hand. There is no power to compound rest. The cutting tool and tool holder are secured in the tool post which is mounted directly to the compound rest.The tool saddle is an H shaped casting mounted on the top of the guideways and houses the cross slide and compound rest. It makes possible longitudinal, cross and angular feeding of the tool bit.The apron is attached to the front of the carriage and contains the gears and feed clutches which transmit motion from the feed rod or lead screw to carriage and cross slide. When cutting screw threads, power is provided to the gearbox of the apron by the lead screw. In all other turning operations, it is the feed rod that drives the carriage.Tailstock is composed of a low base and the movable part of the tail-stock proper, the transverse adjustments being made with a cross screw furnished with a square head. The two parts are hold together by the holding-down bolts which secure the tailstock to the bed.。
数控技术类外文文献翻译、中英文翻译、外文翻译
外文原文：NC Technology1、Research current situation of NC lathe in our timesResearch and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that people's knowledge plays is more outstanding, and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times:（1）、Pay more attention to new technology and innovationWorldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc.. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly.（2）、Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center, are improving rigidity of the lathe, reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe, repeat precision, working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate, software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed.（3）、Improve the research of the machine tooling productivityWorld NC lathe, machining center and corresponding some development of main shaft, electrical machinery of straight line, measuring system, NC system of high speed, under the prerequisite of boosting productivity.（4）、What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedlyA、Intelligent research of the numerical control systemMainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control, adaptive operation , discerning automatically load selects models automatically, since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc..B、The numerical control system melts and studies openMainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety, different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm, disposing the norm, operation platform, numerical control systematic function storehouse and numerical control systematic function software developing instrument, etc. are the core of present research to pass through.C、Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it is a basic unit of realizing the new manufacture mode too.2、Classification of the machining center（1）Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center.Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up. Horizontal machining center for 3-5 sport coordinate axis, acommon one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the working bench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece. Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, the price is high.Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the working bench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally, can find a room for one horizontal numerical control revolving stage (the 4th axle) of axle process the spiral part at working bench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures, can carry on the processing of most work pieces.Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine.Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting, can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest, save 2 times install and insert working, thus improve production efficiency, reduce the process cost.（2）Classify by craft useIs it mill machining center to bore, is it mill for vertical door frame machining center, horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction.（3）Classify by special functionSingle working bench, a pair of working bench machining center;Single axle, dual axle, three axle can change machining center, main shaft of case;Transfer vertically to the tower machining center and transfer;One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers;One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center.3、Development trend of the current numerical control latheAt present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultrafast cutting , ultraprecision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions.（1）. The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe, it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile, adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability, namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe working bench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology, make it lag behind error reduce greatly, thus improve the machining accuracy cut in corner not to track.For meet ultrafast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc.. At present, ceramic cutter and diamond coating cutter have already begun to get application.（2）. Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100 of the above ) automatically tofurnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe, realize so-called "the front desk processes, the backstage supporter is an editor ". In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too.（3）. Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state , thus get the higher machining accuracy and roughness of smaller surface , can improve the service life of the cutter and production efficiency of the equipment at the same time . Diagnose by oneself, repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down, adopt the measure of shutting down etc. immediately, carry on the fault alarm, brief on position, reason to break down, etc.. Can also make trouble module person who take off automatically, put through reserve module ,so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires, its development trend adopts the artificial intelligence expert to diagnose the system.（4）.Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD draw process pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great differencetheir programming necessary processing technology parameter needn't by artificial to participate in most, get from CAPP database in system directly.（5）. The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time. The numerical control system will adopt the circuit chip of higher integrated level, will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts, to improve dependability. Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module, standardization, universalization and seriation of the structure lathe noumenon of the hardware at the same time, make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on. Still through operating and starting many kinds of diagnostic programs of diagnosing, diagnosing, diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware, software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part " redundantly ", in order to realize the trouble resumes by oneself; Utilize various kinds of test, control technology, excess of stroke, knife damages, interfering, cutting out, etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically.（6）. Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine, electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installation method , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more.本文出自：Shigley J E. Mechanical Engineering Design. New York: McGraw-Hill, 1998译文：数控技术1、当前世界NC机床的研究现状世界各国对数控机床、加工中心以至FMS、CIMS等各种新技术的研究与发展进程，是与世界经济形势紧密相连的。
(数控加工)机械类数控外文翻译外文文献英文文献数控精编
（数控加工）机械类数控外文翻译外文文献英文文献数控NumericalControlOneofthemostfundamentalconceptsintheareaofadvancedmanufactur ingtechnologiesisnumericalcontrol(NC).PriortotheadventofNC,allmachine toolsweremanualoperatedandcontrolled.Amongthemanylimitationsassoc iatedwithmanualcontrolmachinetools,perhapsnoneismoreprominentthan thelimitationofoperatorskills.Withmanualcontrol,thequalityoftheproducti sdirectlyrelatedtoandlimitedtotheskillsoftheoperator.Numericalcontrolrep resentsthefirstmajorstepawayfromhumancontrolofmachinetools.Numericalcontrolmeansthecontrolofmachinetoolsandothermanufact uringsystemsthoughtheuseofprerecorded,writtensymbolicinstructions.Ra therthanoperatingamachinetool,anNCtechnicianwritesaprogramthatissue soperationalinstructionstothemachinetool,Foramachinetooltobenumeric allycontrolled,itmustbeinterfacedwithadeviceforacceptinganddecodingth ep2ogrammedinstructions,knownasareader.Numericalcontrolwasdevelopedtoovercomethelimitationofhumanop erator,andithasdoneso.Numericalcontrolmachinesaremoreaccuratethanm anuallyoperatedmachines,theycanproducepartsmoreuniformly,theyarefas ter,andthelong-runtoolingcostsarelower.ThedevelopmentofNCledtothede velopmentofseveralotherinnovationsinmanufacturingtechnology:1.Electricaldischargemachining.sercutting.3.Electronbeamwelding.Numericalcontrolhasalsomademachinetoolsmoreversatilethantheirmanuallyoperatedpredecessors.AnNCmachinetoolcanautomaticallyproduc eawidevarietyofpar4s,eachinvolvinganassortmentofundertaketheproducti onofproductsthatwouldnothavebeenfeasiblefromaneconomicperspective usingmanuallycontrolledmachinetoolsandprocesses.Likesomanyadvancedtechnologies,NCwasborninthelaboratoriesofthe MassachusettsInstituteofTechnology.TheconceptofNCwasdevelopedinthe early1950swithfundingprovidedbytheU.SAirForce.Initsearlieststages,NCm achineswereabletomakestraightcutsefficientlyandeffectively.However,curvedpathswereaproblembecausethemachinetoolhadtobe programmedtoundertakeaseriesofhorizontalandverticalstepstoproducea curve.Theshorteristhestraightlinesmakingupthestep,thesmootheris4hecu rve.Eachlinesegmentinthestepshadtobecalculated.Thisproblemledtothedevelopmentin1959oftheAutomaticallyProgram medTools(APT)languageforNCthatusesstatementssimilartoEnglishlangua getodefinethepartgeometry,describethecuttingtoolconfiguration,andspe cifythenecessarymotions.ThedevelopmentoftheAPTlanguagewasamajors tepforwardinthefurtherdevelopmentofNCtechnology.TheoriginalNCsyste mwerevastlydifferentfromthoseusedpunchedpaper,whichwaslatertorepla cedbymagneticplastictape.Atapereaderwasusedtointerprettheinstruction swrittenonthetapeforthemachine.Together,all/fthisrepresentedgiantstepf orwardinthecontrolofmachinetools.However,therewereanumberofproble mswithNCatthispointinitsdevelopment.Amajorproblemwasthefragilityofthepunchedpapertapemedium.Itwas commonforthepapercontainingtheprogrammedinstructionstobreakortea rduringamachiningprocess,Thisproblemwasexacerbatedbythefactthateac hsuccessivetimeapartwasproducedonamachinetool,thepapertapecarryin gtheprogrammedinstructionshadtorerunthoughtthereader.Ifitwasnecessa rytoproduce100copiesofagivenpart,itwasalsonecessarytorunthepapertap ethoughtthereader100separatetimes.Fragilepapertapessimplycouldnotwi thstandtherigorsofshopfloorenvironmentandthiskindofrepeateduse.Thisledtothedevelopmentofaspecialmagnetictape.Whereasthepapert apecarriedtheprogrammedinstructionsasaseriesofholespunchedinthetap e,theThismostimportantofthesewasthatitwasdifficultorimpossibletochang etheinstructionsenteredonthetape.Tomakeeventhemostminoradjustment sinaprogramofinstructions,itwasnecessarytointerruptmachiningoperation sandmakeanewtape.Itwasalsostillnecessarytorunthetapethoughtthereade rasmanytimesastherewerepartstobeproduced.Fortunately,computertechn ologybecomearealityandsoonsolvedtheproblemsofNC,associatedwithpun chedpaperandplastictape.Thedevelopmentofaconceptknownasnumericalcontrol(DNC)solvethe paperandplastictapeproblemsassociatedwithnumericalcontrolbysimplyeli minatingtapeasthemediumforcarryingtheprogrammedinstructions.Indire ctnumericalcontrol,machinetoolsaretied,viaadatatransmissionlink,toahost computerandfedtothemachinetoolasneededviathedatatransmissionlinkage.Directnumericalcontrolrepresentedamajorstepforwardoverpunchedta peandplastictape.However,itissubjecttothesamelimitationasalltechnologi esthatdependonahostcomputer.Whenthehostcomputergoesdown,thema chinetoolsalsoexperiencedowntime.Thisproblemledtothedevelopmentofc omputernumericalcontrol.Thedevelopmentofthemicroprocessorallowedforthedevelopmentofpr ogrammablelogiccontrollers(PLC)andmicrocomputers.Thesetwotechnolo giesallowedforthedevelopmentofcomputernumericalcontrol(CNC).WithC NC,eachmachinetoolhasaPLCoramicrocomputerthatservesthesamepurpo se.Thisallowsprogramstobeinputandstoredateachindividualmachinetool. CNCsolvedtheproblemsassociateddowntimeofthehostcomputer,butitintr oducedanotherproblemknownasdatamanagement.Thesameprogrammig htbeloadedontendifferentmicrocomputerswithnocommunicationamongt hem.Thisproblemisintheprocessofbeingsolvedbylocalareanetworksthatco nnectDigitalSignalProcessorsTherearenumeroussituationswhereanalogsignalstobeprocessedinma nyways,likefilteringandspectralanalysis,Designinganaloghardwaretoperfo rmthesefunctionsispossiblebuthasbecomelessandpractical,duetoincrease dperformancerequirements,flexibilityneeds,andtheneedtocutdownondev elopment/testingtime.Itisinotherwordsdifficultpmdesignanaloghardware analysisofsignals.Theactofsamplingansignalintothehatarespecialisedforembeddedsignalprocessingoperations,andsuchaprocessoriscalledaDSP,whichstandsforDi gitalSignalProcessor.TodaytherearehundredsofDSPfamiliesfromasmanym anufacturers,eachonedesignedforaparticularprice/performance/usagegro up.Manyofthelargestmanufacturers,likeTexasInstrumentsandMotorola,off erbothspecialisedDSP’sforcertainfieldslikemotor-controlormodems,and generalhigh-performanceDSP’sthatcanperformbroadrangesofprocessin gtasks.Developmentkitsan`softwarearealsoavailable,andtherearecompani esmakingsoftwaredevelopmenttoolsforDSP’sthatallowstheprogrammer toimplementcomplexprocessingalgorithmsusingsimple“drag‘n’drop ”methodologies.DSP’smoreorlessfallintotwocategoriesdependingontheunderlyingar chitecture-fixed-pointandfloating-point.Thefixed-pointdevicesgenerallyo perateon16-bitwords,whilethefloating-pointdevicesoperateon32-40bitsfl oating-pointwords.Needlesstosay,thefixed-pointdevicesaregenerallychea per.Anotherimportantarchitecturaldifferenceisthatfixed-pointprocessorst endtohaveanaccumulatorarchitec ture,withonlyone“generalpurpose”re gister,makingthemquitetrickytoprogramandmoreimportantly,makingC-c ompilersinherentlyinefficient.Floating-pointDSP’sbehavemorelikecomm ongeneral-purposeCPU’s,withregister-files.TherearethousandsofdifferentDSP’sonthemarket,an ditisdifficulttask findingthemostsuitableDSPforaproject.Thebestwayisprobablytosetupaco nstraintandwishlist,andtrytocomparetheprocessorsfromthebiggestmanufacturersagainstit.The“bigfour”manufacturersofDSPs:TexasInstruments,Motorola,AT &TandAnalogDevices.Digital-to-analogconversionInthecaseofMPEG-Audiodecoding,digitalcompresseddataisfedintoth eDSPwhichperformsthedecoding,thenthedecodedsampleshavetobeconv ertedbackintotheanalogdomain,andtheresultingsignalfedanamplifierorsi milaraudioequipment.Thisdigitaltoanalogconversion(DCA)isperformedby acircuitwiththesamename&DifferentDCA’sprovidedifferentperformance andquality,asmeasuredbyTHD(Totalharmonicdistortion),numberofbits,lin earity,speed,filtercharacteristicsandotherthings.TheTMS320familyDQPofTexasInstrumentsTheTLS320familyconsistsoffixed-point,floating-point,multiprocessor digitalsignalprocessors(D[Ps),andfoxed-pointDSPcontrollers.TMS320DSP haveanarchitecturedesignedspecificallyforreal-timesignalprocessing.The ’F/C240isanumberofthe’C2000DSPplatform,andisoptimizedforcontro la pplications.The’C24xseriesofDSPcontrollerscombinesthisreal-timeproce ssingcapabilitywithcontrollerperipheralstocreateanidealsolutionforcontro lsystemapplications.ThefollowingcharacteristicsmaketheTMS320familyth erightchoiceforawiderangeofprocessingapplications:---Veryflexibleinstructionset---Inherentoperationalflexibility---High-speedperformance---Innovativeparallelarchitecture---CosteffectivenessDeviceswithinagenerationoftheTMS320familyhavethesameCPUstruc turebutdifferenton-chipmemoryandperipheralconfigurations.Spin-offdev icesusenewcombinationsofOn-chipmemoryandperipheralstosatisfyawide rangeofneedsintheworldwideelectronicsmarket.Byintegratingmemoryand peripheralsontoasinglechip,TMS320devicesreducesystemcostsandsavecir cuitboardspace.The16-bit,fixed-point DSPcoreofthe‘C24xdevicesprovidesanalogde signersadigitalsolutionthatdoesnotsacrificetheprecisionandperformance oftheirsystemperformancecanbeenhancedthroughtheuseofadvancedcont rolalgorithmsfortechniquessuchasadaptivecontrol,Kalmanfiltering,andsta tecontrol.The‘C24xDSPcontrollerofferreliabilityandprogrammability.Anal ogcontrolsystems,ontheotherhand,arehardwiredsolutionsandcanexperien ceperformancedegradationduetoaging,componenttolerance,anddrift.Thehigh-speedcentralprocessingunit(CPU)allowsthedigitaldesignert oprocessalgorithmsinrealtimeratherthanapproximateresultswithlook-upt ables.TheinstructionsetoftheseDSPcontrollers,whichincorporatesbothsign alprocessinginstructionsandgeneral-purposecontrolfunctions,coupledwit htheextensivedevelopmenttimeandprovidesthesameeaseofuseastradition al8-and16-bitmicrocontrollers.Theinstructionsetalsoallowsyoutoretainyoursoftwareinvestmentwhenmovingfromothergeneral-purpose‘C2xxgen eration,sourcecodecompatiblewiththe’C2xgeneration,andupwardlysour cecodecompatiblewiththe‘C5xgenerationofDSPsfro mTexasInstruments.The‘C24xarchitectureisalsowell-suitedforprocessingcontrolsignals.I tusesa16-bitwordlengthalongwith32-bitregistersforstoringintermediatere sults,andhastwohardwareshiftersavailabletoscalenumbersindependentlyo ftheCPU.Thiscombinationminimizesquantizationandtruncationerrors,andi ncreasesp2ocessingpowerforadditionalfunctions.Suchfunctionsmightincl udeanotchfilterthatcouldcancelmechanicalresonancesinasystemoranesti mationtechniquethatcouldeliminatestatesensorsinasystem.The‘C24xDSPcontrollerstakeadva ntageofansetofperipheralfunction sthatallowTexasInstrumentstoquicklyconfigurevariousseriesmembersfordi fferentprice/performancepointsorforapplicationoptimization.Thislibraryofbothdigitalandmixed-signalperipheralsincludes:---Timers---Serialcommunicationsports(SCI,SPI)---Analog-to-digitalconverters(ADC)---Eventmanager---Systemprotection,suchaslow-voltageandwatchdogtimerTheDSPcontrollerperipherallibraryiscontinuallygrowingandchanging tosuittheoftomorrow’sembeddedcontrolmarketplace.TheTMS320F/C240isthefirs tstandarddeviceintroducedinthe‘24xseriesofDSPcontrollers.Itsetsthestandardforasingle-chipdigitalmotorcontrolle r.The‘240canexecute20MIPS.Almostallinstructionsareexecutedinasimple cycleof50ns.Thishighperformanceallowsreal-timeexecutionofverycomple 8controlalgorithms,suchasadaptivecontrolandKalmanfilters.Veryhighsam plingratescanalsobeusedtominimizeloopdelays.The‘240hasthearchitecturalfeaturesnecessaryforhigh-speedsignalp rocessinganddigitalcontrolfunctions,andithastheperipheralsneededtopro videasingle-chipsolutio nformotorcontrolapplications.The‘240ismanufac turedusingsubmicronCMOStechnology,achievingalogpowerdissipationrat ing.Alsoincludedareseveralpower-downmodesforfurtherpowersavings.So meapplicationsthatbenefitfromtheadvancedprocessingpowerofthe‘240i nclude:---Industrialmotordrives---Powerinvertersandcontrollers---Automotivesystems,suchaselectronicpowersteering,antilockbrake s,andclimatecontrol---ApplianceandHVACblower/compressormotorcontrols---Printers,copiers,andotherofficeproducts---Tapedrives,magneticopticaldrives,andothermassstorageproducts ---RoboticandCNCmillingmachinesTofunctionasasystemmanager,aDSPmusthaverobuston-chipI/Oando therperipherals.Theeventmanagerofthe‘240isunlikeanyotheravailableonaDSP.Thisapplication-optimizedperipheralunit,coupledwiththehighperfor manceDSPcore,enablestheuseofadvancedcontroltechniquesforhigh-preci sionandhigh-efficiencyfullvariable-speedcontrolofallmotortypes.Includei ntheeventmanagerarespecialpulse-widthmodulation(PWM)generationfu nctions,suchasaprogrammabledead-bandfunctionandaspacevectorPWMs tatemachinefor3-phasemotorsthatprovidesstate-of-the-artmaximumeffic iencyintheswitchingofpowertransistors.Thereindependentupdowntimers,eachwithit’sowncompareregister, supportthegenerationofasymmetric(noncentered)aswellassymmetric(cen tered)PWMwaveforms.Open-LoopandClosed-LoopControlOpen-loopControlSystemsThewordautomaticimpliesthatthereisacertainamountofsophisticatio ninthecontrolsystem.Byautomatic,itgenerallymeansThatthesystemisusuall ycapableofadaptingtoavarietyofoperatingconditionsandisabletorespondt oaclassofinputssatisfactorily.However,notanytypeofcontrolsystemhasthea ually,theautomaticfeatureisachievedbyfeed.gthefeedbackstructure,itiscalledanopen-loopsystem,whichisthesimp lestandmosteconomicaltypeofcontrolsystem.inaccuracyliesinthefactthato nemaynotknowtheexactcharacteristicsofthefurther,whichhasadefinitebea ringontheindoortemperature.Thisalcopointstoanimportantdisadvantageo ftheperformanceofanopen-loopcontrolsystem,inthatthesystemisnotcapableofadaptingtovariationsinenvironmentalconitionsortoexternaldisturban ces.Inthecaseofthefurnacecontrol,perhapsanexperiencedpersoncanprovi decontrolforacertaindesiredtemperatureinthehouse;butidthedoorsorwin dowsareopenedorclosedintermittentlyduringtheoperatingperiod,thefinal temperatureinsidethehousewillnotbeaccuratelyregulatedbytheopen-loop control.Anelectricwashingmachineisanothertypicalexampleofanopen-loops ystem,becausetheamountofwashtimeisentirelydeterminedbythejudgmen tandestimationofthehumanoperator.Atrueautomaticelectricwashingmach ineshouldhavethemeansofcheckingthecleanlinessoftheclothescontinuous lyandturnitsedtoffwhenthedesireddegisedofcleanlinessisreached.Closed-LoopControlSystemsWhatismissingintheopen-loopcontrolsystemformoreaccurateandmo readaptablecontrolisalinkorfeedbackfromtheoutputtotheinputofthesyste m.Inordertoobtainmoreaccuratebontrol,thecontrolledsignalc(t)mustbefe dbackandcomparedwiththereferenceinput,andanactuatingsignalproporti onaltothedifferenceoftheoutputandtheinputmustbesentthroughthesyste mtocorrecttheerror.Asystemwithoneormorefeedbackpat(slikethatjustdesc ribediscalledaclosed-loopsystem.humanbeingareprobablythemostcompl exandsophisticatedfeedbackcontrolsysteminexistence.Ahumanbeingmay beconsideredtobeacontrolsystemwithmanyinputsandoutputs,capableofc arryingouthighlycomplexoperations.Toillustratethehumanbeingasafeedbackcontrolsystem,letusconsidert hattheobjectiveistoreachforanobjectonaperformthetask.Theeyesserveasa sensingdevicewhichfeedsbackcontinuouslythepositionofthehand.Thedist ancebetweenthehandandtheobjectistheerror,whichiseventuallybroughtto zeroasthehandreachertheobject.Thisisatypicalexampleofclosed-loopcontr ol.However,ifoneistoldtoreachfortheobjectandthenisblindolded,onecano nlyreachtowardtheobjectbyestimatingitsexactposition.ItisAsantherillustra tiveexampleofaclosed-loopcontrolsystem,showstheblockdiagramoftheru ddercontrolsystemofThebasicalementsandtheblocadiagramofaclosed-loo pcontrolsystemareshowninfig.Ingeneral,theconfigurationofafeedbackcon trolsystemmaynotbeconstrainedtothatoffig&.Incomplexsystemstheremay bemultitudeoffeedbackloopsandelementblocks.数控在先进制造技术领域最根本的观念之壹是数控（NC）。
数控专业的英语作文带翻译
Title: My Journey into the World of CNC Machining正文：Ever since I was a child, Ive been fascinated by the precision and intricacy of machines. The idea of creating something from nothing, with a level of detail that only machines can achieve, has always captivated me. This fascination led me to pursue a career in the field of Computer Numerical Control CNC machining, a decision that has shaped my life in more ways than one.My journey began with a high school elective course in basic machining. It was there that I first laid hands on a lathe and a milling machine, simple tools compared to the sophisticated CNC machines I would later operate. The initial lessons were challenging, as I had to learn to read blueprints, understand measurements, and operate the machines with precision. However, the sense of accomplishment I felt after crafting my first piece was indescribable.As I progressed, I enrolled in a vocational training program that focused on CNC technology. The transition from manual to computeraided machining was a significant leap. I learned to program CNC machines using Gcode, a language that dictates the machines movements. It was a complex process, requiring a deep understanding of the machines capabilities and the material being worked on.One of the most memorable projects I undertook was the creation of aminiature engine block. The project demanded a high level of precision and attention to detail. I spent countless hours programming the CNC machine, ensuring that each cut was made with the utmost accuracy. The final product was a testament to the power of CNC technology and the precision it affords.Working with CNC machines has not only honed my technical skills but also taught me valuable life lessons. Patience, for instance, is a virtue in this field. A single mistake in programming can lead to hours of rework or even the destruction of the material. Moreover, problemsolving has become second nature to me, as I often have to troubleshoot issues that arise during the machining process.The CNC industry is everevolving, with new technologies and techniques emerging regularly. Keeping up with these advancements has been both a challenge and an opportunity. I have attended several workshops and seminars to stay current with the latest trends and have even experimented with 3D printing, which has opened up a whole new world of possibilities in manufacturing.In conclusion, my foray into the world of CNC machining has been a rewarding experience. It has allowed me to combine my passion for technology with my desire to create. As I look to the future, I am excited about the prospect of continuing to learn and grow in this dynamic field.翻译：标题：我进入数控加工世界之旅正文：自从我还是个孩子的时候，我就对机器的精确性和复杂性着迷。
毕业设计_外文翻译=cnc数控技术=5000字符 精品
中国地质大学长城学院本科毕业设计外文资料翻译系别：工程技术系专业：机械设计制造及其自动化姓名：何飞学号：052083082012年 4 月 15 日外文资料翻译译文CNC技术数控（NC）是可编程的自动化的一种形式。
其加工设备由一系列的数字、字母和其他符号控制。
这些数字、字母和符号被编成一定的格式，以便为一个特定的工步或者工作定义一个指令程序。
当工作改变时，指令程序也随之改变。
这种改变程序的能力使NC适应小、中批量生产。
编写新的程序要比大批量调换生产设备容易的多。
1.NC的基本组成部分一个数控系统包括以三个组成部分：指令编程、机械控制单元、加工设备。
三者之间的关系是：程序导入控制单元，控制单元直接指导加工设备的动作。
指令程序是细化的一步步的命令，它控制加工设备。
在它的一般形式中，命令涉及到机床主轴和放置工件的工作台的相对位置。
许多先进的指令包含有选择主轴速度，切削工具等功能。
程序编在一个适当的媒介中，再导入到控制单元中。
在几十年前最常用的媒介是一英尺宽的穿孔纸带。
由于穿孔纸带的广泛应用，NC也叫做“纸带控制”。
现在磁带和软盘得到了广泛的应用。
加工设备的NC系统的第三个基本组成部分。
它是有效工作的执行部分。
在许多数控的例子中，加工设备包括工作台、主轴和驱动和控制它们的设备。
2.控制系统的种类在NC中有两种基本控制类型：点到点和仿型定位。
在点到点系统中（也叫做点定位），机床的每一个轴都单独驱动。
为了减少不加工时间，机床一最大的速度运动。
但刀具达到定位点时开始减速。
因此在一个加工过程中，比如钻削或冲压，加工过程和回程独立完成。
在孔被钻出或冲出后，刀具撤回，移动到另一个地方，继续下一次加工。
从一点到另一点的路径在一个放面十分重要：为提高效率，所需时间必须最小。
点定位主要用于钻削、虫牙和立式洗削加工。
在仿型定位系统中（也被称为沿路径加工系统），定位和加工都沿着指定的路径，但速度不一样。
因此刀具沿着指定的路径运动，速度和运动的同步精确控制十分重要。
机械类数控外文翻译外文文献英文文献数控
Numerical ControlOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control representsthe first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reader.Numerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors.An NC machine tool can automatically produce a wide variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was developed in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.However ,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is 4he curve . Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statementssimilar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this representedgiant step forward in the control of machine tools . However ,there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium . It was common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to rerun thought the reader . If itwas necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigorsof shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associatedwith numerical control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goes down , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connectDigital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, likefiltering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into thehat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usagegroup. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP for certain'fieslds like motor -control or modems ,and general highp- erformance DSP ' s that can perform broad ranges of processingtasks. Development kits an' software are also available , and there are companies making software development tools for DSP' sth at allows the programmer to implement complex processing algorithms using simple “drag ‘n' drop ” methodologies.DSP's more or less fall into two categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “generaplurpose ”register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP'sbehave more like common general-purpose CPU's ,with re g i s-tfei l er s .There are thousands of different DSP 's on the market, and it is difficult task finding themost suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four ” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) is performed by a circuit with the same name & Different DCA provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits,linearity , speed, filter characteristics and other things.The TMS320 family DQP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (D[Ps) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The' F/C240 is a number of the 'C2000DSP platform , and is optimized for control applications. The 'C24x series o controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications:--- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but differenton-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the ‘C24xdevicesprovides analog designers a digital solution that does not sacrifice the precision and performance of their system performance can be enhanced through the use of advanced control algorithms for techniquessuch as adaptive control , Kalman filtering , andstate control. The ‘ C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwiredsolutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use astraditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purpose‘ C2xx generation ,source code compatible with the ' C2gxeneration , and upwardly source code compatible with the ‘ C5x generation of DSPs from Texas Instruments.The ‘C24x architecture is also w-eslul ited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonancesin a system or an estimation technique that could eliminate state sensors in a system.The ‘ C24xDSP controllers take advantage of an set of peripheraful nctions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow ' s embedded control matrpkleace.The TMS320F/C240 is the first standard device introduced in the ‘ 24x series of DScontrollers. It sets the standard for a singlec-hip digital motor controller. The ‘ 240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The ‘ 240 has the architectural features necessfaorryhigh-speed signal processing anddigital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The ‘ 240is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the ‘ 240 include: ---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climate control---Appliance and HVAC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the ‘ 240is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types.Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it 'oswn compare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to avariety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.g the feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the fact that one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantageof the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A human being may be considered to be a control system with many inputs and outputs, capable of carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the objective is to reach for an object on aperform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system ofThe basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there may be multitude of feedback loops and element blocks.数控在先进制造技术领域最根本的观念之一是数控（ NC。
数控系统外文翻译外文文献英文文献
Numerical Control SystemThe numerical control system is the digital control system abbreviation. By early is composed of hardware circuit is called hardware numerical control (Hard NC), after 1970, hardware circuit components gradually instead by the computer called for computer numerical control system.Computerized numerical control system is a system that is use computer control processing function to achieve numerical control system. CNC system according to the computer memory stored in the control program execution part or all, numerical control function, and is equipped with interface circuit and servo drive the special computer system.CNC system consists of NC program, input devices; output devices, computer numerical control equipment (CNC equipment), programmable logic controllers (PLC), the spindle and feed drive (servo) drive (including detection devices) and so on.The core of CNC system is equipment. By using the computer system with the function of software and PLC instead of the traditional machine electric device to make the system logic control more compact, its flexibility and versatility, reliability become more better, easy to implement complex numerical control function, use and maintenance can be more convenient, and it also has connected and super ordination machine and the remote communication function.At present, the numerical control system has variety of different forms; composition structure has its own characteristics. These structural features from thebasic requirements of the initial system design and engineering design ideas. For example, the control system of point and continuous path control systems have different requirements. For the T system and the M system, there are also very different, the former applies to rotary part processing, the latter suitable for special-shaped the axially symmetrical parts processing. For different manufacturers, based on historical development factors and vary their complex factors, may also be thinking in the design is different. For example, the United States Dynapath system uses a small plate for easy replacement and flexible combination of the board; while Japan FANUC system is a large plate structure tends to make the system work in favor of reliability, make the system MTBF rate continues to increase. However, no matter what kind of system, their basic principle and structure are very similar.The numerical control system generally consists of three major components, namely the control system, servo system and position measuring system. Control procedures by interpolation operation work piece, issue control instructions to the servo drive system; servo drive system control instructions amplified by the servo motor-driven mechanical movement required; measurement system detects the movement of mechanical position or speed, and feedback to the control system, to modify the control instructions. These three parts combine to form a complete closed-loop control of the CNC system.Control system mainly consists of bus, CPU, power supply, memory, operating panel and display, position control unit, programmable logic controller control unit and data input / output interface and so on. The latest generation of CNC system alsoincludes a communication unit; it can complete the CNC, PLC's internal data communications and external high-order networks. Servo drive system including servo drives and motors. Position measuring system is mainly used grating, or circular grating incremental displacement encoder.CNC system hardware from the NC device, input / output devices, drives and machine logic control devices, electrical components, between the four parts through the I / O interface to interconnect.Numerical control device is the core of CNC system, its software and hardware to control the implementation of various CNC functions.The hardware structure of no device by CNC installations in the printed circuit board with infixing pattern can be divided into the big board structure and function module (small board) structure; Press CNC apparatus hardware manufacturing mode, can be divided into special structure and personal computer type structure; Press CNC apparatus in the number of microprocessor can be divided into single microprocessor structure and many microprocessor structure.(1)Large panel structure and function templates structure1) Large panel structurePanel structures CNC system CNC equipment from the main circuit board, position control panels, PC boards, graphics control panel, additional I / O board and power supply unit and other components. The main circuit board printed circuit board is big; the other circuit board is a small plate, inserted in the large printed circuit board slot. This structure is similar to the structure of micro-computer.2) Function templates structure(2)Single-microprocessor structure and mulct-microprocessor structure1) Single-microprocessor structureIn a single-microprocessor structure, only a microprocessor to focus on control, time-sharing deals with the various tasks of CNC equipment.2) melt-microprocessor structureWith the increase in numerical control system functions, CNC machine tools to improve the processing speed of a single microprocessor CNC system can not meet the requirement; therefore, many CNC systems uses a multi-microprocessor structure. If a numerical control system has two or more microprocessors, each microprocessor via the data bus or communication to connect, share system memory and common I / O interfaces, each processor sharing system Part of the work, which is multi-processor systems.CNC software is divided into application software and system software. CNC system software for the realization of various functions of the CNC system, the preparation of special software, also known as control software, stored in the computer EPROM memory. CNC Systems feature a variety of settings and different control schemes, and their system software in the structure and size vary widely, but generally include input data processing procedures, computing interpolation procedures, speed control procedures, management procedures and diagnostic procedures.(1)Input data processing proceduresIt receives input part program, the standard code, said processing instructions anddata decoding, data processing, according to the prescribed format for storage. Some systems also calculated to compensate, or interpolation operation and speed control for pre-computation. Typically, the input data processing program, including input, decoding and data processing three elements.(2)Computing interpolation proceduresCNC work piece processing system according to the data provided, such as curve type, start, end, etc. operations. According to the results of operations were sent to each axis feed pulse. This process is called interpolation operation. Feed drive servo system Impulsive table or by a corresponding movement of the tool to complete the procedural requirements of the processing tasks.Interpolation for CNC system is the side of the operation, while processing, is a typical real-time control, so the interpolation directly affects the speed of operation the machine feed rate, and should therefore be possible to shorten computation time, which is the preparation of interpolation Complements the key to the program.(3)Speed control proceduresSpeed control program according to the given value control the speed of operation of the frequency interpolation, in order to maintain a predetermined feed rate. Changes in speed is large, the need for automatic control of acceleration and deceleration to avoid speed drive system caused by mutations in step.(4)Management proceduresManagement procedures responsible for data input, data processing, interpolation processing services operations as the various procedures for regulation and management.Management process but also on the panel command, the clock signal, the interrupt caused by fault signals for processing.(5)Diagnostic proceduresDiagnostic features are found in the running system failure in a timely manner, and that the type of failure. You can also run before or after the failure, check the system main components (CPU, memory, interfaces, switches, servo systems, etc.) function is normal, and that the site of failure.MachiningAny machining must have three basic conditions: machining tools, work piece and machining sports. Machining tool edge should be, the material must be rigid than the work piece. Different forms of tool structure and cutting movements constitute different cutting methods. Blade with a blade-shaped and have a fixed number of methods for cutting tools for turning, drilling, boring, milling, planning, broaching, and sawing, etc.; edge shape and edge with no fixed number of abrasive or abrasive Cutting methods are grinding, grinding, honing and polishing.Machining is the most important machinery manufacturing processing methods. Although the rough improve manufacturing precision, casting, forging, extrusion, powder metallurgy processing applications on widely, but to adapt to a wide range of machining, and can achieve high accuracy and low surface roughness, in Manufacturing still plays an important role in the process. Cutting metal materials have many classifications. Common are the following three kinds.By cutting process feature distinguishing characteristics of the decision process on the structure of cutting tools and cutting tools and work piece relative motion form. According to the technical characteristics of cutting can be divided into: turning, milling, drilling, boring, reaming, planning, shaping, slotting, broaching, sawing, grinding, grinding, honing, super finishing, polishing, gear Processing, the worm process, thread processing, ultra-precision machining, bench and scrapers and so on. By material removal rate and machining accuracy distinction can be divided into: ① rough: with large depth of cut, one or a few times by the knife away from the work cut out most or all allowances, such as rough turning, rough planning, Rough milling, drilling and sawing, etc., rough machining precision high efficiency low, generally used as a pre-processing, and sometimes also for final processing. ② Semi-finishing: General roughing and finishing as the middle between the process, but the work piece accuracy and surface roughness on the less demanding position, but also can be used as the final processing.③ finishing: cutting with a fine way to achieve higher machining surface accuracy and surface quality, such as fine cars, fine planning, precision hinges, grinding and so on. General is the final finishing process. ④ Finishing process: after the finish, the aim is to obtain a smaller surface roughness and to slightly improve the accuracy. Finishing processing allowance is small, such as honing, grinding, ultra-precision grinding and super finishing and so on. ⑤ Modification process: the aim is to reduce the surface roughness, to improve the corrosion, dust properties and improve appearance, but does not require higher precision, such as polishing, sanding, etc. ⑥ ultra-precision machining: aerospace, lasers, electronics, nuclear energy and other cutting-edge technologies thatneed some special precision parts, high accuracy over IT4, surface roughness less than Ra microns. This need to take special measures to ultra-precision machining, such as turning mirror, mirror grinding, chemical mechanical polishing of soft abrasive.Distinguished by method of surface machining, the work piece is to rely on the machined surface for cutting tool and the work piece to obtain the relative motion. By surface methods, cutting can be divided into three categories. ① tip trajectory method: relying on the tip relative to the trajectory of the surface to obtain the required work piece surface geometry, such as cylindrical turning, planning surface, cylindrical grinding, with the forming surface, such as by turning mode. The trajectory depends on the tool tip provided by the cutting tool and work piece relative motion. ② forming tool method: short forming method, with the final work piece surface profile that matches the shape forming cutter or grinding wheel, such as processing a shaped surface. At this time forming part of the machine movement was replaced by the blade geometry, such as the shape of turning, milling and forming grinding forming and so on. The more difficult the manufacture of forming cutter, machine - clamp - work piece - tool formed by the process system can withstand the cutting force is limited, forming method is generally used for processing short shaped surface. ③ generating method: also known as rotary cutting method, cutting tool and work piece during processing as a relatively developed into a campaign tool (or wheel) and the work piece instantaneous center line of pure rolling interaction between the two maintain a certain ratio between Is obtained by processing the surface of the blade in this movement in the envelope. Gear machining hobbling, gear shaping, shaving, honing, and grinding teeth (not including form grindingteeth), etc. are generating method processing.PLCEarly called the programmable logic controller PLC (Programmable Logic Controller, PLC), which is mainly used to replace the logic control relays. With the technology, which uses micro-computer technology, industrial control device function has been greatly exceeded the scope of logic control, therefore, such a device today called programmable logic controller, referred to as the PC. However, in order to avoid personal computer (Personal Computer) in the short confusion, it will be referred to as programmable logic controller PLC, plc since 1966, the . Digital Equipment Corporation (DEC) developed there, the current United States, Japan, Germany, PLC Good quality and powerful.The basic structure of Programmable Logic ControllerA. PowerPLC's power in the whole system plays a very important role. If you do not have a good, reliable power system is not working, so the PLC manufacturers design and manufacture of power very seriously. General AC voltage fluctuations of +10% (+15%) range, you can not take other measures to PLC to connect directly to the AC line.processing unit (CPU)Central processing unit (CPU) is the central PLC control. It is given by the function of PLC system program from the programmer receives and stores the user program and data type; check the power supply, memory, I / O and timer alert status,and to diagnose syntax errors in the user program. When the PLC into run-time, first it scans the scene to receive the status of various input devices and data, respectively, into I / O image area, and then one by one from the user program reads the user program memory, after a shell and press Provisions of the Directive the result of logic or arithmetic operations into the I / O image area or data register. And the entire user program is finished, and finally I / O image area of the state or the output of the output register data to the appropriate output device, and so on to run until stopped.To further improve the reliability of PLC, PLC is also large in recent years constitutes a redundant dual-CPU system, or by three voting systems CPU. Thus, even if a CPU fails, the whole system can still work properly.Storage system software of memory called system program memory. Storage application software of memory called the user program memory.and output interface circuit1, the live input interface circuit by the optical coupling circuit and the computer input interface circuit, the role of PLC and field control of an interface for input channels.2, Field output interface circuit by the output data registers, interrupt request strobe circuit and integrated circuit, the role of PLC output interface circuit through the on-site implementation of parts of the output to the field corresponding control signal.moduleSuch as counting, positioning modules.moduleSuch as Ethernet, RS485, Prefab’s-DP communication module.数控系统数控系统是数字控制系统简称，英文名称为Numerical Control System，初期是由硬件电路组成的称为硬件数控（Hard NC），1970年代以后，硬件电路元件慢慢由专用的运算机代替称为运算机数控系统。
数控机床外文文献翻译、中英文翻译
数控机床外文文献翻译、中英文翻译原文一CNC machine toolsOutdate, J. and Joe, J. Configuration Synthesis of Machining Centers with Tool，JohnWiley & sons, 2001While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing work pieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each work piece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing work pieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate work pieces. T oday's CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical work pieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine toolsis flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today's just-in-time (JIT) product requirements.Motion control - the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion control. Rather than applying completely mechanical devices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (federate) are programmable with almost all CNC machine tools.A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw.And the ball screw drives the linear axis (slide). A feedbackdevice (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1.fig.1 typical drive system of a CNC machine toolThough a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded - understanding coordinate systemsIt would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount4. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the more popular of these two is the rectangular coordinate system.The program zero point establishes the point of reference for motion commands in a CNC program. This allows the programmer to specify movements from a common location. If program zero is chosen wisely, usually coordinates needed forthe program can be taken directly from the print.With this technique, if the programmer wishes the tool to be sent to a position one inch to the right of the program zero point, X1.0 is commanded. If the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3.fig.2, 3.Understanding absolute versus incremental motionAll discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion.In the incremental mode (commonly specified by G91), endpoints for motions are specified from the tool's current position, not from program zero. With this method of commanding motion, the programmer must always be asking "How far should I move the tool?" While there are times when the incremental mode can be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode.Be careful when making motion commands. Beginners have the tendency to think incrementally. If working in the absolute mode (as beginners should), the programmer should always be asking "To what position should the tool be moved?" This position is relative to program zero, NOT from the tools current position.Aside from making it very easy to determine the current position for any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one command of the program, only one movement will be incorrect. On the other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect.Assigning program zeroKeep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. With this method, the programmer tells the control how far it is from the program zero point to the starting position of the machine. This is commonly done with a G92 (or G50) command at least at the beginning of the program and possiblyat the beginning of each tool.Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets.fig.4 assign program zero through G54Flexible manufacturing cellsA flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS:1.An FMC is not under the direct control of thecentral computer. Instead, instructions from the centralcomputer are passed to the cell controller.2.The cell is limited in the number of part families itcan manufacture.The following elements are normally found in an FMC:Cell controllerProgrammable logic controller (PLC)More than one machine toolA materials handling device (robot or pallet)The FMC executes fixed machining operations with parts flowing sequentially between operations.High speed machiningThe term High Speed Machining (HSM) commonly refers to end milling at high rotational speeds and high surface feeds. For instance, the routing of pockets in aluminum airframe sections with a very high material removal rate1. Refer to fig.5 for the cutting data designations and for mulas. Over the past 60 years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the production of components with specific surface topography requirements and machining of materials with hardness of 50 HRC and above. With most steel components hardened to approximately 32-42 HRC, machining options currently include:Fig.5 cutting datarough machining and semi-finishing of the material in its soft (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting tools) finishing and super-finishing of cylindrical/flat/cavity surfaces with appropriate cemented carbide, cermets, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves acombination of these options and in the case of dies and moulds it also includes time consuming hand finishing. Consequently, production costs can be high and lead times excessive.It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering.The main criteria are the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy.One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times.Main economical and technical factors for the development of HSMSurvivalThe ever increasing competition in the marketplace is continually setting new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions...MaterialsThe development of new, more difficult to machine materials has underlined the necessity to find new machining solutions.The aerospace industry has its heat resistant and stainless steel alloys. The automotive industry has different bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The die and mould industry mainly has to face the problem of machining high hardened tool steels, from roughing to finishing.QualityThe demand for higher component or product quality is the result of ever increasing competition. HSM, if applied correctly, offers a number of solutions in thisarea. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry.ProcessesThe demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes can also be reduced or eliminated with HSM.Design & developmentOne of the main tools in today's competition is to sell products on the value of novelty. The average product life cycle on cars today is 4 years, computers and accessories 1.5 years, hand phones 3 months... One of the prerequisites of this development of fast design changes and rapid product development time is the HSM technique.Complex productsThere is an increase of multi-functional surfaces on components, such as new design of turbine blades giving newand optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpiece that have to be machined (medical equipment, electronics, defense products, computer parts).Production equipmentThe strong development of cutting materials, holding tools, machine tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5.Definition of HSMSalomon's theory, "Machining with high cutting speeds..." on which, in 1931, took out a German patent, assumes that "at a certain cutting speed (5-10 times higher than in conventional machining), the chip removal temperature at the cutting edge will start to decrease...".See fig.6.Fig.6 chip removal temperature as a result of the cutting speedGiven the conclusion:" ... seems to give a chance to improve productivity in machining with conventional tools at high cutting speeds..."Modern research, unfortunately, has not been able to verifythis theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials.The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors.Given today's technology, "high speed" is generally accepted to mean surface speeds between 1 and 10 kilometers perminute, or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being used. One trend which is very evident today is the use of very large cutter diameters for these applications - and this has important implications for tool design.There are many opinions, many myths and many different ways to define HSM. Maintenance and troubleshooting Maintenance for a horizontal MCThe following is a list of required regular maintenance for a Horizontal Machining Center as shown in fig.7. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty.Fig. 7 horizontal machining centerDailyTop off coolant level every eight hour shift (especially during heavy TSC usage).Check way lube lubrication tank level.Clean chips from way covers and bottom pan.Clean chips from tool changer.Wipe spindle taper with a clean cloth rag and apply light oil.WeeklyCheck for proper operation of auto drain on filter regulator. See fig. 8Fig. 8 way lube and pneumaticsOn machines with the TSC option, clean the chip basket on the coolant tank.Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank. Do this monthly for machines without the TSC option.Check air gauge/regulator for 85 psi.For machines with the TSC option, place a dab of grease on the V-flange of tools. Do this monthly for machines without the TSC option.Clean exterior surfaces with mild cleaner. DO NOT usesolvents.Check the hydraulic counterbalance pressure according to the machine's specifications.Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools".MonthlyCheck oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank.Clean pads on bottom of pallets.Clean the locating pads on the A-axis and the load station. This requires removing the pallet.Inspect way covers for proper operation and lubricate with light oil, if necessary.Six monthsReplace coolant and thoroughly clean the coolant tank.Check all hoses and lubrication lines for cracking.AnnuallyReplace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil.Check oil filter and clean out residue at bottom for the lubrication chart.Replace air filter on control box every 2 years.Mineral cutting oils will damage rubber based components throughout the machine.TroubleshootingThis section is intended for use in determining the solution to a known problem. Solutions given are intended to give the individual servicing the CNC a pattern to follow in, first, determining the problem's source and, second, solving the problem.Use common senseMany problems are easily overcome by correctly evaluating the situation. All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, don't expect the machine to correct the fault.Don't suspect machine accuracy if the vise bends the part. Don't claim hole miss-positioning if you don't first center-drill the hole.Find the problem firstMany mechanics tear into things before they understand the problem, hoping that it will appear as they go. We know this from the fact that more than half of all warranty returned parts are in good working order. If the spindle doesn't turn, remember that the spindle is connected to the gear box, which is connected to the spindle motor, which is driven by the spindle drive, which is connected to the I/O BOARD, which is driven by the MOCON, which is driven by the processor. The moral here is doing replace the spindle drives if the belt is broken. Find the problem first; don't just replace the easiest part to get to.Don tinker with the machineThere are hundreds of parameters, wires, switches, etc., that you can change in this machine. Don't start randomly changing parts and parameters. Remember, there is a good chance that if you change something, you will incorrectly install it or break something else in the process6. Consider for a moment changing the processor's board. First, you have to download all parameters, remove a dozen connectors, replace the board, reconnect and reload, and if you make one mistake or bend one tiny pin itWON'T WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better.译文一数控机床虽然各种数控机床的功能和应用各不相同，但它们有着共同的优点。
机械类数控外文翻译外文文献英文文献数控
机械类数控外文翻译外文文献英文文献数控IntroductionIn recent years, with the rapid development of science and technology, the traditional manufacturing industry has been facing tremendous challenges. In this context, computerized numerical control (CNC) technology has emerged as a revolutionary methodology that greatly improves the efficiency and accuracy of manufacturing processes. Specifically, CNC technology is a type of automated control system that uses a set of computer instructions to direct the movement and operation of machinery in the manufacturing process. In this regard, this paper will provide a comprehensive overview of CNC technology, including its history, applications, advantages, and challenges.History of CNC TechnologyCNC technology has a history that can be traced back to the 1940s. At that time, the aviation industry in the United States was seeking a way to improve the efficiency and accuracy of manufacturing. Therefore, the US Air Force and the Massachusetts Institute of Technology (MIT) cooperated to develop a system that automatically controlled the movement ofaircraft components during the manufacturing process. This system was called the numerical control (NC) system.In the mid-1950s, John Parsons, a researcher at the Massachusetts Institute of Technology, invented the first NC machine tool. The machine used punched tape to control the movement of the cutting tool. During the 1960s, digital computer technology became more advanced, which paved the way for the development of CNC machines. By 1970, CNC machines had become a mature and widely used technology in the manufacturing industry.Applications of CNC TechnologyCNC technology has a wide range of applications in the manufacturing industry. For example, CNC machines can be used to produce a variety of products, including automobile parts, aircraft components, medical equipment, and consumer goods. CNC technology is also used in many other industries, such as woodworking, metalworking, plastics, and textiles.CNC technology has revolutionized the manufacturing industry by improving the quality, precision, and consistency of products. In addition, CNC machines can work faster and often require less manual labor than traditional manufacturing methods. CNC technology also allows manufacturers to produce complex shapes and designs that would be difficult or impossible to produce using traditional manufacturing methods.Advantages of CNC TechnologyThere are several advantages of using CNC technology in manufacturing. First, CNC machines can produce parts with very high precision and accuracy, which is crucial in industries such as aerospace and medical equipment manufacturing. CNC machines can also work 24/7, which means that manufacturers can produce parts at any time of day or night without having to worry about workers becoming tired.Second, CNC machines are highly flexible and can be programmed to produce a wide range of products. This means that manufacturers can quickly switch between different products without having to buy new machines or invest in expensive retooling. This flexibility also allows manufacturers to respond quickly to changes in market demand.Third, CNC machines can greatly reduce the amount of waste generated during the manufacturing process. This is because CNC machines can accurately measure and cut materials, minimizing the amount of scrap that is created. In addition, CNC machines can be programmed to optimize the use of materials, further reducing waste.Challenges of CNC TechnologyDespite its many advantages, CNC technology also presents several challenges. First, CNC machines can be expensive to purchase and maintain, which can be a barrier for smallmanufacturers. In addition, CNC machines require skilled operators who can program and operate the machines. This means that manufacturers must invest in training their workers, which can also be costly.Second, CNC machines can sometimes be less efficient than traditional manufacturing methods for small production runs. This is because CNC machines require a certain amount of time to set up and program, which can be inefficient for small production runs. In addition, CNC machines require a certain amount of precision, which means that they may not be suitable for certain types of products, such as handmade crafts.Finally, CNC machines also present some ethical challenges. For example, some argue that CNC machines could lead to job loss in the manufacturing industry, as the machines can perform tasks that were previously done by workers. In addition, CNC machines could lead to a reduction in the quality of products, as manufacturers may be more focused on speed and efficiency rather than quality.ConclusionCNC technology has revolutionized the manufacturing industry by improving the quality, precision, and consistency of products. CNC machines are highly flexible and can be programmed to produce a wide range of products. In addition, CNC machines can greatly reduce the amount of waste generated during the manufacturing process. However, CNC technology alsopresents several challenges, including high cost, the need for skilled operators, efficiency issues for small production runs, and ethical concerns. Overall, CNC technology is a powerful tool for manufacturers, but it is important for manufacturers to carefully consider the costs and benefits of using this technology.。
数控专业毕业设计外文翻译----中国数控车床的现状和发展趋势分析
Not only the Chinese numerical control lathe present situation andthe trend of developmentanalysis numerical control technology application has brought the revolutionary change for the traditional manufacturing industry, causes the manufacturing industry to become the industrialization the symbol, moreover along with numerical control technology unceasing development and application domain expansion, it to national economy and the people's livelihood some important professions (IT, automobile, light industry, medical service and so on) development more and more vital role, because these professions must equip the digitization already was the modern development major tendency. The current numerical control lathe presents following trend of development. 1. high speed, high precisionHigh speed, precise is the engine bed development eternal goal.Development progresses by leaps and bounds which along with the science and technology, the mechanical and electrical products renewal speed speeds up, increasingly is also high to the components processing precision and the surface quality request.In order to satisfy this complex changeable market the demand, the current engine bed to the high-speed cutting, is doing the cutting and does the direction of cut to develop, the processing precision also in unceasingly enhances. On the other hand, the electricity main axle and the straight line electrical machinery success application, the ceramics ball bearing, the high accuracy lead greatly hollow in cold and the ball bearing nut strong cold low temperature high speed ball bearing guide screw vice-and the belt ball bearing retainer straight line guide rail vice-and so on engine bed function part appearing on the market, also for the engine bed to high speed, the precise development has created the condition. The numerical control lathe picks uses electricity the main axle, has cancelled links and so on leather belt, band pulley and gear, reduced the master drive rotation inertia greatly, enhanced the main axle dynamic speed of response and the work precision, when thorough settlement main axle high-speed operation transmission and so on leather belt and band pulley vibrations and noise question.Picks uses electricity the main axle structure to be possible to enable the main axle rotational speed to achieve above 10000r/min.The straight line motor-driven speed is high, adds the moderating properties to be good, has the superior response characteristic and the followed precision. Made the servo with the straight line electrical machinery to actuate, to omit the ball bearing guide screw this intermediate drive link, eliminated the transmission gap (including reverse gap), themovement inertia was small, the system rigidity was good, could locate precisely under high speed, thus increased the servo precision enormously.Straight line trundle guide rail, because it has respectively to the gap for the zero and the extremely small rolling friction, wears slightly, gives off heat may ignore, has the extremely good thermostability, increased the entire journey pointing accuracy and the repetition pointing accuracy. Through the straight line electrical machinery and the straight line trundle guide rail vice-application, may make the engine bed the rapid traverse speed to enhance 60~80m/min from present 10~20m/mim, even reaches as high as 120m/min.2. redundant reliablenumerical control engine bed reliability is a numerical control engine bed product quality crucial target.Whether does the numerical control engine bed display its high performance, the high accuracy and the high efficiency, and obtains the good benefit, the key is decided by its reliable height.3. function recombinefunction recombine goal is further enhances the engine bed the production efficiency, uses reduces to few in the non-processing non-cutting time.Through the function recombine, may expand the engine bed the use scope, enhances the efficiency, realizes multipurpose one machine, one machine many energy, namely a numerical control lathe already may realize the turning function, also may realize the milling processing; Or in also may realize the abrasive machining by the mill primarily engine bed on.4. intellectualizations, the network, the flexibility and the integrated21st century numerical control equipments has certain intellectualized system. In order to pursue the processing efficiency and the processing quality aspect intellectualization, like processing process adaptive control, craft parameter automatic production; In order to enhance the actuation performance and the use connection aspect intellectualization, like feed-forward control, electrical machinery parameter auto-adapted operation, automatic diagnosis load automatic designation model, self regulating grade; Simplification programming, simplification operation aspect intellectualization, like intellectualized automatic programming, intellectualized man-machine contact surface and so on; Also has the intelligence to diagnose, aspect and so on intelligent monitoring contents, by facilitates the system the diagnosis and the service and so on. The numerical control engine bed the tendency which develops to the flexibility automated system is: From (numerical control single plane, processing center and numerical control compound processing engine bed), line (FMC, FMS, FTL, FML) to surface (construction sectionworkshop independent manufacture island, FA), body (CIMS, distribution network integration manufacture system) the direction develops, on the other hand develops to the attention utility and the efficient direction. The flexible automation technology is the manufacturing industry adapts the dynamic market demand and the product rapid renewal main method, is the various countries' manufacturing industry development mainstream tendency, is the advanced manufacture domain foundation technology.Its key point is by enhances the system the reliability, changes into the premise practical, take the easy networking and the integration as the goal, the attention enhancement unit technology development and the consummation.The CNC single plane to the high accuracy, the high velocity and the high flexible direction develops. The numerical control engine bed and the constitution flexibility manufacture system can conveniently and joints and so on CAD, CAM, CAPP and MTS, develops to the information integration direction.The network system to the opening, the integration and the intellectualized direction develops.中国数控车床的现状和发展趋势分析数控技术的应用不但给传统制造业带来了革命性的变化，使制造业成为工业化的象征，而且随着数控技术的不断发展和应用领域的扩大，它对国计民生的一些重要行业(IT、汽车、轻工、医疗等)的发展起着越来越重要的作用，因为这些行业所需装备的数字化已是现代发展的大趋势。
数控技术 外文翻译 外文文献 英文文献
外文翻译NUMERICAL CONTROLNumerical control(N／C)is a form of programmable automation in which the processing equipment is controlled by means of numbers，letters，and other symbols．The numbers，letters，and symbols are coded in an appropriate format to define a program of instructions for a particular work part or job．When the job changes，the program of instructions is changed．The capability to change the program is what makes N／C suitable for low-and medium-volume production．It is much easier to write programs th an to make major alterations of the processing equipment．There are two basic types of numerically controlled machine tools：point—to—point and continuous—path(also called contouring)．Point—to—point machines use unsynchronized motors，with the result that the position of the machining head Can be assured only upon completion of a movement，or while only one motor is running．Machines of this type are principally used for straight—line cuts or for drilling or boring．The N／C system consists of the following comp onents：data input，the tape reader with the control unit，feedback devices，and the metal—cutting machine tool or other type of N／C equipment．Data input，also called “man—to—control link”，may be provided to the machine tool manually，or entirely by automatic means．Manual methods when used as the sole source of input data are restricted to a relatively small number of inputs．Examples of manually operated devices are keyboard dials，pushbuttons，switches，or thumbwheel selectors．These are located on a console near t he machine．Dials ale analog devices usually connected to a syn-chro-type resolver or potentiometer．In most cases，pushbuttons，switches，and other similar types of selectors aye digital input devices．Manual input requires that the operator set the controls fo r each operation．It is a slow and tediousprocess and is seldom justified except in elementary machining applications or in special cases．In practically all cases，information is automatically supplied to the control unit and the machine tool by cards，punched tapes，or by magnetic tape．Eight—channel punched paper tape is the most commonly used form of data input for conventional N／C systems．The coded instructions on the tape consist of sections of punched holes called blocks．Each block represents a machine function，a machining operation，or a combination of the two．The entire N／C program on a tape is made up of an accumulation of these successive data blocks．Programs resulting in long tapes all wound on reels like motion-picture film．Programs on relatively short tapes may be continuously repeated by joining the two ends of the tape to form a loop．Once installed，the tape is used again and again without further handling．In this case，the operator simply loads and unloads the parts．Punched tapes ale prepared on typ e writers with special tape—punching attachments or in tape punching units connected directly to a computer system．Tape production is rarelyerror-free．Errors may be initially caused by the part programmer，in card punching or compilation，or as a result of physical damage to the tape during handling，etc．Several trial runs are often necessary to remove all errors and produce an acceptable working tape．While the data on the tape is fed automatically，the actual programming steps ale done manually．Before the coded tape may be prepared，the programmer，often working with a planner or a process engineer, must select the appropriate N／C machine tool，determine the kind of material to be machined，calculate the speeds and feeds，and decide upon the type of tooling needed. The dimensions on the part print are closely examined to determine a suitable zero reference point from which to start the program．A program manuscript is then written which gives coded numerical instructions describing the sequence ofoperations that the machine tool is required to follow to cut the part to the drawing specifications．The control unit receives and stores all coded data until a complete block of information has been accumulated．It then interprets the coded instruction and directs the machine tool through the required motions．The function of the control unit may be better understood by comparing it to the action of a dial telephone，where，as each digit is dialed，it is stored．When the entire number has been dialed，the equipment becomes activated and the call is completed．Silicon photo diodes，located in the tape reader head on the control unit，detect light as it passes through the holes in the moving tape．The light beams are converted to electrical energy，which is amplified to further strengthen the signal．The signals are then sent to registers in the control unit, where actuation signals are relayed to the machine tool drives．Some photoelectric devices are capable of reading at rates up to 1000 characters per second．High reading rates are necessary to maintain continuous machine—tool motion；otherwise dwell marks may be generated by the cutter on the part during contouring operations．The reading device must be capable of reading data blocks at a rate faster than the control system can process the data．A feedback device is a safeguard used on some N／C installations to constantly compensate for errors between the commanded position and the actual location of the moving slides of the machine tool．An N ／C machine equipped with this kind of a direct feedback checking device has what is known as a closed-loop system．Positioning control is accomplished by a sensor which，during the actual operation，records the position of the slides and relays this information back to the control unit．Signals thus received ale compared to input signals on the tape，and any discrepancy between them is automatically rectified．In an alternative system，called an open—loop system，the machine is positioned solely by stepping motor drives in response to commands by a controllers．There are three basic types of NC motions, as follows: Point-to-point or Positional Control In point-to-point control the machine tool elements (tools, table, etc.) are moved to programmed locations and the machining operations performed after the motion s are completed. The path or speed of movement between locations is unimportant; only the coordinates of the end points of the motions are accurately controlled. This type of control is suitable for drill presses and some boring machines, where drilling, t apping, or boring operations must be performed at various locations on the work piece. Straight-Line or Linear Control Straight-Line control systems are able to move the cutting tool parallel to one of the major axes of the machine tool at a controlled rate suitable for machining. It is normally only possible to move in one direction at a time, so angular cuts on the work piece are not possible, consequently, for milling machines, only rectangular configurations can be machined or for lathes only surfaces parall el or perpendicular to the spindle axis can be machined. This type of controlled motion is often referred to as linear control or a half-axis of control. Machines with this form of control are also capable ofpoint-to-point control.Continuous Path or Contouring Control In continuous path control the motions of two or more of the machine axes are controlled simultaneously, so that the position and velocity of the can be tool are changed continuously. In this way curves and surfaces can be machined at a controlled feed rate. It is the function of the interpolator in the controller to determine the increments of the individual controlled axes of the machines necessary to produce the desired motion. This type of control is referred to as continuous control or a full axis of control.Some terminology concerning controlled motions for NC machines has been introduced. For example, some machines are referred to asfour-or five-or even six-axis machines. For a vertical milling machine three axes of control are fairly obvious, these being the usual X, Y, Z coordinate directions. A fourth or fifth axis of control would imply some form of rotary table to index the work piece or possibly to provide angular motion of the work head. Thus, in NC terminology an axis of control is any controlled motion of the machine elements (spindles, tables, etc). A further complication is use of the term half-axis of control; for example, many milling machines are referred to as 2.5-axis machine. This means that continuous control is possib le for two motions (axes) and only linear control is possible for the third axis. Applied to vertical milling machines, 2.5axis control means contouring in the X, Y plane and linear motion only in the Z direction. With these machines three-dimensional objects have to be machined with water lines around the surface at different heights. With an alternative terminology the same machine could be called a 2CL machine (C for continuous, L for linear control). Thus, a milling machine with continuous control in th e X, Y, Z directions could be termed be a three-axis machine or a 3c machine, Similarly, lathes are usually two axis or 2C machines. The degree of work precision depends almost entirely upon the accuracy of the lead screw and the rigidity of the machine st ructure．With this system．there is no self-correcting action or feedback of information to the control unit．In the event of an unexpected malfunction，the control unit continues to put out pulses of electrical current．If，for example，the table on a N／C milling machine were suddenly to become overloaded，no response would be sent back to the controller．Because stepping motors are not sensitive to load variations，many N／C systems are designed to permit the motors to stall when the resisting torque exceeds the motor torque．Other systems are in use，however，which in spite of the possibility of damage to the machine structure or to the mechanical system，ale designed with special high—torque steppingmotors．In this case，the motors have sufficient capacity to “overpower” the system in the event of almost any contingency．The original N／C used the closed—loop system．Of the two systems，closed and open loop，closed loop is more accurate and，as a consequence，is generally more expensive．Initially，open—loop systems were used almost entirely for light-duty applications because of inherent power limitations previously associated with conventional electric stepping motors．Recent advances in the development of electro hydraulic stepping motors have led to increasingly heavier machin e load applications．数控技术数控是可编程自动化技术的一种形式，通过数字、字母和其他符号来控制加工设备。
数控技术 外文翻译 外文文献 英文文献 数控技术的发展与维修
Development and maintenance of CNC technology Numerical control technology and equipment is the development of new high-tech industry and cutting-edge enabling technology, industry and the most basic equipment. The world information industry, biological industry, aviation, aerospace and other defense industry widely used numerical techniques to improve manufacturing capacity and level, to improve the adaptability of the market and competitiveness. Industrial countries and CNC numerical control technology and equipment will also be listed as countries of strategic materials, not only to develop their own numerical control technology and industry, and in "sophisticated" technology and equipment, numerical control key aspects of the policy of closures and restrictions. Therefore, efforts to develop advanced numerical control technology as the core manufacturing technology has become the world's developed countries to accelerate economic development, enhance the comprehensive national strength and an important way to statehood.Part I: the development of CNC machine tools trends in individual1. High speed, high accuracy, high reliabilityHigh speed: To improve the speed and increase feed spindle speed.High precision: the precision from micron to sub-micron level, and even the nano-level (high reliability: the reliability of numerical control system generally higher than the reliability of numerical control equipment more than an order of magnitude, but not the higher the better reliability because the goods by the cost performance constraints.2. CompositeComposite function CNC machine tool development, its core is in a single machine to complete the turning, milling, drilling, tapping, reaming and reaming and other operating procedures, thereby increasing the efficiency and precision machine tools to improve production flexibility.3. IntelligentIntelligent content included in all aspects of the numerical control system: the pursuit of processing efficiency and processing quality of intelligence; to improve the performance and the use of convenient connections and other aspects of intelligence; simplify programming, simplifying operational intelligence; also like the intelligent automatic programming, intelligent man-machine interface, as well as intelligent diagnostics, intelligent monitoring and other aspects, to facilitate system diagnostics and maintenance.4. Flexible, integratedThe world of CNC machine tools to the development trend of flexible automation systems are: from the point (CNC single, composite machining centers and CNC machine tools), line (FMC, FMS, FTL, FML) to the surface (Section workshop independent manufacturing island FA) , body (CIMS, distributed network integrated manufacturing system) direction, the other to focus on applied and economic direction. Flexible automation technology is the industry to adapt to dynamic market demands and quickly update the primary means of product is the main trend of national manufacturing industry is the basis for the field of advanced manufacturing technology.Second, personalization is the adaptability of the market trendsToday's market, gradually formed the pattern of international cooperation, the products becoming more competitive, efficient and accurate processing of the escalating demand means, the user's individual requirements become increasingly strong, professional, specialization, more and more high-tech machine tools by the users of all ages.Third, the open architecture trend isThe core of a new generation of CNC system development is open. Open software platform and hardware platforms are open systems, modular, hierarchical structure, and through out the form to provide a unified application interface.CNC system to address the closure of the traditional CNC applications and industrial production problems. At present, many countries of open CNC system, CNC system has become an open numerical control system of the future of the road. The open numerical control system architecture specification, communication specifications, configuration specifications, operating platform, function libraries and CNC numerical control system software development tools, system function is the core of the current study. Network numerical control equipment is nearly two years of a new focus. NC network equipment will greatly satisfy the production lines, manufacturing systems, manufacturing information integration needs of enterprises, but also achieve new manufacturing model, such as agile manufacturing, virtual enterprises, global manufacturing the base unit. Some well-known at home and abroad, and CNC CNC machine tools manufacturing company inPart II: Machine MaintenanceCNC machine tools is electronic technology, measurement technology, automation technology, semiconductor technology, computer technology and electrical technology, and integrated set of automation equipment, high precision, high efficiency and high flexibility. CNC machine tools is a process control equipment and asked him in real-time control of the accuracy of every moment of work, any part of the fault and failure, so that the machine will shut down, resulting in production stoppages, which seriously affected and restricted the production efficiency . CNC machine tools in many industries to work the device is critical, if not after a failure in its maintenance and troubleshooting time, it will cause greater economic losses. Therefore, the principle that complex numerical control system, structure, maintenance of sophisticated equipment is necessary. CNC machine tools to enhance fault diagnosis and maintenance of power, can improve the reliability of CNC machine tools, CNC machine tools is conducive to the promotion and use.CNC machine tools is a mechanical, electrical, hydraulic, gas combination of complex equipment, though the reasons for failure vary, but the failure occurred, the general idea of the steps are the same. Fails,Spindle start below to stop immediately after the fault diagnosis of CNC machine tools as an example the general process.First, the fault-site investigation. The survey content includes 1, 2 types of failure, the failure frequency of 3, 4, external conditions, the operating conditions 5, 6, machine conditions, the functioning of 7, wiring between machine tools and systems 8, CNC equipment visual inspection. After an investigation, such failure is spindle class failure, only once, outside of all normal, the operator of a boot to reflect this situation.Second, the fault information collation, analysis. For some simple fault, because not alot of time, the method can be used form of logical reasoning, analysis, identification and troubleshooting. After a failed on-site investigation for several reasons we suspect that the system output pulse ①②drive is not enough time to move the state line to control the spindle components ③④damage to the spindle motor short-circuit, causing the spindle thermal relay protection ⑤ not with self-control loop lock circuits, and the parameter is set to pulse signal output, so that the spindle can not operate normally. Identify possible reasons to rule out one by one.Third, conduct fault diagnosis and troubleshooting.Diagnosis usually follows the following principles: 1, after the first outside inside. Reliable line of modern CNC system increasingly high failure rate of CNC system itself less and less, and most are non-occurrence of failure causes the system itself. The CNC machine is a mechanical, hydraulic, electrical as one of the tools, the occurrence of the fault will be reflected by these three comprehensive, maintenance personnel should be from outside to inside one by one investigation to avoid arbitrary unsealed, demolition, otherwise expand the malfunction, so that the loss of precision machine tools, slow performance, outside the system detected the fault is due to open one by one, hydraulic components, pneumatic components, electrical actuators, mechanical devices caused problems. 2, the first after the electrical machinery. In general, the mechanical failure easier to find, and numerical control system and electrical fault diagnosis more difficult, before the troubleshooting to rule out mechanical failure of the first 3, after the first static dynamic. Power off the machine first, quiescent state, through understanding, observation, testing, analysis, confirm the power failure will not result in expansion of the incident only after the power to the machine, run the state, the dynamic of observation, inspection and testing, to find fault. While after the devastating power failure, you must first rule out the danger, before electricity. 4, after the first simple and complex. When multiple failures are intertwined, and sometimes impossible to start with, we should first solve the problem easily, then solve the difficult problem, often a simple problem to solve, the difficulty of the problem may also become easier.CNC machine tools in the fault detection process, should make full use of numerical control system self-diagnostic features to be judged, but also flexibility in the use of some common troubleshooting methods. Troubleshooting common methods are:1. Routine examination methodRoutine examination method is mainly of hands, eyes, ears, nose and other organs of the fault occurrence of various light, sound, smell and abnormal observations and careful look at every system, follow the "first post outside of" the principle of fault diagnosis by looking, listening, smelling, asking, mold and so on, from outside to inside one by one check, the fault can often be narrowed down to a module or a printed circuit board. This requires maintenance personnel have a wealth of practical experience, to the wider multidisciplinary and comprehensive knowledge of the ability to judge.2. Self-diagnostic function methodModern CNC system has yet to achieve a high degree of intelligence. But already has a strong self-diagnostic function. CNC ready to monitor the hardware and software is working. Once the abnormal, immediately displayed on the CRT alarm or fault LEDs indicate the approximate cause. Using self-diagnosis function, but also shows the interface signals between the system and the host state, in order to determine the fault occurred in themechanical part or parts of NC system, and indicate the approximate fault location. This method is currently the most effective maintenance methods.3. Functional program testing methodSo-called functional program testing method is commonly used in the numerical control system functions and special features, such as linear positioning, circular interpolation, helical cut, fixed cycle, such as the user macro programming by hand or automatic programming methods, the preparation of test procedures into a functional program , into the numerical control system, and then start the CNC system to make it run, to check the im time the first boot of CNC whether a programming error or operational error or machine4. Spare parts substitutionSpare parts replacement method is a simple method to determine the scene is one of the most commonly used. The so-called spare substitution is generally the cause of failure in the analysis of the case, maintenance personnel can use the alternate PCB, templates, integrated circuit chip or replace the questionable parts of components, which narrowed the fault to a printed circuit board or chip level. It is actually in the verification analysis is correct. However, before switching the standby board should carefully check the spare board is intact, and should check the status of reserve board should be fully consistent with the original board the state. This includes checking with the board selection switch, set the location and the short rod potentiometer position. In short, we must strictly in accordance with the system's operation, maintenance requirements manual operation.In determining the replacement of a part to, should carefully check the relevant connected to electrical lines and other related, confirming that no failure up to the new replacement to prevent failures caused by external damage to replace the parts up.5. Transfer ActThe so-called transfer method is to have the same numerical control system features two printed circuit boards, templates, integrated circuit chips or components to exchange, observed failure phenomena be transferred. In this way, the system can quickly determine the fault position. This method is actually a kind of spare parts substitution. Therefore, the considerations described in the same spare parts substitution.6. Parameter check methodKnown parameters can directly affect the numerical performance of CNC machine tools. Parameters are usually stored in the magnetic bubble memory, or stored in batteries to be maintained by the CMOS RAM, once the battery is low or because of outside interference and other factors, some parameters will be lost or change in chaos, so that the machine does not work. At this point, through the proofreading, correction parameters, will be able to troubleshoot. When the machine idle for a long time to work again for no reason that there is no normal or failure without warning, it should be based on fault characteristics, inspection and proof-reading the relevant parameters.After a long run of CNC machine tools, wear and tear due to its mechanical drive components, electrical component performance changes and other reasons, also need to adjust the parameters of its. Some machine tool failure is often not timely because the parameters change due to some not meet. Of course, these failures are the fault of the areas are soft.7. Measurement of Comparative LawCNC system in the design of printed circuit board manufacturing plant, in order to adjust, repair facilities, in the printed circuit board designed a number of test terminals. Users can also use normal printed circuit board terminals comparing the measured and the difference between the printed circuit board failure. These terminals can detect the voltage and waveform measurements, analyze the causes of failure and failure location. Even on a normal printed circuit board can sometimes artificially create "fault", such as broken connection or short circuit, unplug the components, in order to determine the real cause of failure. Therefore, maintenance personnel should be in the usual accumulation of key parts of the printed circuit board or failure-prone parts of the right in the normal waveform and voltage values. Because the CNC system manufacturer often does not provide the information in this regard.8. Percussion methodWhen the CNC system failures showed Ruoyouruowu, often used method for detecting the fault struck the site lies. This is because the numerical control system is composed by the multi-block printed circuit boards, each board has a lot of solder joints, plates or between modules and is connected through the connectors and cables. Therefore, any cold solder joint or bad, may cause a malfunction. When the tap with the insulation and poor contact with Weld doubt at fault must be repeated reproduction.9. Local heating methodAfter a long running CNC system components are to be aging, performance will deteriorate. When they are not fully damaged, failures will become from time to time. Then heat can be used such as a hair dryer or electric iron is suspected to local heating components, accelerating the aging so thoroughly exposed fault components. Of course, using this method, be sure to pay attention to components of the temperature parameters, do not roast the original device is a good or bad.10. Principle of analysisThe composition according to principles of numerical control system can be analyzed from various points of logical levels and logical parameters (such as voltage or waveform) and then with a multimeter, logic pen, only the oscilloscope or logic analyzer to measure, analyze and compare, and thus failure positioning. Using this method, which requires maintenance personnel to be on the whole system or the principle of each circuit have a clear, deep understanding.Based on the above principles and methods, we may be itemized on the check it and eliminate the causes.The first possible failure for the system output pulse time is not enough, we adjust the M-code system, start the spindle output time, found the problem still exists, and then find the next possible cause may be in the drive to move the state, refer to the manual drive , set parameters start the spindle, the problem still exists we suspected spindle motor short-circuit, resulting in thermal relay protection. Then find the cause of the short, so that the spindle thermal relay reset the start and found that the normal operation of the spindle, the problem solved.Fourth, do a lessons learned and recorded. After troubleshooting, repair work can not be considered complete, still need technical and management aspects of the underlying causes of failure have to take appropriate measures to prevent failures from happening again. Underfield conditions when necessary use of mature technologies to transform and improve the equipment. Finally, the failure of the maintenance of the phenomenon, cause analysis, resolution process, the replacement of components, legacy, etc. to make a record.数控技术的发展与维修数控技术及装备是发展新兴高新技术产业和尖端工业的使能技术和最基本的装备。
数控技术在机械制造中的有效应用外文文献翻译、中英文翻译、外文翻译
本科生毕业设计 (论文)
外文翻译
原文标题The Effective Use in the Process of Numerical
Technology in Mechanical Manufacturing
译文标题数控技术在机械制造中的有效应用
作者所在系别机电工程学院
作者所在专业车辆工程
作者所在班级B13142
作者姓名郝立新
作者学号201322375
指导教师姓名赵秋芳
指导教师职称副教授
完成时间2017 年 2 月
北华航天工业学院教务处制
注：1. 指导教师对译文进行评阅时应注意以下几个方面：①翻译的外文文献与毕业设计（论文）的主题是否高度相关，并作为外文参考文献列入毕业设计（论文）的参考文献；②翻译的外文文献字数是否达到规定数量（3 000字以上）；③译文语言是否准确、通顺、具有参考价值。
2. 外文原文应以附件的方式置于译文之后。
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数控技术数字控制与计算机数字控制的发展历史数字控制是按照含有机床(刀具)运动信息程序所指定的顺序自动执行操作的加工过程。
数控这一概念是由密歇根洲特拉华城的约翰·帕森于20世纪四十年代后期提出的。
为了在工件上加工光滑的轮廓，帕森提出了一种自动的机床控制方式，它能够引导铣床刀具加工出一种“过轴曲线”。
1949年，美国空军与帕森签署了合同，要求开发一种能够提高生产率的新型机床。
帕森委托麻省理工学院(MIT)来开发一种新概念机床，麻省理工学院的科学家和工程师研制出了一种用穿孔纸带作为输入媒介的二轴联动铣床控制系统。
在较短时间内，当时所有主要的机床生产商都生产了一些数控机床，但直到20世纪七十年代后期，基于计算机的数字控制才被得到广泛的使用。
只有价格低廉且功能强大的微处理芯片代替了计算机数控系统中的硬连线逻辑发生器后，NC才真正成为一门自动化技术。
当数控机床在计算机监控下工作时，它就被称为计算机数控机床(CNC)。
计算机是CNC机床的控制单元，它们内嵌于数控机床或者通过通讯渠道与数控机床联接，当程序员编程时，通过纸带或磁盘将一些信息输入，计算机将对一些必要的数据进行计算的完成工作。
由于第一台数控机床的数据是由纸带控制的，因此数控系统被称为纸带控制机床。
它们只能控制由输入到机床内的纸带或磁带所规定的单一操作，输入到机床内的程序是不能被编辑的，要改变程序必须重做新纸带。
当今的系统都由计算机来控制数据，因而称之为计算机数控机床(简称CNC机床)。
NC和CNC系统两者的工作原理一样，仅仅控制执行的方式不同。
新型的数控系统通常速度更快、功率更大、功能更齐全。
数字控制与计算机数字控制的应用数控技术自创立以来就得到了广泛的应用，包括车床和车削中心、铣床和加工中心、冲床、电火花(EDM)加工机床、线切割机床、磨床以及测试检测装置等。
最复杂的计算机数控机床是车削中心，图4—1所示一个具有十转位的刀架能进行快速换刀的现代车削中心，立式加工中心如图4—2所示(刀具库在机床的左边。
右边的控制面板可由操作者通过转臂转动)，以及卧式加工中心，通过按下按钮每把刀可在数秒钟内定位。
如图4—3所示(配有自动换刀系统。
刀具库储备有200把切削工具)。
当为某项操作编程时，程序员必须选择传统的加工切削数据推荐值。
这些切削数据包括切削速度、进给率、刀具和刀具几何形状等。
当程序员正确选择所有必要信息后，操作人员将程序载入机床并按下按钮，切削循环就开始。
数控技术是一种利用程序实现自动控制的技术，加工制造设备采用数控技术后能由数字、字符和符号等进行控制。
这些数字、字符和符号等被编码成按一定格式定义的指令程序用于一个特定的加工或工件，这些指令可以采用两种二进制编码的数字系统中的任意一种进行定义，这两种二进制编码数字系统分别为电工协会代码(EIA)和美国标准信息交换代码(ASCII)。
一般来说，ASCII编码的机床控制系统不能接受EIA编码的指令，反之亦然。
当然，这样的问题已经逐渐得到解决。
数控加工制造目前已经广泛地应用于几乎所有的金属加工机床：车床，铣床，钻床，镗床，磨床，回转冲床，电火化，线切割和焊接机床，甚至弯管机也采用数控加工技术。
数控技术的基本组成一个数控系统主要由以下3个部分组成：(1)程序指令(2)加工控制单元(3)制造装备程序指令是由一条一条的详细指令所组成，制造装备按要求执行这些指令。
最常用的指令有：可以按要求使机床刀具主轴位于工作台上的具体位置，工作台是用于固定加工零件的，许多更高级的指令还包括用于主轴速度的选择、刀具速度的选择及其他一些功能。
加工控制单元(MCU)包括一些用于阅读和解释程序指令并将其转换为机床刀具或其他制造装备的机械动作的电子和控制硬件。
制造装备是一种进行金属加工的数控技术装备，在常用的数控技术领域中，制造装备用于进行机械制造。
制造装备包括工作台、主轴、电机及控制驱动单元。
数控技术的类型数控技术系统主要有两种类型：点对点数控系统和轮廓线数控系统。
点对点数控系统也称为位置数控系统，比轮廓线数控系统简单，其主要的原理是移动刀具或工件从一个程序控制点到另一一个控制点，通常像钻床这样的加工功能，每个点帮司以通过NC程序中的指令进行控制。
点对点数控系统适用于像钻孔、沉孔加工、沉孔镗孔、铰孔和攻丝等。
其他冲孔机床、点焊机和装配机床等也都采用点对点数控系统。
轮廓线数控系统也称为轮廓线路径数控系统，定位和切割操作都是以不同的速度沿着控制的路径进行的。
由于刀具沿路径进行切削，因此刀具的运动和速度的精确控制和同步性能是非常重要的。
轮廓线数控系统经常应用于车床、铣床、磨床、焊接机床和加工中心中。
刀具沿着路径的运动，或称为插补逐渐出现了几个不同的方法。
有许多类型的插补方法用于处理轮廓线数控系统中生成光滑的轮廓线时遇到的各种问题。
几种比较常用的方法有线性插补，圆形插补，螺旋形插补、抛物线插补和立方插补等，在所有的插补方法中，路径控制是以刀具的旋转中心为标准，对于不同类型、不同直径的刀具，加工过程中的不同刀具磨削量在数控程序中获得不同的补偿。
数控系统的编程一个数控系统(NC)的程序包括使数控(NC)机床进行操作和加工的一系列指令。
数控程序可以由数控机床内部的程序库开发生成，也可以从外面采购获得。
另外，程序可以通过手工编写，也可以进行计算机辅助编程。
数控程序包括一系列指令系统和命令系统。
几何类指令用于定义刀具和工件之间的相对位置和运动：加工类指令用于定义主轴转速、进给、刀具转速等：传送类指令用于定义刀具或工作台的运动速度和插补的类型等；开关类指令用于冷却液供给、主轴旋转、主轴旋转方向选择、换刀、工件进给、夹具等的开关。
第一个用于数控编程的数控编程语言是20世纪50年代由麻省理工学院数控编程系统开发小组专家开发的，并被命名为自动编程工具(APT)。
直接数字控制(DNC)和计算机数字控制(CNC)数控技术的发展在批量生产和车间生产加工中，不管是在技术上还是在商业上都获得了巨大的成功。
目前，已经有两种数控技术系统得到了发展，分别是：(1)直接数字控制(DNC)。
(2)计算机数字控制(CNC)。
直接数字控制(DNC)可以被定义为这样一个生产制造系统，该制造系统有许多台加工机床，而相互之间由一台计算机采用直接连接，进行实时控制。
这样，在传统的数字控制技术中采用的磁带阅读器在直接数字控制中被取消，从而保证了系统的可靠性。
不使用磁带阅读器，被加工的零件程序就从计算机的存储器中直接传送到进行加工的刀具上。
从原理上讲，一台计算机可以控制多达100台加工机床，(在20世纪70年代一个商业使用的DNC系统宣称可以控制多达256个机床刀具)。
直接数字控制计算机用于按要求提供加工指令给每个进行加工的刀具上，当机床需要控制指令时，计算机就可以马上将指令传送到机床上。
随着直接数字控制(DNC)技术和计算机技术的飞速发展，数字式计算机的尺寸和价格的大幅度的降低，数字式计算机的计算能力的大大提高，大量传统的以硬件线路为基础的加工控制单元被以数字计算机为基础的数字控制单元所替代。
最初在20世纪70年代使用了小型计算机。
后来，随着计算机的进一步小型化，早期的小型计算机逐渐被现在的微型计算机所取代。
计算机数控(CNC)使用专用的微型计算机作为加工控制单元。
因为数字计算机都用于计算机数控(CNC)和直接数控(DNC)，所以应该注意两者之间的区别，可以从3个方面来加以区分。
(1) DNC计算机是将指令数据发送到许多机床去或从许多机床中收集数据，而CNC计算机每次只控制一台或几台机床。
(2) DNC计算机一般位于距机床一定距离的位置，而CNC计算机一般都位于距机床较近的位置。
(3) DNC计算机开发的软件不仅可以用于控制单件生产，而且可以用于一个企业制造部门的管理信息系统，而CNC计算机开发的软件一般只用于某个特殊加工的工具。
数控铣床数控铣床是在一般铣床的基础上发展起来的,两者的加工工艺基本相同,结构也有些相似,但数控铣床是靠程序控制的自动加工机床,所以其结构也与普通铣床有很大区别.数控铣床的组成主轴箱包括主轴箱体和主轴传动系统，用于装夹刀具并带动刀具旋转，主轴转速范围和输出扭矩对加工有直接的影响。
进给伺服系统：由进给电机和进给执行机构组成，按照程序设定的进给速度实现刀具和工件之间的相对运动，包括直线进给运动和旋转运动。
控制系统：数控铣床运动控制的中心，执行数控加机床基础件：通常是指底座、立柱、横梁等，它是整个机床的基础和框架。
夹具：数控铣床主要用于加工形状复杂的零件，但所使用夹具的结构往往并不复杂。
数控铣床夹具的选用可首先根据生产零件的批量来确定。
对单件、小批量、工作量较大的模具加工来说，一般可直接在机床工作台面上通过调整实现定位与夹紧，然后通过加工坐标系的设定来确定零件的位置。
数控铣床的组成：数控铣床的基本组成，它由床身、立柱、主轴箱、工作台、滑鞍、滚珠丝杠、伺服电机、伺服装置、数控系统等组成。
床身用于支撑和连接机床各部件。
主轴箱用于安装主轴。
主轴下端的锥孔用于安装铣刀。
当主轴箱内的主轴电机驱动主轴旋转时，铣刀能够切削工件。
主轴箱还可沿立柱上的导轨在Z 向移动，使刀具上升或下降。
工作台用于安装工件或夹具。
工作台可沿滑鞍上的导轨在X 向移动，滑鞍可沿床身上的导轨在Y 向移动，从而实现工件在X和Y 向的移动。
无论是X、Y 向，还是Z 向的移动都是靠伺服电机驱动滚珠丝杠来实现的。
伺服装置用于驱动伺服电机。
控制器用于输入零件加工程序和控制机床工作状态。
控制电源用于向伺服装置和控制器供电。
数控铣床的工作原理根据零件形状、尺寸、精度和表面粗糙度等技术要求制定加工工艺，选择加工参数。
通过手工编程或利用CAM 软件自动编程，将编好的加工程序输入到控制器。
控制器对加工程序处理后，向伺服装置传送指令。
伺服装置向伺服电机发出控制信号。
主轴电机使刀具旋转，X、Y 和Z向的伺服电机控制刀具和工件按一定的轨迹相对运动，从而实现工件的切削。
数控铣床加工的特点（1）用数控铣床加工零件，精度很稳定。
如果忽略刀具的磨损，用同一程序加工出的零件具有相同的精度。
（2）数控铣床尤其适合加工形状比较复杂的零件，如各种模具等。
（3）数控铣床自动化程度很高，生产率高，适合加工批量较大的零件。
NC and CNCThe History of NC and CNC DevelopmentNumerical Control (NC) is any machining process in which the operations are executed automatically in sequences as specified by the program that contains the information for the tool movements. The NC concept was proposed in the late 1940s by John Parsons of Traverse City, Michigan. Parsons recommended a method of automatic machine control that would guide a milling cutter to produce a "thru-axis curve" in order to generate smooth profiles on work pieces.In 1949, The U.S. Air Force awarded Parsons a contract to develop a new type of machine tool that would be able to speed up production methods. Parsons commissioned the Massachusetts Institute of Technology (M.I.T.) to develop a practical implementation of his concept. Scientists and engineers at M.I.T. built a control system for a two-axis milling machine that used a perforated paper tape as the input media. In a short period of time, all major machine tool manufacturers were producing some machineswith NC, but it was not until the late 1970s that computer-based NC became widely used. NC matured as an automation technology when inexpensive and powerful microprocessors replaced hard-wire logic-making computer-based NC systems.When Numerical Control is performed under computer supervision, it is called Computer Numerical Control (CNC). Computers are the control units of CNC machines, they are built in or linked to the machines via communications channels. When a programmer input some information in the program by tape and so on, the computer calculates all necessary data to get the job done.On the first Numerically Controlled (NC) machines were controlled by tape, andbecause of that, the NC systems were known as tape-controlled machines. They were able to control a single operation entered into the machine by punched or magnetic tape. There was no possibility of editing the program on the machine. To change the program, a new tape had to be made.Today's systems have computers to control data; they are called Computer Numerically Controlled (CNC) machines. For both NC and CNC systems, work principles are the same. Only the way in which the execution is controlled is different. Normally, new systems are faster, more powerful, and more versatileThe Applications of NC/CNCSince its introduction, NC technology has found many applications, including lathes and turning Centers, milling machines and machining centers , punches , electrical discharg machines(EDM) Flame cutters,grinders,and inspection equipment. the most complex CNC machinetools are the turning center,shown in Fig.4-1(Amodern turning center with a ten-station turret that accepts quick-chang tools.Each tool can be positioned in Seconds with the press of a button).And the machine center shown in Fig.4-2(Vertical machining center,the tool magazine is on the machine.the control panel on the right can be swiveled by the operator)and Fig.4-3(horizontal machining center,equipped with an automatic tool changer .tool magazines can store 200 ctting tools.When preparing a progam for a particular operation ,the prommer must select all cutting data using recommendations for conventional machining .this includes properSelection of cutting speeds,feedrate,tools and tool geometry,and so on.when the programmer has chosen all of the necessary information properly,the operator loads the programme into the machine and presses a button to start the cutting crycle .the CNC machine moves automatically from one maching operation to another , changing the cutting tols and applying the coolent.in a surprisingly short time ,the workpiece is Machined according to the highest quality stangards. But that is not all.no matter how big the work series is,all of the parts will be almost identical in size and surface finishing. At this time of advanced technology,with its high demands for surface finishing and tolerances of components in,for example ,aerospace,nuclear,and medical equipment manufacturing,only CNC machines provide successful results.Numerical control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particularworkpart or job. The instructions are provided by either of the two binarycoded decimal systems: the Electronic Industries Association (EIA) code,or the American Standard Code for Information Interchange (ASCII).ASCII-coded machine control units will not accept . EIA coded instructionsand vice versa. Increasingly, however, control units are being made toaccept instructions in either code. 121Automation operation by NC isreadily adaptable to theoperation of all metalworking machines. Lathes, milling machines,drill presses, boring machines, grinding machines, turret punches, flameor wire-cutting and welding machines, and even pipe benders are availablewith numerical controls.Basic Components of NCA numerical control system consists of the following three basic components:(1) Program instructions(2) Machine control unit(3) Processing equipmentThe program instructions are the detailed step by step commands thatdirect the processing equipment. [31In its most common form, the commandsrefer to positions of a machine tool spindle with respect to the worktableon which the part is fixtured. More advanced instructions include selectionof spindle speeds, cutting tools, and other functions.The machine control unit (MCU) consists of the electronics and controlhardware that reads and interprets the program of instructions and convertit into mechanical actions of the machine tool or other processing equipment.The processing equipment is the component that performs metal process.In the most common example of numerical control, it is used to performmachining operations. The process-ing equipment consists of the worktableand spindle as well as the motors and controls needed to drive them.Types of NCThere are two basic types of numerical control systems: point to pointand contouring.Point to point control system, also called positioning, is simpler thancontouring control system. Its primary purpose is to move a tool orworkpiece from one programmed point to another. Usually the machinefunction, such as a drilling operation, is also activated at each pointby command from the NC program. Point to point systems are suitable forhole machining operations such as drilling, countersinking, couterbofing,reaming, boring and tapping. Hole punching machines, spotwelding machines,and assembly machines also use point to point NC systems.Contouring system, also known as the continuous path system,positioning and cutting operations are both along controlled paths but atdifferent velocities. Because the tool cuts as it travels along aprescribed path, accurate control and synchronization of velocities andmovements are important. The contouring system is used on lathes, millingmachines, grinders,incrementally, by one of several basic methods. Thereare a number of interpolation schemes that have been developed to deal withthe various problems that are encountered in generating a smooth continuouspath with a contouring type NC system. They include linear interpolation,circular interpolation, helical interpolation, parabolic interpolation and cubic interpolation. In allinterpolations, the path controlled is that of the center of rotation of the tool. Compensation for different tools, different diameter tools, or tools wear during machining, can be made in the NC .Programming for NCA program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process. Programming for NC may be done by an internal programming department, on the shop floor, or purchased from an outside source. Also, programming may be done manually or with computer assistance.The program contains instructions and commands. Geometric instructions pertain to relative movements between the tool and the workpiece. Processing instructions pertain to spindle speeds, feeds, tools, and so on. Travel instructions pertain to the type of interpolation and slow or rapid movements of the tool or worktable. Switching commands pertain to on/off position for coolant supplies, spindle rotation, direction of spindle rotation, tool changes, workpiece feeding, clamping, and so on. The first NC programming language was developed by MIT developmental work on NC programming systems in the late 1950s and called APT(Automatically Programmed Tools).DNC and CNCThe development of numerical control was a significant achievement in batch and job shop manufacturing, from both a technological and a commercial viewpoint. There have been two enhancements and extensions of NC technology, including:(1)Direct numerical control(2) Computer numerical controlDirect numerical control can be defined as a manufacturing system in which a number of machines are controlled by a computer through direct connection and in real time. The tape reader is omitted in DNC, thus relieving the system of its least reliable component. Instead of using the tape reader, the part program is transmitted to the machine tool directly from the computer memory. In principle, one computer can be used to control more than 100 separate machines. (One commercial DNC system during the 1970s boasted a control capability of up to 256 machine tools.) The DNC computer is designed to provide instructions to each machine tool on demand. When the machine needs control commands, they are communicated to it immediately.Since the introduction of DNC, there have been dramatic advances in computer technology. The physical size and cost of a digital computer has been significantly reduced at the same time that its computational capabilities have been substantially increased. In numerical control, the result of these advances has been that the large hard-wired MCUs of conventionalNC have been replaced by control units based on the digital computer. Initially, minicomputers were utilized in the early 1970s. As further miniaturization occurred in computers, minicomputers were replaced by today's microcomputers.Computer numerical control is an NC system using dedicated microcomputer as the machine control unit. Because a digital computer is used in both CNC and DNC, it is appropriate to distinguish between the two types of system. There are three principal differences:1) DNC computers distribute instructional data to, and collect data from, a large number of machines. CNC computers control only one machine, or a small number of machines.2) DNC computers occupy a location that is typically remote from the machines under their control. CNC computer are located very near their machine tools.3) DNC software is developed not only to control individual pieces of production equipment, but also to serve as part of a management information system in the manufacturing sector of the firm. CNC software is developed to augment the capabilities of a particular machine Tool.CNC milling machine CNC milling machine milling in general developed on the basis of, both processing the same, somewhat similar structure, but the CNC milling machine is programmed by automatic machine tools, so its structure is verydifferent with ordinary milling machine.The composition of CNC milling machineIncluding the spindle headstock spindle box and transmission, and drive tool for rotating clamping tool, spindle speed range and output torque has a direct impact on the process. Feed servo system: from the feed motor and feed the implementation of institutions, in accordance with the procedures set feed rate to achieve tool and the workpiece relative motion between, including the linear feed motion and rotation. Control system: CNC milling machine motor control center, the implementation of CNC machine tools based on additional pieces: usually refers to the base, columns, beams, etc., it is the basis and framework for the entire machine. Clamp: CNC milling machine is mainly used for processing of complex shape parts, but the use of the structure is often complicated jig. CNC milling machine fixtures used to manufacture parts under the first batch to determine. Single piece,small batch and volume of the larger mold, the general directly in the machine table surface by adjusting the positioning and clamping to achieve, and then processed to determine the coordinates of the set location of parts. The composition of CNC milling machine: CNC milling machine elements, which consists of bed, column, spindle boxes, tables, slide saddle, ball screws, servo motors, servo devices, composed of CNC system. Bed machine for support and to connect the various parts. Headstock spindle for the installation. Bottom of the cone spindle hole cutter for installation. When the spindle inside the spindle motor drive spindle, the cutter can cut the workpiece. Spindle box also on the rail along the column in the Z to move the tool up or down. Table for mounting the workpiece or fixture. Table can slide along the rails on the saddle to move in X, the saddle can slip along the bed rail body to move in the Y to achieve the workpiece in the X and Y to the mobile. Both X, Y direction, or Z to the mobile are driven by ball screw servo motor to achieve. Servo devices for driving servo motors. Controller for input processing and control machine parts working condition. Control power for the power supply to the servo unit and controller.CNC milling machine worksAccording to the part shape, size, accuracy and surface roughness and other technical requirements to develop processing technology, select the machining parameters. Programming by hand or using CAM software, automatic programming, processing will be programmed input to the controller. Controller of the processing procedures, and send commands to the servo device. Servo devices send control signals to the servo motor. Tool spindle motor to rotate, X, Y and Z servo motor control to the tool and workpiece relative motion trajectory of a certain order to achieve the workpiece cutting.CNC milling machine features(1) with a CNC milling machine parts, precision is stable. If you ignore the tool wear, machined with the same procedure with the same precisionparts.(2), CNC milling machine is particularly suitable for processing more complex shape parts, such as various molds.(3) a high degree of automation, CNC milling, high productivity, large quantities of parts for processing.。