毕业设计外文翻译---控制系统介绍
毕业设计外文翻译 西门子公司的提升机控制系统的特点
英文原文SIEMENSSiemens to enhance the characteristics of control system1. the controller division of labor in differentSpecificity for the mining industry, Siemens PLC + FM458 proposed control system architecture. Logic control in part by the S7-400 PLC to implement, process control achieved in part by the FM458 controller.Siemens S7-400 PLC series of high-end production company, and its processing time, processing accuracy, fault tolerance, failure rate, expansion capability, communications capability, ease of use, etc. all have a certain superiority. PLC logic chain is mainly used to implement control and protection functions.FM458 is for certain sectors of the automation and process control requirements are relatively high situation developed under the 64-bit processors. The traditional way is PLC scan process control, cycle time, with the program scan the length and structure of the program changes. FM458 program function block is fixed scan operation, the program processing time is fixed. PLC's computing power of ordinary floating-point capability is not particularly strong, FM458 high floating point operations and procedures, fixed-time processing capability to fully meet the mining industry on the accuracy of process control and real-time requirements. FM458 mainly used to implement process control, such as location, shaft switch signal detection, stroke control, speed control, process control.Other common PLC control system to use more direct control. PLC's CPU need of a large number of operations that control the system precision, accuracy, control response on both deficiencies.2. electrical signals transmitted in different waysControl system will enhance the high-pressure tank, pressure cabinets, transformers, borehole signal, loading / unloading signal, console, electric motors, fans and other equipment for signal collection and chain of control.Siemens to all the remote signal acquisition and control were conducted using Profibus communications, placed in the remote station ET200 device. This distributed network control wiring is simple, topological expansion is convenient, reduces the field wiring, easy maintenance and low failure rate, and troubleshooting for the equipment for a lot of time and manpower. S7-400 PLC scalable Ethernet communications, scheduling and information company focused on providing a convenient centralized display.Other control systems to use more hard-line connections. Increased maintenance costs and maintenance time, extend it will increase a lot of wiring.3. position, speed, torque the three closed-loop controlSiemens control for the mining industry, the particularity and complexity, enhance the development of mine-specific process control function block, just a simple parameter setting, we can achieve a variety of conditions to enhance process control.Position control: control the process to enhance the location determines the speed, position setpoint determines the speed reference value. Through the shaft encoder position signal fed back by the actual, real-time adjustment of speed reference value, to ensure the lifts running in full accordance with the design curve. At the same time the position back based on feedback to determine when the value of parking, accurate parking.Speed control: Siemens to enhance the system to full digital control, closed-loop variable speed. As inclusion of the momentum value (acceleration derivative) control, making the speed of the corner of the smooth realization of the absolute changes, reduce wire rope and mechanical equipment on the impact and wear. Accurate detection and closed-loop speed control to achieve a speed of 0 in the case of the work of gate parking facilities, changing the traditional way by parking under the parking switch, parking brake by grinding.Torque Control: Siemens high-performance gear to ensure that the static accuracy and dynamic torque response. Torque preset function will not guarantee the winch started to fall, start smooth. Feature to ensure zero torque to maintain speed when the winch brake parking facilities will not slip down. Reduce the time of start and stop the impact and shoe machinery and equipment wear.Three closed-loop control mode enables the system to run in strict accordance with set curves, all-digital closed-loop control to stop position is accurate, do not rely on parking switch parking, reducing points of failure, high degree of automation, reducing the system is running in manual .Many other control systems used by the hardware switch to achieve speed, parking, Shi gate, control precision of the method is not high, the reliability is poor, large machinery and equipment damage.4. the three control loops: the safety circuit, electrical parking loop, closed loopThe severity level of the signal is different from the fault into three segments, clear, easy to find and eliminate the actual fault.Safety circuit: fault occurred, the elevator brake immediately implement mechanical brake, hoist can not be started until the fault is reset.Electrical stop circuits: fault occurs, the system will immediately implement electric car. After the elevator will not start until the fault is reset.Closed circuit:fault, still allow the elevator to finish this upgrade. However, after the completion of this cycle, hoist will be closed, can not start until the fault is reset.Many other control signal classification system is chaotic, to fault find and eliminate trouble.5. double-master PLC control and monitoring systemElevator control complex process, more chain between devices on the real-time and high security requirements. Siemens to enhance the safety and reliability of control system in the first place.All field devices and safety signals related respectively to the main control and monitoring system for chain compared to any found in a system fault signal immediately take appropriate measures to effectively prevent the occurrence of a single PLC system may collect the signal error, CPU error, etc. their own operations failure.Master PLC, PLC control system, process control functions in the implementation of dual-independent signal acquisition, the state judge, real-time computing, control command generator, etc., and then compared to each other the way to ensure control of each step is safe.Many other control systems for the single signal acquisition mode, to achieve some important signals can not be two-way protection. Some even single PLC control, with more than double when the PLC control can not be achieved between the double-PLC mutual monitoring, in terms of security there are some hidden dangers.6. dual detection sensor signalsSiemens digital control system to enhance the control must be accurate and reliable and accurate signal acquisition, real-time premise, high-performance S7-400 PLC and FM458 as signal acquisition, transmission, processing to provide a guarantee.Shaft encoder: Siemens Company Location (roller shaft locations), speed (at the outer edge of drum), slip rope (days Axle Division) detection were set up a dual high-precision encoder output signal respectively to the main control and monitoring system. The three encoder feedback data to compare, to ensure that every operation in accuracy of the data.Shaft Switches: Siemens sophisticated manufacturing process to improve the life of the switch shaft, image stabilization treatment reduced the malfunction. Shaft directly into the control system switch signal, the middle does not use relays, greatly reducing the hardware delay is not caused by the control accuracy. Shaft into the main control switch signal and control systems, respectively, forming a two-way protection.Many other control systems using two encoders, the lack of data between the encoder comparison. Switching signal in the low speed shaft prone to malfunction, there is no two-way protection.7. the elevator control-specific function blocks and process control proceduresControl of any system there own particularity, Siemens developed with independent intellectual property rights of private elevator control block. Position, velocity, acceleration, momentum (acceleration derivative), reptiles and other curve parameters can be set only needs to be changed, saving development time programming, labor costs, testing time. Enhance the function block to ensure optimal processing time, reduce unnecessary crawling time.Process control envelope is added to the speed, point by point speed, continuous speed, speedmonitoring; heavy promotion, heavy decentralization, enhance the overload, slippery rope, mutagenesis, speeding, over-roll and other software protection.Enhance the control of all process parameters are input parameters of function blocks the way to the future maintenance and diagnosis of the advantage.FM458's CFC (continuous function chart) programming environment to generate their own library, the library file for the compiled binary files, not to decompile, complete with independent intellectual property rights protection algorithms and procedures.Many other control systems and then manually fill in the value of the calculated curve the way, when conditions change, modify the difficulties and increase the debugging time, makes it difficult to maintain. Process control and more do not have the full protection.8. the elevator control software development SpecificSiemens in the design of electric control system, taking into account not just the starting point of electrical control, but more eyes on the electrical control from the perspective of how to extend the service life of mechanical systems devices, such as wire rope, plate-type brake brake shoes and so on.Siemens design system, it is also considering lifting height, maximum lifting speed, the maximum enhance acceleration, deceleration, under the premise remains the same, by a significant reduction in vibration of wire rope, making the whole upgrade cycle, the shortest time, thus improving the upgrade system efficiency, improve the user output in unit time.中文译文:SIEMENS西门子公司的提升机控制系统的特点1、控制器分工不同针对矿山行业的特殊性,西门子公司提出PLC+FM458构架的控制系统。
OPINIONS-ON-INTERNAL-CONTROL关于内部控制的意见大学毕业论文外文文献翻译及原文
毕业设计(论文)外文文献翻译文献、资料中文题目:关于内部控制的意见文献、资料英文题目:OPINIONS ON INTERNAL CONTROL 文献、资料来源:文献、资料发表(出版)日期:院(部):专业:班级:姓名:学号:指导教师:翻译日期: 2017.02.14LNTU---Acc附录A关于内部控制的意见如果要证明功能扩展到包含内部控制的有效性,那么报告准则则必须制定,若干基本问题必须被解决。
随着日益频繁增长,审计员听取了他们应该发表的一个效力于客户的内部控制制度建议的意见。
这一证明功能扩展的主张者迅速指出,目前已经有了实例如独立审计师的报告公开他们的客户的内部控制制度和一些政府机构的成效,包括一些空置中的美国证券和交易委员会,都需要一个报告。
这些证实类型的反对者公布了任何关于内部控制的有效性,他们认为,目前有显着性差异监管机构的报告要求和提出意见的内部控制将会误导公众。
本文综述了目前报告的做法,考虑到理想状态相关的危害的特点,并最后提出了一些在任何给与最后判决之前必要的予以回答的问题。
现状报告虽然审计员的报告中的一些情况提及了内部控制的性质,但作出的本质陈述还有很大不同的效应。
大型银行。
关于对内部控制的观点事实上出现在一些大型银行和看法发行的年度报告中。
有时这些意见是被董事会要求的。
例如,下面的主张出现在1969年年度报告的一个大型纽约银行中,作为第3款的独立会计师的标准短形式的报告:我们的审核工作包括评价有效性,大块的内部会计控制,其中还包括内部审计。
我们认为,在于程序的影响下,再加上银行内部审计工作人员所进行的审核,这些构成一个有效的系统的内部会计控制。
意见被提供给几个其他银行,但它们基本上引用的意见是一样的。
美国证券交易委员会的规定。
美国证券交易委员会表格X-17A-5,要求独立审计师作出某些有关的内部控制陈述,并必须在每年的大多数成员国家与每一个证券经纪或注册的交易商根据1934年证券交易法第15条进行交流时。
本科毕业设计外文翻译(中文)
本科生毕业设计(论文)外文翻译外文原文题目:Real-time interactive optical micromanipulation of a mixture of high- and low-index particles中文翻译题目:高低折射率微粒混合物的实时交互式光学微操作毕业设计(论文)题目:阵列光镊软件控制系统设计姓名:任有健学院:生命学院班级:06210501指导教师:李勤高低折射率微粒混合物的实时交互式光学微操作Peter John Rodrigo Vincent Ricardo Daria Jesper Glückstad丹麦罗斯基勒DK-4000号,Risø国家实验室光学和等离子研究系jesper.gluckstad@risoe.dkhttp://www.risoe.dk/ofd/competence/ppo.htm摘要:本文论证一种对于胶体的实时交互式光学微操作的方法,胶体中包含两种折射率的微粒,与悬浮介质(0n )相比,分别低于(0L n n <)、高于(0H n n >)悬浮介质的折射率。
球形的高低折射率微粒在横平板上被一批捕获激光束生成的约束光势能捕获,捕获激光束的横剖面可以分为“礼帽形”和“圆环形”两种光强剖面。
这种应用方法在光学捕获的空间分布和个体几何学方面提供了广泛的可重构性。
我们以实验为基础证实了同时捕获又独立操作悬浮于水(0 1.33n =)中不同尺寸的球形碳酸钠微壳( 1.2L n ≈)和聚苯乙烯微珠( 1.57H n =)的独特性质。
©2004 美国光学学会光学分类与标引体系编码:(140.7010)捕获、(170.4520)光学限制与操作和(230.6120)空间光调制器。
1 引言光带有动量和角动量。
伴随于光与物质相互作用的动量转移为我们提供了在介观量级捕获和操作微粒的方法。
过去数十年中的巨大发展已经导致了在生物和物理领域常规光学捕获的各种应用以及下一代光学微操作体系的出现[1-5]。
温度控制系统外文翻译--光刻投影镜头多闭环温度控制系统
毕业设计(论文)外文资料翻译学院:机械工程学院专业:机械设计制造及其自动化姓名:学号:指导老师:附件: 1.外文资料翻译译文;2.外文原文。
附件1:外文资料翻译译文光刻投影镜头多闭环温度控制系统聂宏飞1,李晓平1,*,何艳2。
1国家重点实验室,数字制造装备与工艺,华中科技大学,武汉430074,中国大学2天华学院,上海师范大学,上海201815,中国2008年5月27日收稿; 2009年1月8日修订; 2009年1月22日定稿;2009年2月6日电子出版摘要:图像质量是光学光刻工具的最重要指标之一,尤其易受温度、振动和投影镜头(PL)污染的影响。
本地温度控制的传统方法更容易引入振动和污染,因此研发多闭环温度控制系统来控制PL内部温度,并隔离振动和污染的影响。
一个新的远程间接温度控制(RITC)方案,提出了利用冷却水循环完成对PL的间接温度控制。
嵌入温度控制单元(TCU)的加热器和冷却器用于控制冷却水的温度,并且,TCU必须远离PL,以避免震动和污染的影响。
一种包含一个内部级联控制结构(CCS)和一个外部并行串联控制结构(PCCS)的新型多闭环控制结构被用来防止大惯性,多重迟滞,和RITC系统的多重干扰。
一种非线性比例积分(PI)的算法应用,进一步提高收敛速度和控制过程的精度。
不同的控制回路和算法的对比实验被用来验证对控制性能的影响。
结果表明,精度达到0.006℃规格的多闭环温度控制系统收敛率快,鲁棒性强,自我适应能力好。
该方法已成功地应用于光学光刻工具,制作了临近尺寸(CD)100纳米的模型,其性能令人满意。
关键词:投影镜头,远程间接温度串级控制结构,并行串连控制结构,非线性比例积分(PI)的算法1简介由于集成电路缩小,更小的临界尺寸(CD)要求,生产过程的控制越来越严格。
作为最重要的制造工艺设备,先进的光学光刻工具需要更严格的微控制环境[1],如严格控制其温度、洁净度、气压、湿度等。
温度波动,特别是导致图像失真和平面图像转变,成为了光学光刻工具对图像质量影响的一个关键因素。
机器人自动寻迹控制系统-外文翻译【范本模板】
南京理工大学毕业设计(论文)外文资料翻译学院(系):机械工程学院专业:机械工程及其自动化姓名:陆建学号:0701500122外文出处:IEEE/IEE Electronic(用外文写)library(IEL)附件:1。
外文资料翻译译文;2.外文原文。
注:请将该封面与附件装订成册。
附件1:外文资料翻译译文导电胶粘剂机器人—一种新型,健壮,电力可控制附着技术的爬墙机器人Harsha Prahlad, Ron Pelrine,Scott Stanford,John Marlow, and Roy Kornbluh摘要本文介绍了一种新型夹紧称为兼容电胶合技术,同时也是第一次将这种技术应用于爬墙机器人.正如其名称所示电胶合是一种电气控制粘连技术,它涉及到采用电源连接到适合机器人移动的顺滑板来诱导墙体表面的静电荷。
立足于移动机人,夹紧力高(1平方厘米的夹紧表面承受0.2-1.4牛顿的力,力的具体大小取决于基板)已经在各种各样的常见的建筑基质中得到证实,无论是在粗糙还是光滑抑或是导电体还是绝缘体中都得到证实,与传统的粘合剂或干燥粘合剂不同,它可以为了符合流动性或配合清洗而被调制或关掉,该技术利用数量非常小的力量(大约20微瓦/牛顿的承受力量)并且展示了能重复地夹在有大量灰尘或其他杂物覆盖在基板的墙中的能力,通过使用这项技术,国际斯坦福研究所展示了各种各样的爬墙机器人包括跟踪和腿机器人。
I 引言最近的事件,诸如自然灾害,军事行动,或公众安全的威胁,强大的侦察机器人已经得到越来越多的重视,而能在三维空间里穿越地形复杂的城市的机器人更加受到重视。
创新地机器人具有良好的净空能力,通常使用很多模式的移动,如轮式或跟踪运动,腿运动,跳跃运动的机器人。
然而,它的攀爬或者停在垂直的表面建筑物及其他设施的能力,对其在军事用途提供了独特的应用空间.如城市侦察,传感器部署,建立城市网络节点,以及在民事搜索和救援行动.其垂直机动性和在高处栖息方面的能力也有众多的商业应用,如管道和槽罐检查或访问够不着的场合,如窗口区域清洁。
中英文文献翻译pid控制器--大学毕业设计论文
附件1:外文原文PID controllerZuo Xin and Sun Jinming(Research Institute ofAutomation, University of Petroleum,Belting 102249,China)Received April 2,2005Abstract:Performance assessment of a proportional-integral-derivative(PID)controller is condueted using the PID achievable minimum variance as abenchmark.When the process model is unknown,we carl estimate the P/D·achievable minimum variance and the corresponding parameters by routine closed-loop operation data.Simulation results show that the process output variance is reduced by retuning controller parameters.Key words:Performance assessment,PID control,minimum varianceA proportional–integral–derivative controller (PID controller) is a generic .control loop feedback mechanism widely used in industrial control systems.A PID controller attempts to correct the error between a measured process variable and a desired setpoint by calculating and then outputting a corrective action that can adjust the process accordingly.The PID controller calculation (algorithm) involves three separate parameters; the Proportional, the Integral and Derivative values. The Proportional value determines the reaction to the current error, the Integral determines the reaction based on the sum of recent errors and the Derivative determines the reaction to the rate at which the error has been changing. The weightedsum of these three actions is used to adjust the process via a control element such as the position of a control valve or the power supply of a heating element.By "tuning" the three constants in the PID controller algorithm the PID can provide control action designed for specific process requirements. The response of the controller can be described in terms of the responsiveness of the controller to an error, the degree to which the controller overshoots the setpoint and the degree of system oscillation. Note that the use of the PID algorithm for control does not guarantee optimal control of the system or systemstability.Some applications may require using only one or two modes to provide the appropriate system control. This is achieved by setting the gain of undesired control outputs to zero. A PID controller will be called a PI, PD, P or I controller in the absence of the respective control actions. PI controllers are particularly common, since derivative action is very sensitive to measurement noise, and the absence of an integral value may prevent the system from reaching its target value due to the control action.Note: Due to the diversity of the field of control theory and application, many naming conventions for the relevant variables are in common use.1.Control loop basicsA familiar example of a control loop is the action taken to keep one's shower water at the ideal temperature, which typically involves the mixing of two process streams, cold and hot water. The person feels the water to estimate its temperature. Based on this measurement they perform a control action: use the cold water tap to adjust the process. The person would repeat this input-output control loop, adjusting the hot water flow until the process temperature stabilized at the desired value.Feeling the water temperature is taking a measurement of the process value or process variable (PV). The desired temperature is called the setpoint (SP). The output from the controller and input to the process (the tap position) is called the manipulated variable (MV). The difference between the measurement and the setpoint is the error (e), too hot or too cold and by how much.As a controller, one decides roughly how much to change the tap position (MV) after one determines the temperature (PV), and therefore the error. This first estimate is the equivalent of the proportional action of a PID controller. The integral action of a PID controller can be thought of as gradually adjusting the temperature when it is almost right. Derivative action can be thought of as noticing the water temperature is getting hotter or colder, and how fast, and taking that into account when deciding how to adjust the tap.Making a change that is too large when the error is small is equivalent to a high gain controller and will lead toovershoot. If the controller were to repeatedly make changes that were too large and repeatedly overshoot the target, this control loop would be termed unstable and the output would oscillate around the setpoint in either a constant, growing, or decaying sinusoid. A human would not do this because we are adaptive controllers, learning from the process history, but PID controllers do not have the ability to learn and must be set up correctly. Selecting the correct gains for effective control is known as tuning the controller.If a controller starts from a stable state at zero error (PV = SP), then further changes by the controller will be in response to changes in other measured or unmeasured inputs to the process that impact on the process, and hence on the PV. Variables that impact on the process other than the MV are known as disturbances and generally controllers are used to reject disturbances and/or implement setpoint changes. Changes in feed water temperature constitute a disturbance to the shower process.In theory, a controller can be used to control any process which has a measurable output (PV), a known ideal value for that output (SP) and an input to the process (MV) that will affect the relevant PV. Controllers are used in industry to regulate temperature, pressure, flow rate, chemical composition, speed and practically every other variable for which a measurement exists. Automobile cruise control is an example of a process which utilizes automated control.Due to their long history, simplicity, well grounded theory and simple setup and maintenance requirements, PID controllers are the controllers of choice for many of these applications.2.PID controller theoryNote: This section describes the ideal parallel or non-interacting form of the PID controller. For other forms please see the Section "Alternative notation and PID forms".The PID control scheme is named after its three correcting terms, whose sum constitutes the manipulated variable (MV). Hence:Where Pout, Iout, and Dout are the contributions to the output from the PID controller from each of the three terms, as defined below.2.1. Proportional termThe proportional term makes a change to the output that is proportional to the current error value. The proportional response can be adjusted by multiplying the error by a constant Kp, called the proportional gain.The proportional term is given by:WherePout: Proportional outputKp: Proportional Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)Change of response for varying KpA high proportional gain results in a large change in the output for a given change in the error. If the proportional gain is too high, the system can become unstable (See the section on Loop Tuning). In contrast, a small gain results in a small output response to a large input error, and a less responsive (or sensitive) controller. If the proportional gain is too low, the control action may be too small when responding to system disturbances.In the absence of disturbances, pure proportional control will not settle at its target value, but will retain a steady state error that is a function of the proportional gain and the process gain. Despite the steady-state offset, both tuning theory and industrial practice indicate that it is the proportional term that should contribute the bulk of the output change.2.2.Integral termThe contribution from the integral term is proportional to both the magnitude of the error and the duration of the error. Summing the instantaneous error over time (integrating the error) gives the accumulated offset that should have been correctedpreviously. The accumulated error is then multiplied by the integral gain and added to the controller output. The magnitude of the contribution of the integral term to the overall control action is determined by the integral gain, Ki.The integral term is given by:Iout: Integral outputKi: Integral Gain, a tuning parametere: Error = SP − PVτ: Time in the past contributing to the integral responseThe integral term (when added to the proportional term) accelerates the movement of the process towards setpoint and eliminates the residual steady-state error that occurs with a proportional only controller. However, since the integral term is responding to accumulated errors from the past, it can cause the present value to overshoot the setpoint value (cross over the setpoint and then create a deviation in the other direction). For further notes regarding integral gain tuning and controller stability, see the section on loop tuning.2.3 Derivative termThe rate of change of the process error is calculated by determining the slope of the error over time (i.e. its first derivative with respect to time) and multiplying this rate of change by the derivative gain Kd. The magnitude of the contribution of the derivative term to the overall control action is termed the derivative gain, Kd.The derivative term is given by:Dout: Derivative outputKd: Derivative Gain, a tuning parametere: Error = SP − PVt: Time or instantaneous time (the present)The derivative term slows the rate of change of the controller output and this effect is most noticeable close to the controller setpoint. Hence, derivative control is used to reduce the magnitude of the overshoot produced by the integral component and improve the combined controller-process stability. However, differentiation of a signal amplifies noise and thus this term in the controller is highly sensitive to noise in the error term, and can cause a process to become unstable if the noise and the derivative gain are sufficiently large.2.4 SummaryThe output from the three terms, the proportional, the integral and the derivative terms are summed to calculate the output of the PID controller. Defining u(t) as the controller output, the final form of the PID algorithm is:and the tuning parameters areKp: Proportional Gain - Larger Kp typically means faster response since thelarger the error, the larger the Proportional term compensation. An excessively large proportional gain will lead to process instability and oscillation.Ki: Integral Gain - Larger Ki implies steady state errors are eliminated quicker. The trade-off is larger overshoot: any negative error integrated during transient response must be integrated away by positive error before we reach steady state.Kd: Derivative Gain - Larger Kd decreases overshoot, but slows down transient response and may lead to instability due to signal noise amplification in the differentiation of the error.3. Loop tuningIf the PID controller parameters (the gains of the proportional, integral and derivative terms) are chosen incorrectly, the controlled process input can be unstable, i.e. its output diverges, with or without oscillation, and is limited only by saturation or mechanical breakage. Tuning a control loop is the adjustment of its control parameters (gain/proportional band, integral gain/reset, derivative gain/rate) to the optimumvalues for the desired control response.The optimum behavior on a process change or setpoint change varies depending on the application. Some processes must not allow an overshoot of the process variable beyond the setpoint if, for example, this would be unsafe. Other processes must minimize the energy expended in reaching a new setpoint. Generally, stability of response (the reverse of instability) is required and the process must not oscillate for any combination of process conditions and setpoints. Some processes have a degree of non-linearity and so parameters that work well at full-load conditions don't work when the process is starting up from no-load. This section describes some traditional manual methods for loop tuning.There are several methods for tuning a PID loop. The most effective methods generally involve the development of some form of process model, then choosing P, I, and D based on the dynamic model parameters. Manual tuning methods can be relatively inefficient.The choice of method will depend largely on whether or not the loop can be taken "offline" for tuning, and the response time of the system. If the system can be taken offline, the best tuning method often involves subjecting the system to a step change in input, measuring the output as a function of time, and using this response to determine the control parameters.Choosing a Tuning MethodMethodAdvantagesDisadvantagesManual TuningNo math required. Online method.Requires experiencedpersonnel.Ziegler–NicholsProven Method. Online method.Process upset, sometrial-and-error, very aggressive tuning.Software ToolsConsistent tuning. Online or offline method. May includevalve and sensor analysis. Allow simulation before downloading.Some cost and training involved.Cohen-CoonGood process models.Some math. Offline method. Onlygood for first-order processes.3.1 Manual tuningIf the system must remain online, one tuning method is to first set the I and D values to zero. Increase the P until the output of the loop oscillates, then the P should be left set to be approximately half of that value for a "quarter amplitude decay" type response. Then increase D until any offset is correct in sufficient time for the process. However, too much D will cause instability. Finally, increase I, if required, until the loop is acceptably quick to reach its reference after a load disturbance. However, too much I will cause excessive response and overshoot. A fast PID loop tuning usually overshoots slightly to reach the setpoint more quickly; however, some systems cannot accept overshoot, in which case an "over-damped" closed-loop system is required, which will require a P setting significantly less than half that of the P setting causing oscillation.3.2Ziegler–Nichols methodAnother tuning method is formally known as the Ziegler–Nichols method, introduced by John G. Ziegler and Nathaniel B. Nichols. As in the method above, the I and D gains are first set to zero. The "P" gain is increased until it reaches the "critical gain" Kc at which the output of the loop starts to oscillate. Kc and the oscillation period Pc are used to set the gains as shown:3.3 PID tuning softwareMost modern industrial facilities no longer tune loops using the manual calculation methods shown above. Instead, PID tuning and loop optimization software are used to ensure consistent results. These software packages will gather the data, develop process models, and suggest optimal tuning. Some software packages can even develop tuning by gathering data from reference changes.Mathematical PID loop tuning induces an impulse in the system, and then uses the controlled system's frequency response to design the PID loop values. In loops with response times of several minutes, mathematical loop tuning is recommended, because trial and error can literally take days just to find a stable set of loop values.Optimal values are harder to find. Some digital loop controllers offer a self-tuning feature in which very small setpoint changes are sent to the process, allowing the controller itself to calculate optimal tuning values.Other formulas are available to tune the loop according to different performance criteria.4 Modifications to the PID algorithmThe basic PID algorithm presents some challenges in control applications that have been addressed by minor modifications to the PID form.One common problem resulting from the ideal PID implementations is integralwindup. This can be addressed by:Initializing the controller integral to a desired valueDisabling the integral function until the PV has entered the controllable region Limiting the time period over which the integral error is calculatedPreventing the integral term from accumulating above or below pre-determined boundsMany PID loops control a mechanical device (for example, a valve). Mechanical maintenance can be a major cost and wear leads to control degradation in the form of either stiction or a deadband in the mechanical response to an input signal. The rate of mechanical wear is mainly a function of how often a device is activated to make a change. Where wear is a significant concern, the PID loop may have an output deadband to reduce the frequency of activation of the output (valve). This is accomplished by modifying the controller to hold its output steady if the change would be small (within the defined deadband range). The calculated output must leave the deadband before the actual output will change.The proportional and derivative terms can produce excessive movement in the output when a system is subjected to an instantaneous "step" increase in the error, such as a large setpoint change. In the case of the derivative term, this is due to taking the derivative of the error, which is very large in the case of an instantaneous step change.5. Limitations of PID controlWhile PID controllers are applicable to many control problems, they can perform poorly in some applications.PID controllers, when used alone, can give poor performance when the PID loop gains must be reduced so that the control system does not overshoot, oscillate or "hunt" about the control setpoint value. The control system performance can be improved by combining the feedback (or closed-loop) control of a PID controller with feed-forward (or open-loop) control. Knowledge about the system (such as the desired acceleration and inertia) can be "fed forward" and combined with the PID output to improve the overall system performance. The feed-forward value alone can often provide the major portion of the controller output. The PID controller can then be used primarily to respond to whatever difference or "error" remains between the setpoint (SP) and the actual value of the process variable (PV). Since the feed-forward output is not affected by the process feedback, it can never cause the control system to oscillate, thus improving the system response and stability.For example, in most motion control systems, in order to accelerate a mechanical load under control, more force or torque is required from the prime mover, motor, or actuator. If a velocity loop PID controller is being used to control the speed of the load and command the force or torque being applied by the prime mover, then it is beneficial to take the instantaneous acceleration desired for the load, scale that value appropriately and add it to the output of the PID velocity loop controller. This means that whenever the load is being accelerated or decelerated, a proportional amount of force is commanded from the prime mover regardless of the feedback value. The PID loop in this situation uses the feedback information to effect any increase or decrease of the combined output in order to reduce the remaining difference between the process setpoint and thefeedback value. Working together, the combined open-loop feed-forward controller and closed-loop PID controller can provide a more responsive, stable and reliable control system.Another problem faced with PID controllers is that they are linear. Thus, performance of PID controllers in non-linear systems (such as HV AC systems) isvariable. Often PID controllers are enhanced through methods such as PID gain scheduling or fuzzy logic. Further practical application issues can arise from instrumentation connected to the controller. A high enough sampling rate, measurement precision, and measurement accuracy are required to achieve adequate control performance.A problem with the Derivative term is that small amounts of measurement or process noise can cause large amounts of change in the output. It is often helpful to filter the measurements with a low-pass filter in order to remove higher-frequency noise components. However, low-pass filtering and derivative control can cancel each other out, so reducing noise by instrumentation means is a much better choice. Alternatively, the differential band can be turned off in many systems with little loss of control. This is equivalent to using the PID controller as a PI controller.6. Cascade controlOne distinctive advantage of PID controllers is that two PID controllers can be used together to yield better dynamic performance. This is called cascaded PID control. In cascade control there are two PIDs arranged with one PID controlling the set point of another. A PID controller acts as outer loop controller, which controls the primary physical parameter, such as fluid level or velocity. The other controller acts as inner loop controller, which reads the output of outer loop controller as set point, usually controlling a more rapid changing parameter, flowrate or accelleration. It can be mathematically proved that the working frequency of the controller is increased and the time constant of the object is reduced by using cascaded PID controller.[vague]7. Physical implementation of PID controlIn the early history of automatic process control the PID controller was implemented as a mechanical device. These mechanical controllers used a lever, spring and a mass and were often energized by compressed air. These pneumatic controllers were once the industry standard.Electronic analog controllers can be made from a solid-state or tube amplifier, a capacitor and a resistance. Electronic analogPID control loops were often found within more complex electronic systems, for example, the head positioning of a disk drive, the power conditioning of a power supply, or even the movement-detection circuit of a modern seismometer. Nowadays, electronic controllers have largely been replaced by digital controllers implemented with microcontrollers or FPGAs.Most modern PID controllers in industry are implemented in software in programmable logic controllers (PLCs) or as a panel-mounted digital controller. Software implementations have the advantages that they are relatively cheap and are flexible with respect to the implementation of the PID algorithm.References[1]Byung,S.K.(2000)On Performance Assessment of Feedback Control Loops.Austin:The University of Texas Austin[2]Desborough,L.and Harris,T.(1992)Performance Assessment Measures for Univariate Feedback Control. The Canadian Journal of Chemical Engineering,70(12).1186-1197[3]Ender,D.B.(1993)Process Control Performance:Not as Good as You Think.Control Engineering,40(10)[4]Harris,T(1993)Pefformance Assessment Measllres for Univariate Feedforward/Feedback Control.The Canadian Journal of Chemical Engineering,71(8),1186-1197[5]Qin,S.J.(1 998)Contr01 Performance Monitoring: A Review and Assessment.Com.Chem.Eng.,(23),173.186[6]Sun,Jinming(2004)PID Performance Assessment and Parameters Tuning.Beijing:China University of Petroleum[7]Xu,Xi;Li,Tao and Bo,Xiaochen(2000)Matlab Toolbox Application--Control Engineering.Bering:Electron Industry Press附件2:外文资料翻译译文PID控制器左信孙金明(石油大学自动化研究所,北京,102249,中国)发表于2005.4.2摘要:一个比例积分微分(PID)控制器的性能评价进行使用PID实现的最小方差作为参照。
汽车电子毕设设计外文文献翻译(适用于毕业论文外文翻译+中英文对照)
Ultrasonic ranging system designPublication title: Sensor Review. Bradford: 1993.Vol.ABSTRACT: Ultrasonic ranging technology has wide using worth in many fields, such as the industrial locale, vehicle navigation and sonar engineering. Now it has been used in level measurement, self-guided autonomous vehicles, fieldwork robots automotive navigation, air and underwater target detection, identification, location and so on. So there is an important practicing meaning to learn the ranging theory and ways deeply. To improve the precision of the ultrasonic ranging system in hand, satisfy the request of the engineering personnel for the ranging precision, the bound and the usage, a portable ultrasonic ranging system based on the single chip processor was developed.Keywords: Ultrasound, Ranging System, Single Chip Processor1. IntroductiveWith the development of science and technology, the improvement of people’s standard of living, speeding up the development and construction of the city. Urban drainage system have greatly developed their situation is construction improving. However, due to historical reasons many unpredictable factors in the synthesis of her time, the city drainage system. In particular drainage system often lags behind urban construction. Therefore, there are often good building excavation has been building facilities to upgrade the drainage system phenomenon. It brought to the city sewage, and it is clear to the city sewage and drainage culvert in the sewage treatment system.Co mfort is very important to people’s lives. Mobile robots designed to clear the drainage culvert and the automatic control system Free sewage culvert clear guarantee robots, the robot is designed to clear the culvert sewage to the core. Control system is the core component of the development of ultrasonic range finder. Therefore, it is very important to design a good ultrasonic range finder.2. A principle of ultrasonic distance measurementThe application of AT89C51:SCM is a major piece of computer components are integrated into the chip micro-computer. It is a multi-interface and counting on the micro-controller integration, and intelligence products are widely used in industrial automation. and MCS-51 microcontroller is a typical and representative.Microcontrollers are used in a multitude of commercial applications such as modems, motor-control systems, air conditioner control systems, automotive engine and among others. The high processing speed and enhanced peripheral set of these microcontrollers make them suitable for such high-speed event-based applications. However, these critical application domains also require that these microcontrollers are highly reliable. The high reliability and low market risks can be ensured by a robust testing process and a proper tools environment for the validation of these microcontrollers both at the component and at the system level. Intel Plaform Engineering department developed an object-oriented multi-threaded test environment for the validation of its AT89C51 automotive microcontrollers. The goals of this environment was not only to provide a robust testing environment for the AT89C51 automotive microcontrollers, but to develop an environment which can be easily extended and reused for the validation of several other future microcontrollers. The environment was developed in conjunction with Microsoft Foundation Classes(AT89C51).1.1 Features* Compatible with MCS-51 Products* 2Kbytes of Reprogrammable Flash MemoryEndurance: 1,000Write/Erase Cycles* 2.7V to 6V Operating Range* Fully Static operation: 0Hz to 24MHz* Two-level program memory lock* 128x8-bit internal RAM* 15programmable I/O lines* Two 16-bit timer/counters* Six interrupt sources*Programmable serial UART channel* Direct LED drive output* On-chip analog comparator* Low power idle and power down modes1.2 DescriptionThe AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with 2Kbytes of flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard MCS-51 instruction set and pinout. By combining a versatile 8-bit CPU with flash on a monolithic chip, the Atmel AT89C2051 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications.The AT89C2051 provides the following standard features: 2Kbytes of flash,128bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator and clock circuitry. In addition, the AT89C2051 is designed with static logicfor operation down to zero frequency and supports two software selectable power saving modes. The idle mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The power down mode saves the RAM contents but freezer the oscillator disabling all other chip functions until the next hardware reset.1.3 Pin Configuration1.4 Pin DescriptionVCC Supply voltage.GND Ground.Prot 1Prot 1 is an 8-bit bidirectional I/O port. Port pins P1.2 to P1.7 provide internal pullups. P1.0 and P1.1 require external pullups. P1.0 and P1.1 also serve as the positive input (AIN0) and the negative input (AIN1), respectively, of the on-chip precision analog comparator. The port 1 output buffers can sink 20mA and can drive LED displays directly. When 1s are written to port 1 pins, they can be used as inputs. When pins P1.2 to P1.7 are used as input and are externally pulled low, they will source current (IIL) because of the internal pullups.Port 3Port 3 pins P3.0 to P3.5, P3.7 are seven bidirectional I/O pins with internal pullups. P3.6 is hard-wired as an input to the output of the on-chip comparator and is not accessible as a general purpose I/O pin. The port 3 output buffers can sink 20mA. When 1s are written to port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs, port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89C2051 as listed below.1.5 Programming the FlashThe AT89C2051 is shipped with the 2 Kbytes of on-chip PEROM code memory array in the erased state (i.e., contents=FFH) and ready to be programmed. The code memory array is programmed one byte at a time. Once the array is programmed, to re-program any non-blank byte, the entire memory array needs to be erased electrically.Internal address counter: the AT89C2051 contains an internal PEROM address counter which is always reset to 000H on the rising edge of RST and is advanced applying a positive going pulse to pin XTAL1.Programming algorithm: to program the AT89C2051, the following sequence is recommended.1. power-up sequence:Apply power between VCC and GND pins Set RST and XTAL1 to GNDWith all other pins floating , wait for greater than 10 milliseconds2. Set pin RST to ‘H’ set pin P3.2 to ‘H’3. Apply the appropriate combination of ‘H’ or ‘L’ logic to pins P3.3, P3.4, P3.5,P3.7 to select one of the programming operations shown in the PEROM programming modes table.To program and Verify the Array:4. Apply data for code byte at location 000H to P1.0 to P1.7.5.Raise RST to 12V to enable programming.5. Pulse P3.2 once to program a byte in the PEROM array or the lock bits. The byte-write cycle is self-timed and typically takes 1.2ms.6. To verify the programmed data, lower RST from 12V to logic ‘H’ level and set pins P3.3 to P3.7 to the appropriate levels. Output data can be read at the port P1 pins.7. To program a byte at the next address location, pulse XTAL1 pin once to advance the internal address counter. Apply new data to the port P1 pins.8. Repeat steps 5 through 8, changing data and advancing the address counter for the entire 2 Kbytes array or until the end of the object file is reached.9. Power-off sequence: set XTAL1 to ‘L’ set RST to ‘L’Float all other I/O pins Turn VCC power off2.1 The principle of piezoelectric ultrasonic generatorPiezoelectric ultrasonic generator is the use of piezoelectric crystal resonators to work. Ultrasonic generator, the internal structure as shown, it has two piezoelectric chip and a resonance plate. When it’s two plus pulse signal, the frequency equal to the intrinsic piezoelectric oscillation frequency chip, the chip will happen piezoelectric resonance, and promote the development of plate vibration resonance, ultrasound is generated. Conversely, it will be for vibration suppression of piezoelectric chip, the mechanical energy is converted to electrical signals, then it becomes the ultrasonic receiver.The traditional way to determine the moment of the echo’s arrival is based on thresholding the received signal with a fixed reference. The threshold is chosen well above the noise level, whereas the moment of arrival of an echo is defined as the first moment the echo signal surpasses that threshold. The intensity of an echo reflecting from an object strongly depends on the object’s nature, size and distance from the sensor. Further, the time interval from the echo’s starting point to the moment when it surpasses the threshold changes with the intensity of the echo. As a consequence, a considerable error may occur even two echoes with different intensities arriving exactly at the same time will surpass the threshold at different moments. The stronger one will surpass the threshold earlier than the weaker, so it will be considered as belonging to a nearer object.2.2 The principle of ultrasonic distance measurementUltrasonic transmitter in a direction to launch ultrasound, in the moment to launch the beginning of time at the same time, the spread of ultrasound in the air, obstacles on his way to return immediately, the ultrasonic reflected wave received by the receiverimmediately stop the clock. Ultrasound in the air as the propagation velocity of 340m/s, according to the timer records the time t, we can calculate the distance between the launch distance barrier(s), that is: s=340t / 23. Ultrasonic Ranging System for the Second Circuit DesignSystem is characterized by single-chip microcomputer to control the use of ultrasonic transmitter and ultrasonic receiver since the launch from time to time, single-chip selection of 875, economic-to-use, and the chip has 4K of ROM, to facilitate programming.3.1 40 kHz ultrasonic pulse generated with the launchRanging system using the ultrasonic sensor of piezoelectric ceramic sensorsUCM40, its operating voltage of the pulse signal is 40kHz, which by the single-chip implementation of the following procedures to generate.puzel: mov 14h, # 12h; ultrasonic firing continued 200msHere: cpl p1.0; output 40kHz square wavenop;nop;nop;djnz 14h, here;retRanging in front of single-chip termination circuit P1.0 input port, single chip implementation of the above procedure, the P1.0 port in a 40kHz pulse output signal, after amplification transistor T, the drive to launch the first ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the continued launch of 200ms. Ranging the right and the left side of the circuit, respectively, then input port P1.1 and P1.2, the working principle and circuit in front of the same location.3.2 Reception and processing of ultrasonicUsed to receive the first launch of the first pair UCM40R, the ultrasonic pulse modulation signal into an alternating voltage, the op-amp amplification IC1A and after polarization IC1B to IC2. IC2 is locked loop with audio decoder chip LM567, internal voltage-controlled oscillator center frequency of f0=1/1.1R8C3, capacitor C4 determinetheir target bandwidth. R8-conditioning in the launch of the high jump 8 feet into a low-level, as interrupt request signals to the single-chip processing.Ranging in front of single-chip termination circuit output port INT0 interrupt the highest priority, right or left location of the output circuit with output gate IC3A access INT1 port single-chip, while single-chip P1.3 and P1.4 received input IC3A, interrupted by the process to identify the source of inquiry to deal with, interrupt priority level for the first left right after. Part of the source code is as follows:Receivel: push pswpush accclr ex1; related external interrupt 1jnb p1.1, right; P1.1 pin to 0, ranging from right to interrupt service routine circuitjnb p1.2, left; P1.2 pin to 0, to the left ranging circuit interrupt service routinereturn: SETB EX1; open external interrupt 1pop accpop pswretiright: …; right location entrance circuit interrupt service routineAjmp Returnleft: …; left ranging entrance circuit interrupt service routineAjmp Return3.3 The calculation of ultrasonic propagation timeWhen you start firing at the same time start the single-chip circuitry within the timer T0, the use of timer counting function records the time and the launch of ultrasonic reflected wave received time. When you receive the ultrasonic reflected wave, the receiver circuit output a negative jump in the end of INT0 or INT1 interrupt request generates a signal, single-chip microcomputer in response to external interrupt request, the implementation of the external interrupt service subroutine, read the time difference, calculating the distance. Some of its source code is as follows:RECEIVE0: PUSH PSWPUSH ACCCLR EX0; related external interrupt 0MOV R7, TH0; read the time valueMOV R6, TL0CLR CMOV A, R6SUBB A, #0BBH; calculate the time differenceMOV 31H, A; storage resultsMOV A, R7SUBB A, # 3CHMOV 30H, ASETB EX0; open external interrupt 0\POP ACCPOP PSWRETIFor a flat target, a distance measurement consists of two phases: a coarse measurement and a fine measurement:Step 1: Transmission of one pulse train to produce a simple ultrasonic wave.Step 2: Changing the gain of both echo amplifiers according to equation, until the echo is detected.Step 3: Detection of the amplitudes and zero-crossing times of both echoes.Step 4: Setting the gains of both echo amplifiers to normalize the output at, say 3 volts. Setting the period of the next pulses according to the: period of echoes. Setting the time window according to the data of step 2.Step 5: Sending two pulse trains to produce an interfered wave. Testing the zero-crossing times and amplitudes of the echoes. If phase inversion occurs in the echo, determine to otherwise calculate to by interpolation using the amplitudes near the trough. Derive t sub m1 and t sub m2.Step 6: Calculation of the distance y using equation.4、The ultrasonic ranging system software designSoftware is divided into two parts, the main program and interrupt service routine. Completion of the work of the main program is initialized, each sequence of ultrasonic transmitting and receiving control.Interrupt service routines from time to time to complete three of the rotation direction of ultrasonic launch, the main external interrupt service subroutine to read the value of completion time, distance calculation, the results of the output and so on.5、ConclusionsRequired measuring range of 30cm-200cm objects inside the plane to do a number of measurements found that the maximum error is 0.5cm, and good reproducibility. Single-chip design can be seen on the ultrasonic ranging system has a hardware structure is simple, reliable, small features such as measurement error. Therefore, it can be used not only for mobile robot can be used in other detection system.Thoughts: As for why the receiver do not have the transistor amplifier circuit, because the magnification well, integrated amplifier, but also with automatic gain control level, magnification to 76dB, the center frequency is 38k to 40k, is exactly resonant ultrasonic sensors frequency.6、Parking sensor6.1 Parking sensor introductionReversing radar, full name is "reversing the anti-collision radar, also known as" parking assist device, car parking or reversing the safety of assistive devices, ultrasonic sensors(commonly known as probes), controls and displays (or buzzer)and other components. To inform the driver around the obstacle to the sound or a moreintuitive display to lift the driver parking, reversing and start the vehicle around tovisit the distress caused by, and to help the driver to remove the vision deadends and blurred vision defects and improve driving safety.6.2 Reversing radar detection principleReversing radar, according to high-speed flight of the bats in thenight, not collided with any obstacle principles of design anddevelopment. Probe mounted on the rear bumper, according to different price and brand, the probe only ranging from two, three, four, six, eight,respectively, pipe around. The probe radiation, 45-degree angle up and downabout the search target. The greatest advantage is to explore lower than the bumper of the driver from the rear window is difficult to see obstacles, and the police, suchas flower beds, children playing in the squatting on the car.Display parking sensor installed in the rear view mirror, it constantlyremind drivers to car distance behindthe object distance to the dangerous distance, the buzzer starts singing, allow the driver to stop. When the gear lever linked into reverse gear, reversing radar, auto-start the work, the working range of 0.3 to 2.0 meters, so stop when the driver was very practical. Reversing radar is equivalent to an ultrasound probe for ultrasonic probe can be divided into two categories: First, Electrical, ultrasonic, the second is to use mechanical means to produce ultrasound, in view of the more commonly used piezoelectric ultrasonic generator, it has two power chips and a soundingboard, plus apulse signal when the poles, its frequency equal to the intrinsic oscillation frequency of the piezoelectric pressure chip will be resonant and drivenby the vibration of the sounding board, the mechanical energy into electrical signal, which became the ultrasonic probe works. In order to better study Ultrasonic and use up, people have to design and manufacture of ultrasonic sound, the ultrasonic probe tobe used in the use of car parking sensor. With this principle in a non-contactdetection technology for distance measurement is simple, convenient and rapid, easyto do real-time control, distance accuracy of practical industrial requirements. Parking sensor for ranging send out ultrasonic signal at a givenmoment, and shot in the face of the measured object back to the signal wave, reversing radar receiver to use statistics in the ultrasonic signal from the transmitter to receive echo signals calculate the propagation velocity in the medium, which can calculate the distance of the probe and to detect objects.6.3 Reversing radar functionality and performanceParking sensor can be divided into the LCD distance display, audible alarm, and azimuth directions, voice prompts, automatic probe detection function is complete, reversing radar distance, audible alarm, position-indicating function. A good performance reversing radar, its main properties include: (1) sensitivity, whether theresponse fast enough when there is an obstacle. (2) the existence of blind spots. (3) detection distance range.6.4 Each part of the roleReversing radar has the following effects: (1) ultrasonic sensor: used tolaunch and receive ultrasonic signals, ultrasonic sensors canmeasure distance. (2) host: after the launch of the sine wave pulse to the ultrasonic sensors, and process the received signal, to calculate the distance value, the data and monitor communication. (3) display or abuzzer: the receivinghost from the data, and display the distance value and provide differentlevels according to the distance from the alarm sound.6.5 Cautions1, the installation height: general ground: car before the installation of 45 ~55: 50 ~ 65cmcar after installation. 2, regular cleaningof the probe to prevent the fill. 3, do not use the hardstuff the probe surface cover will produce false positives or ranging allowed toprobe surface coverage, such as mud. 4, winter to avoid freezing. 5, 6 / 8 probe reversing radar before and after the probe is not free to swap may cause the ChangMing false positive problem. 6, note that the probe mounting orientation, in accordance with UP installation upward. 7, the probe is not recommended to install sheetmetal, sheet metal vibration will cause the probe resonance, resulting in false positives.超声测距系统设计原文出处:传感器文摘布拉福德:1993年超声测距技术在工业现场、车辆导航、水声工程等领域具有广泛的应用价值,目前已应用于物位测量、机器人自动导航以及空气中与水下的目标探测、识别、定位等场合。
毕业设计(论文)外文资料翻译(学生用)
毕业设计外文资料翻译学院:信息科学与工程学院专业:软件工程姓名: XXXXX学号: XXXXXXXXX外文出处: Think In Java (用外文写)附件: 1.外文资料翻译译文;2.外文原文。
附件1:外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂,而且极易出错。
程序员必须掌握与网络有关的大量细节,有时甚至要对硬件有深刻的认识。
一般地,我们需要理解连网协议中不同的“层”(Layer)。
而且对于每个连网库,一般都包含了数量众多的函数,分别涉及信息块的连接、打包和拆包;这些块的来回运输;以及握手等等。
这是一项令人痛苦的工作。
但是,连网本身的概念并不是很难。
我们想获得位于其他地方某台机器上的信息,并把它们移到这儿;或者相反。
这与读写文件非常相似,只是文件存在于远程机器上,而且远程机器有权决定如何处理我们请求或者发送的数据。
Java最出色的一个地方就是它的“无痛苦连网”概念。
有关连网的基层细节已被尽可能地提取出去,并隐藏在JVM以及Java的本机安装系统里进行控制。
我们使用的编程模型是一个文件的模型;事实上,网络连接(一个“套接字”)已被封装到系统对象里,所以可象对其他数据流那样采用同样的方法调用。
除此以外,在我们处理另一个连网问题——同时控制多个网络连接——的时候,Java内建的多线程机制也是十分方便的。
本章将用一系列易懂的例子解释Java的连网支持。
15.1 机器的标识当然,为了分辨来自别处的一台机器,以及为了保证自己连接的是希望的那台机器,必须有一种机制能独一无二地标识出网络内的每台机器。
早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。
但Java面向的是整个因特网,这要求用一种机制对来自世界各地的机器进行标识。
为达到这个目的,我们采用了IP(互联网地址)的概念。
IP以两种形式存在着:(1) 大家最熟悉的DNS(域名服务)形式。
我自己的域名是。
所以假定我在自己的域内有一台名为Opus的计算机,它的域名就可以是。
外文翻译---电锅炉温度控制系统
毕业设计外文翻译题目(外文):Electric boiler temperature control system题目(中文):电锅炉温度控制系统出处:信息技术(Information technology)可以说,二十世纪跨越了三个“电”的时代,即电气时代、电子时代和现已进入的电脑时代。
不过,这种电脑,通常是指个人计算机,简称PC机,它由主机、键盘、显示器等组成。
还有一类计算机,大多数人却不怎么熟悉。
这种计算机就是把智能赋予各种机械的单片机(亦称微控制器)。
顾名思义,这种计算机的最小系统只用了一片集成电路,即可进行简单运算和控制。
因为它体积小,通常都藏在被控机械的“肚子”里。
它在整个装置中,起着有如人类头脑的作用,它出了毛病,整个装置就瘫痪了。
现在,这种单片机的使用领域已十分广泛,如智能仪表、实时工控、通讯设备、导航系统、家用电器等。
各种产品一旦用上了单片机,就能起到使产品升级换代的功效,常在产品名称前冠以形容词——“智能型”,如智能型洗衣机等。
现在有些工厂的技术人员或其它业余电子开发者搞出来的某些产品,不是电路太复杂,就是功能太简单且极易被仿制。
究其原因,可能就卡在产品未使用单片机或其它可编程逻辑器件上。
单片机的基本组成是由中央处理器(即CPU中的运算器和控制器)、只读存贮器(通常表示为ROM)、读写存贮器(又称随机存贮器通常表示为RAM)、输入/输出口(又分为并行口和串行口,表示为I/O口)等等组成。
实际上单片机里面还有一个时钟电路,使单片机在进行运算和控制时,都能有节奏地进行。
另外,还有所谓的“中断系统”,这个系统有“传达室”的作用,当单片机控制对象的参数到达某个需要加以干预的状态时,就可经此“传达室”通报给CPU,使CPU根据外部事态的轻重缓急来采取适当的应付措施。
1.单片机单片机即单片微型计算机,是把中央处理器、存储器、定时/计数器、输入输出接口都集成在一块集成电路芯片上的微型计算机。
智能控制系统毕业论文中英文资料对照外文翻译文献
智能控制系统中英文资料对照外文翻译文献附录一:外文摘要The development and application of Intelligence controlsystemModern electronic products change rapidly is increasingly profound impact on people's lives, to people's life and working way to bring more convenience to our daily lives, all aspects of electronic products in the shadow, single chip as one of the most important applications, in many ways it has the inestimable role. Intelligent control is a single chip, intelligent control of applications and prospects are very broad, the use of modern technology tools to develop an intelligent, relatively complete functional software to achieve intelligent control system has become an imminent task. Especially in today with MCU based intelligent control technology in the era, to establish their own practical control system has a far-reaching significance so well on the subject later more fully understanding of SCM are of great help to.The so-called intelligent monitoring technology is that:" the automatic analysis and processing of the information of the monitored device". If the monitored object as one's field of vision, and intelligent monitoring equipment can be regarded as the human brain. Intelligent monitoring with the aid of computer data processing capacity of the powerful, to get information in the mass data to carry on the analysis, some filtering of irrelevant information, only provide some key information. Intelligent control to digital, intelligent basis, timely detection system in the abnormal condition, and can be the fastest and best way to sound the alarm and provide usefulinformation, which can more effectively assist the security personnel to deal with the crisis, and minimize the damage and loss, it has great practical significance, some risk homework, or artificial unable to complete the operation, can be used to realize intelligent device, which solves a lot of artificial can not solve the problem, I think, with the development of the society, intelligent load in all aspects of social life play an important reuse.Single chip microcomputer as the core of control and monitoring systems, the system structure, design thought, design method and the traditional control system has essential distinction. In the traditional control or monitoring system, control or monitoring parameters of circuit, through the mechanical device directly to the monitored parameters to regulate and control, in the single-chip microcomputer as the core of the control system, the control parameters and controlled parameters are not directly change, but the control parameter is transformed into a digital signal input to the microcontroller, the microcontroller according to its output signal to control the controlled object, as intelligent load monitoring test, is the use of single-chip I / O port output signal of relay control, then the load to control or monitor, thus similar to any one single chip control system structure, often simplified to input part, an output part and an electronic control unit ( ECU )Intelligent monitoring system design principle function as follows: the power supply module is 0~220V AC voltage into a0 ~ 5V DC low voltage, as each module to provide normal working voltage, another set of ADC module work limit voltage of 5V, if the input voltage is greater than 5V, it can not work normally ( but the design is provided for the load voltage in the 0~ 5V, so it will not be considered ), at the same time transformer on load current is sampled on the accused, the load current into a voltage signal, and then through the current - voltage conversion, and passes through the bridge rectification into stable voltage value, will realize the load the current value is converted to a single chip can handle0 ~ 5V voltage value, then the D2diode cutoff, power supply module only plays the role of power supply. Signal to the analog-to-digital conversion module, through quantization, coding, the analog voltage value into8bits of the digital voltage value, repeatedly to the analog voltage16AD conversion, and the16the digital voltage value and, to calculate the average value, the average value through a data bus to send AT89C51P0, accepted AT89C51 read, AT89C51will read the digital signal and software setting load normal working voltage reference range [VMIN, VMAX] compared with the reference voltage range, if not consistent, then the P1.0 output low level, close the relay, cut off the load on the fault source, to stop its sampling, while P1.1 output high level fault light, i.e., P1.3 output low level, namely normal lights. The relay is disconnected after about 2minutes, theAT89C51P1.0outputs high level ( software design), automatic closing relay, then to load the current regular sampling, AD conversion, to accept the AT89C51read, comparison, if consistent, then the P1.1 output low level, namely fault lights out, while P1.3 output high level, i.e. normal lamp ( software set ); if you are still inconsistent, then the need to manually switch S1toss to" repair" the slip, disconnect the relay control, load adjusting the resistance value is: the load detection and repair, and then close the S1repeatedly to the load current sampling, until the normal lamp bright, repeated this process, constantly on the load testing to ensure the load problems timely repair, make it work.In the intelligent load monitoring system, using the monolithic integrated circuit to the load ( voltage too high or too small ) intelligent detection and control, is achieved by controlling the relay and transformer sampling to achieve, in fact direct control of single-chip is the working state of the relay and the alarm circuit working state, the system should achieve technical features of this thesis are as follows (1) according to the load current changes to control relays, the control parameter is the load current, is the control parameter is the relay switch on-off and led the state; (2) the set current reference voltage range ( load normal working voltage range ), by AT89C51 chip the design of the software section, provide a basis for comparison; (3) the use of single-chip microcomputer to control the light-emitting diode to display the current state of change ( normal / fault / repair ); specific summary: Transformer on load current is sampled, a current / voltage converter, filter, regulator, through the analog-digital conversion, to accept the AT89C51chip to read, AT89C51 to read data is compared with the reference voltage, if normal, the normal light, the output port P.0high level, the relay is closed, is provided to the load voltage fault light; otherwise, P1.0 output low level, The disconnecting relay to disconnect the load, the voltage on the sampling, stop. Two minutes after closing relay, timing sampling.System through the expansion of improved, can be used for temperature alarm circuit, alarm circuit, traffic monitoring, can also be used to monitor a system works, in the intelligent high-speed development today, the use of modern technology tools, the development of an intelligent, function relatively complete software to realize intelligent control system, has become an imminent task, establish their own practical control system has a far-reaching significance. Micro controller in the industry design and application, no industry like intelligent automation and control field develop so fast. Since China and the Asian region the main manufacturing plant intelligence to improve the degree of automation, new technology to improve efficiency, have important influence on the product cost. Although the centralized control can be improved in any particular manufacturing process of the overall visual, but not for those response and processingdelay caused by fault of some key application.Intelligent control technology as computer technology is an important technology, widely used in industrial control, intelligent control, instrument, household appliances, electronic toys and other fields, it has small, multiple functions, low price, convenient use, the advantages of a flexible system design. Therefore, more and more engineering staff of all ages, so this graduate design is of great significance to the design of various things, I have great interest in design, this has brought me a lot of things, let me from unsuspectingly to have a clear train of thought, since both design something, I will be there a how to design thinking, this is very important, I think this job will give me a lot of valuable things.中文翻译:智能控制系统的开发应用现代社会电子产品日新月异正在越来越深远的影响着人们的生活,给人们的生活和工作方式带来越来越大的方便,我们的日常生活各个方面都有电子产品的影子,单片机作为其中一个最重要的应用,在很多方面都有着不可估量的作用。
电子信息毕业设计外文翻译--微型计算机控制系统(单片机控制系统)
毕业设计外文资料翻译Graduation design foreign language translation学院:电气工程与自动化学院专业班级:电子信息科学与技术三班学生姓名:学号:指导教师:外文资料:Microcomputer SystemsElectronic systems are used for handing information in the most general sense; this information may be telephone conversation, instrument read or a company‟s accounts, but in each case the same main type of operation are involved: the processing, storage and transmission of information. in conventional electronic design these operations are combined at the function level; for example a counter, whether electronic or mechanical, stores the current and increments it by one as required. A system such as an electronic clock which employs counters has its storage and processing capabilities spread throughout the system because each counter is able to store and process numbers.Present day microprocessor based systems depart from this conventional approach by separating the three functions of processing, storage, and transmission into different section of the system. This partitioning into three main functions was devised by V on Neumann during the 1940s, and was not conceived especially for microcomputers. Almost every computer ever made has been designed with this structure, and despite the enormous range in their physical forms, they have all been of essentially the same basic design.In a microprocessor based system the processing will be performed in the microprocessor itself. The storage will be by means of memory circuits and the communication of information into and out of the system will be by means of special input/output(I/O) circuits. It would be impossible to identify a particular piece of hardware which performed the counting in a microprocessor based clock because the time would be stored in the memory and incremented at regular intervals but the microprocessor. However, the software which defined the system‟s behavior would contain sections th at performed as counters. The apparently rather abstract approach to the architecture of the microprocessor and its associated circuits allows it to be very flexible in use, since the system is defined almost entirely software. The design process is largely one of software engineering, and the similar problems of construction and maintenance which occur inconventional engineering are encountered when producing software.The figure1-1 illustrates how these three sections within a microcomputer are connected in terms of the communication of information within the machine. The system is controlled by the microprocessor which supervises the transfer of information between itself and the memory and input/output sections. The external connections relate to the rest (that is, the non-computer part) of the engineering system.Fig.1-1 Three Sections of a Typical Microcomputer Although only one storage section has been shown in the diagram, in practice two distinct types of memory RAM and ROM are used. In each case, the word …memory‟ is rather inappropriate since a computers memory is more like a filing cabinet in concept; information is stored in a set of numbered …boxes‟ and it is referenced by the serial number of the …box‟ in question.Microcomputers use RAM (Random Access Memory) into which data can be written and from which data can be read again when needed. This data can be read back from the memory in any sequence desired, and not necessarily the same order in which it was written, hence the expres sion …random‟ access memory. Another type of ROM (Read Only Memory) is used to hold fixed patterns of information which cannot be affected by the microprocessor; these patterns are not lost when power is removed and are normally used to hold the program which defines the behavior of a microprocessor based system. ROMs can be read like RAMs, but unlike RAMs they cannot be used to store variable information. Some ROMs have their data patterns put in during manufacture, while others are programmable by the user by means of special equipment and are called programmable ROMs. The widely used programmable ROMs are erasable by means of special ultraviolet lamps and are referred to as EPROMs, short for Erasable Programmable Read Only Memories. Other new types of device can be erased electrically without the need for ultraviolet light, which are called Electrically Erasable Programmable Read OnlyMemories, EEPROMs.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor processes data under the control of the program, controlling the flow of information to and from memory and input/output devices. Some input/output devices are general-purpose types while others are designed for controlling special hardware such as disc drives or controlling information transmission to other computers. Most types of I/O devices are programmable to some extent, allowing different modes of operation, while some actually contain special-purpose microprocessors to permit quite complex operations to be carried out without directly involving the main microprocessor.The microprocessor , memory and input/output circuit may all be contained on the same integrated circuit provided that the application does not require too much program or data storage . This is usually the case in low-cost application such as the controllers used in microwave ovens and automatic washing machines . The use of single package allows considerable cost savings to e made when articles are manufactured in large quantities . As technology develops , more and more powerful processors and larger and larger amounts of memory are being incorporated into single chip microcomputers with resulting saving in assembly costs in the final products . For the foreseeable future , however , it will continue to be necessary to interconnect a number of integrated circuits to make a microcomputer whenever larger amounts of storage or input/output are required.Another major engineering application of microcomputers is in process control. Here the presence of the microcomputer is usually more apparent to the user because provision is normally made for programming the microcomputer for the particular application. In process control applications the benefits lf fitting the entire system on to single chip are usually outweighed by the high design cost involved, because this sort lf equipment is produced in smaller quantities. Moreover, process controllers are usually more complicatedso that it is more difficult to make them as single integrated circuits. Two approaches are possible; the controller can be implemented as a general-purpose microcomputer rather like a more robust version lf a hobby computer, or as a …packaged‟ system, signed for replacing controllers based on older technologies such as electromagnetic relays. In the former case the system would probably be programmed in conventional programming languages such as the ones to9 be introduced later, while in the other case a special-purpose language might be used, for example one which allowed the function of the controller to be described in terms of relay interconnections, In either case programs can be stored in RAM, which allows them to be altered to suit changes in application, but this makes the overall system vulnerable to loss lf power unless batteries are used to ensure continuity of supply. Alternatively programs can be stored in ROM, in which case they virtually become part of the electronic …hardware‟ and are often referred to as firmware. More sophisticated process controllers require minicomputers for their implementation, although the use lf large scale integrated circuits …the distinction between mini and microcomputers, Products and process controllers of various kinds represent the majority of present-day micro computer applications, the exact figures depending on one‟s interpretation of the word …product‟. Virtually all engineering and scientific uses of microcomputers can be assigned to one or other of these categories. But in the system we most study Pressure and Pressure Transmitters. Pressure arises when a force is applied over an area. Provided the force is one Newton and uniformly over the area of one square meters, the pressure has been designated one Pascal. Pressure is a universal processing condition. It is also a condition of life on the planet: we live at the bottom of an atmospheric ocean that extends upward for many miles. This mass of air has weight, and this weight pressing downward causes atmospheric pressure. Water, a fundamental necessity of life, is supplied to most of us under pressure. In the typical process plant, pressure influences boiling point temperatures, condensing point temperatures, process efficiency, costs, and other important factors. The measurement and control of pressure or lack of it-vacuum-in the typical process plant is critical.The working instruments in the plant usually include simple pressure gauges, precision recorders and indicators, and pneumatic and electronic pressure transmitters. A pressure transmitter makes a pressure measurement and generates either a pneumatic orelectrical signal output that is proportional to the pressure being sensed.In the process plant, it is impractical to locate the control instruments out in the place near the process. It is also true that most measurements are not easily transmitted from some remote location. Pressure measurement is an exception, but if a high pressure of some dangerous chemical is to be indicated or recorded several hundred feet from the point of measurement, a hazard may be from the pressure or from the chemical carried.To eliminate this problem, a signal transmission system was developed. This system is usually either pneumatic or electrical. And control instruments in one location. This makes it practical for a minimum number of operators to run the plant efficiently.When a pneumatic transmission system is employed, the measurement signal is converted into pneumatic signal by the transmitter scaled from 0 to 100 percent of the measurement value. This transmitter is mounted close to the point of measurement in the process. The transmitter output-air pressure for a pneumatic transmitter-is piped to the recording or control instrument. The standard output range for a pneumatic transmitter is 20 to 100kPa, which is almost universally used.When an electronic pressure transmitter is used, the pressure is converted to electrical signal that may be current or voltage. Its standard range is from 4 to 20mA DC for current signal or from 1 to 5V DC for voltage signal. Nowadays, another type of electrical signal, which is becoming common, is the digital or discrete signal. The use of instruments and control systems based on computer or forcing increased use of this type of signal.Sometimes it is important for analysis to obtain the parameters that describe the sensor/transmitter behavior. The gain is fairly simple to obtain once the span is known. Consider an electronic pressure transmitter with a range of 0~600kPa.The gain isdefined as the change in output divided by the change in input. In this case, the output is electrical signal (4~20mA DC) and the input is process pressure (0~600kPa). Thus the gain. Beside we must measure Temperature Temperature measurement is important in industrial control, as direct indications of system or product state and as indirect indications of such factors as reaction rates, energy flow, turbine efficiency, and lubricant quality. Present temperature scales have been in use for about 200 years, the earliestkPamA kPa mA kPa kPa mA mA Kr 027.0600160600420==--=instruments were based on the thermal expansion of gases and liquids. Such filled systems are still employed, although many other types of instruments are available. Representative temperature sensors include: filled thermal systems, liquid-in-glass thermometers, thermocouples, resistance temperature detectors, thermostats, bimetallic devices, optical and radiation pyrometers and temperature-sensitive paints.Advantages of electrical systems include high accuracy and sensitivity, practicality of switching or scanning several measurements points, larger distances possible between measuring elements and controllers, replacement of components(rather than complete system), fast response, and ability to measure higher temperature. Among the electrical temperature sensors, thermocouples and resistance temperature detectors are most widely used.DescriptionThe AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The device is manufactured using Atmel‟s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. Function characteristicThe AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.Pin DescriptionVCC:Supply voltage.GND:Ground.Port 0:Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as highimpedance inputs.Port 0 may also be configured to be the multiplexed loworder address/data bus during accesses to external program and data memory. In this mode P0 has internal pullups.Port 0 also receives the code bytes during Flash programming,and outputs the code bytes during programverification. External pullups are required during programverification.Port 1Port 1 is an 8-bit bi-directional I/O port with internal pullups.The Port 1 output buffers can sink/source four TTL inputs.When 1s are written to Port 1 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bi-directional I/O port with internal pullups.The Port 2 output buffers can sink/source four TTL inputs.When 1s are written to Port 2 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 2 pins that are externally being pulled low will source current, because of the internal pullups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses. In this application, it uses strong internal pullupswhen emitting 1s. During accesses to external data memory that use 8-bit addresses, Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bi-directional I/O port with internal pullups.The Port 3 output buffers can sink/source four TTL inputs.When 1s are written to Port 3 pins they are pulled high by the internal pullups and can be used as inputs. As inputs,Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functionsof various special features of the AT89C51 as listed below:Port 3 also receives some control signals for Flash programming and verification.RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROGAddress Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable is the read strobe to external program memory.When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage(VPP) during Flash programming, for parts that require12-volt VPP.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit. XTAL2Output from the inverting oscillator amplifier.Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively,of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1.Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed.中文翻译:微型计算机控制系统(单片机控制系统)广义地说,微型计算机控制系统(单片机控制系统)是用于处理信息的,这种被用于处理的信息可以是电话交谈,也可以是仪器的读数或者是一个企业的帐户,但是各种情况下都涉及到相同的主要操作:信息的处理、信息的存储和信息的传递。
外文翻译--步进电机运动控制系统设计
密级分类号编号成绩本科生毕业设计 (论文)外文翻译原文标题Stepper Motor Motion Control System Design 译文标题步进电机运动控制系统设计作者所在系别机械工程系作者所在专业机械设计制造及其自动化作者所在班级作者姓名作者学号指导教师姓名指导教师职称完成时间2012 年 2 月的个数严格成正比,在时间上与输入脉冲同步,因此只要控制输入脉冲的数量、频率及电动机绕组通电的相序,便可获得所需的转角、转速及转动方向。
在没有脉冲输入时,在绕组电源的激励下气隙磁场能使转子保持原有位置处于定位状态。
因此非常适合于单片机控制。
步进电机还具有快速启动、精确步进和定位等特点,因而在数控机床,绘图仪,打印机以及光学仪器中得到广泛的应用。
步进电动机已成为除直流电动机和交流电动机以外的第三类电动机。
传统电动机作为机电能量转换装置,在人类的生产和生活进入电气化过程中起着关键的作用。
步进电机可以作为一种控制用的特种电机,利用其没有积累误差(精度为100%)的特点,广泛应用于各种开环控制。
现在比较常用的步进电机包括反应式步进电机(VR)、永磁式步进电机(PM)、混合式步进电机(HB)和单相式步进电机等。
一步进电机的工作原理步进电机是一种用电脉冲进行控制 ,将电脉冲信号转换成相位移的电机 ,其机械位移和转速分别与输入电机绕组的脉冲个数和脉冲频率成正比 ,每一个脉冲信号可使步进电机旋转一个固定的角度.脉冲的数量决定了旋转的总角度 ,脉冲的频率决定了电机运转的速度.当步进驱动器接收到一个脉冲信号,它就驱动步进电机按设定的方向转动一个固定的角度(称为“步距角”),它的旋转是以固定的角度一步一步运行的。
可以通过控制脉冲个数来控制角位移量,从而达到准确定位的目的;同时可以通过控制脉冲频率来控制电机转动的速度和加速度,从而达到调速的目的。
二步进电机详细调速原理步进电机的调速一般是改变输入步进电机的脉冲的频率来实现步进电机的调速,因为步进电机每给一个脉冲就转动一个固定的角度,这样就可以通过控制步进电机的一个脉冲到下一个脉冲的时间间隔来改变脉冲的频率,延时的长短来具体控制步进角来改变电机的转速,从而实现步进电的调速。
门禁监管系统外文翻译(含原文)access-control-system
工业大学本科生毕业设计(论文)外文翻译毕业设计题目:楼宇门禁监管系统软件设计学院:信息科学与工程学院专业班级:通信工程0902学生:格根哈斯090404049指导教师:柏山2013年 03 月 18 日门禁管理系统原理门禁系统是最近几年才在国广泛应用的又一高科技安全设施之一,现已成为现代建筑的智能化标志之一。
门禁,即出入口控制系统,是对出入口通道进行管制的系统,门禁系统是在传统的门锁基础上发展而来的(英文E NTRANCE G UARD /A CCESS C ONTROL)。
在现实中访问控制是,我们的日常生活中的现象。
一车门上的锁,本质上是一种形式的访问控制。
在一家银行的ATM系统是一个PIN访问控制的另一种方式。
站在一家夜总会门前的安保人员是缺乏涉及信息技术,也许是更原始的访问控制模式。
拥有访问控制是当人寻求安全,或敏感的信息和设施时非常重要的.项目控制或电子钥匙管理的区域(和有可能集成),一个访问控制系统,它涉及到管理小资产或物理(机械)键的位置。
一个人可以被允许物理访问,根据支付,授权等。
有可能是单向交通的人,这些都可以执行人员,如边防卫兵,一个看门人,检票机等,或与设备,如旋转门。
有可能会有围栏,以避免规避此访问控制。
在严格意义上的访问控制(实际控制访问本身)的另一种方法是一个系统的检查授权的存在,例如,车票控制器(运输)。
一个变种是出口控制,例如的店(结帐)或一个国家。
在物理安全方面上的访问控制是指属性,建筑,或授权人一个房间,限制入口的做法。
在这些环境中,物理密钥管理还可以进一步管理和监控机械键区或某些小资产。
物理访问控制访问的一种手段,是谁,地点和时间的问题。
访问控制系统决定谁可以进入或退出,在那里他们被允许离开或进入,而当他们被允许进入或退出。
从历史上看,这已经部分实现通过钥匙和锁。
当门被锁定只有有人用一把钥匙可以通过门禁,这时取决于锁定如何配置。
机械锁和钥匙的钥匙持有人在特定的时间或日期允许访问。
毕业设计论文外文文献翻译计算机科学与技术微软VisualStudio中英文对照
外文文献翻译(2012届)学生姓名学号********专业班级计算机科学与技术08-5班指导教师微软Visual Studio1微软Visual StudioVisual Studio 是微软公司推出的开发环境,Visual Studio可以用来创建Windows平台下的Windows应用程序和网络应用程序,也可以用来创建网络服务、智能设备应用程序和Office 插件。
Visual Studio是一个来自微软的集成开发环境IDE(inteqrated development environment),它可以用来开发由微软视窗,视窗手机,Windows CE、.NET框架、.NET精简框架和微软的Silverlight支持的控制台和图形用户界面的应用程序以及Windows窗体应用程序,网站,Web应用程序和网络服务中的本地代码连同托管代码。
Visual Studio包含一个由智能感知和代码重构支持的代码编辑器。
集成的调试工作既作为一个源代码级调试器又可以作为一台机器级调试器。
其他内置工具包括一个窗体设计的GUI应用程序,网页设计师,类设计师,数据库架构设计师。
它有几乎各个层面的插件增强功能,包括增加对支持源代码控制系统(如Subversion和Visual SourceSafe)并添加新的工具集设计和可视化编辑器,如特定于域的语言或用于其他方面的软件开发生命周期的工具(例如Team Foundation Server的客户端:团队资源管理器)。
Visual Studio支持不同的编程语言的服务方式的语言,它允许代码编辑器和调试器(在不同程度上)支持几乎所有的编程语言,提供了一个语言特定服务的存在。
内置的语言中包括C/C + +中(通过Visual C++),(通过Visual ),C#中(通过Visual C#)和F#(作为Visual Studio 2010),为支持其他语言,如M,Python,和Ruby等,可通过安装单独的语言服务。
软件工程毕业论文文献翻译中英文对照
软件工程毕业论文文献翻译中英文对照学生毕业设计(论文)外文译文学生姓名: 学号专业名称:软件工程译文标题(中英文):Qt Creator白皮书(Qt Creator Whitepaper)译文出处:Qt network 指导教师审阅签名: 外文译文正文:Qt Creator白皮书Qt Creator是一个完整的集成开发环境(IDE),用于创建Qt应用程序框架的应用。
Qt是专为应用程序和用户界面,一次开发和部署跨多个桌面和移动操作系统。
本文提供了一个推出的Qt Creator和提供Qt开发人员在应用开发生命周期的特点。
Qt Creator的简介Qt Creator的主要优点之一是它允许一个开发团队共享一个项目不同的开发平台(微软Windows?的Mac OS X?和Linux?)共同为开发和调试工具。
Qt Creator的主要目标是满足Qt开发人员正在寻找简单,易用性,生产力,可扩展性和开放的发展需要,而旨在降低进入新来乍到Qt的屏障。
Qt Creator 的主要功能,让开发商完成以下任务: , 快速,轻松地开始使用Qt应用开发项目向导,快速访问最近的项目和会议。
, 设计Qt物件为基础的应用与集成的编辑器的用户界面,Qt Designer中。
, 开发与应用的先进的C + +代码编辑器,提供新的强大的功能完成的代码片段,重构代码,查看文件的轮廓(即,象征着一个文件层次)。
, 建立,运行和部署Qt项目,目标多个桌面和移动平台,如微软Windows,Mac OS X中,Linux的,诺基亚的MeeGo,和Maemo。
, GNU和CDB使用Qt类结构的认识,增加了图形用户界面的调试器的调试。
, 使用代码分析工具,以检查你的应用程序中的内存管理问题。
, 应用程序部署到移动设备的MeeGo,为Symbian和Maemo设备创建应用程序安装包,可以在Ovi商店和其他渠道发布的。
, 轻松地访问信息集成的上下文敏感的Qt帮助系统。
机械毕业设计英文外文翻译589专题 精密校直机的控制系统
专题精密校直机的控制系统一、概述机械、汽车、电机等行业大量使用轴类、杆类零件,这些零件的原材料在粗加工火热处理等过程中不可避免地会出现弯曲变形,如果不进行校直处理会直接影响工件的后序加工和使用,甚至可能出现相当数量的废品。
所以为了能获得下道工序所允许的最小切削量或通过精密校直保证工件达到严格的最终设计公差要求,校直机成了工件热处理后不可缺少的关键设备。
在传统工艺中,多数厂家选用手动压力机,校直量难以控制,效率低下,难以满足校直要求;而自动校直是一种先进的生产制造工艺,近年来随着我国工业整体技术水平和技术要求的提高,该工艺被越来越广泛地应用于机械、汽车、电机等行业中。
自动校直技术通过数控精密校直液压机(简称精校机)完成对轴、管、棒等类零件的校直,是一种先进制造技术,是机械加工过程中保证产品质量的重要工序,广泛应用于汽车、拖拉机、工程机械、机床、纺织机械等机械制造行业。
发达国家对该项技术的研究起步较早,已开发出具有本国特色的自动精校机产品。
而我国在这一领域才刚刚起步,目前国内应用的大部分精校机都从国外引进。
随着我国机械工业的发展,对机械产品质量的要求不断提高,此项技术的重要性日益显现出来,迫切需要自动校直技术及其成套设备,实现对轴类零件的精密校直,以提高轴类零件的加工精度。
二、BUM系列轴类自动校直机一)设备说明该产品适用范围包括:转向齿条、凸轮轴、曲轴、半轴、齿轮轴、电机轴、减震器杆、活塞杆、车桥壳等轴杆类零件。
该系列产品在消化吸收国外技术的同时,针对国内客户情况,在校直原理、测量方式、人机交互、特殊工件处理方面都作了大量创新设计。
普通零部件国内设计加工,关键器件选用的是日本、韩国、德国等国家著名公司的进口产品,从而保证了利用国内产品价格拥有世界级自动校直机的整体品质。
该系列产品主要特性:1、高可靠性、高精度的测量系统,测量精度±5μm、显示分辨率1μm ;2、修正量的自适应调整系统,精密液压控制,自动分析计算修正量对工件缺陷(中心偏心、椭圆、毛刺等)的特殊处理,解决了假性弯曲的问题;3、先进的WINDOWS测量系统,友好的人机对话界面,较好地实现了操作者与设备的人机交互;4、简洁方便的工件夹持定位装置,用户可快速方便地调整工装,满足不同工件生产要求;5、声发射装置可供选择,可检测出工件裂纹缺陷;6、高效生产效率,满足大批量生产要求7、可存储多种不同工件参数,满足不同种类产品校直需要二)主要部分介绍1、液压控制系统泵站、液压阀组、执行油缸,液压控制回路等组成了校直机的液压系统。
毕业设计外文翻译
基于自抗扰控制器的永磁同步电机控制系统刘德俊电气与信息工程学院北华大学吉林,中国电子邮件:dejunliu@车长进周振雄电气与信息工程学院北华大学吉林,中国电子邮件:bhchecj@zzx701111@摘要-磁场定向控制技术被广泛应用于运动控制的感应电动机。
然而,在实时执行,这需要准确的电机参数的精确的去耦不能充分认识到由于显著的的植物不确定性,如外部干扰,参数变化和植物非线性动力学,这可能磁通和转矩的动态性能显着恶化。
为了实现高动力驱动系统的性能,非线性自抗扰控制器控制交流永磁同步伺服电机(AC-PMSM)直接转矩控制调速系统.关键词:交流永磁同步电机,自动抗扰,直接转矩控制系统仿真1.简介通常用在高性能交流调速系统矢量控制,动态性能取决于型号。
但交流调速系统具有的特性是非线性的强耦合,多变量[1],它是难以得到精确的数学模型,这使得在改善的动态性能的矢量控制的限制。
学者提出了异步电机直接转矩控制(DTC),去耦矢量控制的想法被放弃DTC,复杂的坐标变换,避免磁场定向,定子磁链的估计仅涉及定子电阻,它被削弱依赖电机参数。
这个方法很简单,它具有的扭矩响应速度快和良好的动态性能。
直接转矩控制的感应电机控制系统,在目前的这些优点,一些学者致力于发展同步电机直接转矩控制模式,初步实现了永磁同步,反映电机直接转矩控制,直接转矩控制是一个简单的控制方法,并具有优良的动态性能[2]。
自抗扰控制器应用到DTC速度控制系统,在本文中,观察到系统的状态和系统的内部和外部扰动扩张状态观测器,获得干扰被添加到由前馈控制系统的输入,使系统作为一个简单的线性系统。
基于传统的自抗扰控制器的非线性函数进行了分析,提出了改进的自抗扰控制器仿真结果表明,该控制方案具有良好的实时性能和较强的鲁棒性。
2. 永磁同步电动机直接转矩控制理论在转子运动的参考坐标,di和qi和sω是状态变量,3相交流永久磁铁的同步伺服电机非线性动态数学模型可以表示为以下:qd s dd q rd d dq q fs dq d r sq q q dLdi R Ui idt L L Ldi LR Ui idt L L L Lωψωω=-++=---+⎧⎪⎨⎪⎩通过坐标变换,在dq坐标轴的转矩是:()32sin sin2 4s f q s q dd qpT L L LL Lψψδψδ⎡⎤=--⎣⎦当定子交链磁通是恒定的,转矩可以表示为以下:()32cos2cos2 4s f q s q dd qdT pL L Ldt L Lψψδψδδ⎡⎤=--⎣⎦从方程(3)中,我们可以得出结论,当定子磁链是一个恒定值,电磁转矩电机决定的交链磁通的分离角δ。
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英文原文Introductions to Control SystemsAutomatic control has played a vital role in the advancement of engineering and science. In addition to its extreme importance in space-vehicle, missile-guidance, and aircraft-piloting systems, etc, automatic control has become an important and integral part of modern manufacturing and industrial processes. For example, automatic control is essential in such industrial operations as controlling pressure, temperature, humidity, viscosity, and flow in the process industries; tooling, handling, and assembling mechanical parts in the manufacturing industries, among many others.Since advances in the theory and practice of automatic control provide means for attaining optimal performance of dynamic systems, improve the quality and lower the cost of production, expand the production rate, relieve the drudgery of many routine, repetitive manual operations etc, most engineers and scientists must now have a good understanding of this field.The first significant work in automatic control was James Watt’s centrifugal governor for the speed control of a steam engine in the eighteenth century. Other significant works in the early stages of development of control theory were due to Minorsky, Hazen, and Nyquist, among many others. In 1922 Minorsky worked on automatic controllers for steering ships and showed how stability could be determined by the differential equations describing the system. In 1934 Hazen, who introduced the term “ervomechanisms”for position control systems, discussed design of relay servomechanisms capable of closely following a changing input.During the decade of the 1940’s, frequency-response methods made it possible for engineers to design linear feedback control systems that satisfied performance requirements. From the end of the 1940’s to early 1950’s, the root-locus method in control system design was fully developed.The frequency-response and the root-locus methods, which are thecore of classical theory, lead to systems that are stable and satisfy a set of more or less arbitrary performance requirements. Such systems are, in general, not optimal in any meaningful sense. Since the late 1950’s, the emphasis on control design problems has been shifted from the design of one of many systems that can work to the design of one optimal system in some meaningful sense.As modern plants with many inputs and outputs become more and more complex, the description of a modern control system requires a large number of equations. Classical control theory, which deals only with single-input-single-output systems, becomes entirely powerless for multiple-input-multiple-output systems. Since about 1960, modern control theory has been developed to cope with the increased complexity of modern plants and the stringent requirements on accuracy, weight, and industrial applications.Because of the readily available electronic analog, digital, and hybrid computers for use in complex computations, the use of computers in the design of control systems and the use of on-line computers in the operation of control systems are now becoming common practice.The most recent developments in modern control theory may be said to be in the direction of the optimal control of both deterministic and stochastic systems as well as the adaptive and learning control of complex systems. Applications of modern control theory to such nonengineering fields as biology, economics, medicine, and sociology are now under way, and interesting and significant results can be expected in the near future.Next we shall introduce the terminology necessary to describe control systems.Plants. A plant is a piece of equipment, perhaps just a set of machine parts functioning together, the purpose of which is to perform a particular operation. Here we shall call any physical object to be controlled (such as a heating furnace, a chemical reactor, or a spacecraft) a plant.Processes. The Merriam-Webster Dictionary defines a process to be a natural, progressively continuing operation or development marked by a series of gradual changes that succeed one another in a relatively fixedway and lead toward a particular result or end; or an artificial or voluntary, progressively continuing operation that consists of a series of controlled actions or movements systematically directed toward a particular result or end.Here we shall call any operation to be controlled a process. Examples are chemical, economic, and biological process.Systems. A system is a combination of components that act together and perform a certain objective. A system is not limited to abstract, dynamic phenomena such as those encountered in economics. The word “system” should, therefore, be interpreted to imply physical, biological, economic, etc., system.Disturbances. A disturbance is a signal which tends to adversely affect the value of the output of a system. If a disturbance is generated within the system, it is called internal, while an external disturbance is generated outside the system and is an input.Feedback control.Feedback control is an operation which, in the presence of disturbances, tends to reduce the difference between the output of a system and the reference input (or an arbitrarily varied, desired state) and which does so on the basis of this difference. Here, only unpredictable disturbance (i.e., those unknown beforehand) are designated for as such, since with predictable or known disturbances, it is always possible to include compensation with the system so that measurements are unnecessary.Feedback control systems. A feedback control system is one which tends to maintain a prescribed relationship between the output and the reference input by comparing these and using the difference as a means of control.Note that feedback control systems are not limited to the field of engineering but can be found in various nonengineering fields such as economics and biology. For example, the human organism, in one aspect, is analogous to an intricate chemical plant with an enormous variety of unit operations.The process control of this transport and chemical-reaction network involves a variety of control loops. In fact, human organism is an extremely complex feedback control system.Servomechanisms. A servomechanism is a feedback control systemin which the output is some mechanical position, velocity, or acceleration. Therefore, the terms servomechanism and position- (or velocity- or acceleration-) control system are synonymous. Servomechanisms are extensively used in modern industry. For example, the completely automatic operation of machine tools, together with programmed instruction, may be accomplished by use of servomechanisms.Automatic regulating systems. An automatic regulating system is a feedback control system in which the reference input or the desired output is either constant or slowly varying with time and in which the primary task is to maintain the actual output at the desired value in the presence of disturbances.A home heating system in which a thermostat is the controller is an example of an automatic regulating system. In this system, the thermostat setting (the desired temperature) is compared with the actual room temperature. A change in the desired room temperature is a disturbance in this system. The objective is to maintain the desired room temperature despite changes in outdoor temperature. There are many other examples of automatic regulating systems, some of which are the automatic control of pressure and of electric quantities such as voltage, current and frequency.Process control systems. An automatic regulating system in which the output is a variable such as temperature, pressure, flow, liquid level, or pH is called a process control system.Process control is widely applied in industry. Programmed controls such as the temperature control of heating furnaces in which the furnace temperature is controlled according to a preset program are often used in such systems. For example, a preset program may be such that the furnace temperature is raised to a given temperature in a given time interval and then lowered to another given temperature in some other given time interval. In such program control the set point is varied according to the preset time schedule. The controller then functions to maintain the furnace temperature close to the varying set point. It should be noted that most process control systems include servomechanisms as an integral part.译文:控制系统介绍自动控制在工程学和科学的推进扮演一个重要角色。