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传感器技术论文中英文对照资料外文翻译文献

传感器技术论文中英文对照资料外文翻译文献Development of New Sensor TechnologiesSensors are devices that can convert physical。

chemical。

logical quantities。

etc。

into electrical signals。

The output signals can take different forms。

such as voltage。

current。

frequency。

pulse。

etc。

and can meet the requirements of n n。

processing。

recording。

display。

and control。

They are indispensable components in automatic n systems and automatic control systems。

If computers are compared to brains。

then sensors are like the five senses。

Sensors can correctly sense the measured quantity and convert it into a corresponding output。

playing a decisive role in the quality of the system。

The higher the degree of n。

the higher the requirements for sensors。

In today's n age。

the n industry includes three parts: sensing technology。

n technology。

and computer technology。

传感器技术外文文献及中文翻译

Sensor technologyA sensor is a device which produces a signal in response to its detecting or measuring a property ,such as position , force , torque , pressure , temperature , humidity , speed , acceleration , or vibration .Traditionally ,sensors (such as actuators and switches )have been used to set limits on the performance of machines .Common examples are (a) stops on machine tools to restrict work table movements ,(b) pressure and temperature gages with automatics shut-off features , and (c) governors on engines to prevent excessive speed of operation . Sensor technology has become an important aspect of manufacturing processes and systems .It is essential for proper data acquisition and for the monitoring , communication , and computer control of machines and systems .Because they convert one quantity to another , sensors often are referred to as transducers .Analog sensors produce a signal , such as voltage ,which is proportional to the measured quantity .Digital sensors have numeric or digital outputs that can be transferred to computers directly .Analog-to-coverter(ADC) is available for interfacing analog sensors with computers .Classifications of SensorsSensors that are of interest in manufacturing may be classified generally as follows:Machanical sensors measure such as quantities aspositions ,shape ,velocity ,force ,torque , pressure , vibration , strain , and mass .Electrical sensors measure voltage , current , charge , and conductivity .Magnetic sensors measure magnetic field ,flux , and permeablity .Thermal sensors measure temperature , flux ,conductivity , and special heat .Other types are acoustic , ultrasonic , chemical , optical , radiation , laser ,and fiber-optic .Depending on its application , a sensor may consist of metallic , nonmetallic , organic , or inorganic materials , as well as fluids ,gases ,plasmas , or semiconductors .Using the special characteristics of these materials , sensors covert the quantity or property measured to analog or digital output. The operation of an ordinary mercury thermometer , for example , is based on the difference between the thermal expansion of mercury and that of glass.Similarly , a machine part , a physical obstruction , or barrier in a space can be detected by breaking the beam of light when sensed by a photoelectric cell . A proximity sensor ( which senses and measures the distance between it and an object or a moving member of a machine ) can be based on acoustics , magnetism , capacitance , or optics . Other actuators contact the object and take appropriate action ( usually by electromechanical means ) . Sensors are essential to the conduct of intelligent robots , and are being developed with capabilities that resemble those of humans ( smart sensors , see the following ).This is America, the development of such a surgery Lin Bai an example, through the screen, through a remote control operator to control another manipulator, through the realization of the right abdominal surgery A few years ago our country theexhibition, the United States has been successful in achieving the right to the heart valve surgery and bypass surgery. This robot has in the area, caused a great sensation, but also, AESOP's surgical robot, In fact, it through some equipment to some of the lesions inspections, through a manipulator can be achieved on some parts of the operation Also including remotely operated manipulator, and many doctors are able to participate in the robot under surgery Robot doctor to include doctors with pliers, tweezers or a knife to replace the nurses, while lighting automatically to the doctor's movements linked, the doctor hands off, lighting went off, This is very good, a doctor's assistant.Tactile sensing is the continuous of variable contact forces , commonly by an array of sensors . Such a system is capable of performing within an arbitrarythree-dimensional space .has gradually shifted from manufacturing tonon-manufacturing and service industries, we are talking about the car manufacturer belonging to the manufacturing industry, However, the services sector including cleaning, refueling, rescue, rescue, relief, etc. These belong to the non-manufacturing industries and service industries, so here is compared with the industrial robot, it is a very important difference. It is primarily a mobile platform, it can move to sports, there are some arms operate, also installed some as a force sensor and visual sensors, ultrasonic ranging sensors, etc. It’s surrounding environment for the conduct of identification, to determine its campaign to complete some work, this is service robot’s one of the basic characteristicsIn visual sensing (machine vision , computer vision ) , cameral optically sense the presence and shape of the object . A microprocessor then processes the image ( usually in less than one second ) , the image is measured , and the measurements are digitized ( image recognition ) .Machine vision is suitable particularly for inaccessible parts , in hostile manufacturing environments , for measuring a large number of small features , and in situations where physics contact with the part may cause damage .Small sensors have the capability to perform a logic function , to conducttwo-way communication , and to make a decisions and take appropriate actions . The necessary input and the knowledge required to make a decision can be built into a smart sensor . For example , a computer chip with sensors can be programmed to turn a machine tool off when a cutting tool fails . Likewise , a smart sensor can stop a mobile robot or a robot arm from accidentally coming in contact with an object or people by using quantities such as distance , heat , and noise .Sensor fusion . Sensor fusion basically involves the integration of multiple sensors in such a manner where the individual data from each of the sensors ( such as force , vibration , temperature , and dimensions ) are combined to provide a higher level of information and reliability . A common application of sensor fusion occurs when someone drinks a cup of hot coffee . Although we take such a quotidian event for granted ,it readily can be seen that this process involves data input from the person's eyes , lips , tongue , and hands .Through our basic senses of sight , hearing , smell , taste , and touch , there is real-time monitoring of relative movements , positions , and temperatures . Thus if the coffee is too hot , the hand movement of the cup toward the lip is controlled and adjusted accordingly .The earliest applications of sensor fusion were in robot movement control , missile flight tracking , and similar military applications . Primarily because these activities involve movements that mimic human behavior . Another example of sensor fusion is a machine operation in which a set of different but integrated sensors monitors (a) the dimensions and surface finish of workpiece , (b) tool forces , vibrations ,and wear ,(c) the temperature in various regions of the tool-workpiece system , and (d) the spindle power .An important aspect in sensor fusion is sensor validation : the failure of one particular sensor is detected so that the control system maintains high reliability . For this application ,the receiving of redundant data from different sensors is essential . It can be seen that the receiving , integrating of all data from various sensors can be a complex problem .With advances in sensor size , quality , and technology and continued developments in computer-control systems , artificial neural networks , sensor fusion has become practical and available at low cost .Movement is relatively independent of the number of components, the equivalent of our body, waist is a rotary degree of freedom We have to be able to hold his arm, Arm can be bent, then this three degrees of freedom, Meanwhile there is a wrist posture adjustment to the use of the three autonomy, the general robot has six degrees of freedom. We will be able to space the three locations, three postures, the robot fully achieved, and of course we have less than six degrees of freedomFiber-optic sensors are being developed for gas-turbine engines . These sensors will be installed in critical locations and will monitor the conditions inside the engine , such as temperature , pressure , and flow of gas . Continuous monitoring of the signals from thes sensors will help detect possible engine problems and also provide the necessary data for improving the efficiency of the engines .传感器技术传感器一种通过检测某一参数而产生信号的装置。

智能红外传感器外文文献翻译中英文

外文文献翻译(含：英文原文及中文译文）文献出处：M G B r a y.Smart Infrared Sensors[J] International Journal of Computational Science & Engineering, 2015, 3(1 ):21-31 •英文原文Smart Infrared SensorsMG BrayKeeping up with continuously evolving process technologies is a major challenge for process engineers. Add to that the demands of staying current with rapidly evolving methods of monitoring and controlling those processes, and the assignment can become quite intimidating. However，infrared (IR) temperature sensor manufacturers are giving users the tools they need to meet these challenges: the latest computer-related hardware, software, and communications equipment, as well as leading-edge digital circuitry. Chief among these tools, though, is the next generation of IR thermometers —the smart sensor. Today^s new smart IR sensors represent a union of two rapidly evolving sciences that combine IR temperature measurement with high-speed digital technologies usually associated with the computer These instruments are called smart sensors because they incorporate microprocessors programmed to act as transceivers for bidirectional, serial communications between sensors onthe manufacturing floor and computers in the control room (see Photo 1).And because the circuitry is smaller，the sensors are smaller，simplifying installation in tight or awkward areas. Integrating smart sensors into new or existing process control systems offers an immediate advantage to process control engineers in terms of providing a new level of sophistication in temperature monitoring and controLIntegrating Smart Sensors into Process LinesWhile the widespread implementation of smart IR sensors is new, IR temperature measurement has been successful 1 y used in process monitoring and control for decades (see the sidebar，“How Infrared Temperature Sensors W o r k，‟‟below). In the past, if process engineers needed to change a sensor‟s settings，they would have to either shut down the line to remove the sensor or try to manually reset it in place. Either course could cause delays in the line，and，in some cases, be very dangerous. Upgrading a sensor usually required buying a new unit，calibrating it to the process, and installing it while the process line lay inactive. For example, some of the sensors in a wire galvanizing plant used to be mounted over vats of molten lead，zinc，and/or muriatic acid and accessible only by reaching out over the vats from a catwalk. In the interests of safety, the process line would have to be shut down for at least24 hours to cool before changing and upgrading a sensor.Today, process engineers can remotely configure, monitor，address，upgrade, and maintain their IR temperature sensors. Smart models with bidirectional RS-485 or RS-232 communications capabilities simplify integration into process control systems. Once a sensor is installed on a process line，engineers can tailor all its parameters to fit changing conditions—all from a PC in the control room. If, for example, the ambient temperature fluctuates, or the process itself undergoes changes in type, thickness, or temperature, all a process engineer needs to do is customize or restore saved settings at a computer terminal. If a smart sensor fails due to high ambient temperature conditions， a cut cable，or failed components, its fail-safe conditions engage automatically. The sensor activates an alarm to trigger a shutdown, preventing damage to product and machinery. If ovens or coolers fail, HI and LO alarms can also signal that there is a problem and/or shut down the line.Extending a Sensor‟s Useful LifeFor smart sensors to be compatible with thousands of different types of processes, they must be fully customizable. Because smart sensors contain EPROMs (erasable programmable read only memory), users can reprogram them to meet their specific process requirements using field calibration, diagnostics，and/or utility software from the sensor manufacturer.Another benefit of owning a smart sensor is that its firmware, the software embedded in its chips, can be upgraded via the communications link to revisions as they become available —without removing the sensor from the process line. Firmware upgrades extend the working life of a sensor and can actually make a smart sensor smarter.The Raytek Marathon Series is a full line of 1- and 2-color ratio IR thermometers that can be networked with up to 32 smart sensors. Available models include both integrated units and fiber-optic sensors with electronic enclosures that can be mounted away from high ambienttemperatures.Clicking on a sensor window displays the configuration settings for that particular sensor. The Windows graphical interface is intuitive and easy to use. In the configuration screen, process engineers can monitor current sensor settings, adjust them to meet their needs, or reset the sensor back to the factory defaults. All the displayed information comes from the sensor by way of the RS-485 or RS-232 serial connection.The first two columns are for user input. The third monitors the sensor‟s parameters in real time. Some parameters can be changed through other screens, custom programming, and direct PC-to-sensor commands. Parameters that can be changed by user input include the following:•Relay contact can be set to NO (normally open) or NC (normallyclosed).•Relay function can be set to alarm or setpoint.•Temperature units can be changed from degrees Celsius to degrees Fahrenheit，or vice versa. -Display and analog output mode can be changed for smart sensors that have combined one- and two-color capabilities-•Laser (if the sensor is equipped with laser aiming) can be turned on or off.•Milliamp output settings and range can be used as automaticprocess triggers or alarms.•Emissivity (for one-color) or slope (for two-color) ratio thermometers values can be set. Emissivity and slope values for common metal and nonmetal materials, and instructions on how to determine emissivity and slope, are usually included with sensors.•Signal processing defines the temperature parameters returned. Average returns an object‟s average temperature over a period of time; peak-hold returns an object‟s peak temperature either over a period of time or by an external trigger.•HI alarm/LO alarm can be set to warn of improper changes in temperature. On some process lines, this could be triggered by a break in a product or by malfunctioning heater or cooler elements-•Attenuation indicates alarm and shut down settings for two-color ratio smart sensors. In this example, if the lens is 95% obscured, an alarm warns that the temperature results might be losing accuracy (known as a “dirty window”alarm). More than 95% obscurity can trigger an automatic shutdown of the process-Using Smart SensorsSmart IR sensors can be used in any manufacturing process in which temperatures are crucial to high-quality product.Six IR temperature sensors can be seen monitoring producttemperatures before and after the various thermal processes and before and after drying. The smart sensors are configured on a high-speed multidrop network (defined below) and are individually addressable from the remote supervisory computer. Measured temperatures at all sensor locations can be polled individually or sequentially; the data can be graphed for easy monitoring or archived to document process temperature data. Using remote addressing features，set points, alarms, emissivity，and signal processing，information can be downloaded to each sensor. The result is tighter process control.Remote Online Addressability,smart sensors can In a continuous process similar to that in Figure 2be connected to one another or to other displays，chart recorders, and controllers on a single network. The sensors may be arranged in multidrop or point-to-point configurations, or simply stand alone.In a multidrop configuration, multiple sensors (up to 32 in some cases) can be combined on a network-type cable. Each can have its own ……address，”allowing it to be configured separately with different operating parameters- Because smart sensors use RS-485 or FSK (frequency shift keyed) communications, they can be located at considerable distances from the control room computer —up to 1200 m (4000 ft.) for RS-485, or 3000 m (10,000 ft.) for FSK. Some processes use RS-232communications, but cable length is limited to <100 ftIn a point-to-point installation, smart sensors can be connected to chart recorders，process controllers, and displays, as well as to the controlling computer In this type of installation, digital communications can be combined with milliamp current loops for a complete all-around process communications package. Sometimes，however，specialized processes require specialized software. A wallpaper manufacturer might need a series of sensors programmed to check for breaks and tears along the entire press and coating run，but each area has different ambient and surface temperatures, and each sensor must trigger an alarm if it notices irregularities in the surface. For customized processes such as this，engineers can write their own programs using published protocol data. These custom programs can remotely reconfigure sensors on the fly —without shutting down the process line.Field Calibration and Sensor UpgradesWhether using multidrop，point-to-point, or single sensor networks，process engineers need the proper software tools on their personal computers to calibrate, configure, monitor, and upgrade those sensors. Simple，easy-to-use data acquisition，configuration，and utility programs are usually part of the smart sensor package when purchased, or custom software can be usedWith field calibration software, smart sensors can be calibrated, new parameters downloaded directly to the sensor‟s circuitry，and the sensor‟s current parameters saved and stored as computer data files to ensure that a complete record of calibration and/or parameter changes is kept. One set of calibration techniques can include one-point offset and two- and three-point with variable temperatures:•One-point offset. If a single temperature is used in a particular process, and the sensor reading needs to be offset to make it match a known temperature, one-point offset calibration should be used. This offset will be applied to all temperatures throughout the entire temperature range. For example, if the known temperature along a float glass line is exactly 1800°F, the smart sensor, or series of sensors, can be calibrated to that temperature.•Two-point. If sensor readings must match at two specific temperatures, the two-point calibration shown in Figure 3 should be selected. This technique uses the calibration temperatures to calculate a gain and an offset that are applied to all temperatures throughout the entire range.•Three-point with variable temperature. If the process has a wide range of temperatures，and sensor readings need to match at three specific temperatures, the best choice is three-point variable temperaturecalibration (see Figure 4). This technique uses the calibration temperatures to calculate two gains and two offsets. The first gain and offset are applied to all temperatures below a midpoint temperature, and the second set to all temperatures above the midpoint. Three-point calibration is less common than one- and two-point, but occasionally manufacturers need to perform this technique to meet specific standards- Field calibration software also allows routine diagnostics, including power supply voltage and relay tests, to be run on smart sensors. The results let process engineers know if the sensors are performing at their optimum and make any necessary troubleshooting easier.ConclusionThe new generation of smart IR temperature sensors allows process engineers to keep up with changes brought on by newer manufacturing techniques and increases in production. They now can configure as many sensors as necessary for their specific process control needs and extend the life of those sensors far beyond that of earlier，“non -smart”designs. As production rates increase, equipment downtime must decrease. By being able to monitor equipment and fine-tune temperature variables without shutting down a process, engineers can keep the process efficientand the product quality high. A smart IR sensor\s digital processing components and communications capabilities provide a level of flexibility,safety, and ease of use not achieved until now.How Infrared Temperature Sensors WorkInfrared (IR) radiation is part of the electromagnetic spectrum，which includes radio waves，microwaves，visible light, and ultraviolet light, as well as gamma rays and X-rays. The IRrange falls between the visible portion of the spectrum and radio waves. IR wavelengths are usually expressed in microns，with the IR spectrum extending from 0.7 to 1000 microns. Only the 0.7-14 micron band is used for IR temperature measurement.Using advanced optic systems and detectors, noncontact IR thermometers can focus on nearly any portion or portions of the 0.7-14 micron band. Because every object (with the exception of a blackbody) emits an optimum amount of IR energy at a specific point along the IR band, each process may require unique sensor models with specific optics and detector types. For example, a sensor with a narrow spectral range centered at 3.43 microns is optimized for measuring the surface temperature of polyethylene and related materials- A sensor set up for 5 microns is used to measure glass surfaces. A 1 micron sensor is used for metals and foils. The broader spectral ranges are used to measure lower temperature surfaces, such as paper, board, poly, and foil composites.The intensity of an object's emitted IR energy increases or decreasesin proportion to its temperature. It is the emitted energy, measured as the t a rg e t‟s emissive，that indicates an object丨s temperature.Emissive is a term used to quantify the energy-emitting characteristics of different materials and surfaces. IR sensors have adjustable emissive settings, usually from 0.1 to 1.0, which allow accurate temperature measurements of several surface types.The emitted energy comes from an object and reaches the IR sensor through its optical system, which focuses the energy onto one or more photosensitive detectors. The detector then converts the IR energy into an electrical signal, which is in turn converted into a temperature value based on the sensor's calibration equation and the target's emissive. This temperature value can be displayed on the sensor, or, in the case of the smart sensor, converted to a digital output and displayed on a computer terminal。

传感器英文文献

Fuzzy logic control of wind energy conversion systemHassan M. Farh and Ali M. EltamalyCitation: Journal of Renewable and Sustainable Energy 5, 023125 (2013); doi: 10.1063/1.4798739View online: /10.1063/1.4798739View Table of Contents: /content/aip/journal/jrse/5/2?ver=pdfcovPublished by the AIP PublishingArticles you may be interested inNew application of predictive direct torque control in permanent magnet synchronous generator-based wind turbineJ. Renewable Sustainable Energy 7, 023108 (2015); 10.1063/1.4915261Power quality assessment of a solar photovoltaic two-stage grid connected system: Using fuzzy and proportional integral controlled dynamic voltage restorer approachJ. Renewable Sustainable Energy 7, 013113 (2015); 10.1063/1.4906980A new hybrid control method for controlling back-to-back converter in permanent magnet synchronous generator wind turbinesJ. Renewable Sustainable Energy 6, 033133 (2014); 10.1063/1.4884198New methodology of speed-control of photovoltaic pumping systemJ. Renewable Sustainable Energy 5, 053109 (2013); 10.1063/1.4821213Recurrent modified Elman neural network control of permanent magnet synchronous generator system based on wind turbine emulatorJ. Renewable Sustainable Energy 5, 053103 (2013); 10.1063/1.4811792Fuzzy logic control of wind energy conversion systemHassan M.Farh 1,a)and Ali M.Eltamaly 2,a)1Department of Electrical Engineering,College of Engineering,King Saud University,P.O.Box 800,Riyadh 11421,Saudi Arabia 2Sustainable Energy Technologies Center,Department of Electrical Engineering,College of Engineering,King Saud university,Riyadh 11421,Saudi Arabia(Received 4November 2012;accepted 11March 2013;published online 3April 2013)This paper proposes a variable speed control scheme of grid-connected windenergy conversion system,WECS,using permanent magnet synchronousgenerator.The control algorithm tracking the maximum power for wind speedsbelow rated speed of wind turbines (WTs)and ensure the power will not exceedthe rated power for wind speeds higher than the rated speed of wind turbine.Thecontrol algorithm employed fuzzy logic controller (FLC)to effectively do thisjob.The WT is connected to the grid via back-to-back pulse width modulation-voltage source converter (PWM-VSC).Two effective computer simulationsoftware packages (PSIM and SIMULINK)have been used to carry out thesimulation effectively where PSIM contains the power circuit of the WECS andMATLAB/SIMULINK contains the control circuit of the system.The controlsystem has two controllers for generator side and grid side converters.The mainfunction of the generator side controller is to track the maximum power fromwind through controlling the rotational speed of the turbine using FLC.In thegrid side converter,active and reactive power control has been achieved bycontrolling d-axis and q-axis current components,respectively.VC 2013American Institute of Physics .[/10.1063/1.4798739]I.INTRODUCTIONWind is one of the most promising renewable energy resources for producing electricitydue to its cost competitiveness compared to other conventional types of energy resources.Ittakes a particular place to be the most suitable renewable energy resources for electricity pro-duction.It isn’t harmful to the environment and it is an abundant resource available in nature.Hence,wind power could be utilized by mechanically converting it to electrical power usingwind turbines (WTs).Various WT concepts have a quick development of wind power technolo-gies and signiﬁcant growth of wind power capacity during last two decades.Variable speedoperation and direct drive (DD)WTs have been the modern developments in the technology ofwind energy conversion system (WECS).Variable-speed operation has many advantages overﬁxed-speed generation such as increased energy capture,operation at MPPT over a wide rangeof wind speeds,high power quality,reduced mechanical stresses,and aerodynamic noiseimproved system reliability,and it can provide (10%–15%higher output power and has lessmechanical stresses when compared with the operation at a ﬁxed speed.1,2WTs can be classiﬁed,according to the type of drive train,into DD and gear drive (GD).The GD type uses a gear box,squirrel cage induction generator,SCIG,and classiﬁed as stall,active stall,and pitch control WT,and work in constant speed applications.The variable speedWT uses doubly fed induction generator,DFIG,especially in high power WTs.The gearlessDD and WTs have been used with small and medium size WTs employing permanent magnetsynchronous generator (PMSG)with higher numbers of poles to eliminate the need for gearboxa)Authors to whom correspondence should be addressed.Electronic addresses:eltamaly@.sa (Tel.:þ966553334130)and hfarh1@.sa (Tel.:þ966500507630).Fax:þ96614676757.1941-7012/2013/5(2)/023125/13/$30.00V C 2013American Institute of Physics 5,023125-1JOURNAL OF RENEWABLE AND SUSTAINABLE ENERGY 5,023125(2013)which can be translated to higher efﬁciency.PMSG appears more and more attractive,because of the advantages of permanent magnet,PM machines over electrically excited machines such as its higher efﬁciency,higher energy yield,no additional power supply for the magnetﬁeld excitation,and higher reliability due to the absence of mechanical components such as slip rings.In addition,the performance of PM materials is improving,and the cost is decreasing in recent years.Therefore,these advantages make direct-drive PM wind turbine generator systems more attractive in application of small and medium-scale wind turbines.1,3,4Robust controller has been developed in many literatures5–15to track the maximum power available in the wind.They include tip speed ratio,TSR,5,13power signal feedback,PSF,8,14 and the hill-climb searching,HCS11,12methods.The TSR control method regulates the rota-tional speed of the generator to maintain an optimal TSR at which power extracted is maxi-mum.13For TSR calculation,both the wind speed and turbine speed need to be measured,and the optimal TSR must be given to the controller.Theﬁrst barrier to implement TSR control is the wind speed measurement,which adds to system cost and presents difﬁculties in practical implementations.The second barrier is the need to obtain the optimal value of TSR;this value is different from one system to another.This depends on the turbine-generator characteristics that result in custom-designed control software tailored for individual wind turbines.14In PSF control,8,14it is required to have the knowledge of the wind turbine’s maximum power curve, and track this curve through its control mechanisms.The power curves need to be obtained via simulations or off-line experiment on individual wind turbines or from the datasheet of WT which makes it difﬁcult to implement with accuracy in practical applications.7,8,15The HCS technique does not require the data of wind,generator speeds and the turbine characteristics. But,this method works well only for very small wind turbine inertia.For large inertia wind tur-bines,the system output power is interlaced with the turbine mechanical power and rate of change in the mechanically stored energy,which often renders the HCS method ineffective.11,12 On the other hand,different algorithms have been used for maximum power extraction from WT in addition to the three methods mentioned above.For example,Oghafy and Nikkhajoei1presents an algorithm for maximum power extraction and reactive power control of an inverter through the power angle,d of the inverter terminal voltage and the modulation index,m a based variable-speed WT without wind speed sensor.Chinchilla et al.16present an algorithm for MPPT via controlling the generator torque through q-axis current and,hence,con-trolling the generator speed with variation of the wind speed.These techniques are used for a decoupled control of the active and reactive power from the WT through q-axis and d-axis cur-rent,respectively.Also,Song et al.17present a decoupled control of the active and reactive power from the WT,independently through q-axis and d-axis current but maximum power point operation of the WECS has been produced through regulating the input dc current of the dc/dc boost converter to follow the optimized current reference.Eltamaly18presents an algorithm for MPPT through directly adjusting duty ratio of the dc/dc boost converter and modulation index of the PWM-VSC.Hussein et al.19present MPPT control algorithm based on measuring the dc-link voltage and current of the uncontrolled rectiﬁer to attain the maximum available power from wind.Finally,MPPT control based on fuzzy logic controller(FLC)has been presented in (Pati and Sahu;Yao and Liu;Abo-Khalil and Seok).20–22The function of FLC is to track the generator speed with the reference speed for maximum power extraction at variable speeds.In this study,the WECS is designed as PMSG connected to the grid via a back-to-back PWM-VSC as shown in Fig.1.MPPT control algorithm has been introduced using FLC to reg-ulate the rotational speed to force the PMSG to work around its maximum power point in speeds below rated speeds and to produce the rated power in wind speed higher than the rated wind speed of the WT.Indirect vector-controlled PMSG system has been used for this purpose. The input to FLC is two real time measurements which are the change of output power and rotational speed between two consequent iterations(D P m and D x m).The output from FLC is the required change in the rotational speed D x m*.The detailed logic behind the new proposed technique is explained in detail in the following sections.Two effective computer simulation software packages(PSIM and SIMULINK)have been integrated to carry out the simulation effectively.PSIM contains the power circuit of the WECS and MATLAB/SIMULINK containsthe control circuit of the system.The idea behind integrating these two different software pack-ages is the effective tools provided with PSIM for power circuit and the effective tools inSIMULINK for control circuit and FLC.This integration between PSIM and SIMULINK has neverbeen used in MPPT of wind energy systems in the literature and this approach will helpresearchers to develop many other control techniques in this area.The interconnection betweenPSIM and SIMULINK makes the simulation process easier,efﬁcient,fast response,and powerful.In the grid side converter,active and reactive power control has been achieved by controllingd-axis and q-axis grid current components,respectively.The q-axis grid current is controlled tobe zero for unity power factor and the d-axis grid current is controlled to deliver the powerﬂowing from the dc-link to the grid.II.WIND ENERGY CONVERSION SYSTEM DESCRIPTIONFig.2shows a co-simulation (PSIM/SIMULINK)program for interconnecting WECS toelectric utility.The PSIM program contains the power circuit of the WECS and MATLAB /SIMULINK program contains the control of this system.The interconnection between PSIM andMATLAB /SIMULINK has been done via the SimCoupler block.The basic topology of the power cir-cuit,which has PMSG driven wind turbine connected to the utility grid through the ac-dc-acconversion system,is shown in Fig.1.The PMSG is connected to the grid through back-to-back bidirectional PWM voltage source converters VSC.The generator side converter is con-nected to the grid side converter through dc-link capacitor.The control of the overall systemhas been done through the generator side converter and the grid side converter.MPPTalgorithm has been achieved through controlling the generator side converter using FLC.TheFIG.1.Schematic diagram of the overallsystem.FIG.2.Co-simulation block of wind energy system interfaced to electric utility.grid-side converter controller maintains the dc-link voltage at the desired value by exporting active power to the grid and it controls the reactive power exchange with the grid.A.Wind turbine modelWind turbine converts the wind power to a mechanical power.This mechanical power gen-erated by wind turbine at the shaft of the generator can be expressed asP m¼12C Pðk;bÞq A u3;(1)where q is the air density(typically1.225kg/m3),b is the pitch angle(in degree),A is the area swept by the rotor blades(in m2);u is the wind speed(in m/s),and C p(k,b)is the wind-turbine power coefﬁcient(dimensionless).The turbine power coefﬁcient,C p(k,b),describes the power extraction efﬁciency of the wind turbine and is deﬁned as the ratio between the mechanical power available at the turbine shaft and the power available in wind.A generic equation is used to model C p(k,b).This equa-tion,based on the modeling turbine characteristics,is shown as follows:23C Pðk;bÞ¼0:5176116Ã1k iÀ0:4bÀ5eÀ21k iþ0:0068k;(2)with 1k i¼1kþ0:08bÀ0:0351þb3;where C P is a nonlinear function of both tip speed ratio,k and the blade pitch angle,b.k is the ratio of the turbine tip speed,x m*R to the wind speed,u.k is deﬁned as24k¼x mÃR;(3)where x m is the rotational speed and R is the turbine blade radius,respectively.For aﬁxed pitch angle,b,C P becomes a nonlinear function of k only.According to Eq.(3),there is a relation between k and x m.Hence,at a certain u,the power is maximized at a certain x m called opti-mum rotational speed,x opt.This speed corresponds to optimum tip speed ratio,k opt.15The value of the tip speed ratio is constant for all maximum power points.So,to extract maximum power at variable wind speed,the WT should always operate at k opt in speeds below the rated speed.This occurs by controlling the rotational speed of the WT to be equal to the optimum rotational speed.Fig.3shows that the mechanical power generated by WT at the shaft of the generator as a function of x m.These curves have been extracted from PSIM support team for the wind turbine used in this paper.It is clear from thisﬁgure that for each wind speed the me-chanical output power is maximized at particular rotational speed,x opt,as shown in Fig.3.B.PMSG modelThe generator is modeled by the following voltage equations in the rotor reference frame (dq-axes):25v sd¼R s i sdþd k sddtÀx r k sqv sq¼R s i sqþd k sqdtþx r k sd;(4)where k sq and k sd are the statorﬂux linkages in the direct and quadrature axis of rotor which in the absence of damper circuits can be expressed in terms of the stator currents and the magnetic ﬂux as follows:25k sd ¼L s i sd þw Fk sq ¼L s i sq ;(5)where w F is the ﬂux of the permanent magnets.The electrical torque,T e ,of the three-phasegenerator can be calculated as follows:25,26T e ¼32P ½k sd i sq Àk sq i sd ;(6)where P is the number of pole pairs.For a non-salient-pole machine,the stator inductances L sdand L sq are approximately equal.25This means that the direct-axis current i sd does not contrib-ute to the electrical torque.Our concept is to keep i sd to zero in order to obtain maximal torquewith minimum current.Then,the electromagnetic torque results,T e ¼32P w F i sq ¼K c i sq ;(7)where i sq is the quadrature-axis component of the stator-current space vector expressed in therotor reference frame and K c is called the torque constant and represents the proportional coefﬁ-cient between T e and i sq .III.CONTROL OF THE GENERATOR SIDE CONVERTERThe generator side controller controls the rotational speed to produce the maximum outputpower via controlling the electromagnetic torque according to Eq.(7),where the indirect vectorcontrol is used.The proposed control logic of the generator side converter is shown in Fig.4.The speed loop will generate the q-axis current component to control the generator torqueand speed at different wind speed via estimating the references value of i a and i b as shown inFig.4.The torque control can be achieved through the control of the i sq current as shown inEq.(7).Fig.5shows the stator and rotor current space phasors and the excitation ﬂux of thePMSG.25The quadrature stator current,i sq ,can be controlled through the rotor reference frame(a ,b axes)as shown in Fig.5.So,the references value of i a and i b can be estimated easilyfrom the amplitude of i sq*and the rotor angle,⍜r .Initially,to ﬁnd the rotor angle,⍜r ,the rela-tionship between the electrical angular speed,x r ,and the rotor mechanical speed (rad/s),x mmay be expressedasFIG.3.Typical output power characteristics.x r ¼P 2x m :(8)So,the rotor angle,⍜r ,can be estimated by integrating of the electrical angular speed,x r .Theinput to the speed control is the actual and reference rotor mechanical speed (rad/s)and the out-put is the (a ,b )reference current components.The actual values of the (a ,b )current compo-nents are estimated using Clark’s transformation to the three phase current of PMSG.The FLCcan be used to ﬁnd the reference speed along which tracks the maximum power point.IV.FUZZY LOGIC CONTROLLER FOR MPPTAt certain wind speed,the power is maximized at a certain x called optimum rotationalspeed,x opt .This speed corresponds to optimum tip speed ratio,k opt .15So,to extractmaximumFIG.4.Control block diagram of the generator sideconverter.FIG.5.The stator and rotor current space phasors and the excitation ﬂux of the PMSG.power at variable wind speed,the turbine should always operate at k opt.This occurs by control-ling the rotational speed of the turbine.Controlling of the turbine to operate at optimum rota-tional speed can be done using the FLC.Each wind turbine has one value of k opt at variable speed but x opt changes from a certain wind speed to another.From Eq.(3),the relation between x opt and wind speed,u,for constants R and k opt can be obtained as follows:x opt¼k optRu:(9)From Eq.(9),the relation between the optimum rotational speed and wind speed is linear. FLC is used to search the rotational speed reference which tracks the maximum power point at variable wind speeds.The block diagram of FLC is shown in Fig.6.Two variables are used as input to FLC(D P m and D x m)and the output is(D x m*).Membership functions are shown in Fig.7.Triangular symmetrical membership functions are suitable for the input and output, which give more sensitivity especially as variables approach to zero value.FLC does not require any detailed mathematical model of the system and its operation is governed simply by a set of rules.The principle of the FLC is to perturb the reference speed,x m*and to observe the corresponding change of power,D P m.If the output power increases with the last speed increment,the searching process continues in the same direction.On the other hand,if the speed increment reduces the output power,the direction of the searching is reversed.The FLC is efﬁcient to track the maximum power point,especially in case of frequently changing wind conditions.22The input and output membership functions have been shown in Fig.7.The control rule for input and output variables are listed in Table I.D x m is varied fromÀ0.15rad/s to0.15rad/s and D P m is varied fromÀ30W to30W.The membership deﬁnitions are used as follows:N (negative),NB(negative big),NS(negative small),ZE(zero),P(positive),PS(positive small), and PB(positive big).V.CONTROL OF THE GRID SIDE CONVERTERThe powerﬂow of the grid-side converter is controlled in order to maintain the dc-link voltage at reference value,600V.Since increasing the output power than the input power to dc-link capacitor causes a decrease of the dc-link voltage and vise versa,the output power will be regulated to keep dc-link voltage approximately constant.The dc-link voltage has been maintained and the reactive powerﬂowing into the grid has been controlled at zero value.This has been done via controlling the grid side converter currents using the d-q vector control approach.By aligning the d-axis of the reference frame along with the grid voltage position v q¼0and then the active and reactive power can be obtained from the following equations:FIG.6.Input and output of fuzzy controller.P s ¼32v d i d ;(10)Q s ¼32v d i q :(11)Active and reactive power control has been achieved by controlling d-axis and q-axis cur-rent components,respectively,using two control loops.An outer dc-link voltage control loopis used to set the d-axis current reference for active power control.The inner control loop con-trols the reactive power by setting the q-axis current reference to zero value for unity powerfactor as shown in Eq.(11).The control block diagram of the grid side converter is shown inFig.8.VI.SIMULATION RESULTSTwo effective computer simulation software packages (PSIM and SIMULINK)have beenintegrated together to carry out the simulation of the modiﬁed system effectively.The modelof WECS (power circuit)in PSIM contains the WT connected to the utility grid through back-to-back bidirectional PWM converter.The control of whole system in SIMULINK contains thegenerator side controller and the grid side controller.The idea behind integrating these twodifferent software packages is that PSIM is a very effective and a simple tool for modeling thepower electronics circuits whereas SIMULINK is a very effective and a simple tool for model-ing the control system especially for FLC and mathematical manipulation.The windturbineFIG.7.Membership functions of FLC.TABLE I.Rules of FLC.D P m /D x mNB NS ZE PS PB NPB PS ZE NS NB ZENM NS ZE PS PM P NB NS ZE PM PBcharacteristics and the parameters of the PMSG are listed in the Appendix.The generator can be directly controlled by the generator side controller to track the maximum power available from the WT.To extract maximum power at variable wind speed,the turbine should always operate at k opt.This occurs by controlling the rotational speed of the WT.So,it always oper-ates at the optimum rotational speed,x opt,for different wind speed.The fuzzy logic controller is used to search the optimum rotational speed which tracks the maximum power point at vari-able wind speeds.The proposed system has been compared with the system shown in Ref.22to validate the results.The whole simulation results of the proposed system and results from Ref.22are shown in Fig.9in left hand side(LHS)and right hand side(RHS),respectively.The input wind speeds have been assumed to be saw-tooth as the wind speed in Ref.22for easy compari-son.Figs.9(a1)and9(a2)show the input wind speed variation for the proposed system and the system shown in Ref.22,respectively.Reference rotational speed for the proposed system and the system shown in Ref.22are shown in Figs.9(b1)and9(b2),respectively.At a certain wind speed,the actual and reference rotational speed have been estimated and this agrees with the power characteristic of the wind turbine shown later in Fig.3(i.e.,the WT always operates at the optimum rotational speed which can be obtained from the output of FLC).Figs.9(c1)and 9(c2)show the variation of the actual rotational speed for the proposed system and the system shown in Ref.22,respectively.It is clear from Figs.9(c1)and9(c2)that the rotational speed variation of the proposed system follows the reference rotational speed strictly without noise in the waveform.Figs.9(d1)and9(d2)show the active power extraction from the proposed system and the system shown in Ref.22,respectively.It is clear from thisﬁgure that the output power generated from the proposed system is higher and follows strictly the maximum power ofFIG.8.Control block diagram of grid-side converter.Fig.3than the output power from the system shown in Ref.22.The reference value of the reactive power has been set at zero value.Figs.9(e1)and9(e2)show the waveform of the actual reactive power for the proposed system and the system shown in Ref.22,respectively.It is clear from thisﬁgure that the reactive power obtained from the proposed system is strictly following the reference value without spikes more than the one obtained from the system shown in Ref.22.Also,the dc-link voltage has been set at600V in both systems.The actual dc-link voltage waveforms are shown in Figs.9(f1)and9(f2)for the proposed system and the system shown in Ref.22,respectively.It is clear that the dc-link voltage obtained from the proposed system is following the reference value strictly more than the one obtained from the system shown in Ref.22.It is clear from the above discussion that the proposed system in this paper is superior and showed a stable operation and followed strictly the reference values of rotational speed,reactive power,and the dc-link voltage.Also,it is clear from the simulation results of the proposed sys-tem that the maximum power has been extracted strictly as the maximum power obtained from Fig.3.FIG.9.Different simulation waveforms of prposed system in LHS compared to the same waveforms obtained from Ref.22 in RHS:(a)Wind speed variation,(b)reference rotational speed(rad/s),(c)actual rotational speed(rad/s),(d)active power (W),(e)reactive power(Var),and(f)dc-link volltage(V).VII.CONCLUSIONA co-simulation (PSIM/SIMULINK)program has been proposed for WECS where PSIMcontains the power circuit of the WECS and MATLAB /SIMULINK contains the control circuit of theWECS.The integration between PSIM and SIMULINK is the ﬁrst time to be used in modelingWECS which help researchers in modifying the modeling of WECS in the future.The intercon-nection between PSIM and SIMULINK makes the simulation process easier,efﬁcient,fastresponse and powerful.The WT is connected to the grid via back-to-back PWM-VSC.The gen-erator side controller and the grid side controller have been done in SIMULINK .The main func-tion of the generator side controller is to track the maximum power from wind through control-ling the rotational speed of the turbine using fuzzy logic controller.The fuzzy logic algorithmfor the maximum output power of the grid-connected wind power generation system using aPMSG has been proposed and implemented above.The PMSG was controlled in indirect-vectorﬁeld oriented control method and its speed reference was determined using fuzzy logic control-ler.In the grid side converter,active and reactive power control has been achieved by control-ling d-axis and q-axis grid current components,respectively.The q-axis grid current is con-trolled to be zero for unity power factor and the d-axis grid current is controlled to delivertheFIG.9.(Continued).power ﬂowing from the dc-link to the grid.The simulation results prove the superiority of FLCand the whole control system.ACKNOWLEDGMENTSThe authors acknowledge the College of Engineering Research Center and Deanship ofScientiﬁc Research at King Saud University in Riyadh for the ﬁnancial support to carry out theresearch work reported in this paper.APPENDIX:PARAMETERS OF WT MODEL AND PMSG1V.Oghafy and H.Nikkhajoei,“Maximum power extraction for a wind-turbine generator with no wind speed sensor,”inProceedings on IEEE,Conversion and Delivery of Electrical Energy in the 21st Century (2008),pp.1–6.2T.Ackerman and L.S €o der,“An overview of wind energy status 2002,”Renewable sustainable Energy Rev.6,67–128(2002).3M.R.Dubois,“Optimized permanent magnet generator topologies for direct-drive wind turbines,”Ph.D.dissertation(Delft University of Technology,Delft,the Netherlands,2004).4A.Grauers,“Design of direct-driven permanent-magnet generators for wind turbines,”Ph.D.dissertation (ChalmersUniversity Technology,Goteborg,Sweden,1996).5T.Thiringer and J.Linders,“Control by variable rotor speed of a ﬁxed pitch wind turbine operating in a wide speedrange,”IEEE Trans.Energy Convers.EC-8,520–526(1993).6I.K.Buehring and L.L.Freris,“Control policies for wind energy conversion system,”IEE Proceedings C:Generation,Transmission &Distribution,128,253–261(1981).7M.Erimis,H.B.Ertan,E.Akpinar,and F.Ulgut,“Autonomous wind energy conversion systems with a simple controllerfor maximum power transfer,”IEE Proceedings B:Electric Power Applications 139,421–428(1992).8R.Chedid,F.Mrad,and M.Basma,“Intelligent control of a class of wind energy conversion systems,”IEEE Trans.Energy Convers.EC-14,1597–1604(1999).9M.G.Simoes,B.K.Bose,and R.J.Spiegal,“Fuzzy logic-based intelligent control of a variable speed cage machinewind generation system,”IEEE Trans.Power Electron.PE-12,87–94(1997).10J.H.Enslin and J.V.Wyk,“A study of a wind power converter with micro-computer based maximum power control uti-lizing an over-synchronous electronic scherbius cascade,”Renewable Energy World 2(6),551–562(1992).11Q.Wang and L.Chang,“An intelligent maximum power extraction algorithm for inverter-based variable speed wind tur-bine systems,”IEEE Trans.Power Electron.19(5),1242–1249(2004).12Q.Wang,“Maximum wind energy extraction strategies using power electronic converters,”Ph.D.dissertation(University of New Brunswick,Canada,2003).13H.Li,K.L.Shi,and P.G.McLaren,“Neural-network-based sensorless maximum wind energy capture with compensatedpower coefﬁcient,”IEEE Trans.Ind.Appl.41(6),1548–1556(2005).14A.B.Raju,B.G.Fernandes,and K.Chatterjee,“A UPF power conditioner with maximum power point tracker for gridconnected variable speed wind energy conversion system,”in Proceedings of 1st International Conference on PESA,Bombay,India,9-11November (2004),pp.107–112.15M.A.Abdullah,A.H.M.Yatim,and C.W.Tan,“A study of maximum power point tracking algorithms for wind energysystem,”in Procedings of 1st IEEE Conference on Clean Energy and Technology CET,2011.16M.Chinchilla,S.Arnaltes,and J.C.Burgos,“Control of permanent-magnet generators applied to variable-speed wind-energy systems connected to the grid,”IEEE Trans.Energy Convers.21(1),130–135(2006).17S.Song,S.Kang,and N.Hahm,“Implementation and control of grid connected AC-DC-AC power converter for variablespeed wind energy conversion system,”in Applied Power Electronics Conference and Exposition,IEEE,2003.18A.M.Eltamaly,“Modelling of wind turbine driving permanent Magnet Generator with maximum power point trackingsystem,”J.King Saud Univ.19(2),223–237(2007).19M.M.Hussein,M.Orabi,M.E.Ahmed,and M.A.Sayed,“Simple sensorless control technique of permanent magnetsynchronous generator wind turbine,”in Proceedings of IEEE International Conference on Power and Energy(PEC2010),Kuala Lumpur,Malaysia (2010),pp.512–517.TABLE II.Parameters of wind turbine model and PMSG.Wind turbinePMSG Nominal output power19kW R s (stator resistance)1m Wind speed input8:12m/s (saw tooth)L d (d-axis inductance)1m Base wind speed10m/s L q (q-axis inductance)1m Base rotational speeds190rpm No.of poles P 30Moment of inertia1m Moment of inertia 100m Blade pitch angle input 0 Mech.time constant 1。

数字温度传感器毕业论文中英文资料外文翻译文献[管理资料]

毕业论文中英文资料外文翻译文献外文资料DS1722 Digital ThermometerWith scientific and technological progress and development of the types of temperature sensors increasingly wide range of application of the increasingly widespread, and the beginning analog toward digital, single-bus, dual-bus and bus-3 direction. And the number of temperature sensors because they apply to all microprocessor interface consisting of automatic temperature control system simulation can be overcome sensor and microprocessor interface need signal conditioning circuit and A / D converters advant ages of the drawbacks, has been widely used in industrial control, electronic transducers, medical equipment and other temperature control system. Among them, which are more representative of a digital temperature sensor DS18B20, MAX6575, the DS1722, MAX6636 other. This paper introduces the DS1722 digital temperature sensor characteristics, the use of the method and its timing. Internal structure and other relevant content.FEATURES:Temperature measurements require no external components;Measures temperatures from -55°C to +120°C. Fahrenheit equivalent is -67°F to +248°F;Thermometer accuracy is ±°C;Thermometer resolution is configurable from 8 to 12 bits (°C to °C resolution);Data is read from/written to via a Motorola Serial Peripheral Interface (SPI) or standard 3-wire serial interface;Wide analog power supply range ( - );Separate digital supply allows for logic;Available in an 8-pin SOIC (150 mil), 8-pin USOP, and flip chip package;PIN ASSIGNMENTFIGURE 1 PIN ASSIGNMENTPIN DESCRIPTION:SERMODE - Serial Interface Mode.CE - Chip Enable.SCLK - Serial Clock.GND – Ground.VDDA - Analog Supply Voltage.SDO - Serial Data Out.SDI - Serial Data In.VDDD - Digital Supply Voltage.DESCRIPTION:The DS1722 Digital Thermometer and Thermostat with SPI/3-Wire Interface provides temperature readings which indicate the temperature of the device. No additional components are required; the device is truly a temperature-to-digital converter. Temperature readings are communicated from the DS1722 over a Motorola SPI interface or a standard 3-wire serial interface. The choice of interface standard is selectable by the user. For applications that require greater temperature resolution, the user can adjust the readout resolution from 8 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be detected quickly.For application flexibility, the DS1722 features a wide analog supply rail of - . A separate digital supply allows a range of to . The DS1722 is available in an 8-pin SOIC (150-mil), 8-pin USOP, and flip chip package.Applications for the DS1722 include personal computers/servers/workstations, cellular telephones, office equipment, or any thermally-sensitive system.OVERVIEW:A block diagram of the DS1722 is shown in Figure 2. The DS1722 consists offour major components:1. Precision temperature sensor.2. Analog-to-digital converter.3. SPI/3-wire interface electronics.4. Data registers.The factory-calibrated temperature sensor requires no external components. The DS1722 is in a power conserving shutdown state upon power-up. After power-up, the user may alter the configuration register to place the device in a continuous temperature conversion mode or in a one-shot conversion mode. In the continuous conversion mode, the DS1722 continuously converts the temperature and stores the result in the temperature register. As conversions are performed in the background, reading the temperature register does not affect the conversion in progress. In the one-shot temperature conversion mode, the DS1722 will perform one temperature conversion, store the result in the temperature register, and then eturn to the shutdown state. This conversion mode is ideal for power sensitive applications. More information on the configuration register is contained in the “OPERATION-Programming”section. The temperature conversion results will have a default resolution of 9 bits. In applications where small incremental temperature changes are critical, the user can change the conversion resolution from 9 bits to 8, 10, 11, or 12. This is accomplished by programming the configuration register. Each additional bit of resolution approximately doubles the conversion time. The DS1722 can communicate using either a Motorola Serial Peripheral Interface (SPI) or standard 3-wire interface. The user can select either communication standard through the SERMODE pin, tying it to VDDD for SPI and to ground for 3-wire. The device contains both an analog supply voltage and a digital supply voltage (VDDA and VDDD, respectively). The analog supply powers the device for operation while the digital supply provides the top rails for the digital inputs and outputs. The DS1722 was designed to be Logic-Ready.DS1722 FUNCTIONAL BLOCK DIAGRAM Figure 2OPERATION-Measuring Temperature:The core of DS1722 functionality is its direct-to-digital temperature sensor. The DS1722 measures temperature through the use of an on-chip temperature measurement technique with an operating range from -55°to +120°C. The device powers up in a power-conserving shutdown mode. After power-up, the DS1722 may be placed in a continuous conversion mode or in a one-shot conversion mode. In the continuous conversion mode, the device continuously computes the temperature and stores the most recent result in the temperature register at addresses 01h (LSB) and 02h (MSB). In the one-shot conversion mode, the DS1722 performs one temperature conversion and then returns to the shutdown mode, storing temperature in the temperature register. Details on how to change the setting after power up are contained in the “OPERATION-Programming”section. The resolution of the temperature conversion is configurable (8, 9, 10, 11, or 12 bits), with 9-bit readings the default state. This equates to a temperature resolution of °C, °C, °C, °C, or °C. Following each conversion, thermal data is stored in the thermometer register in two’s complement format; the information can be retrieved over the SPI or 3-wire interface with the address set to the temperature register, 01h (LSB) and then 02h (MSB). Table 2 describesthe exact relationship of output data to measured temperature. The table assumes the DS1722 is configured for 12-bit resolution; if the evince is configured in a lower resolution mode, those bits will contain 0s. The data is transmitted serially over the digital interface, MSB first for SPI communication and LSB first for 3-wire communication. The MSB of the temperature register contains the “sign” (S) bit, denoting whether the temperature is positive or negative. For Fahrenheit usage, a lookup table or conversion routine must be used.AddressLocation S 2625242322212002h MSB (unit = ℃) LSB2-12-22-32-40 0 0 0 01hTEMPERATURE DIGITAL OUTPUT(BINARY) DIGITAL OUTPUT(HEX)+120℃0111 1000 0000 0000 7800h+ 0001 1001 0001 0000 1910h+ 0000 1010 0010 0000 0a20h+ 0000 0000 1000 0000 0080h0 0000 0000 0000 0000 0000h1111 1111 1000 0000 Ff80h1111 0101 1110 0000 F5e0h1110 0110 1111 0000 E6f0h-55 1100 1001 0000 0000 C900h OPERATION-Programming:The area of interest in programming the DS1722 is the Configuration register. All programming is done via the SPI or 3-wire communication interface by selecting the appropriate address of the desired register location. Table 3 illustrates the addresses for the two registers (configuration and temperature) of the DS1722.Register Address Structure Table 3CONFIGURATION REGISTER PROGRAMMING:The configuration register is accessed in the DS1722 with the 00h address for reads and the 80h address for writes. Data is read from or written to the configuration register MSB first for SPI communication and LSB first for 3-wire communication. The format of the register is illustrated in Figure 2. The effect each bit has on DS1722 functionality is described below along with the power-up state of the bit. The entire register is volatile, and thus it will power-up in the default state.CONFIGURATION/STATUS REGISTER Figure 21SHOT = One-shot temperature conversion bit. If the SD bit is "1", (continuous temperature conversions are not taking place), a "1" written to the 1SHOT bit will cause the DS1722 to perform one temperature conversion and store the results in the temperature register at addresses 01h (LSB) and 02h (MSB). The bit will clear itself to "0" upon completion of the temperature conversion. The user has read/write access to the 1SHOT bit, although writes to this bit will be ignored if the SD bit is a "0", (continuous conversion mode). The power-up default of the one-shot bit is "0".R0, R1, R2 = Thermometer resolution bits. Table 4 below defines the resolution of the digital thermometer, based on the settings of these 3 bits. There is a direct tradeoff between resolution and conversion time, as depicted in the AC Electrical Characteristics. The user has read/write access to the R2, R1 and R0 bits and the power-up default state is R2="0", R1="0", and R0="1" (9-bit conversions).THERMOMETER RESOLUTION CONFIGURATION Table 4SD = Shutdown bit. If SD is "0", the DS1722 will continuously perform temperature conversions and store the last completed result in the temperature register. If SD is changed to a "1", the conversion in progress will be completed and stored and then the device will revert to a low-power shutdown mode. The communication port remains active. The user has read/write access to the SD bit and the power-up default is "1" (shutdown mode).SERIAL INTERFACE:The DS1722 offers the flexibility to choose between two serial interface modes. The DS1722 can communicate with the SPI interface or with a standard 3-wire interface. The interface method used is determined by the SERMODE pin. When this pin is connected to VDDD SPI communication is selected. When this pin is connected to ground, standard 3-wire communication is selected.SERIAL PERIPHERAL INTERFACE (SPI):The serial peripheral interface (SPI) is a synchronous bus for address and data transfer. The SPI mode of serial communication is selected by tying the SERMODE pin to VDDD. Four pins are used for the SPI. The four pins are the SDO (Serial Data Out), SDI (Serial Data In), CE (Chip Enable), and SCLK (Serial Clock). The DS1722 is the slave device in an SPI application, with the microcontroller being the master. The SDI and SDO pins are the serial data input and output pins for the DS1722, respectively. The CE input is used to initiate and terminate a data transfer. The SCLK pin is used to synchronize data movement between the master (microcontroller) and the slave (DS1722) devices. The shift clock (SCLK), which is generated by the microcontroller, is active only when CE is high and during address and data transfer to any device on the SPI bus. The inactive clock polarity is programmable in somemicrocontrollers. The DS1722 offers an important feature in that the level of the inactive clock is determined by sampling SCLK when CE becomes active. Therefore, either SCLK polarity can be accommodated. There is one clock for each bit transferred. Address and data bits are transferred in groups of eight, MSB first.3-WIRE SERIAL DATA BUS:The 3-wire communication mode operates similar to the SPI mode. However, in 3-wire mode, there is one bi-directional I/O instead of separate data in and data out signals. The 3-wire consists of the I/O (SDI and SDO pins tied together), CE, and SCLK pins. In 3-wire mode, each byte is shifted in LSB first unlike SPI mode where each byte is shifted in MSB first. As is the case with the SPI mode, an address byte is written to the device followed by a single data byte or multiple data bytes.外文资料译文DS1722数字温度传感器随着科学技术的不断进步和发展，温度传感器的种类日益繁多，应用逐渐广泛，并且开始由模拟式向着数字式、单总线式、双总线式和三总线式发展。

《传感器英文论文》

《电气工程及其自动化专业英语》课程论文年级专业姓名学号TransformerThe basic concept of transformerPower transformer is a kind of static electrical equipment, is used for AC voltage is a numerical (current) into a voltage value of the same frequency one or several different (current) equipment. When a winding with alternating current, is generated by the alternating magnetic flux, the alternating magnetic flux through the iron core of the magnetic effect, the AC induction electromotive force in the two secondary winding. The two induction electromotive force level and one or two times the number of winding turns the number of voltage size and number of turns is proportional to. The main function is to transmit electricity, therefore, the rated capacity is its main parameters. Rated capacity is used in a performance of power value, it is the characterization of electrical energy transmission size, with kVA or MVA said that when the rated voltage is applied to the transformer, according to it to determine under specified conditions does not exceed the rated current value of temperature riseThe development trend of transformerDistribution transformer in China usually refers to the voltage of 35kV and 10kV and below, capacity below 6300kVA power transformer terminal user directly to the power supply. At present, the national online operation of distribution transformer total power loss is about 41100000000kWh, accounting for about 3.16% of total generating capacity in 2000. Although the distribution transformer is high-efficiency equipment (95-99%), but because of the large quantity and fixed the no-load power consumption, transformer efficiency even small improvements can also considerable energy saving and reduction of greenhouse gas emissions, so its itself there is a huge energy saving potentialIn the late 90, the speed of the development of industry of our country distribution transformer faster. Since 1997, due to urban and rural power grid renovation project of the pull, the power transformer industry has maintained a good momentum of development. Power transformer output growth of 24.81% in 1999. In 2000 the power transformer production increased by 15.88%, the proportion of the number of distribution transformer increase: in 1999 the number of distribution transformer proportion rose from 34.72% in 1998 to 39.51%, an increase of 5 percentage points; in 2000 the proportion of the number of distribution transformer 36.89%. (10kV and below 6300KVA transformer output was 304099 units, 41778KVA, 35kV, 6300KVA and below transformers production was 7821 units, 9316.4KVA). Oil immersed distribution transformer equipment of urban and rural power grid renovation project selected have all realized the transition from type S7 to type S9.With the continuous progress of the development of market economy and science and technology, the continuous application of new material and new technology, the low loss, the new distribution transformer have been successfully developed. Many domestic transformer manufacturers have invested a lot of money to introduce advanced foreign technology and equipment manufacturing, continuous research and development of low loss transformer and various structure forms such as transformer, oil immersed transformer has appeared more energy-saving than the new S9 series S10, S11 series, new SC9 series dry type transformer, amorphous alloy core and other low loss etc. products have shown the potential of energy saving distribution transformer in china. In addition, in the distribution transformer online operation of age over 20 years old in the transformer low efficiency to about 10% above, to estimate the capacity of about 240000000 kVA, the transformer is in accordance with the six, seventy's standard design products, the loss is very high, if you take a certain investment by S9 to replace the old transformer will be great economic benefit. According to the calculation of different capacity, the purchase of S9 transformer to replace the old transformer investment returns years generally only 2~3 years (not counting the old transformer recycling fee and dismounting fee condition), the enormous energy saving potentialThe structure of transformerTransformer (of a large capacity transformer speaking) generally is composed of iron core, winding, oil tank, insulation casing and cooling system five major part. The following diagramThe core is the main part of the transformer magnetic circuit. Usually made of silicon content is higher, the thickness of 0.35 or 0.5 mm, the surface is coated with insulating paint rolled or cold-rolled silicon steel sheet piled up. The basic form of iron core structure of transformer has two kinds, one kind is called the core type iron core, also called the inner iron core. The other is called a shell type iron core, also called the outer iron coreThe winding is part of the circuit of transformer, it is insulated flat line or circle line wrapped around a. Power transformer of domestic generally adopts a concentric winding, the so-called concentric winding is in each cross section of iron core column, winding are based on the same center of a circle cylindrical coil is sheathed on the outside of the iron core column. Concentric winding according to its structure can be divided into cylindrical, segmented, continuous, double pancake, kink type, spiral type etc.. The tank is the oil immersed transformer shell, a transformer body is placed in the tank, tank filled with transformer oil, transformer oil has two functions, one hand as an insulating medium, on the other hand, as a cooling medium, namely through thetransformer oil circulation, will send out winding and iron core in the heat, bring the box wall and the radiator, oil cooler for cooling. The insulation of transformer bushing is high and low pressure wire inside the transformer tank is introduced to the outside, not only as a lead insulation to ground, and bear a fixed lead role. Therefore, must have provisions in manufacturing standard electrical strength and mechanical strength. Cooling method of cooling system of transformer according to its size can be divided into: oil immersed self cooling type, oil immersed forced air cooled, forced oil circulation cooling.The working principle of transformerThe transformer is based on electromagnetic induction principle. Because of its working principle and working process and internal electromagnetic motor (generators and motors) are exactly the same, so it will be designated as a class is only a motor, rotating speed is zero (i.e. stationary). The transformer body is mainly composed of winding and iron core. When working, the winding is the "power" of the path, and the iron core is the "magnetic" pathway, which plays the role of winding frame. A measuring input power, because its change creates an alternating magnetic field in the core (from the electric energy into magnetic energy); because of turns (penetration), two winding magnetic field lines in the constantly changing alternately, so induces two electric potential, when the external circuit communication, it created a sense of current, output power (from the magnetic field can be changed into electrical energy). This "electric magnetic electric" transformation process is based on the principle of electromagnetic induction to on the energy conversion process, this is also the work process of transformer. Here again by theory analysis and formula calculation to further illustrate: in the schematic diagram of single phase transformer in (below)The closure of the iron core is wound with two mutually insulated winding. One side access power called a winding, one side of the output power is called the two secondary windings when the ACpower supply voltage U1 to the primary winding, there are alternating current through the winding and I1 in the core generates an alternating magnetic flux phi. Not only the alternating magnetic flux through a winding, but also through the two secondary windings, the two windings are respectively E1 and E2 induced electromotive force. Then if the two secondary windings and the outer circuit load is connected, will have a current I2 flowing into the load of Z, namely two windings have the power output.。

传感器英文文献翻译-光电传感器

传感器英文文献翻译
———光电传感器报告人: 学号：专业：老师：
Photoelectric sensor
Key word: photoelectric effect photoelectric element photoelectric sensor classification sensor application characteristics . Abstract: in the rapid development of science and technology in the modern society, mankind has into the rapidly changing information era, people in daily life, the production process, rely mainly on the detection of information technology by acquiring, screening and transmission, to achieve the brake control, automatic adjustment, at present our country has put detection techniques listed in one of the priority to the development of science and technology. Because of microelectronics technology, photoelectric semiconductor technology, optical fiber technology and grating technical development makes the application of the photoelectric sensor is growing. The sensor has simple structure, non-contact, high reliability, high precision, measurable parameters and quick response and more simple structure, form etc, and flexible in automatic detection technology, it has been widely applied in photoelectric effect as the theoretical basis, the device by photoelectric material composition.

传感器技术外文文献及中文翻译

传感器技术外文文献及中文翻译Sensor technologyA sensor is a device which produces a signal in response to its detecting or measuring a property ,such as position , force , torque , pressure , temperature , humidity , speed , acceleration , or vibration .Traditionally ,sensors (such as actuators and switches )have been used to set limits on the performance of machines .Common examples are (a) stops on machine tools to restrict work table movements ,(b) pressure and temperature gages with automatics shut-off features , and (c) governors on engines to prevent excessive speed of operation . Sensor technology has become an important aspect of manufacturing processes and systems .It is essential for proper data acquisition and for the monitoring , communication , and computer control of machines and systems .Because they convert one quantity to another , sensors often are referred to as transducers .Analog sensors produce a signal , such as voltage ,which is proportional to the measured quantity .Digital sensors have numeric or digital outputs that can be transferred to computers directly .Analog-to-coverter(ADC) is available for interfacing analog sensors with computers .Classifications of SensorsSensors that are of interest in manufacturing may be classified generally as follows:Machanical sensors measure such as quantities aspositions ,shape ,velocity ,force ,torque , pressure , vibration , strain , andmass .Electrical sensors measure voltage , current , charge , and conductivity .Magnetic sensors measure magnetic field ,flux , and permeablity .Thermal sensors measure temperature , flux ,conductivity , and special heat .Other types are acoustic , ultrasonic , chemical , optical , radiation ,laser ,and fiber-optic .Depending on its application , a sensor may consist of metallic , nonmetallic , organic , or inorganic materials , as well as fluids ,gases ,plasmas , or semiconductors .Using the special characteristics of these materials , sensors covert the quantity or property measured to analog or digital output. The operation of an ordinary mercury thermometer , for example , is based on the difference between the thermal expansion of mercury and that of glass.Similarly , a machine part , a physical obstruction , or barrier in a space can be detected by breaking the beam of light when sensed by a photoelectric cell . A proximity sensor ( which senses and measures the distance between it and an object or a moving member of a machine ) can be based on acoustics , magnetism , capacitance , or optics . Other actuators contact the object and take appropriate action ( usually by electromechanical means ) . Sensors are essential to the conduct of intelligent robots , and are being developed with capabilities that resemble those of humans ( smart sensors , see the following ).This is America, the development of such a surgery Lin Bai an example,through the screen, through a remote control operator to control another manipulator, through the realization of the right abdominal surgery A few years ago our country the exhibition, the United States has been successful in achieving the right to the heart valve surgery and bypass surgery. This robot has in the area, caused a great sensation, but also, AESOP's surgical robot, In fact, it through some equipment to some of the lesions inspections, through a manipulator can be achieved on some parts of the operation Also including remotely operated manipulator, and many doctors are able to participate in the robot under surgery Robot doctor to include doctors with pliers, tweezers or a knife to replace the nurses, while lighting automatically to the doctor's movements linked, the doctor hands off, lighting went off, This is very good, a doctor's assistant.Tactile sensing is the continuous of variable contact forces , commonly by an array of sensors . Such a system is capable of performing within an arbitrary three-dimensional space .has gradually shifted from manufacturing tonon-manufacturing and service industries, we are talking about the car manufacturer belonging to the manufacturing industry, However, the services sector including cleaning, refueling, rescue, rescue, relief, etc. These belong to the non-manufacturing industries and service industries, so here is compared with the industrial robot, it is a very important difference. It is primarily a mobile platform, it can move to sports, there are some arms operate, also installed some as a force sensor and visual sensors, ultrasonic ranging sensors, etc. It’s surrounding environment for the conduct of identification, to determine its campaign to complete some work, this is service robot’s one of the basic characteristicsIn visual sensing (machine vision , computer vision ) , cameral optically sense the presence and shape of the object . A microprocessor then processes the image ( usually in less than one second ) , the image is measured , and the measurements are digitized ( image recognition ) .Machine vision is suitable particularly for inaccessible parts , in hostile manufacturing environments , for measuring a large number of small features , and in situations where physics contact with the part may cause damage .Small sensors have the capability to perform a logic function , to conduct two-way communication , and to make a decisions and take appropriate actions . The necessary input and the knowledge required to make a decision can be built into a smart sensor . For example , a computer chip with sensors can be programmed to turn a machine tool off when a cutting tool fails . Likewise , a smart sensor can stop a mobile robot or a robot arm from accidentally coming in contact with an object or people by using quantities such as distance , heat , and noise .Sensor fusion . Sensor fusion basically involves the integration of multiple sensors in such a manner where the individual data from each of the sensors ( such as force , vibration , temperature , and dimensions ) are combined to provide a higher level of information and reliability . A common application ofsensor fusion occurs when someone drinks a cup of hot coffee . Although we take such a quotidian event for granted ,it readily can be seen that this process involves data input from the person's eyes , lips , tongue , and hands .Through our basic senses of sight , hearing , smell , taste , and touch , there is real-time monitoring of relative movements , positions , and temperatures . Thus if the coffee is too hot , the hand movement of the cup toward the lip is controlled and adjusted accordingly .The earliest applications of sensor fusion were in robot movement control , missile flight tracking , and similar military applications . Primarily because these activities involve movements that mimic human behavior . Another example of sensor fusion is a machine operation in which a set of different but integrated sensors monitors (a) the dimensions and surface finish of workpiece , (b) tool forces , vibrations ,and wear ,(c) the temperature in various regions of the tool-workpiece system , and (d) the spindle power .An important aspect in sensor fusion is sensor validation : the failure of one particular sensor is detected so that the control system maintains high reliability . For this application ,the receiving of redundant data from different sensors is essential . It can be seen that the receiving , integrating of all data from various sensors can be a complex problem .With advances in sensor size , quality , and technology and continued developments in computer-control systems , artificial neural networks , sensor fusion has become practical and available at low cost .Movement is relatively independent of the number of components, the equivalent of our body, waist is a rotary degree of freedom We have to be able to hold his arm, Arm can be bent, then this three degrees of freedom, Meanwhile there is a wrist posture adjustment to the use of the three autonomy, the general robot has six degrees of freedom. We will be able to space the three locations, three postures, the robot fully achieved, and of course we have less than six degrees of freedom Fiber-optic sensors are being developed for gas-turbine engines . These sensors will be installed in critical locations and will monitor the conditions inside the engine , such as temperature , pressure , and flow of gas . Continuous monitoring of the signals from thes sensors will help detect possible engine problems and also provide the necessary data for improving the efficiency of the engines .传感器技术传感器一种通过检测某一参数而产生信号的装置。

传感器外文翻译外文文献英文文献分布是温度传感器

Distributed Temperature SensorIn the human living environment, temperature playing an extremely important role。

No matter where you live, engaged in any work, ever-present dealt with temperature under. Since the 18th century, industry since the industrial revolution to whether can master send exhibition has the absolute temperature touch. In metallurgy, steel, petrochemical, cement, glass, medicine industry and so on, can say almost eighty percent of industrial departments have to consider the factors with temperature. Temperature for industrial so important, thus promoting the development of the temperature sensor.Major general through three sensor development phase: analog integrated temperature sensor. The sensor is taken with silicon semiconductor integrated workmanship, therefore also called silicon sensor or monolithic integrated temperature sensor. Such sensing instruments have single function (only measuring temperature), temperature measurement error is smaller, price low, fast response, the transmission distance, small volume, micro-consumption electronic etc, suitable for long distance measurement temperature, temperature control, do not need to undertake nonlinear calibration, peripheral circuit is simple. It is currently the most common application at home and abroad, an integrated sensor。

传感器相关英语文献

DiMo:Distributed Node Monitoring in WirelessSensor NetworksAndreas Meier†,Mehul Motani∗,Hu Siquan∗,and Simon Künzli‡†Computer Engineering and Networks Lab,ETH Zurich,Switzerland∗Electrical&Computer Engineering,National University of Singapore,Singapore‡Siemens Building T echnologies,Zug,SwitzerlandABSTRACTSafety-critical wireless sensor networks,such as a distributed ﬁre-or burglar-alarm system,require that all sensor nodes are up and functional.If an event is triggered on a node, this information must be forwarded immediately to the sink, without setting up a route on demand or having toﬁnd an alternate route in case of a node or link failure.Therefore, failures of nodes must be known at all times and in case of a detected failure,an immediate notiﬁcation must be sent to the network operator.There is usually a bounded time limit,e.g.,ﬁve minutes,for the system to report network or node failure.This paper presents DiMo,a distributed and scalable solution for monitoring the nodes and the topology, along with a redundant topology for increased robustness. Compared to existing solutions,which traditionally assume a continuous data-ﬂow from all nodes in the network,DiMo observes the nodes and the topology locally.DiMo only reports to the sink if a node is potentially failed,which greatly reduces the message overhead and energy consump-tion.DiMo timely reports failed nodes and minimizes the false-positive rate and energy consumption compared with other prominent solutions for node monitoring.Categories and Subject DescriptorsC.2.2[Network Protocols]:Wireless Sensor NetworkGeneral TermsAlgorithms,Design,Reliability,PerformanceKeywordsLow power,Node monitoring,Topology monitoring,WSN 1.INTRODUCTIONDriven by recent advances in low power platforms and protocols,wireless sensor networks are being deployed to-day to monitor the environment from wildlife habitats[1] Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for proﬁt or commercial advantage and that copies bear this notice and the full citation on theﬁrst page.To copy otherwise,to republish,to post on servers or to redistribute to lists,requires prior speciﬁc permission and/or a fee.MSWiM’08,October27–31,2008,Vancouver,BC,Canada.Copyright2008ACM978-1-60558-235-1/08/10...$5.00.to mission-criticalﬁre-alarm systems[5].There are,how-ever,still some obstacles in the way for mass application of wireless sensor networks.One of the key challenges is the management of the wireless sensor network itself.With-out a practical management system,WSN maintenance will be very diﬃcult for network administrators.Furthermore, without a solid management plan,WSNs are not likely to be accepted by industrial users.One of the key points in the management of a WSN is the health status monitoring of the network itself.Node failures should be captured by the system and reported to adminis-trators within a given delay constraint.Due to the resource constraints of WSN nodes,traditional network management protocols such as SNMP adopted by TCP/IP networks are not suitable for sensor networks.In this paper,we con-sider a light-weight network management approach tailored speciﬁcally for WSNs and their unique constraints. Currently,WSN deployments can be categorized by their application scenario:data-gathering applications and event-detection applications.For data-gathering systems,health status monitoring is quite straight forward.Monitoring in-formation can be forwarded to the sink by speciﬁc health status packets or embedded in the regular data packets.Ad-ministrators can usually diagnose the network with a helper program.NUCLEUS[6]is one of the network management systems for data-gathering application of WSN.Since event-detection deployments do not have regular traﬃc to send to the sink,the solutions for data-gathering deployments are not suitable.In this case,health status monitoring can be quite challenging and has not been discussed explicitly in the literature.In an event-detection WSN,there is no periodic data trans-fer,i.e.,nodes maintain radio silence until there is an event to report.While this is energy eﬃcient,it does mean that there is no possibility for the sink to decide whether the net-work is still up and running(and waiting for an event to be detected)or if some nodes in the network have failed and are therefore silent.Furthermore,for certain military ap-plications or safety-critical systems,the speciﬁcations may include a hard time constraint for accomplishing the node health status monitoring task.In an event-detection WSN,the system maintains a net-work topology that allows for forwarding of data to a sink in the case of an event.Even though there is no regular data transfer in the network,the network should always be ready to forward a message to the sink immediately when-ever necessary.It is this urgency of data forwarding that makes it undesirable to set up a routing table and neighborlist after the event has been detected.The lack of regular data transfer in the network also leads to diﬃculty in de-tecting bad quality links,making it challenging to establish and maintain a stable robust network topology.While we have mentioned event-detection WSNs in gen-eral,we accentuate that the distributed node monitoring problem we are considering is inspired by a real-world ap-plication:a distributed indoor wireless alarm system which includes a sensor for detection of a speciﬁc alarm such as ﬁre(as studied in[5]).To illustrate the reporting require-ments of such a system,we point out that regulatory speci-ﬁcations require aﬁre to be reported to the control station within10seconds and a node failure to be reported within 5minutes[9].This highlights the importance of the node-monitoring problem.In this paper,we present a solution for distributed node monitoring called DiMo,which consists of two functions: (i)Network topology maintenance,introduced in Section2, and(ii)Node health status monitoring,introduced in Sec-tion3.We compare DiMo to existing state-of-the-art node monitoring solutions and evaluate DiMo via simulations in Section4.1.1Design GoalsDiMo is developed based on the following design goals:•In safety critical event monitoring systems,the statusof the nodes needs to be monitored continuously,allow-ing the detection and reporting of a failed node withina certain failure detection time T D,e.g.,T D=5min.•If a node is reported failed,a costly on-site inspectionis required.This makes it of paramount interest todecrease the false-positive rate,i.e.,wrongly assuminga node to have failed.•In the case of an event,the latency in forwarding theinformation to the sink is crucial,leaving no time toset up a route on demand.We require the system tomaintain a topology at all times.In order to be robustagainst possible link failures,the topology needs toprovide redundancy.•To increase eﬃciency and minimize energy consump-tion,the two tasks of topology maintenance(in par-ticular monitoring of the links)and node monitoringshould be combined.•Maximizing lifetime of the network does not necessar-ily translate to minimizing the average energy con-sumption in the network,but rather minimizing theenergy consumption of the node with the maximal loadin the network.In particular,the monitoring shouldnot signiﬁcantly increase the load towards the sink.•We assume that the event detection WSN has no reg-ular data traﬃc,with possibly no messages for days,weeks or even months.Hence we do not attempt to op-timize routing or load balancing for regular data.Wealso note that approaches like estimating links’perfor-mance based on the ongoing dataﬂow are not possibleand do not take them into account.•Wireless communications in sensor networks(especially indoor deployments)is known for its erratic behav-ior[2,8],likely due to multi-path fading.We assumesuch an environment with unreliable and unpredictablecommunication links,and argue that message lossesmust be taken into account.1.2Related WorkNithya et al.discuss Sympathy in[3],a tool for detect-ing and debugging failures in pre-and post-deployment sen-sor networks,especially designed for data gathering appli-cations.The nodes send periodic heartbeats to the sink that combines this information with passively gathered data to detect failures.For the failure detection,the sink re-quires receiving at least one heartbeat from the node every so called sweep interval,i.e.,its lacking indicates a node fail-ure.Direct-Heartbeat performs poorly in practice without adaptation to wireless packet losses.To meet a desired false positive rate,the rate of heartbeats has to be increased also increasing the communication cost.NUCLEUS[6]follows a very similar approach to Sympathy,providing a manage-ment system to monitor the heath status of data-gathering applications.Rost et al.propose with Memento a failure detection sys-tem that also requires nodes to periodically send heartbeats to the so called observer node.Those heartbeats are not directly forwarded to the sink node,but are aggregated in form of a bitmask(i.e.,bitwise OR operation).The ob-server node is sweeping its bitmask every sweep interval and will forward the bitmask with the node missing during the next sweep interval if the node fails sending a heartbeat in between.Hence the information of the missing node is disseminated every sweep interval by one hop,eventually arriving at the sink.Memento is not making use of ac-knowledgements and proactively sends multiple heartbeats every sweep interval,whereas this number is estimated based on the link’s estimated worst-case performance and the tar-geted false positive rate.Hence Memento and Sympathy do both send several messages every sweep interval,most of them being redundant.In[5],Strasser et al.propose a ring based(hop count)gos-siping scheme that provides a latency bound for detecting failed nodes.The approach is based on a bitmask aggre-gation,beingﬁlled ring by ring based on a tight schedule requiring a global clock.Due to the tight schedule,retrans-missions are limited and contention/collisions likely,increas-ing the number of false positives.The approach is similar to Memento[4],i.e.,it does not scale,but provides latency bounds and uses the beneﬁts of acknowledgements on the link layer.2.TOPOLOGY MAINTENANCEForwarding a detected event without any delay requires maintaining a redundant topology that is robust against link failures.The characteristics of such a redundant topology are discussed subsequently.The topology is based on so called relay nodes,a neighbor that can provide one or more routes towards the sink with a smaller cost metric than the node itself has.Loops are inherently ruled out if packets are always forwarded to relay nodes.For instance,in a simple tree topology,the parent is the relay node and the cost metric is the hop count.In order to provide redundancy,every node is connected with at least two relay nodes,and is called redundantly con-nected.Two neighboring nodes can be redundantly con-nected by being each others relay,although having the same cost metric,only if they are both connected to the sink. This exception allows the nodes neighboring the sink to be redundantly connected and avoids having a link to the sinkas a single point of failure.In a(redundantly)connected network,all deployed nodes are(redundantly)connected.A node’s level L represents the minimal hop count to the sink according to the level of its relay nodes;i.e.,the relay with the least hop count plus one.The level is inﬁnity if the node is not connected.The maximal hop count H to the sink represents the longest path to the sink,i.e.,if at every hop the relay node with the highest maximal hop count is chosen.If the node is redundantly connected,the node’s H is the maximum hop count in the set of its relays plus one, if not,the maximal hop count is inﬁnity.If and only if all nodes in the network have aﬁnite maximal hop count,the network is redundantly connected.The topology management function aims to maintain a redundantly connected network whenever possible.This might not be possible for sparsely connected networks,where some nodes might only have one neighbor and therefore can-not be redundantly connected by deﬁnition.Sometimes it would be possible toﬁnd alternative paths with a higher cost metric,which in turn would largely increase the overhead for topology maintenance(e.g.,for avoiding loops).For the cost metric,the tuple(L,H)is used.A node A has the smaller cost metric than node B ifL A<L B∨(L A=L B∧H A<H B).(1) During the operation of the network,DiMo continuously monitors the links(as described in Section3),which allows the detection of degrading links and allows triggering topol-ogy adaptation.Due to DiMo’s redundant structure,the node is still connected to the network,during this neighbor search,and hence in the case of an event,can forward the message without delay.3.MONITORING ALGORITHMThis section describes the main contribution of this paper, a distributed algorithm for topology,link and node monitor-ing.From the underlying MAC protocol,it is required that an acknowledged message transfer is supported.3.1AlgorithmA monitoring algorithm is required to detect failed nodes within a given failure detection time T D(e.g.,T D=5min).A node failure can occur for example due to hardware fail-ures,software errors or because a node runs out of energy. Furthermore,an operational node that gets disconnected from the network is also considered as failed.The monitoring is done by so called observer nodes that monitor whether the target node has checked in by sending a heartbeat within a certain monitoring time.If not,the ob-server sends a node missing message to the sink.The target node is monitored by one observer at any time.If there are multiple observer nodes available,they alternate amongst themselves.For instance,if there are three observers,each one observes the target node every third monitoring time. The observer node should not only check for the liveliness of the nodes,but also for the links that are being used for sending data packets to the sink in case of a detected event. These two tasks are combined by selecting the relay nodes as observers,greatly reducing the network load and maximiz-ing the network lifetime.In order to ensure that all nodes are up and running,every node is observed at all times. The speciﬁed failure detection time T D is an upper bound for the monitoring interval T M,i.e.,the interval within which the node has to send a heartbeat.Since failure detec-tion time is measured at the sink,the detection of a missing node at the relay needs to be forwarded,resulting in an ad-ditional maximal delay T L.Furthermore,the heartbeat can be delayed as well,either by message collisions or link fail-ures.Hence the node should send the heartbeat before the relay’s monitoring timer expires and leave room for retries and clock drift within the time window T R.So the monitor-ing interval has to be set toT M≤T D−T L−T R(2) and the node has to ensure that it is being monitored every T M by one of its observers.The schedule of reporting to an observer is only deﬁned for the next monitoring time for each observer.Whenever the node checks in,the next monitoring time is announced with the same message.So for every heartbeat sent,the old monitoring timer at the observer can be cancelled and a new timer can be set according the new time.Whenever,a node is newly observed or not being observed by a particular observer,this is indicated to the sink.Hence the sink is always aware of which nodes are being observed in the network,and therefore always knows which nodes are up and running.This registration scheme at the sink is an optional feature of DiMo and depends on the user’s requirements.3.2Packet LossWireless communication always has to account for possi-ble message losses.Sudden changes in the link quality are always possible and even total link failures in the order of a few seconds are not uncommon[2].So the time T R for send-ing retries should be suﬃciently long to cover such blanks. Though unlikely,it is possible that even after a duration of T R,the heartbeat could not have been successfully for-warded to the observer and thus was not acknowledged,in spite of multiple retries.The node has to assume that it will be reported miss-ing at the sink,despite the fact it is still up and running. Should the node be redundantly connected,a recovery mes-sage is sent to the sink via another relay announcing be-ing still alive.The sink receiving a recovery message and a node-missing message concerning the same node can neglect these messages as they cancel each other out.This recov-ery scheme is optional,but minimizes the false positives by orders of magnitudes as shown in Section4.3.3Topology ChangesIn the case of a new relay being announced from the topol-ogy management,a heartbeat is sent to the new relay,mark-ing it as an observer node.On the other hand,if a depre-cated relay is announced,this relay might still be acting as an observer,and the node has to check in as scheduled.How-ever,no new monitor time is announced with the heartbeat, which will release the deprecated relay of being an observer.3.4Queuing PolicyA monitoring buﬀer exclusively used for monitoring mes-sages is introduced,having the messages queued according to a priority level,in particular node-missing messagesﬁrst. Since the MAC protocol and routing engine usually have a queuing buﬀer also,it must be ensured that only one single monitoring message is being handled by the lower layers atthe time.Only if an ACK is received,the monitoring mes-sage can be removed from the queue(if a NACK is received, the message remains).DiMo only prioritizes between the diﬀerent types of monitoring messages and does not require prioritized access to data traﬃc.4.EV ALUATIONIn literature,there are very few existing solutions for mon-itoring the health of the wireless sensor network deployment itself.DiMo is theﬁrst sensor network monitoring solution speciﬁcally designed for event detection applications.How-ever,the two prominent solutions of Sympathy[3]and Me-mento[4]for monitoring general WSNs can also be tailored for event gathering applications.We compare the three ap-proaches by looking at the rate at which they generate false positives,i.e.,wrongly inferring that a live node has failed. False positives tell us something about the monitoring pro-tocol since they normally result from packet losses during monitoring.It is crucial to prevent false positives since for every node that is reported missing,a costly on-site inspec-tion is required.DiMo uses the relay nodes for observation.Hence a pos-sible event message and the regular heartbeats both use the same path,except that the latter is a one hop message only. The false positive probability thus determines the reliability of forwarding an event.We point out that there are other performance metrics which might be of interest for evaluation.In addition to false positives,we have looked at latency,message overhead, and energy consumption.We present the evaluation of false positives below.4.1Analysis of False PositivesIn the following analysis,we assume r heartbeats in one sweep for Memento,whereas DiMo and Sympathy allow sending up to r−1retransmissions in the case of unac-knowledged messages.To compare the performance of the false positive rate,we assume the same sweep interval for three protocols which means that Memento’s and Sympa-thy’s sweep interval is equal to DiMo’s monitoring interval. In the analysis we assume all three protocols having the same packet-loss probability p l for each hop.For Sympathy,a false positive for a node occurs when the heartbeat from the node does not arrive at the sink in a sweep interval,assuming r−1retries on every hop.So a node will generate false positive with a possibility(1−(1−p r l)d)n,where d is the hop count to the sink and n the numbers of heartbeats per sweep.In Memento,the bitmask representing all nodes assumes them failed by default after the bitmap is reset at the beginning of each sweep interval. If a node doesn’t report to its parent successfully,i.e.,if all the r heartbeats are lost in a sweep interval,a false positive will occur with a probability of p l r.In DiMo the node is reported missing if it fails to check in at the observer having a probability of p l r.In this case,a recovery message is triggered.Consider the case that the recovery message is not kept in the monitoring queue like the node-missing messages, but dropped after r attempts,the false positive rate results in p l r(1−(1−p l r)d).Table1illustrates the false positive rates for the three protocols ranging the packet reception rate(PRR)between 80%and95%.For this example the observed node is in aﬁve-hop distance(d=5)from the sink and a commonPRR80%85%90%95% Sympathy(n=1) 3.93e-2 1.68e-2 4.99e-3 6.25e-4 Sympathy(n=2) 1.55e-3 2.81e-4 2.50e-5 3.91e-7 Memento8.00e-3 3.38e-3 1.00e-3 1.25e-4 DiMo 3.15e-4 5.66e-5 4.99e-67.81e-8Table1:False positive rates for a node with hop count5and3transmissions under diﬀerent packet success rates.number of r=3attempts for forwarding a message is as-sumed.Sympathy clearly suﬀers from a high packet loss, but its performance can be increased greatly sending two heartbeats every sweep interval(n=2).This however dou-bles the message load in the network,which is especially substantial as the messages are not aggregated,resulting in a largely increased load and energy consumption for nodes next to the paring DiMo with Memento,we ob-serve the paramount impact of the redundant relay on the false positive rate.DiMo oﬀers a mechanism here that is not supported in Sympathy or Memento as it allows sending up to r−1retries for the observer and redundant relay.Due to this redundancy,the message can also be forwarded in the case of a total blackout of one link,a feature both Memento and Sympathy are lacking.4.2SimulationFor evaluation purposes we have implemented DiMo in Castalia1.3,a state of the art WSN simulator based on the OMNet++platform.Castalia allows evaluating DiMo with a realistic wireless channel(based on the empiricalﬁndings of Zuniga et al.[8])and radio model but also captures eﬀects like the nodes’clock drift.Packet collisions are calculated based on the signal to interference ratio(SIR)and the radio model features transition times between the radio’s states (e.g.,sending after a carrier sense will be delayed).Speck-MAC[7],a packet based version of B-MAC,with acknowl-edgements and a low-power listening interval of100ms is used on the link layer.The characteristics of the Chipcon CC2420are used to model the radio.The simulations are performed for a network containing80 nodes,arranged in a grid with a small Gaussian distributed displacement,representing an event detection system where nodes are usually not randomly deployed but rather evenly spread over the observed area.500diﬀerent topologies were analyzed.The topology management results in a redun-dantly connected network with up to5levels L and a max-imum hop count H of6to8.A false positive is triggered if the node fails to check in, which is primarily due to packet errors and losses on the wireless channel.In order to understand false positives,we set the available link’s packet reception rate(PRR)to0.8, allowing us to see the eﬀects of the retransmission scheme. Furthermore,thisﬁxed PRR also allows a comparison with the results of the previous section’s analysis and is shown in Figure1(a).The plot shows on the one hand side the monitoring based on a tree structure that is comparable to the performance of Memento,i.e.,without DiMo’s possibil-ity of sending a recovery message using an alternate relay. On the other hand side,the plot shows the false positive rate of DiMo.The plot clearly shows the advantage of DiMo’s redundancy,yet allowing sending twice as many heartbeats than the tree approach.This might not seem necessarily fair atﬁrst;however,in a real deployment it is always possible(a)Varying number of retries;PRR =0.8.(b)Varying link quality.Figure 1:False positives:DiMo achieves the targeted false positive rate of 1e-7,also representing the reliability for successfully forwarding an event.that a link fails completely,allowing DiMo to still forward the heartbeat.The simulation and the analysis show a slight oﬀset in the performance,which is explained by a simulation artifact of the SpeckMAC implementation that occurs when the receiver’s wake-up time coincides with the start time of a packet.This rare case allows receiving not only one but two packets out of the stream,which artiﬁcially increases the link quality by about three percent.The nodes are observed every T M =4min,resulting in being monitored 1.3e5times a year.A false positive rate of 1e-6would result in having a particular node being wrongly reported failed every 7.7years.Therefore,for a 77-node net-work,a false positive rate of 1e-7would result in one false alarm a year,being the targeted false-positive threshold for the monitoring system.DiMo achieves this rate by setting the numbers of retries for both the heartbeat and the recov-ery message to four.Hence the guard time T R for sending the retries need to be set suﬃciently long to accommodate up to ten messages and back-oﬀtimes.The impact of the link quality on DiMo’s performance is shown in Figure 1(b).The tree topology shows a similar performance than DiMo,if the same number of messages is sent.However,it does not show the beneﬁt in the case of a sudden link failure,allowing DiMo to recover immedi-ately.Additionally,the surprising fact that false positives are not going to zero for perfect link quality is explained by collisions.This is also the reason why DiMo’s curve for two retries ﬂattens for higher link qualities.Hence,leaving room for retries is as important as choosing good quality links.5.CONCLUSIONIn this paper,we presented DiMo,a distributed algorithm for node and topology monitoring,especially designed for use with event-triggered wireless sensor networks.As a de-tailed comparative study with two other well-known moni-toring algorithm shows,DiMo is the only one to reach the design target of having a maximum error reporting delay of 5minutes while keeping the false positive rate and the energy consumption competitive.The proposed algorithm can easily be implemented and also be enhanced with a topology management mechanism to provide a robust mechanism for WSNs.This enables its use in the area of safety-critical wireless sensor networks.AcknowledgmentThe work presented in this paper was supported by CTI grant number 8222.1and the National Competence Center in Research on Mobile Information and Communication Sys-tems (NCCR-MICS),a center supported by the Swiss Na-tional Science Foundation under grant number 5005-67322.This work was also supported in part by phase II of the Embedded and Hybrid System program (EHS-II)funded by the Agency for Science,Technology and Research (A*STAR)under grant 052-118-0054(NUS WBS:R-263-000-376-305).The authors thank Matthias Woehrle for revising a draft version of this paper.6.REFERENCES[1] A.Mainwaring et al.Wireless sensor networks for habitatmonitoring.In 1st ACM Int’l Workshop on Wireless Sensor Networks and Application (WSNA 2002),2002.[2] A.Meier,T.Rein,et al.Coping with unreliable channels:Eﬃcient link estimation for low-power wireless sensor networks.In Proc.5th Int’l worked Sensing Systems (INSS 2008),2008.[3]N.Ramanathan,K.Chang,et al.Sympathy for the sensornetwork debugger.In Proc.3rd ACM Conf.Embedded Networked Sensor Systems (SenSys 2005),2005.[4]S.Rost and H.Balakrishnan.Memento:A health monitoringsystem for wireless sensor networks.In Proc.3rd IEEE Communications Society Conf.Sensor,Mesh and Ad Hoc Communications and Networks (IEEE SECON 2006),2006.[5]M.Strasser,A.Meier,et al.Dwarf:Delay-aware robustforwarding for energy-constrained wireless sensor networks.In Proceedings of the 3rd IEEE Int’l Conference onDistributed Computing in Sensor Systems (DCOSS 2007),2007.[6]G.Tolle and D.Culler.Design of an application-cooperativemanagement system for wireless sensor networks.In Proc.2nd European Workshop on Sensor Networks (EWSN 2005),2005.[7]K.-J.Wong et al.Speckmac:low-power decentralised MACprotocols for low data rate transmissions in specknets.In Proc.2nd Int’l workshop on Multi-hop ad hoc networks:from theory to reality (REALMAN ’06),2006.[8]M.Zuniga and B.Krishnamachari.Analyzing thetransitional region in low power wireless links.In IEEE SECON 2004,2004.[9]Fire detection and ﬁre alarm systems –Part 25:Componentsusing radio links.European Norm (EN)54-25:2008-06,2008.。

传感器技术外文文献及中文翻译讲课讲稿

传感器技术论文中英文对照资料外文翻译文献

传感器技术论文中英文对照资料外文翻译文献中英文对照资料外文翻译文献附件1:外文资料翻译译文传感器新技术的发展传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。

输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。

如果把计算机比作大脑，那么传感器则相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。

自动化程度越高，系统对传感器要求越高。

在今天的信息时代里，信息产业包括信息采集、传输、处理三部分，即传感技术、通信技术、计算机技术。

现代的计算机技术和通信技术由于超大规模集成电路的飞速发展，而已经充分发达后，不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高，还要求其成本低廉且使用方便。

显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。

世界许多发达国家都在加快对传感器新技术的研究与开发，并且都已取得极大的突破。

如今传感器新技术的发展，主要有以下几个方面:利用物理现象、化学反应、生物效应作为传感器原理，所以研究发现新现象与新效应是传感器技术发展的重要工作，是研究开发新型传感器的基础。

日本夏普公司利用超导技术研制成功高温超导磁性传感器，是传感器技术的重大突破，其灵敏度高，仅次于超导量子干涉器件。

它的制造工艺远比超导量子干涉器件简单。

可用于磁成像技术，有广泛推广价值。

利用抗体和抗原在电极表面上相遇复合时，会引起电极电位的变化，利用这一现象可制出免疫传感器。

用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。

如用肝炎病毒抗体可检查某人是否患有肝炎，起到快速、准确作用。

美国加州大学巳研制出这类传感器。

传感器材料是传感器技术的重要基础，由于材料科学进步，人们可制造出各种新型传感器。

例如用高分子聚合物薄膜制成温度传感器;光导纤维能制成压力、流量、温度、位移等多种传感器;用陶瓷制成压力传感器。

传感器英相关英语作文

传感器英相关英语作文Sensors and their Transformative Impact on Modern TechnologySensors have revolutionized the way we interact with and understand the world around us. These remarkable devices have become an integral part of our daily lives, seamlessly integrating into a wide range of technological applications. From the smartphones we rely on to the smart home systems that provide convenience and security, sensors have become the unsung heroes that power the digital age.At the heart of sensor technology lies the ability to detect and measure various physical, chemical, and biological phenomena. These sensors can range from the simple temperature or pressure sensors found in household appliances to the highly sophisticated imaging sensors used in medical diagnostics or autonomous vehicles. Regardless of their complexity, sensors share a common purpose: to gather data and convert it into meaningful information that can be used to make informed decisions.One of the most significant impacts of sensors has been in the field of Internet of Things (IoT). IoT is the interconnected network of devices, appliances, and systems that can communicate with eachother and exchange data. Sensors play a crucial role in this ecosystem, enabling the collection of real-time data from a multitude of sources. This data can then be analyzed and used to optimize processes, improve efficiency, and enhance user experiences.For example, in a smart home setting, sensors can monitor temperature, humidity, and energy consumption, allowing the system to automatically adjust settings to maintain optimal comfort and efficiency. Similarly, in industrial applications, sensors can monitor the performance of machinery, detect potential issues, and trigger maintenance alerts, reducing downtime and improving overall productivity.Beyond the realm of consumer and industrial applications, sensors have also made significant strides in the field of healthcare. Wearable devices, such as fitness trackers and smartwatches, are equipped with sensors that can monitor vital signs, track physical activity, and even detect potential health issues. This data can be used by healthcare professionals to provide personalized care and early intervention, improving patient outcomes and reducing the burden on the healthcare system.The advancements in sensor technology have also paved the way for the development of autonomous systems, such as self-driving carsand drones. These systems rely on a complex network of sensors, including cameras, radar, and lidar, to perceive their surroundings, detect obstacles, and navigate safely. As the technology continues to evolve, the integration of sensors in autonomous systems is expected to become even more sophisticated, leading to enhanced safety and reliability.Another area where sensors have had a significant impact is in the field of environmental monitoring. Sensors can be deployed to measure air quality, water purity, and soil conditions, providing valuable data that can be used to track and address environmental challenges. This data can also be used to inform policy decisions and guide sustainable practices, contributing to the overall well-being of our planet.Despite the numerous benefits and applications of sensors, the technology is not without its challenges. One of the primary concerns is the issue of data privacy and security. As sensors collect and transmit large amounts of data, there is a growing need to ensure that this information is protected from unauthorized access and misuse. Addressing these concerns will be crucial as sensor technology continues to evolve and become more ubiquitous.In conclusion, sensors have become the unsung heroes of the digital age, transforming the way we interact with and understand the worldaround us. From smart homes and autonomous vehicles to healthcare and environmental monitoring, sensors have become the backbone of modern technology. As the technology continues to advance, the potential applications of sensors are limitless, and the impact they will have on our lives is only expected to grow. It is clear that sensors will play a pivotal role in shaping the future of technology and the way we live our lives.。

Research-of-Intelligent-Gas-Detecting-System温度传感器信号采集系统设计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：研究智能气体检测系统文献、资料英文题目：Research of Intelligent Gas DetectingSystem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： 2017.02.14Research of Intelligent Gas Detecting System Detecting system in this paper adopts single-chip microcomputer as control computer;the overall schematic diagram of system is shown in Figure 1. The reason for selectingsingle-chip microcomputer as a control core is that it possesses advantages of smallsize, high reliability, low price which made it very suitable to be used in industries ofintelligent instrument and real time control .The operating interface of system is shown in Figure 1.Number at upper right cornershows the default or user-defined gas concentration value, number at upper left cornershows detected gas concentration value. One alarm lamp is equipped. All functions arecontrolled by keys arranged on the control panel, including POWER key, RESET key,DATA COLLECTION key. Other keys including ten number keys, ADJUST VALUEkey and ENTER key are used to change threshold valuesFig.1 The operating interface of systemBasic operating procedures are as follows:Firstly press POWER key, the system initialized.Press DATA COLLECTION key, LED at upper right corner displays the threshold value 1.00;User can customized threshold value by press ADJUST VALUE key and tennumber keys, then press ENTER to confirm the change.System starts to detect gas concentration and display these parameters on upperleft LED area, at meantime transmit real-time data by RS-485 to host computerabove ground.The Hardware architecture of system mainly including main control unit, sensors andsignal amplifier circuit, A/D converter module, sound-light alarming circuit, keyboardand display module, serial-communication module.Featured by high integration level, small size and low prices, Single chip microcomputer has been widely used in a broad range of industrial applications including process controlling, data collection, electromechanical integration, intelligent instrument,household appliances and network technology, and significantly improved the degree of technology and automation.Fig.2 Main control unitTwo factors are taken into account here in chip selecting, first one is anti-interferenceability, increase the interferences in SCM application systems, so the SCM must have highresistance to outside interference; second one is the performance-price ratio of the SCM.Considering the aforementioned factors, we adopted the AT89S52 developed by ATMELas main control unit, and the final scheme of main control circuit consists ofAT89S52, timer and reset circuit .A crucial issue in gas detecting system design is how to select gas sensors.Common gassensors are metal oxide semiconductor such as tin oxide, zin coxide, titanium oxide andaluminum oxide. Problems encountered with these sensors are lack of flexibility, poor response times and operated at elevated temperature. A new method of ch4 detecting based on infrared techniques was presented in recent years, but it is still in progress and much work should be done before it can be applied to solve the practice problems .This system adopted catalytic combustion type gas sensor MC112 developed by SUNSTAR group to measure the gas (ch4) concentration. Figure 4 shows the outside view and internal circuit of MC112, table 1 lists the main technology parameters of MC112. MC112 gas detector exploits catalytic combustion principle; the two-arm bridge is comprised of measure and compensate components pairs. When it is exposed to combustible gases, measure components resistance RS increased and transmit output voltage parameter through measuring bridge, the voltage parameter is directly proportional to the gas concentration value. The compensate component works as temperature compensation and reference. Main features of MC112 include good repeatability, work stably, reliability, linear output voltage, and quick response. The mine safety rules stated that if methane gas concentration exceeds 1%, safety system should make an alert, if gas concentration exceeds 2%, all people must evacuate immediately. Since the detecting range of MC112 for low concentration methane is 0%-2%.Fig. 3 Outside viewIt is necessary to amplify the weak electrical signal detected by MC112 (1% gas concentration fluctuation will result in 16mv voltage change). The system adopted AD623 developed by AD Company as the high performance instrumentationamplifier. It has many merits: (1) output with 3-12v single supply (2) easy to modify signal gain though an external resistor, it will be act as a unit gain without external resistor and signal gain can reach to 1000 with an external resistor; (3)low power consumption, large-scale operation voltage, good linearity, good thermal stability and high reliability. The schematic diagram of signal amplifier circuit is shown in figure 4.Fig.4 Signal amplifier circuitAs shown in Figure 5, this module consists of multiplexer CD4051, sampling holder LF389, A/D converter AD574A and parallel I/O chip 8255A. As a core part, AD574A is a 12-bit successive-approximation A/D converter chip with three-state buffer, its conve rsion time is about 25μs. AD574A can directly connected to AT89S52 without additional interface logic circuit, with internal high accuracy reference power supply and clock circuit, AD574A can operate normally without external clock sourceand reference power supply.Fig.5 A/D converter modelTraditional LCD module is unsuitable in this system because the working environment mainly lies deep in dark coal mine tunnel. LED with soft light should be the alternative. It is suitable for the adverse circumstances under coal mine features by damp-proof, excellence temperature characteristics and long distance visual effects. In this system, a 6-bit LED is adopted to dynamically display the ch4 gas concentration value, with the segment port and bit port connected with PA port and PB port of 8155(1) separately.In keyboard input module, we arranged 13 keys including 10 number keys and “Data collection” key, “Enter” key, “reset” key. Adopted opposite direction connect method, PB port and PC port of 8155(2) connected to keyboard’s row circuit and column circuit respectively.The serial communications module is shown at the left part in Figure 9, signal of microcontroller is transmitted to host computer above ground by RS-485, and MAX485 is used to convert the voltage. RS-485 is a multi-point two-way half-duplex communication link based on single balanced-wire circuit featured by high noise suppression, high transfer rate, long distance transmission and Wide common-mode range, its maximum transfer rate reaches to 10Mbps, maximum cable distance reaches to 1200m.The primary functions of the software control system including system initializing, threshold value setting, methane gas concentration data collecting and displaying, serial communications etc. To achieve the above functions, we developed serial programsusing 51 serials microcontroller assemble program language including main program, keyboard scanning program, A/D converter program, alarming program, serial communications program, data display program, system alarming diagnosis program, double-byte multiply program, triple-byte to binary-coded-decimal program and watching dog program. The system is comprised of many modules, Owing to limited space we introduce main program only. main program initializing single chi p microcomputer’s registers and I/O ports, then scanning keyboard to see if the data collection key is pressed, if no, keep scanning keyboard until data collection key is pressed. When the collection key is pressed down, default threshold value 1.00 is shown on the panel, if user wants to reset threshold value, just press the ADJUST VALUE key to set a new value, and press ENTER key to finish this step. When ENTER key is pressed, system start the operating of data collection and A/D conversion, then transmit the converted data into binary format by calling a subprogram of double-byte multiply. We need three storage units to hold these data because they are 24 bits data in binary format. Next, system will transmit these binary format data into binary-coded-decimal format by calling a subprogram of triple-byte to binary-coded-decimal. In the last step, comparing the value with pre-set threshold value to decide if the system should send an alarm signal. In the meantime, these data will be sending to host computer above ground through RS-485 serial communications unit. Still, the system will send a positive pulse to reset the watchdogtimer every 1.6 sec. the Crystal Oscillator frequency of the SCM adopted in this system is 12MHZ, with timer/counter TO, working in mode 1(16bit timer/counter), its maximal timing interval is about 66ms, so the system will send a feeding dog signal to watch dog circuit every 66ms.In this study, an intelligent gas detecting system is presented. It can be used to real-time monitoring the methane gas concentration . The measuring scope of this system range from zero to 2 percent, the sensitivity of the sensor reach to 0.01 percent.It is equipped with the quick speed and high performance 12-bit A/D converter, the operating environment temperature ranged from -20℃～+70℃. Still this system features with high reliability, easy to operate, high performance-price ratio. In this paper, the total plan and software and hardware design of a gas detecting system are presented, by using Proteus to test hardware circuit and using Keil to test assemble language source program, the simulation test result shows this system is of high accuracy, quick response and is feasible.研究智能气体检测系统在本文中，检测系统采用单片机作为控制计算机。

老外写的传感器应用电路书籍

老外写的传感器应用电路书籍以下是一些老外写的关于传感器应用电路的书籍推荐：1. "Sensor Technologies: Healthcare, Wellness and Environmental Applications" by Michael Y. Wang2. "Sensor and Actuator Systems: Instrumentation and Design" by Clarence W. de Silva3. "Practical Electronics for Inventors" by Paul Scherz and Simon Monk4. "Embedded Systems and Robotics with Open Source Tools" by Dimitris Loukas5. "Sensors and Sensor Systems for Manufacturing" by Sabrie Soloman6. "Wireless Sensor Networks: Principles, Design, and Applications" by Holger Karl and Andreas Willig7. "Sensors: Theory, Algorithms, and Applications" by Srikanta Patnaik and Ashish Ghosh8. "Sensor Technology Handbook" by Jon S. Wilson9. "Introduction to Sensors for Ranging and Imaging" by Graham Brooker10. "Fundamentals of Sensors for Engineering and Science" by Patrick F. Dunn这些书籍涵盖了传感器应用电路的原理、设计、应用以及相关领域的实践经验和案例研究，希望对你有所帮助。

传感器技术外文文献及中文翻译

传感器技术外文文献及中文翻译引言传感器是现代检测技术的重要组成部分，它能将物理量、化学量等非电信号转换为电信号，从而实现检测和控制。

传感器广泛应用于工业、医疗、军事等领域中，如温度、湿度、气压、光强度等参数检测。

随着科技的发展，传感器不断新型化、微型化和智能化，已经涵盖了人体所有的感官，开启了大规模的物联网与智能化时代。

本文将介绍几篇与传感器技术相关的外文文献，并对其中较为重要的内容进行中文翻译。

外文文献1标题“Flexible Sensors for Wearable Health: Why Materials Matter”作者Sarah O’Brien, Michal P. Mielczarek, and Fergal J. O’Brien文献概述本文主要介绍了柔性传感器在可穿戴健康监测中的应用，以及传感材料的选择对柔性传感器性能的影响。

文章先介绍了柔性传感器的基本工作原理和常见的柔性传感材料，然后重点探讨了传感材料对柔性传感器灵敏度、稳定性、响应速度等性能的影响。

最后，文章提出未来柔性传感器材料需满足的性能要求，并对可能的研究方向和应用进行了展望。

翻译摘要柔性传感器是可穿戴健康监测中重要的成分，通过将身体状态转化为电信号进行检测。

选择合适的传感材料对柔性传感器产品的成本、性能及标准化有着面向未来的影响。

本文对柔性材料的常见种类 (如: 聚合物、金属、碳复合材料等) 进行了介绍，并重点探讨了传感材料选择的影响因素，如对柔性传感器的灵敏度、特异性和响应时间等。

此外，文章还探讨了柔性传感器的性能要求和建议未来的技术方向。

外文文献2标题“Smart sensing system for precision agriculture”作者Olivier Strauss, Lucas van der Meer, and Benoit Figliuzzi文献概述本文主要介绍智能传感系统在精准农业中的应用。

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Photoelectric sensorKey word:photoeletric effect photoelectric element photoeletric sensor classification sensor application characteristics. Abstract:in the development of science and technology in the modern society,mankind has into rapidly changing information era,people in daily life,the production process,rely mainly on the detection of information technology by acquiring,screening and transmission,to achieve the brake control,automation adjustment,at present our country has put detection techniques listed in one of the priority to the development of science and technology.Because ofmicroelectronics technology,photoelectric semiconductor technology,optical fiber technology and grating technical development makes the application of the photoelectric sensor is growing .The sensor has simple structure, non-contact,high reliability,high precision,measurable parameters and quick response and more simple structure,form etc,and flexible in automatic detection technology,it has been widely applied in photoelectric effect as the theoretical basis,the device by photoelectric material composition.Text:First,theoretical foundation-photoelectric effect Photoelectric effect generally have the photoelectric effect ,optical effect,light born volts effect.The light shines in photoelectric material,according to the electronic absorption material surface energy,if absorbed energy large enough electronic will overcome bound from material and enter the outside space,which changes photoelectron materials ,this king of phenomenon become the conductivity of the photoelectric effect.According to Einstein’s photoelectron effect,photon is moving particles,each photon energy for hv(v for light frequency,h for Planck’s constant,h=6.63*10-34J/HZ),thus different frequency of photons have different energy,light,the higher the frequency,the photon energy is bigger.Assuming all the energy photons to photons,electronic energy will increase,increased energy part of the fetter,positive ions used to overcome another part of converted into electronic energy.According to the law of conservation of energy:1／2mv =hv-A2Type,m for electronic quality,v for electronic escaping the velocity,A microelectronics the work done.From the type that will make the optoelectronic cathode surface escape the necessary conditions are h>A.Due to the different materials have different escaping,so reactive to each kind ofcathode material,incident light has a certain frequency is restricted,when the frequency of incident light under this frequency limit,no matter how the light intensity,won’t produce photoelectron lauch,this frequency limit called“red limit”.The corresponding wavelength for type,c for the speed of light,A reactive for escaping.When is the sun,its electronic energy,absorb the resistivity reduce conductive phenomenon called optical effects.It belongs to the photoelectric effect within.When light is,if in semiconducter electronic energy big with semiconductor of forbidden band width,the electronic energy from the valence band jump into the conduction band,form,and at the same time,the valence band electronic left the corresponding cavities. Electronics,cavitation remained in semiconducter,and participate in electric conductive outside formed under the current role.In addition to metal outer,most insulators and semiconducter have photoelectric effect,particularly remarkable,semiconductor optical effect according to the optoelectronics manufacturing incident light inherent frequency,when light resistance in light,its conductivity increases,resistance drops.The light intensity is strong,its value,if the smaller,its resistance to stop light back to the original value.Semiconductor producted by light illuminate the phenomenon is called light emf,born volts effect on the effect of photoelectric devices have made si-based ones,photoelectric diode,control thyristor and optical couplers,etc.Second,optoelectronic components and characteristics According to the outside optoelectronics manufacturing optoelectronic devices have photoelectron,inflatable phototubes and photoelectric times once tube.1.Phototubes phototubes are various and typical products arevacuum phototubes and inflatable phototubes,light its appearance and structure as shown in figure 1 shows,made of cylindrical metal half cathodic K and is located in the wires cathodic axis of anode in A package of smoke into the vacuum,when incident light within glass shell in the cathode,illuminate A single photon took all of its energy transfer to the cathode materials A free electrons,so as to make the freedom electronic energy increase h.When electrons gain energy more than escape of cathode materials,it reactive A metal surface constraints can overcome escape,form electron emission.This kind of electronic called optoelectronics,optoelectronic escaping the metal surface for after initial kinetic energyPhototubes normal work,anode potential than the cathode, show in figure 2.In one shot more than “red light frequency is premise,escape from the optoelectronic cathode surface by positive potential attracted the anode in photoelectric tube forming space,called the current stream.Then if light intensity increases,the number of photons bombarded the cathode multiplied,unit of time to launch photoelectron number are also increasing,photo-current greatens.In figure 2 shows circuit,current so as to achieve a photoelectric conversion.When the LTT optoelectronic cathode K, electronic escape from the cathode surface,and was the photoelectric anode is an electric current,power plants absorb deoxidization device in the load resistance-I,the voltage. Phototubes photoelectric characteristics fig.03 shows,from the graph in flux knowable,not too big,photoelectric basis characteristics is a straight line.2.Photoelectric times had the sensitivity of vacuum tube duo tolow,so with people developed has magnified the photomultiplier tubes photo-current ability.Figure 4 isphotomultiplier tube structure schematic drawing.From the graph can see photomultiplier tubes also have A cathode K and an anode A,and phototubes different is in its between anode and cathode set up several secondary emission electrodes,D1,D2 and D3…Usually,double electrode for 10~15 levels.Photomultiplier tubes work between adjacent electrode,keeping a certain minimum,including the cathode potential potentials,each multiply electrode potential filtering increases, the anode potential supreme.When the incident light irradiation, cathodic K escape from the optoelectronic cathode multiplied by first accelerated,by high speed electrode D1 bombarded caused secondary electron emission,D1,an incident can generate multiple secondary electron photonics,D1 emit of secondary electron was D1,D2 asked electric field acceleration,converged on D2 and again produce secondary electron emission…So gradually produce secondary electron emission,make electronic increased rapidly,these electronic finally arrived at the anode, form a large anode current.If an level,multiply electrodes at alllevels for sigma,the multiplication of rate is the multiplication of photomultiplier tubes can be considered sigma n rate,therefore,photomultiplier tube has high sensitivity.In the output current is less than 1mA circumstances,it in a very wide photoelectric properties within the scope of the linear relationship with good.Photomultiplier tubes this characteristic, Make it more for light measurement.3.and photoconductive resistance photoconductive resistance within the working principle is based on the photoelectric effect. In semiconducter photosensitive material ends of mount electrode lead,it contains transparent window sealed in the tube and shell element photoconductive resistance.Photoconductive resistance properties and parameters are:1)dark resistance photoconductive resistance at roomtemperature,total dark conditions stable resistance called dark resistance,at the current flow resistance is called dark current.2)Light resistance photoconductive resistance at roomtemperature and certain lighting conditions stable resistance measured,right now is called light resistance of current flow resistance is called light current.4.V olt-ampere characteristics of both ends photoconductive resistance added voltage and current flows throughphotoconductive resistance of the relationship between called volt-ampere characteristics shown,as shown in figure 5.From the graph,the approximate linear volt-ampere characteristics that use should be limited,but when the voltage ends photoconductive resistance,lest than shown dotted lines of power consumption area.光敏电阻的伏安特性5.photoelectric characteristics photoconductive resistance between the poles,light when voltage fixed the relationship between with bright current photoelectric characteristics.Called photoconductive resistance photoelectric characteristics is nonlinear,this is one of the major drawback of photoconductive resistance.6.Spectral characteristics is not the same incident wavelength the sensitivity of photoconductive resistance is different also.Incidence wavelength and photodetector the relationship between relative sensitivity called spectral characteristics.When used according to the wavlength range by metering,choosedifferent material photoconductive resistance.7.Response time by photoconductive resistance after photo-current need light,over a period of time (time) rise to reach its steady value.Similarly,in stop light photo-current also need,over a period of time (down time) to restore the its dark current,this is photoconductive resistance delay characteristic . Photoconductive resistance rise response time and falling response time about 10-1~10-3s,namely the frequency response is 10Hz~1000Hz,visible photoconductive resistance cannot be used in demand quick response occasion,this is one of the main photoconductive resistance shortcoming.8、and temperature characteristic photoconductive resistance by temperature affects greatly,temperature rise,dark current increase,reduced sensitivity,which is another photoconductive resistance shortcoming.9、frequency characteristic frequency characteristics refers to an external voltage and incident light,strong must be photo-current I and incident light,modulation frequency,the relationship between the f,photoelectric diode is the freqency characteristic of the ptotoelectric triode frequency characteristics,this is because of the photoelectric triode shot “yankees there capacitance and carrier base-combed need time’s sake.By usingthe principle of the photoelectric effciency of optoelectronics manufacturing frequency characteristic of the worst,this is due to capture charge carriers and release charge need a certain time’s sake.Three,photoelectric sensorsPhotoelectric sensor is through the light intensity changes into electrical signal changes to achieve control,its basic structure,it first figure 6 by measuring the change of converting the light signal,and then using photoelectric element further will light signals into electrical signal by photoelectric sensor general. Illuminant,optical path and optoelectronics.Three components of photoelectric detection method has high precision,fast response,non-contact wait for an advantage,but measurable parameters of simple structure,sensors,form flexible,threefore, photoelectric sensor in the test and control is widely used.By photoelectric sensor generally is composed of three parts, they are divided into:transmitter and receiver and detection circuit shown,as shown in figure 7,transmitter aimed at the target launch beam,the launch of the beam from semiconductor illuminant,general light emitting diode(LED),laser diode and infrared emission diode.Beam uninterrupted lauch,or change the pulse width. Receivers have photoelectric diode,photoelectrictriode,composed si-based ones.In front of the receiver, equipped with optical components such as lens and aperture,etc.In its back is detection circuit,it can filter out effective signal and the application of the signal.In addition,the structural components in photoelectric switch and launch plate and optical fiber,triangle reflex plate is solid structure launch device.It consists of small triangle cone of reflective materials,can make a beam accurately reflected back from plate,with practical significance.It can be in with the scope of optical axis 0 to 25,make beams change launch Angle from a root almost after launch line,passes reflection or from the rotating polygon.some basic returns.Photoelectric sensor is a kind of depend on is analyte andoptoelectronics and light source,to achieve the relationship between the measured purpose,so the light source photoelectric sensor plays a very important role,photoelectric sensor power if a constant source,power is very important for design,the stability of power directly affect the accuracy of measurement,comonly used illuminant have the following kinds:1,leds is a change electric energy into light energy semiconductor devices.It has small volume,low power consumption,long life,fast response,the advantages of high mechanical strength,and can match and integrated circuits. Therefore,widely used in computer,instruments and automatic control equipment.2,Silk light bulb that is one of the most commomly used illuminant,it has rich infrare light.If chosen optoelectronics, constitutes of infrared sensor sensitive colour filter can be added to the visible tungsten lamps,but only filter with its infrared does illuminant,such,which can effectively prevent other light interference.3,compared with ordinary light laser with energy concentration, directional good,frequency pure,coherence as well as good,is very ideal light sources.The light source,optical path and photoelectric device composition photoelectric sensor used inphotoelectric detection,still must be equipped with appropriate measurement circuit.The photoelectric effect to the measurement circuit of photoelectric element of widerange caused changes needed to convert the voltage or current. Different photoelectric element,the measurement circuit required is not identical also.Several semiconductor introduces below optoelectronic devices commonly used measurement circuit.Figure 9(a)with temperature compensation given the photosensitive diode bridge type measuring circuit.When the incident light intensity slow change,the reverse resistance photosensitive diode is the slow change,the change of the temperature will cause the bridge output voltage,must compensate.Drift picture a photosensitive diode as the test components,another into windows,in neighboring bridge,the change of the temperature in the arms of the influence of two photosensitive diode,therefore,can eliminate the same output with tempereture bridge road drift.Light activated triode incident light in work under low illumination,or hope to get bigger output power,also can match with amplifying circuit,as shown in figure 9 shows.Because even in the glare photosensitive batteries,maximum output voltage also only 0.6V,still cannot make the next level 1 transistor have larger current output,so must add positive bias,as shown in figure 9(a)below.In order to reduce the transistor circuit impedance variations,base si-based ones to reduce as much as possible without light,when the reverse bias inherit in parallel a resistor si-based ones at both ends.Or like figure 9(b)as shown by the positive ge diode produces pressure drop and test the voltage produced when exposed to light,make silicon tube e stack,b the voltage between actuators than 0.7V,and conduction work.This kind of circumstance also can use silicon light batteries,as shown in figure 10(c)below.Semiconductor photoelectric element of photoelectric circuit can also use integrated operational amplifier.Silicon photosensitive diode can be obtained by integrating op-amp large output amplitude,as shown in figure 11(a)below.When light is produced,the optical output voltage in order to guarantee photosensitive diode is reverse biased,in its positive to add a load voltage.Figure 11.(b) give the photocell transform circuit,because the photoelectric si-based ones short-circuit current and illumination of a linear relationship between,so will it up in the op-amp is,inverse-phase input,using these two potential difference between the characteristics of close to zero,can get better effect.In the picture shows conditions,the output voltage U0=2IφR FThe photoelectric element by flux the role of different made from the principle of optical measurement and control system is varied,press the photoelectric element (optical measurement andcontrol system)output nature,namely,can be divided into second analog photoelectric sensor and pulse (switch)photoelectric sensor.Analog photoelectric sensors will be converted into continuous variation of the measure,it is measuered optical with a single value relations between analog photoelectric sensor. According to be measured (objects)method detection of target can be divided into transmission (absorption)type,diffuse type, shading type(beam resistance gears)three categories.So-called transmission style means the object to be tested in optical path in constant light source,the light energy through things,part of being measured by absorption,transmitted light onto photoelectric element,such as measured liquid,gas transparency and photoelectric BiSeJi etc;speed.gratifying the so-called diffuse style means the constant light by the light onto the analyte from the object to be tested,and projected onto surfaces reflect on after optoelectronic devices,such as photoelectric colorrimetric thermometer and light gauge etc;The so-called shading style means the when illuminant issued by the flux of light analyte covered by a part Jing optoelectronics,make projection on the flux change,change the object to be tested and extent of the position with the light path,such as vibration measurement,the size measurement;And in pulse photoelectricsensor in the sensors,photoelectric element in switch work of the state,the current output it is usually only two steady state of the signal,the pulse form used for photoelectric counting and photoelectric speed measurement and so on.And infrared photoelectric sensor classification and working way generally have the following kinds:1,groove photoelectric sensor put a light emitter and a receiver in a slot face-to-face outfit are on opposite sides of the photoelectric groove.Lighter emits infrared light or visible light, and in unimpeded cases light receptors can receive light.But when tested objects from slot zhongtong obsolete , light occluded ,photoelectric switches and action.Output a switch control signal,cut off or connect load current,thus completing a control movement.Groove switch is the overall of detection distance because general structure limits only a few centimeters. 2,DuiShe type optoelectronic sensor if you put lighter and receive light is separated,can make the detection distance increase.By a lighter and an inbox light sensor into a photoelectric switch is called DuiShe separate photoelectric switches,referred to DuiShe photoelectric switch.Its detection distance can reach a few meters and even a dozen meters.When using light-emitting device and recive light device are installedin test object through the path of the sides,test object by blocking light path,accept light implement action output a switch control signals.3,Reflex plate.it photoelectric switch light-emitting device type and receive light device into the same device inside,in its front pack a reflex plate.the using the reflection principle of complete photoelectric control function is called reflex plate.it reflex (or reflector reflx)photoelectric switch.Under normal circumstances, lighter the light reflected by reflex plate.it is received by accept light;Once the light path be test object to block,accept light,the light is not received photoelectric switch is action,output a switch control signals.4,Diffusion reflective photoelectric switches its detection head with a lighter and also an inbox light ware,but no reflex plate.it ahead.Normally lighter for the light collect light is not found. When test object by blocking the light,and the light reflected light,receive part implement received light signals,output a switch signals.Four,I’m the idea of photoelectric sensorWith the development of science and technology people on measuring accuracy had the higher request,this has prompted the pace with the times photoelectric sensor have updated,improvethe main means photoelectric sensor performance is the application of new materials,new technology manufacturing performance is more superior photoelectric element.For example,today the prototype of the photoelectric sensor is a small metal cylindrical equipment,with a calibration lens,transmitter into receiver focused light,the receiver out of cable to the device got to a vacuum tube amplifiers in metal cylinder on the incandescent light bulb inside a small as the light source a strong incandescent lamp sensor.Due to the sensor various defects existing in the fields,gradually faded.To appear, because of it of fiber of excellent performance,then appeared with sensors supporting the use of optical passive components, another fiber without any interference of electromagnetic signal, and can make the sensor of the electronic components and other electrical disturbance in isolation.Have a piece of plastic optical fiber core or plass light core,light outside a metallic core skins and bread this layer metal cortical density lower than light core, so low,the beam refraction in the two materials according to the border(incident Angle within a certain range,reflected),is all. Based on optical principle,all beams can be made by optical fiber to transmission.Two incident beam Angle in an Angle (along the fiber length direction within)by multiple reflectionsfrom the other end after injection,another incident angles than accept the incident light in metal skin,loss.This accept Angle within the biggest incident Angle than two times,this is because fiber slightly larger from air into density larger fiber materials hitting may have a slight refraction.In light of the optical fiber transmission from inside the influence of fiber bending(whether more than bending radius minimal bending radius).Most optical fiber is flexible,easy to install in the narrow space. Photoelectric sensor is a kind of non-contact measurement small electronic measurement equipment,rely on detect its receives the light intensity change,to achieve measurement purposes,and it’s also a vulnerable to external disturbance and lose the measurement accuracy of the device.When be being designed so besides the choice optoelectronic components,still must set GSCC signal and temperature compensating measures used to weaken or eliminate the impact of these factors.。

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