外文资料翻译---传感器新技术的发展
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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。
中英文资料外文翻译文献英文:The right design for a relative humidity sensor systemOptimizing the response characteristics and accuracy of a humidity sensor system1 OverviewTo make the right choice when selecting a relative humidity sensor for an application, it is important to know and to be able to judge the deciding factors. In addition to long-term stability, which is a measure on how much a sensor changes its properties over time, these factors also include the measurement accuracy and the response characteristics of the sensor. Capacitive humidity sensors are based on the principle that a humidity-sensitive polymer absorbs or releases moisture as a function of the relative ambient humidity. Because this method is only a spot measurement at the sensor location, and usually the humidity of the surroundings is the desired quantity, the sensor must be brought into moisture equilibrium with the surroundings to obtain a precise measurement value. This process is realized by various transport phenomena (cf. the section titled "The housing effect on the response time"), which exhibit a time constant. Accuracy and response time are thus closely dependent on each other, and the design of a humidity measurement system becomes a challenge.2Measurement accuracyThe term measurement accuracy of a humidity sensor is understood primarily to refer to the deviation of the value measured by the sensor from the actual humidity. To determine the measurement accuracy, references, such as chilled mirror hygrometers, whose own tolerance must be taken into account, are used. In addition to this trivial component, humidity sensors require a given time for reaching stable humidity and temperature equilibrium (the humidity is a function of temperature and decreases with increasing temperature; a difference between sensor and ambient temperature leads to measurement errors). This response time thus has a significant effect on the value measured by the sensor and thus on the determinedaccuracy.This time-dependent characteristic is explained in more detail in the following.3Response characteristics and response timeThe response characteristics are defined by various parameters. These are:●The actual response characteristics of the humidity sensor at constant temperature.(1) How quickly the sensitive polymer absorbs or releases moisture until equilibrium is reached (intrinsic response time)(2) How fast the entire system reaches humidity equilibrium (housing effect)●The thermal response characteristics of the humidity sensor at a non-constant temperature(3) The thermal mass of the sensor(4) The system's thermal mass, which is thermally coupled to the sensor (e.g. printed circuit board)(5) Heat sources in the direct surroundings of the sensor (electronic components)(1) and (3) are determined entirely by the sensor itself, (1) primarily by the characteristics of the sensitive polymer.(2) and (4) are primarily determined by the construction of the entire system (shape and size of housing andreadout circuitry).(5) is determined by heat-emitting electronic components.These points will be discussed in more detail in the following.The intrinsic response time (1)Qualitatively, the response characteristics of capacitive humidity sensors look like the following (Fig. 1).Fig. 1: Typical and idealized response characteristics of capacitive humidity sensors (schematic)Because these response characteristics are especially pronounced at high humidity values, an isothermal humidity jump from 40% to 100% was selected here for illustration. The desired ideal behavior of the sensor is indicated in blue. In practice, however, the sensor behaves according to the red line, approximately according to:RH-t=(E-S)*(1-e)+S(t)Here, the time span 1 is usually very short (typ. 1 – 30 min.), in contrast, the time span 2 is very long (typ. Many hours to days). Here the connection of measurement accuracy and response characteristics becomes clear (t until RH=100% is reached). The value at t4 (Fig. 1) is considered to be an exact measured value. However, this assumes that both the humidity and also the temperature remain stable during this entire time, and that the testing waits until this very long measurement time is completed. These conditions are both very hard to achieve and unusual in practice. For the calibration, there are the following two approaches, which both find use in practice (cf. Fig. 2):1.The measured value at t2 (Fig. 1) is used as a calibration reference.Advantage:●The required measurement time for reaching the end value (in the example 100%) isclearly shortened,corresponds to practice, and achieves an apparent short responsetime of the sensor (cf. Fig. 2).Disadvantage:●If the conditions are similar for a long time (e.g., wet periods in outdoor operation),the sensors exceed the correct end value (in the example 100%) undesirably by upto 10% (cf. Fig. 2).2. The measured value at t4 (Fig. 1) is used as a calibration reference.Advantage:●Even for similar conditions over a long time (e.g., wet periods in outdoor operation),an exact measurement result is obtained (cf. Fig. 2).Disadvantage:●For a humidity jump like in Fig. 1, the sensors very quickly deliver the measuredvalue at t2, but reaching a stable end value (about 3-6% higher) takes a long time(apparent longer response time)(cf. Fig. 2).In order to take into account both approaches optimally, the measured values at t3 (cf. Fig. 1) are used as the calibration reference by Sensirion AG.Fig. 2: Response characteristics of different humidity measurement systemsThe housing effect on the response time (2)Here, two types of transport phenomena play a deciding role:●Convection: For this very fast process, the air, whose humidity is to be determined,is transported to the sensor by means of ventilation.●Diffusion: This very slow process is determined by the thermal, molecularself-motion of the water molecules. It occurs even in "stationary" air (e.g., within ahousing), but leads to a long response time.In order to achieve favorable response characteristics in the humidity measurement system, the very fast convection process must be supported by large housing openings and the slow diffusion process must be supported by a small housing around the sensor (small "deadvolume") with "stationary" air reduced to a minimum. The following applies:Thermal effects (3), (4), and (5)Because the total thermal mass of the humidity measurement system (sensor + housing)has a significant effect on its response time, the total thermal mass must be kept as low aspossible. The greater the total thermal mass, the more inert the measurement system becomesthermally and its response time, which is temperature-dependent, increases. In order toprevent measurement errors, the sensor should not be mounted in the vicinity of heatgenerating components.4Summary –what should be taken into account when designing a humidity measurement systemIn order to achieve error-free operation of a humidity-measurement system with response times as short as possible, the following points should be taken into account especially for the selection of the sensor and for the design of the system.●The selection of the humidity sensor element. It should●be as small as possible,●have a thermal mass that is as low as possible,●work with a polymer, which exhibits minimal fluctuations in measured values duringthe time span 2(cf. Fig. 1); testing gives simple information on this condition,●provide calibration, which corresponds to the requirements (see above), e. g.,SHT11/SHT15 from Sensirion.●The housing design (cf. Formula 1). It should●have air openings that are as large as possible in the vicinity of the sensor or thesensor should be operated outside of the housing à good convection!●enclose a "dead volume" that is as small as possible around the sensor àlittlediffusion!●The sensor should be decoupled thermally as much as possible from other components,so that the response characteristics of the sensor are not negatively affected by the thermal inertia of the entire system.(e.g., its own printed circuit board for the humidity sensor, structurally partitioning the housing to create a small volume for the humidity sensor, see Fig. 3)Fig. 3: Mounting example for Sensirion sensors SHT11 and SHT15 with slits for thermal decoupling●The sensor should not be mounted in the vicinity of heat sources. If it was, measuredtemperature would increase and measured humidity decrease.5Design proposalThe challenge is to realize a system that operates cleanly by optimally taking into account all of the points in section 4. The already calibrated SMD humidity sensors SHT11 and SHT15 from Sensirion are the ideal solution. For optimum integration of the sensors in a measurement system, Sensirion AG has also developed a filter cap as an adapter aid, which takes into account as much as possible the points in section 4 and also protects the sensor against contaminants with a filter membrane. Fig. 4 shows schematically how the sensors can be ideally integrated into a housing wall by means of the filter cap SF1.Fig. 4: Filter cap for SHT11 and SHT15In addition to the advantages mentioned above, there is also the option of building an IP67-compatible humidity measurement device (with O-ring, cf. Fig. 4) with optimal performance. Detailed information is available on the Sensirion Web site.译文:相对湿度传感器系统的正确设计湿度传感器系统精度及响应特性的优化1.综述为了在相对湿度的应用方面对传感器做出正确的选择,了解和评估那些起决定作用的因素是非常重要的。
中英文对照翻译外文资料Moving Object Counting with an Infrared Sensor NetworkAbstractWireless Sensor Network (WSN) has become a hot research topic recently. Great benefit can be gained through the deployment of the WSN over a wide range ofapplications, covering the domains of commercial, military as well as residential. In this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. Such a system can be deployed in traffic control, resource management, and human flow control. Our design is based on our self-made cost-effective Infrared Sensing Module board which co-operates with a WSN. The design of our system includes Infrared Sensing Module design, sensor clustering, node communication, system architecture and deployment. We conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our Moving Object Counting system.Keywords:Infrared radiation,Wireless Sensor Node1.1 Introduction to InfraredInfrared radiation is a part of the electromagnetic radiation with a wavelength lying between visible light and radio waves. Infrared have be widely used nowadaysincluding data communications, night vision, object tracking and so on. People commonly use infrared in data communication, since it is easily generated and only suffers little from electromagnetic interference. Take the TV remote control as an example, which can be found in everyone's home. The infrared remote control systems use infrared light-emitting diodes (LEDs) to send out an IR (infrared) signal when the button is pushed. A different pattern of pulses indicates the corresponding button being pushed. To allow the control of multiple appliances such as a TV, VCR, and cable box, without interference, systems generally have a preamble and an address to synchronize the receiver and identify the source and location of the infrared signal. To encode the data, systems generally vary the width of the pulses (pulse-width modulation) or the width of the spaces between the pulses (pulse space modulation). Another popular system, bi-phase encoding, uses signal transitions to convey information. Each pulse is actually a burst of IR at the carrier frequency.A 'high' means a burst of IR energy at the carrier frequency and a 'low' represents an absence of IR energy. There is no encoding standard.However, while a great many home entertainment devices use their own proprietary encoding schemes, some quasi-standards do exist. These include RC-5, RC-6, and REC-80. In addition, many manufacturers, such as NEC, have also established their own standards.Wireless Sensor Network (WSN) has become a hot research topic recently. Great benefit can be gained through the deployment of the WSN over a wide range ofapplications, covering the domains of commercial, military as well as residential. In this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. Such a system can be deployed in traffic control, resource management, and human flow control. Our design is based on our self-made cost-effective Infrared Sensing Module board which co-operates with a WSN. The design of our system includes Infrared Sensing Module design, sensor clustering, node communication, system architecture and deployment. We conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our Moving Object Counting system.1.2 Wireless sensor networkWireless sensor network (WSN) is a wireless network which consists of a vast number of autonomous sensor nodes using sensors to monitor physical or environmental conditions, such as temperature,acoustics, vibration, pressure, motion or pollutants, at different locations. Each node in a sensor network is typically equipped with a wireless communications device, a small microcontroller, one or more sensors, and an energy source, usually a battery. The size of a single sensor node can be as large as a shoebox and can be as small as the size of a grain of dust, depending on different applications. The cost of sensor nodes is similarly variable, ranging from hundreds of dollars to a few cents, depending on the size of the sensor network and the complexity requirement of the individual sensor nodes. The size and cost are constrained by sensor nodes, therefore, have result in corresponding limitations on available inputs such as energy, memory, computational speed and bandwidth. The development of wireless sensor networks (WSN) was originally motivated by military applications such as battlefield surveillance. Due to the advancement in micro-electronic mechanical system technology (MEMS), embedded microprocessors, and wireless networking, the WSN can be benefited in many civilian application areas, including habitat monitoring, healthcare applications, and home automation.1.3 Types of Wireless Sensor NetworksWireless sensor network nodes are typically less complex than general-purpose operating systems both because of the special requirements of sensor network applications and the resource constraintsin sensor network hardware platforms. The operating system does not need to include support for user interfaces. Furthermore, the resource constraints in terms of memory and memory mapping hardware support make mechanisms such as virtual memory either unnecessary or impossible to implement. TinyOS [TinyOS] is possibly the first operating system specifically designed for wireless sensor networks. Unlike most other operating systems, TinyOS is based on an event-driven programming model instead of multithreading. TinyOS programs are composed into event handlers and tasks with run to completion-semantics. When an external event occurs, such as an incoming data packet or a sensor reading, TinyOS calls the appropriate event handler to handle the event. The TinyOS system and programs are both written in a special programming language called nesC [nesC] which is an extension to the C programming language. NesC is designed to detect race conditions between tasks and event handlers. There are also operating systems that allow programming in C. Examples of such operating systems include Contiki [Contiki], and MANTIS. Contiki is designed to support loading modules over the network and supports run-time loading of standard ELF files. The Contiki kernel is event-driven, like TinyOS, but the system supports multithreading on a per-application basis. Unlike the event-driven Contiki kernel, the MANTIS kernel is based on preemptive multithreading. With preemptive multithreading, applications do not needto explicitly yield the microprocessor to other processes.1.4 Introduction to Wireless Sensor NodeA sensor node, also known as a mote, is a node in a wireless sensor network that is capable of performing processing, gathering sensory information and communicating with other connected nodes in the network. Sensor node should be in small size, consuming extremely low energy, autonomous and operate unattended, and adaptive to the environment. As wireless sensor nodes are micro-electronic sensor device, they can only be equipped with a limited power source. The main components of a sensor node include sensors, microcontroller, transceiver, and power source. Sensors are hardware devices that can produce measurable response to a change in a physical condition such as light density and sound density. The continuous analog signal collected by the sensors is digitized by Analog-to-Digital converter. The digitized signal is then passed to controllers for further processing. Most of the theoretical work on WSNs considers Passive and Omni directional sensors. Passive and Omni directional sensors sense the data without actually manipulating the environment with active probing, while no notion of “direction” involved in these measurements. Commonly people deploy sensor for detecting heat (e.g. thermal sensor), light (e.g. infrared sensor), ultra sound (e.g. ultrasonic sensor), or electromagnetism (e.g. magnetic sensor). In practice, a sensor node can equip with more than one sensor.Microcontroller performs tasks, processes data and controls the operations of other components in the sensor node. The sensor node is responsible for the signal processing upon the detection of the physical events as needed or on demand. It handles the interruption from the transceiver. In addition, it deals with the internal behavior, such as application-specific computation.The function of both transmitter and receiver are combined into a single device know as transceivers that are used in sensor nodes. Transceivers allow a sensor node to exchange information between the neighboring sensors and the sink node (a central receiver). The operational states of a transceiver are Transmit, Receive, Idle and Sleep. Power is stored either in the batteries or the capacitors. Batteries are the main source of power supply for the sensor nodes. Two types of batteries used are chargeable and non-rechargeable. They are also classified according to electrochemical material used for electrode such as NiCd(nickel-cadmium), NiZn(nickel-zinc), Nimh(nickel metal hydride), and Lithium-Ion. Current sensors are developed which are able to renew their energy from solar to vibration energy. Two major power saving policies used areDynamic Power Management (DPM) and Dynamic V oltage Scaling (DVS). DPM takes care of shutting down parts of sensor node which are not currently used or active. DVS scheme varies the power levelsdepending on the non-deterministic workload. By varying the voltage along with the frequency, it is possible to obtain quadratic reduction in power consumption.1.5 ChallengesThe major challenges in the design and implementation of the wireless sensor network are mainly the energy limitation, hardware limitation and the area of coverage. Energy is the scarcest resource of WSN nodes, and it determines the lifetime of WSNs. WSNs are meant to be deployed in large numbers in various environments, including remote and hostile regions, with ad-hoc communications as key. For this reason, algorithms and protocols need to be lifetime maximization, robustness and fault tolerance and self-configuration. The challenge in hardware is to produce low cost and tiny sensor nodes. With respect to these objectives, current sensor nodes usually have limited computational capability and memory space. Consequently, the application software and algorithms in WSN should be well-optimized and condensed. In order to maximize the coverage area with a high stability and robustness of each signal node, multi-hop communication with low power consumption is preferred. Furthermore, to deal with the large network size, the designed protocol for a large scale WSN must be distributed.1.6 Research IssuesResearchers are interested in various areas of wireless sensornetwork, which include the design, implementation, and operation. These include hardware, software and middleware, which means primitives between the software and the hardware. As the WSNs are generally deployed in the resources-constrained environments with battery operated node, the researchers are mainly focus on the issues of energy optimization, coverage areas improvement, errors reduction, sensor network application, data security, sensor node mobility, and data packet routing algorithm among the sensors. In literature, a large group of researchers devoted a great amount of effort in the WSN. They focused in various areas, including physical property, sensor training, security through intelligent node cooperation, medium access, sensor coverage with random and deterministic placement, object locating and tracking, sensor location determination, addressing, energy efficient broadcasting and active scheduling, energy conserved routing, connectivity, data dissemination and gathering, sensor centric quality of routing, topology control and maintenance, etc.中文译文移动目标点数与红外传感器网络摘要无线传感器网络(WSN)已成为最近的一个研究热点。
外文参考资料二:Abstract: In order to solve the weight problem often encountered in measuring the low-mass objects in the trade and daily life of the modern business, the design of a new pocket-sized electronic scales. This pocket-sized electronic scales Force Sensor gravity signals into electrical signals to measure, and measuring the results of the digital display. The pocket-sized electronic scales with a small size, light weight, easy to carry, intuitive display, measurement and high precision; complex structure, the cost disadvantages. This article focuses on the load cell works, error compensation, the main parameters of selection. And the technical and economic analysis.Keywords: pocket-sized electronic scales; weighing; sensor; error compensationCLC number: TH715. 1] sign code: A Article ID: 100 522 895 (2007) 022*******1 A needs analysisIn modern commerce and trade and everyday life, often encounter the problem of measuring the weight of the low-mass objects. Although the traditional steelyard can solve this problem, but inconvenient to carry, the efficiency is not high, the display is not intuitive and low measurement accuracy; mechanical spring balance can solve this problem, but the inertia inherent low frequency, high sensitivity, measurement accuracy is not high. With the progress and update of the micro-computer technology, integrated circuit technology, sensor technology, electronic scales rapiddevelopment, it has a responsive, high accuracy, fully functional, the display is intuitive, compact, easy to use and so on.For these reasons, in order to solve the low-mass objects weighing problem, if a small size, light weight, portable, digital display electronic scales, will be popular. Discussed below, that is, the scope of a weighing 5 kg compact electronic scales.2 DesignThe principle of the structure of the pocket-sized electronic scales shown in Figure 1. The main task is to design compact electronic scales weighing the choice of the force sensors. Dynamometer sensor types to achieve the weighing and digital display, the key is to want to force (gravity) signals into electrical signals to measure method is mainly divided into two categories: one is the direct method, namely the use of pressure magnetic sensor, piezoelectric sensor, Piezoresistive sensors directly to the force signal converted into electrical signals; the other is the indirect method, the elastic element as the sensor will pull, pressure changes in strain, displacement, or frequency, and then strain sensors, displacement sensors, or frequency sensor strain, displacement or frequency changes for power. Comprehensive comparison of a variety of sensors, use the indirect method of strain gauge force transducer.Pocket-sized electronic scale structural principle:Sensor → amplifier → CPU→ display → AöD converter3 sensor device design3.1 worksThe working principle of the strain gauge force transducer strain gauge pasted into force, force-sensitive elasticelement, the corresponding strain when the elastic element force deformation, the strain gauge into a resistance change, which led to the voltage measuring circuit changes by measuring the output voltage value, and then through the conversion can be obtained by the measurement of body weight. Since the pocket-sized electronic scales require small size, weighing in scope, precision and angle even consistency, sensor and display integration, it is selected parallel to the two holes cantilever beam strain gauge load-bearing sensor. Its characteristics are: high precision, ease of processing, simple and compact structure, strong resistance to partial load, high natural frequency.Strain gauge choice of a metal palisade metal mooring paste on the insulating substrate parked strain gages, mechanical strain resistance strain gauge feelings generally 10 - 10 - 2mm, the resistance rate of change of the attendant about 10 - 6 10 - 2 orders of magnitude, such a small change in resistance measured using the general resistance of the instrument is hard to measure out, you must use some form of measurement.Circuit into small changes in resistance rates to changes in voltage or current, in order to secondary instrument display. Bridge measurement circuit to meet this requirement. In the load cell, R 1, R 2, R 3, R 44 strain gauge resistor bridge measurement circuit shown in Figure 3. R m is the temperature compensation resistor, e is the excitation voltage, V is the output voltage.外文参考资料三:The load cell is a quality signal into a measurable electrical signal outputdevice. Must consider the actual working environment of the sensor which sensor Yin, this is essential for the correct selection of the load cell, and it is related to the sensor can work as well as its safety and service life, and the whole weighing the reliability and safety sex. On the basic concepts and methods of evaluation of the major technical indicators of the load cell, the new and old GB qualitative differences.The traditional concept, the load sensor weighing sensors, force sensors, collectively referred to using a single parameter to evaluate its measurement properties. Old GB will be completely different application objects and the use of environmental conditions "weighing" and "measured force" two sensors into one to consider, not given to distinguish between the test and evaluation methods. Old GB total of 21 indicators, were tested at room temperature; and non-linearity, hysteresis error, repeatability error, creep, the additional error of the zero temperature and the maximum error in the six indicators of the rated output additional temperature error, to determine said The level of accuracy of the weight sensor, respectively 0.02,0.03,0.05 said.Proportion to convert the output signal can be measured. Taking into account the different place of use of the acceleration due to gravity and air buoyancy on the conversion, the main performance indicators of the load cell linearity error, hysteresis error, repeatability error, creep, zero-temperature characteristics and temperature sensitivity characteristics. In a variety of weighing and measuring the quality of the system, usually the integrated error accuracy of the integrated control sensors, and integrated error band or scale error band (Figure 1) linked so that selection corresponds to a certain accuracy weighing weighing sensors. International Organization of Legal Metrology(OIML) requirements, sensor error with total weighing instrument error δ with Δ of 70% of the load cell linearity error, hysteresis error within the specified temperature range due to the effect of temperature on the sensitivity of the error the sum can not exceed the error band of δ. This allows the manufacturer of the components that make up the total measurement error adjustment to obtain the desired accuracy.The load cell conversion method is divided into photoelectric, hydraulic, electromagnetic force type, capacitive, magnetic poles change the form of vibratory gyroscope ceremony, resistance strain type, to the most extensive use of resistance strain.Electromagnetic force sensorIt uses a load-bearing stage load and the principle of electromagnetic force Equilibrium (Figure 5). Put the loading stage, the measured object at one end of the lever upward tilt; photoelectric detect the tilt signal, amplified into the coil, the electromagnetic force, so that the lever to return to equilibrium. Currents produce electromagnetic counterweight digital converter, you can determine the quality of the measured object. The electromagnetic force sensor accuracy, up to 1/2000 ~ 1/60000, but the weighing range is only tens of mg to 10 kg.Capacitive sensorsItcapacitor oscillator circuit of the oscillation frequency f and the plate spacing d is directly proportional relationship between the work (Figure 6). There are two plates, one fixed and the other one can move. Bearing load measured object, the leaf spring deflection, the distance between the twoplates changes, the oscillation frequency of the circuit also changes. The measured frequency change can be calculated to the quality of the load-bearing stage, the measured object. Capacitive sensor power consumption, low cost, accuracy of 1/200 to 1/500.Pole change the form of sensorFerromagneticcomponents in the measured object gravity under mechanical deformation, internal stress and cause changes in permeability, and also changes so that the induced voltage of the secondary coil wound on both sides of the ferromagnetic component (pole). Measure the voltage variation can be calculated added to the force on the pole, and then determine the quality of the measured object. Pole to change the form of sensor accuracy is not high, usually 1/100, applicable to the large tonnage weighing, weighing ranging from tens to tens of thousands of kilograms.Vibration sensorThe force of the elastic element, the natural vibration frequency of the force is proportional to the square root of. Measure the natural frequency changes, you can find the measured object role in the elastic component of the force, and then calculate the quality. The vibration sensor vibrating wire and tuning fork.The elastic component of the vibrating wire sensor string wire. When the load-bearing stage, plus the measured object, the intersection of the V-shaped string wire is pulled down, and left strings of tension increases, the right string tension decreases. The natural frequency of the two strings of different changes. Calculate the frequency difference between the two strings, you can find the quality of the measured object. The higher the accuracy of the vibrating wire sensor, up to 1/1000 ~ 1/10000, weighing 100 g to hundreds of kilograms, but the structure is complex anddifficult process, and high cost.The elastic component of the tuning fork sensor is a tuning fork. Fixed tuning fork end of the piezoelectric element, the natural frequency of oscillation of a tuning fork, it can be measured oscillation frequency. When the load-bearing stage and the measured object, the tuning fork direction of tensile force while the increase in natural frequency, increasing levels of applied force is proportional to the square root. Measure the changes of natural frequency can be calculated heavy loads imposed on the tuning fork on the force, and then calculate the quality of heavy objects. The tuning fork sensor power consumption, measurement accuracy up to 1/10000 to 1/200 000, weighing range of 500g ~ 10kg.外文参考文献中文翻译参考资料二:摘要: 为解决现代商业贸易和日常生活中经常遇到的测量小质量物体的重量问题, 介绍了一种新型的袖珍式电子秤的设计。
毕业设计(论文)外文文献翻译院系:光电与通信工程年级专业:12电子信息工程姓名:刘燊学号:1106012133附件:Advances in Sensor Technology Development指导老师评语:指导教师签名:年月日——摘自夏伟强,樊尚春传感器技术的的新发展仪器仪表学报传感器技术的新进展传感器技术是新技术革命和信息社会的重要技术基础,是一门多学科交叉的科学技术,被公认为现代信息技术的源头。
近些年,传感器技术发展很快,取得了许多新进展,尤其在气体传感器、生物传感器、视觉传感器等方面取得了很多进展。
美国麻省理工学院华人科学家张曙光领导的研究小组借助一种特殊溶液,成功地找到了大规模制造嗅觉感受器的办法;同样是麻省理工学院的研究人员利用气相色谱-质谱技术感受识别气体分子,研制出一种能对微量有毒气体做出强烈反应的微型传感器;俄罗斯科学家以从一种普通蘑菇中提取的混合物为原料,与压电石英晶振构成谐振式传感器,能够探测空气中含量极低的酚成分;日本科学家研制出能快速识别流感病毒纳米传感器,有望以纳米技术为快速识别流感病毒、乙型肝炎病毒、疯牛病病原体和残留农药等物质提供新手段;西班牙巴塞罗那自治大学研制出新型缩微DNA分析传感器,这种传感器能将分析 DNA链的时间缩短到几分钟或几小时,智能仪器与传感器技术、空间生物智能传感技术。
可以在亲子鉴定到检测遗传修饰食物的一系列化验中应用,此外还能确定新药的遗传毒性;美国国家标准与技术研究院研发出一种超灵敏微型核磁共振(NMR)传感器,该微型传感器与微流体通道并列置于一个硅芯片之上,这项技术将核磁共振的探测灵敏度提升到一个新的台阶,将在化学分析中具有广泛的应用前景。
我国传感器技术虽然与国外相比还有很大差距,但近两年也取得了一些进展和突破,诞生了一些新产品,有些在国家重大型号工程中获得应用。
如资源环境技术领域中的环境监测及环境风险评价技术、大气复合污染关键气态污染物的快速在线监测技术和大气细粒子和超细粒子的快速在线监测技术,海洋技术领域中的海洋水质污染综合参数在线监测技术和海洋金属污染物现场和在线监测技术等。
外文翻译中英文对照翻译智能红外传感器跟上不断发展的工艺技术对工艺工程师来说是一向重大挑战。
再加上为了保持目前迅速变化的监测和控制方法的过程的要求,所以这项任务已变得相当迫切。
然而,红外温度传感器制造商正在为用户提供所需的工具来应付这些挑战:最新的计算机相关的硬件、软件和通信设备,以及最先进的数字电路。
其中最主要的工具,不过是新一代的红外温度计---智能传感器。
今天新的智能红外传感器代表了两个迅速发展的结合了红外测温和通常与计算机联系在一起的高速数字技术的科学联盟。
这些文书被称为智能传感器,因为他们把微处理器作为编程的双向收发器。
传感器之间的串行通信的生产车间和计算机控制室。
而且因为电路体积小,传感器因此更小,简化了在紧张或尴尬地区的安装。
智能传感器集成到新的或现有的过程控制系统,从一个新的先进水平,在温度监测和控制方面为过程控制方面的工程师提供了一个直接的好处。
1 集成智能传感器到过程线同时广泛推行的智能红外传感器是新的,红外测温已成功地应用于过程监测和控制几十年了。
在过去,如果工艺工程师需要改变传感器的设置,它们将不得不关闭或者删除线传感器或尝试手动重置到位。
当然也可能导致路线的延误,在某些情况下,是十分危险的。
升级传感器通常需要购买一个新单位,校准它的进程,并且在生产线停滞的时候安装它。
例如,某些传感器的镀锌铁丝厂用了安装了大桶的熔融铅、锌、和/或盐酸并且可以毫不费力的从狭窄小道流出来。
从安全利益考虑,生产线将不得不关闭,并且至少在降温24小时之前改变和升级传感器。
今天,工艺工程师可以远程配置、监测、处理、升级和维护其红外温度传感器。
带有双向RS - 485接口或RS - 232通信功能的智能模型简化了融入过程控制系统的过程。
一旦传感器被安装在生产线,工程师就可以根据其所有参数来适应不断变化的条件,一切都只是从控制室中的个人电脑。
举例来说,如果环境温度的波动,或程序本身经历类型、厚度、或温度的改变,所有过程工程师需要做的是定制或恢复保存在计算机终端的设置。
新型传感器的研究现状及未来发展趋势传感器是一种现代化技术所必需的元件,它能够将各种物理量转化为电信号。
传感器的应用范围广泛,例如自动化生产、交通运输、医疗诊断、安全监测等领域,因此传感器技术的发展对现代化生产、生活、科学技术的发展有着非常重要的作用。
传感器的种类很多,根据测量的物理量不同,可以分为温度传感器、压力传感器、流量传感器、湿度传感器、加速度传感器、光学传感器等等。
在这些传感器中,新型传感器是一种备受关注的技术。
一、新型传感器的研究现状1. MEMS技术传感器MEMS是微电子机械系统(Micro-Electro-Mechanical System)的缩写,它是一种微型化的电气机械系统,它能够将机械元件和电子元件进行集成化处理。
因此,MEMS技术传感器的优势在于体积很小、功耗低、响应速度快、可靠性高、价格便宜等等。
如今,MEMS技术传感器的应用已经非常广泛,例如手机中的加速度传感器、陀螺仪、磁力计、压力传感器等等,这些传感器的应用大大提升了手机的功能和用户体验。
2. 光纤传感器光纤传感器是一种基于光学原理的传感器,它使用光的传输来测量物理量。
与传统传感器相比,光纤传感器具有很多优势,例如高灵敏度、抗干扰能力强、安全可靠、经济实用,能够实现长距离传递、分布式检测等等。
目前,光纤传感器主要应用在石油天然气、交通运输、环境监测、生命科学等领域。
例如,在石油天然气开采中,光纤传感器可以测量油井的温度、压力、流量等参数,可以帮助确定油井的产量和工作状态,并且可以提高油井的生产效率。
3. 生物传感器生物传感器主要是应用在医疗诊断领域中的,它能够检测人体内的生物分子、细胞和组织等信息。
例如,可以测量血液中的血糖、白细胞计数、酸碱度等指标,可以帮助医生进行疾病的诊断和治疗。
目前,生物传感器技术发展非常迅速,尤其是以DNA、RNA 等为基础的生物传感器,它可以快速、准确地检测病原体、基因变异等信息,有望成为未来医疗诊断中的主要手段。
外文文献翻译译稿1基于电阻应变式称重传感器的高精度和低容量电子秤开发Baoxiang He,Guirong Lu ,Kaibin Chu ,Guoqiang Ma摘要:基于称重传感器的应变计优化设计中除了一些先进的稳定技术比如温度的影响之外,静态超载和计算机模式识别(CRT)技术也被用来进行动态模拟与分析。
这种多谐振荡的压力释放方法是在生产中创造性的使用了压力传感器,由于这种技术,量程30G的压力传感器才能做到高精度,高稳定性。
由于使用了这种压力传感器,使得基于传感器的电子秤拥有300,00种分类和小于0.2mg的精度。
这种压力传感器的量程和精度远远高于市场上的同类产品,而其价格却远低于电磁压力传感器。
因此,这种压力传感器的商业前景是十分广阔的。
关键词:设计;电阻应变式称重传感器;精度;电子秤1.介绍众所周知,压力传感器的精度是决定一个的电子秤精度的关键。
目前,用于高精度称重的传感器主要是电磁平衡式称重传感器。
低成本电阻应变式称重传感器仅能用于使低精度的称量。
主要影响精度应变式称重传感器的误差是蠕变和温度漂移,特别是对于低负荷的传感器来说。
一般来说,高精度传感器的负载能力最低是300克。
称重传感器的最大分配平衡只有50K,最小分辨率是不小于0.01克。
总而言之,对于超低容量称重传感器来说设计和制造技术是很难被应用到敏感的称重传感器的加工和生产中的。
因此很难做出足够好的高精度平衡的称重传感器。
使得低量程和高精度的传感器始终是全世界的热门话题。
本文将分析应力释放及补偿技术,探索低量程高精度应变式称重传感器的制造技术。
2.原理与方法A. 残余应力的释放制作压力传感器主要部件的材料是铝棒。
为了获得更好的综合性能,铝条会在挤压后进行淬火。
由于淬火的残余应力不能被自然老化而得到充分释放,此外,机械加工和固化过程中也会造成很大的残余应力,特别是对于超低容量称重传感器来说,如果这个压力不及时释放,可能就会在压力传感器被测试或者是最终使用的时候释放出来。
英文文献Semiconductor Gas SensorsResearch and development of gas sensors have shown great advances during the past decade. Semiconductor gas sensors mainly using SnO2 elements have been prevailing as detectors or alarms for leakage of LP (Liquefied Propane) gas and town gas, in addition to other applications. Gas sensors based on MOSFET, first proposed in 1975, have attracted interests of many researchers of many researchers, and have been developed to a point of commercialization as a hydrogen detectors. Solid electrolytes, represented by stabilized zirconia, have proven to be very promising sensors materials for oxygen, SO2,etc. This paper aims at reviewing briefly recent advances and trends in semiconductors gas sensors which were developed in a recent few years.Semiconductors gas sensors detect gases from a change in electrical resistance of an element made with a semi conductive metal oxide, typically SnO2 sensor. Although sensors utilizing γ-Fe2O3 or α-Fe2O3 have been put into practical use, SnO2 sensor still has an overwhelming market share. The production of semiconductor gas sensors has grown into a large industry: more than 5 million pieces were production in 1983.Most of them have been used in domestic homes as detectors or alarms for gas leakage. Field statistic has shown that gas alarms are quite effective to prevent an outbreak of gas leakage accident; the accident rate. Anyway semiconductors have been so far given much credit as an important device for home security and the installation rate of gas alarms is increasing year after year. Several years ago a problem arose about SnO2 gas sensor when it was adopted at places like kitchens of underground restaurants where various inflammable gases came out into atmosphere from fuels and cooking very frequently during working time. In such a dirty atmosphere, the gas sensor tended to given an alarm at an inflammable gas concentration which was lowered gradually with an elapse of operation time. It has been pointed out that the problem was contributed by electric resistance of the sensor element due to its sintering at unexpectedly high working temperatures. The problem has been solved after revisions were made to the sensor element.半导体气敏传感器在过去的十年间,气敏传感器的研究和发展已经有了很大的进步。
中英文对照资料外文翻译文献附录Ⅰ:Magnetoelastic Torque Sensor Utilizing a Thermal Sprayed Sense-Element for Automotive Transmission ApplicationsABSTRACTA Magnetoelastic based Non-Contacting, Non-Compliant Torque Sensor is being developed by Siemens VDO for automotive transmission applications. Such a sensor would benefit the automotive industry by providing the feedback needed for precise computer control of transmission gear shifting under a wide range of road conditions and would also facilitate cross-platform usage of a common transmission unit.Siemens VDO has prototyped transmission torque sensors operating on the principle of Inverse- magnetostriction, also referred to as the Inverse-Joule Effect and the Villari Effect. Magnetostriction, first documented in the mid 1800’s, is a structural property of matter that defines a material’s dimensional changes as a result of exposure to a magnetic field. Magnetostriction is caused when the atoms that constitute a material reorient in order to align their magnetic moments with an external magnetic field. This effect is quantified for a specific material by its saturation magnetostriction constant, which is a value that describes a material’s maximum change in length per unit length.Inverse-magnetostriction, conversely, defines changes in a material’s magnetic properties in response to applied mechanical forces. Material that is highly magnetostrictive and elastic in nature is referred to as being magnetoelastic. The premise of the Siemens VDO torque sensor design is that a magnetoelastic material can be bonded to a cylindrical shaft and magnetized in its mechanical quiescent state to create a sense- element. While under torque, principle tensile and compressive stress vectors in the form of counter- spiraling, mutually orthogonal helices develop in the shaft and are conveyed to the magnetoelastic sense-element giving rise to a measurable magnetic field change. The magnetic field deviation that arises from the magnetoelastic sense-element is directly proportional to the magnitude of the imposed torque. In effect, the magnetic field is modulated by torque. A sensitive magnetometer then translates the field strength into an analog voltage signal, thereby completing the torque-to-voltage transducer function.Critical to the success of the Siemens VDO torque sensor design is an intimate attachment of the sense- element to the torque-bearing member. Inconsistencies in the boundary between the sense-element and the torque-bearing member will result in aberrant coupling of stresses into the sense-element manifesting in performance degradation. Boundary inconsistenciescan include such imperfections as voids, contaminates, lateral shearing, and localized zones of stress pre-load. Such inhomogeneities may be inherent to an attachment method itself or may subsequently be caused by systemically rendered malformations.Thermal spray, the process where metal particles are deposited onto a substrate to form a coating, was used to address the issue of securely affixing magnetic material to a torque-bearing member. In addition to achieving the prerequisite of an intimate and secure bond, the thermal spray process can be regulated such that the deposited magnetic material is pre-loaded with the internal stresses needed to invoke the inverse- magnetostriction effect.Summarizing, the passive nature of the magnetic sense- element provides an intrinsically simple kernel for the Siemens VDO torque sensor that makes for a highly reliable and stable design. The thermal spray process adds robustness to the mechanical aspect by permitting torque excursions to an unprecedented ±2000% of full scale (per prototype validation testing of certain constructs) without the need for ancillary torque limiting protection devices. Furthermore, accuracy, repeatability, stability, low hysteresis, rotational position indifference, low cost and amenability to the high-volume manufacturing needs of the automotive marketplace are all attributes of this torque sensing technique. When coupled with a magnetometer that is grounded in well- established fluxgate technology, the resultant sensor is inherently dependable and can potentially establish a new standard for torque measuring sensors.INTRODUCTIONAs is well known, automotive transmissions are designed to alter the power transfer ratio between the engine and the drive wheels effectively optimizing engine loading. The engine thereby runs in a narrow and efficient operating band even though the vehicle travels over a wide range of speeds. For automatic transmissions, shift valves select the gear ratio based generally on the throttle position, engine vacuum and the output shaft governor valve state. With the advent of electronic sensors and computerized engine controllers, transmission shift functions have been migrating towards closed-loop operation under software processing control. Along with this progression came the realization that the transmission output torque would provide a valuable feedback parameter for shift and traction control algorithms. The measurement of output torque, however, proved elusive due to the extremely harsh operating conditions. One particular SUV application under consideration required 1% accuracy in measurements of roughly 2700 Nm with possible torque excursion of 4700 Nm; all while exposed to temperature extremes -45 to +160 o C.One method for measuring torque is to examine the physical stresses that develop in a shaft when it is subjected to an end-to-end twisting force. The principle stresses are compressive and tensile in nature and develop along the two counter-spiraling, mutually orthogonal 45 o helices. They are defined by the equation :t = Tr / JWhere T is the torque applied to the shaft, r is the shaft radius and J is the polar moment of inertia.Setting p r4/ 2 = J for a solid cylindrical shaft and r = d/2 yields:t = 16T / p dOnce again, T is the torque applied to the shaft and d is the shaft diameter.Furthermore, the degree of twist experienced by the shaft for a given torque is given by2: q = 32(LT) / (p d4G)Where L is the length of the shaft, T is the applied toque, d is the diameter of the shaft and G is the modulus of rigidity of the shaft. The modulus of rigidity defines the level of elasticity of the shaft material, thus, a lower G value would manifest in a shaft with a higher degree of twist for any given applied torque.Torque induced stresses that occur in the shaft material are transferred into an affixed magnetic coating and give rise to measurable changes in its surrounding magnetic field that are directly proportional to the magnitude of the applied torque; with the polarity of the magnetic field, i.e., north or south, governed by the direction of the applied torque. In essence, this is the premise of torque sensing by means of inverse magnetostriction.TORQUE SENSOR EMBODIMENTTo effectively invoke the inverse-magnetostriction effect, the magnetic material must be correctly pre-loaded with stress anisotropy in its quiescent state. In the case of a cylindrically shaped magnetic element, the anisotropic forces must be circumferential (i.e., tangential) in nature and can be either compressive or tensile –depending on the polarity or sign of the material’s saturation magnetostriction constant. Achieving a homogenous pre-load throughout the magnetic material is crucial if the sensor is to accurately interpret torque regardless of its rotational position within a stationary magnetometer.POSITIVE MAGNETOELASTIC DEVICESEarlier efforts to create such a torque sensing element relied on a sense element made of material with a positive saturation magnetostriction constant. This embodiment was realized with a ring-shaped magnetoelastic element made from 18% nickel-iron alloy that intrinsically requires tensile circumferential pre- loading 3 . Such a pre-load was achieved by pressing the ring onto a tapered area of the base shaft – effectively stretching it. The effect of tensile stress on the magnetic hysteresis behavior is shown in Figure 1 where the remnant inductance, B r , nearly triples. The “easy-axes” of the magnetic domains align circumferentially due to the anisotropy defined by the principal tensile stress vector. When magnetically biased, the system in effect operates as a circumferentially shorted magnet with B approaching B r and H approaching zero.NEGATIVE MAGNETOELASTIC DEVICESTo advance the state of the art, Siemens VDO Automotive has opted for a magnetoelastic element witha negative saturation magnetostriction constant. In this case, the alloy is very high in nickel content exhibiting a saturation magnetostriction, l s , in the range of -3e-5 dl/l and requires the stress pre-load to be tangentially compressive in nature. To achieve this embodiment, the magnetoelastic material that constitutes the sense element is “deposited” onto the base shaft using a high- velocity-oxygen-fuel (HVOF) thermal spray process. The coating thickness is only 0.5mm with an axial length of 25mm. The sense element material is endowed with compressive stress by means of precise control of the thermal spray process parameters. This proprietary procedure transforms a deposition process that normally confers isotropic material properties into one that renders the requisite stress anisotropy.Prototype FabricationMagnetoelastic ElementThe specification for the shaft requires the measurement of torque levels of 2700 Nm with no deleterious effects following exposures of up to 4700 Nm. Operating temperature is -45 o C to 160 o C.By converting from the earlier torque sensor “pressed-on ring” concept to one based on a magnetoelastic material with a negative saturation magnetostriction constant, l s , the design is advanced in several respects. Primarily, its resiliency against stress/corrosion cracking is enhanced by 1) the inherent insusceptibility of high nickel content alloys towards corrosives and 2) by the lower porosity of material in compression. This is in distinct contrast with the high iron content ring placed in tension which is vulnerable to fissuring, material creep and stress corrosion cracking which can, over time, relieve the necessary anisotropic forces causing performancedegradation.An important consequence of using the thermal spray technology is the intimate bond provided between the deposited magnetoelastic element and the base shaft. By using a thermal spray process, the boundary whereby torque induced stresses are transferred is free of such imperfections as voids, galled or furrowed material and localized stress gradients that are all characteristically associated with the pressed-on ring technique. These imperfections can induce aberrations in the magnetic field shape thereby imparting torque measurement errors relative to the rotational position of the shaft with respect to a stationary magnetometer. Furthermore, the strong bond at the interface effectively eliminates the slippage commonly associated with the interference fit of a pressed-on ring during extreme torque exposures. Any movement at this interface will manifest as a biasing of material stresses causing a zero-shift measurement error. This is not a concern when the magnetoelastic element is deposited using an HVOF thermal spray gun. Torque excursions to an unprecedented ±2000% of full scale have been successfully applied directly to prototype sensors without ancillary torque limiting protection devices.In addition, depositing the magnetoelastic element onto a rotating shaft provides an inherently mechanically balanced assembly that imposes no angular velocity (RPM) or angular acceleration limits on the system.Other thermal spray technology attributes are its amenability to high volume manufacturing environments, the robustness of the process insuring consistent reproducibility, and an overall reduction in fabrication steps –such as the elimination of machining procedures to mass-produce rings, cutting operations for precisely matching tapers on the shaft and ring, and pressing operations to install rings onto shafts.Magnetic Field ShapingContributions from the mechanical mounting tolerances of system components (e.g., bearings and bushings) can manifest as a misalignment between the centroid centerlines of the magnetometer and the magnetoelastic element. Once calibrated, any displacement in the positional relationship between these two components will alter the system’s transfer function, possibly causing the overall error to exceed specification. The sharply focused nature of the magnetic field radially emanating from the magnetoelastic element during the application of torque (see Figure 3) accentuates this effect. This error can be minimized by shaping the physical structure of the magnetoelastic element resulting in a contouring of the magnetic field to a more favorable shape. As shown in Figure 4, the magnetic field is made to be less pronounced with an hourglass shaped magneto elastic element and sensitivity to misalignment is, thus, reduced. In this example, the magneto elastic element is contoured such that the air gap between the magneto elastic element and the magnetometer is reduced when axial displacement between their centroid centerlines occurs. The expected reduction in magnetic signal strength caused by this displacement is thus compensated by the air gap reduction.Shafts can be fabricated with a variety of contoured surface adaptations and the thermal sprayed magnetoelastic element’s shape will expectedly follow suit. As is evident, a pressed-on ring manifestation of the magnetoelastic element would be incompatible with this technique. Various contours are being considered for further reducing the sensitivity to misalignment and for improving other performance parameters such as magnetic field strength and hysteresis.Cylindrical Shaft Shown with Superimposed Associated Magnetic Field (i.e., Radially Directed Flux Density)Contoured Shaft (Hourglass Shape) Shown with Superimposed Associated Magnetic Field (i.e., Radially Directed Flux Density)In Figures 3 and 4, the spatial image of the shaft is mapped using a laser displacement system and the superimposed magnetic field is mapped in 3-space with a hall cell.MagnetometerRounding out the torque sensor hardware complement is a non-contacting magnetometer that translates the magnetic signal emitted by the shaft’s sense element into an electrical signal that can be read by system-level devices. Coupling the torque signal to some interim conditioning electronics magnetically is an attractive option due to its “non-contacting” attribute. A signal transference scheme capable of spanning an air gap is advantageous sinceit requires no slip rings, brushes or commutators that can be affected by wear, vibration, corrosion or contaminants.The fundamental magnetometer embodiment, shown in Figure 5, is circular with the shaft passing through its center. The magnetometer encompasses the magnetoelastic element of the shaft and the shaft is allowed to freely rotate within the fixed magnetometer. Power and the output signal pass through the magnetometer’s wiring harness.Transmission Torque Sensor MagnetometerThe magnetometer actually performs several functions beyond measuring a magnetic field’s strength. These functions include magnetic signal conditioning, electrical signal conditioning, implementation of self-diagnostics, and the attenuation of magnetic and electromagnetic noise sources.The magnetic detection method chosen for the torque sensor is fluxgate magnetometry, also known as saturable-core magnetometry. This is a well-established technology that has been in use since the early 1900’s. Fluxgate ma gnetometers are capable of measuring small magnetic field of strengths down to about 10 -4 A/m (or 10 -6 Oe) with a high level of stability. This performance is roughly three orders of magnitude better than that achieved by Hall Effect devices. Although many fluxgate designs use separate drive and pickup coils, the torque sensor magnetometer was designed to use a single coil for both functions.Magnetic signal conditioning is accomplished by use of flux guides integral to the magnetometer. These flux guid es amplify the magnetic signal radiating from the shaft’s sense element prior to detection by the fluxgates thereby improving the signal-to-noise ratio. The flux guides provide additional signal conditioning by integrating inhomogeneities in the magnetic signal relative to the shaft rotational position that might otherwise be misinterpreted as torque variations. The flux guide configuration is shown in Figure 6 and a magnetic simulation of the resulting field concentration is shown in Figure 7.Flux guides surrounding magnetoelastic elementAxial view of magnetic simulation with flux guide material’s relative DC permeability set to 50,000 (e.g., HyMu “80”)To further improve the magnetometer’s immunity to stray signals present in the ambient, common-mode rejection schemes are employed in the design of both the electronic and magnetic circuits. For example, wherever possible, differential circuitry was used in theelectronic design in order to negate common-mode noise. This practice was carried over to the magnetic design through the use of symmetrically shaped flux guides and symmetrically placed fluxgates that cancel common- mode magnetic signals that originate outside the system.Finally, to augment the electrical and magnetic common- mode rejection strategies, EMI and magnetic shielding practices were incorporated into the design to further improve the signal-to-noise ratio. Stray magnetic and electro-magnetic signals found in the ambient are prevented from reaching the fluxgates and the shaft’s magnetic torque-sensing element through the use of shielding material that encompasses these critical components.The functional diagram of Figure 8 depicts the concept of the magnetometer by showing a simplified version of the circuitry with extraneous components removed for additional clarity. An application specific integrated circuit (ASIC) contains all the circuitry necessary to perform the indicated functions.Magnetometer Functional DiagramSummarizing, the multi-function, fluxgate based magnetometer design provides the optimal platform for detecting the modulated magnetic field that emanates from the shaft’s torque-sensing magnetic element. By coupling time-proven fluxgate technology with an innovative flux guide configuration and with sophisticated electronic circuitry, the resultant magnetometer is durable, accurate, and stable and comprehensively achieves the design goals dictated by the application.CONCLUSIONThe latest developments in the magnetoelastic torque sensor that are presented here advance the current state of the technology by addressing many obstacles that have delayed itsacceptance by the automotive industry. Thermal spray deposition of the magnetoelastic element has resolved problems that have plagued earlier versions of the magnetoelastic torque sensor’s active element. The lack of integrity of the shaft/magnetoelastic element interface, stress-corrosion cracking, long term stability, inhomogeneity of magnetic properties and manufacturing processes that run counter to high volume production, are no longer hindering the introduction of magnetoelastic torque sensors into the automotive marketplace. With design goals clearly defined and an aggressive development program invariably progressing, the prospect of an automotive, magnetoelastic based non-compliant torque sensor is now more readily attainable.ACKNOWLEDGMENTSI would like to acknowledge the efforts of Ivan Garshelis who pioneered this approach to torque sensing and who had the unwavering vision to recognize this technology’s potential; and Carl Gandarillas whose scientific and analytical investigative approach has explicated much of the mystery associated with thermal sprayed magnetics. I would also like to express my gratitude to the torque sensor development team at Siemens VDO Automotive for their dedication and the extra effort that they put forth; and to Siemens VDO Automotive management for having the courage to invest in a new technology and the patience to see it through.REFERENCES1. Raymond J. Roark and Warren C. Young, Formulas for Stress and Strain, 5 th Edition, McGraw-Hill; Chapter 9, Torsion2. Stephen H.Crandall and Norman C. Dahl, An Introduction to the Mechanics of Solids, McGraw-Hill; Chapter 6, Torsion3. Ivan J. Garshelis, Magnetoelastic Devices, Inc., IEEE Transaction On Magnetics ; 0018-9464/92 V ol. 28, No. 5 September 5, 1992ADDITIONAL SOURCES1. Richard L. Carlin, Magnetochemistry; Springer-Verlag2. Rollin J. Parker, Advances In Permanent Magnetism; John Wiley & Sons3. Etienne du Tremolet de Lachhesserie, Magnetostriction Theory and Applications of Magnetostriction; CRC Press4. Richard M. Bozorth, Ferromagnetism; IEEE Press附录Ⅱ:磁力矩传感器利用一个热喷涂感知元件在汽车变速器中的应用摘要一个非接触式的,非兼容扭矩的传感器是由西门子VDO正在开发应用于汽车传动之中。
中英文资料外文翻译文献原文:Temperature Sensor ICs Simplify DesignsWhen you set out to select a temperature sensor, you are no longer limited to either an analog output or a digital output device. There is now a broad selection of sensor types, one of which should match your system's needs.Until recently, all the temperature sensors on the market provided analog outputs. Thermistors, RTDs, and thermocouples were followed by another analog-output device, the silicon temperature sensor. In most applications, unfortunately, these analog-output devices require a comparator, an ADC, or an amplifier at their output to make them useful.Thus, when higher levels of integration became feasible, temperature sensors with digital interfaces became available. These ICs are sold in a variety of forms, from simple devices that signal when a specific temperature has been exceeded to those that report both remote and local temperatures while providing warnings at programmed temperature settings. The choice now isn't simply between analog-output and digital-output sensors; there is a broad range of sensor types from which to choose.Classes of Temperature SensorsFour temperature-sensor types are illustrated in Figure 1. An ideal analog sensor provides an output voltage that is a perfectly linear function of temperature (A). In the digital I/O class of sensor (B), temperature data in the form of multiple 1s and 0s are passed to the microcontroller, often via a serial bus. Along the same bus, data are sent to the temperature sensor from the microcontroller, usually to set the temperature limit at which the alert pin's digital output will trip. Alert interrupts the microcontroller when the temperature limit has been exceeded. This type of device can also provide fan control.Figure 1. Sensor and IC manufacturers currently offer four classes of temperature sensors."Analog-plus" sensors (C) are available with various types of digital outputs. The V OUT versus temperature curve is for an IC whose digital output switches when a specific temperature has been exceeded. In this case, the "plus" added to the analog temperature sensor is nothing more than a comparator and a voltage reference. Other types of "plus" parts ship temperature data in the form of the delay time after the part has been strobed, or in the form of the frequency or the period of a square wave, which will be discussed later.The system monitor (D) is the most complex IC of the four. In addition to the functions provided by the digital I/O type, this type of device commonly monitors the system supply voltages, providing an alarm when voltages rise above or sink below limits set via the I/O bus. Fan monitoring and/or control is sometimes included in this type of IC. In some cases, this class of device is used to determine whether or not a fan is working. More complex versions control the fan as a function of one or more measured temperatures. The system monitor sensor is not discussed here but is briefly mentioned to give a complete picture of the types of temperature sensors available.Analog-Output Temperature SensorsThermistors and silicon temperature sensors are widely used forms of analog-output temperature sensors. Figure 2 clearly shows that when a linear relationship between voltage and temperature is needed, a silicon temperature sensor is a far better choice than a thermistor. Over a narrow temperature range, however, thermistors can provide reasonable linearity and good sensitivity. Many circuits originally constructed with thermistors have over time been updated using silicon temperature sensors.Figure 2. The linearity of thermistors and silicon temperature sensors, two popular analog-output temperature detectors, is contrasted sharply.Silicon temperature sensors come with different output scales and offsets. Some, for example, are available with output transfer functions that are proportional to K, others to °C or °F. Some of the °C parts provide an offset so that negative temperatures can be monitored using a single-ended supply.In most applications, the output of these devices is fed into a comparator or a n A/D converterto convert the temperature data into a digital format. Despite the need for these additional devices, thermistors and silicon temperature sensors continue to enjoy popularity due to low cost and convenience of use in many situations.Digital I/O Temperature SensorsAbout five years ago, a new type of temperature sensor was introduced. These devices include a digital interface that permits communication with a microcontroller. The interface is usually an I²C or SMBus serial bus, but other serial interfaces such as SPI are common. In addition to reporting temperature readings to the microcontroller, the interface also receives instructions from the microcontroller. Those instructions are often temperature limits, which, if exceeded, activate a digital signal on the temperature sensor IC that interrupts the microcontroller. The microcontroller is then able to adjust fan speed or back off the speed of a microprocessor, for example, to keep temperature under control.This type of device is available with a wide variety of features, among them, remote temperature sensing. To enable remote sensing, most high-performance CPUs include an on-chip transistor that provides a voltage analog of the temperature. (Only one of the transistor's two p-n junctions is used.) Figure 3 shows a remote CPU being monitored using this technique. Other applications utilize a discrete transistor to perform the same function.Figure 3. A user-programmable temperature sensor monitors the temperature of a remote CPU's on-chip p-n junction.Another important feature found on some of these types of sensors (including the sensor shown in Figure 3) is the ability to interrupt a microcontroller when the measured temperature falls outside a range bounded by high and low limits. On other sensors, an interrupt is generated when the measured temperature exceeds either a high or a low temperature threshold (i.e., not both). For the sensor in Figure 3, those limits are transmitted to the temperature sensor via the SMBus interface. If the temperature moves above or below the circumscribed range, the alert signal interrupts the processor.Pictured in Figure 4 is a similar device. Instead of monitoring one p-n junction, however, it monitors four junctions and its own internal temperature. Because Maxim's MAX1668 consumes a small amount of power, its internal temperature is close to the ambient temperature. Measuring the ambient temperature gives an indication as to whether or not the system fan is operating properly.Figure 4. A user-programmable temperature sensor monitors its own local temperature and the temperatures of four remote p-n junctions.Controlling a fan while monitoring remote temperature is the chief function of the IC shown in Figure 5. Users of this part can choose between two different modes of fan control. In the PWM mode, the microcontroller controls the fan speed as a function of the measured temperature by changing the duty cycle of the signal sent to the fan. This permits the power consumption to be far less than that of the linear mode of control that this part also provides. Because some fans emit an audible sound at the frequency of the PWM signal controlling it, the linear mode can be advantageous, but at the price of higher power consumption and additional circuitry. The added power consumption is a small fraction of the power consumed by the entire system, though.Figure 5. A fan controller/temperature sensor IC uses either a PWM- or linear-mode control scheme.This IC provides the alert signal that interrupts the microcontroller when the temperature violates specified limits. A safety feature in the form of the signal called "overt" (an abbreviated version of "over temperature") is also provided. If the microcontroller or the software were to lock up while temperature is rising to a dangerous level, the alert signal would no longer be useful. However, overt, which goes active once the temperature rises above a level set via the SMBus, is typically used to control circuitry without the aid of the microcontroller. Thus, in thishigh-temperature scenario with the microcontroller not functioning, overt could be used to shut down the system power supplies directly, without the microcontroller, and prevent a potentially catastrophic failure.This digital I/O class of devices finds widespread use in servers, battery packs, and hard-disk drives. Temperature is monitored in numerous locations to increase a server's reliability: at the motherboard (which is essentially the ambient temperature inside the chassis), inside the CPU die, and at other heat-generating components such as graphics accelerators and hard-disk drives. Battery packs incorporate temperature sensors for safety reasons and to optimize charging profiles, which maximizes battery life.There are two good reasons for monitoring the temperature of a hard-disk drive, which depends primarily on the speed of the spindle motor and the ambient temperature: The read errors in a drive increase at temperature extremes, and a hard disk's MTBF is improved significantly through temperature control. By measuring the temperature within the system, you can control motor speed to optimize reliability and performance. The drive can also be shut down. In high-end systems, alerts can be generated for the system administrator to indicate temperature extremes or situations where data loss is possible.Analog-Plus Temperature Sensors"Analog-plus" sensors are generally suited to simpler measurement applications. These ICs generate a logic output derived from the measured temperature and are distinguished from digital I/O sensors primarily because they output data on a single line, as opposed to a serial bus.In the simplest instance of an analog-plus sensor, the logic output trips when a specific temperature is exceeded. Some of these devices are tripped when temperature rises above a preset threshold, others, when temperature drops below a threshold. Some of these sensors allow the temperature threshold to be adjusted with a resistor, whereas others have fixed thresholds.The devices shown in Figure 6 are purchased with a specific internal temperature threshold. The three circuits illustrate common uses for this type of device: providing a warning, shutting down a piece of equipment, or turning on a fan.Figure 6. ICs that signal when a temperature has been exceeded are well suited forover/undertemperature alarms and simple on/off fan control.When an actual temperature reading is needed, and a microcontroller is available, sensors that transmit the reading on a single line can be useful. With the microcontroller's internal counter measuring time, the signals from this type of temperature sensor are readily transformed to a measure of temperature. The sensor in Figure 7 outputs a square wave whose frequency is proportional to the ambient temperature in Kelvin. The device in Figure 8 is similar, but theperiod of the square wave is proportional to the ambient temperature in kelvins.Figure 7. A temperature sensor that transmits a square wave whose frequency is proportional tothe measured temperature in Kelvin forms part of a heater controller circuit.Figure 8. This temperature sensor transmits a square wave whose period is proportional to the measured temperature in Kelvin. Because only a single line is needed to send temperature information, just a single optoisolator is required to isolate the signal path.Figure 9, a truly novel approach, allows up to eight temperature sensors to be connected on this common line. The process of extracting temperature data from these sensors begins when the microcontroller's I/O port strobes all the sensors on the line simultaneously. The microcontroller is then quickly reconfigured as an input in order to receive data from each of the sensors. The data are encoded as the amount of time that transpires after the sensors are strobed. Each of the sensors encodes this time after the strobe pulse within a specific range of time. Collisions are avoided by assigning each sensor its own permissible time range.Figure 9. A microcontroller strobes up to eight temperature sensors connected on a common line and receives the temperature data transmitted from each sensor on the same line.The accuracy achieved by this method is surprisingly high: 0.8°C is typical at room temperature, precisely matching that of the IC that encodes temperature data in the form of the frequency of the transmitted square wave. The same is true of the device that uses the period of the square wave.These devices are outstanding in wire-limited applications. For example, when a temperature sensor must be isolated from the microcontroller, costs are kept to a minimum because only one optoisolator is needed. These sensors are also of great utility in automotive and HVAC applications, because they reduce the amount of copper running over distances.Anticipated Temperature Sensor DevelopmentsIC temperature sensors provide a varied array of functions and interfaces. As these devicescontinue to evolve, system designers will see more application-specific features as well as new ways of interfacing the sensors to the system. Finally, the ability of chip designers to integrate more electronics in the same die area ensures that temperature sensors will soon include new functions and special interfaces.翻译:温度传感器芯片简化设计当选择一个温度传感器时,将不再局限于模拟输出或数字输出设备。
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 。
外文资料翻译资料来源:第七届国际测试技术研讨会文章名:The Principle of the Intelligent Temperature Sensor DS18B20and Its Application作者:LI Shuo LI Xiaomi文章译名:智能温度传感器DS18B20的原理与测量姓名:学号:指导教师(职称):专业:班级:所在学院:译文智能温度传感器DS18B20的原理及其应用摘要:功能和结构的数字本文介绍了温度测量芯片DS18B20的温度测量系统的介绍,8051单片机作为其作品CPU和DALLAS18B20其温度数据收集 - 转换。
硬件的原理,软件程图和一个短暂的时间延迟子程序也都给予列出。
关键词:DS18B20温度传感器,单片机微机,硬件设计一、导言单轨数字温度传感器DS18B20的生产由美国DALLAS公司。
它可以转换的温度信号成字信号提供的微电脑处理直接。
与传统的相比热敏电阻器,它可以直接读出的措施温度并根据实际它可以actualize 9〜12的数值读数方式通过简单的编程。
信息读取或写入DS18B20的,只需要一个单一的线。
温度变换功率来源于为主线,主线本身可以供电源DS18B20的,不需要额外的电源。
因此,如果使用DS18B20的,系统的结构会更简单,更可靠。
因为每个DS18B20包含一个独特的硅序列号,多个DS18B20s 可以存在于相同的1-Wire总线。
这允许浇筑温度传感器在许多不同的地方。
应用场合此功能是有用的,包括HVAC环境控制,检测建筑物内的温度,设备或机械,过程监测和控制。
二、 DS18B20的结构DS18B20的四个组成部分的主要数据:(1)64位光刻ROM(2)温度传感器(3)非易失性温度报警触发器TH和TL(4)配置寄存器。
设备源于其权力从1-Wire通信线通过储能在一段时间的内部电容当信号线为高,并继续操作此期间的低倍的电源关闭1-Wire线,直到它返回来补充高寄生虫(电容器)供应。
英文Automobile sensor technologyModern electron controls technology, control systematic, and transmission system for having advanced engine, regulating system as well as travel to guide the performance of systematic automobile takes decision role. Can say , now automobile manufacturing industry is the technical field that will adopt electronic system in large quantities , is also each kind of sensor develop vigorously the land of its specialty that used force. To ensure the safe, comfortable, low pollution of automobile and burn high to lead, each kind of sensor of development application has become the key of modern automobile electromechanical unifinication.Now automobile sensor and its production technology have become better day-by-day, each kind of sensor tends to mature basically, is batch production and sensor, and on high-grade luxury automobile and intelligent automobile, have used 200 to 300 sensors probably. Thus it can be seen, sensor technology is to realize the necessary foundation that automobile electron melts with guarantee condition, its application scope is very extensive.1 present situation with develop developmentIn recent years, automobile sensor development is quick, partial products have formed scale abroad to produce. As, pressure sensor and temperature sensor. Especially enter 90 decade, it is grown increasingly that it uses quantity. According to statistics, in Japan concerning leave empty burn than the high measure of detection, speed and vehicle and for barrier survey etc. have used approximately 50 kinds of sensor in all. In which, it is hot to study to measure 11 kinds; mechanics measure 31 kinds, 8 kinds of other. Now, using magneto resistive element, photo sensor and thermistor, the various sensors that strain gauge makes already extensive application in measure temperature, pressure, acceleration, displacement and rate of flow etc.. Use IC technical, tiny processing technique etc. make breath to press , rate of flow and pressure sensor will enter practical stage step by step.The practical level of 2 automobile sensorsThe major system of automobile application sensor has: ( l ) engine electronic control system; ( 2 ) automobile state information control system; ( 3 ) communication control system. In above-mentioned system, have used pressure, temperature, revolving, air rate of flow, gas and speed respectively , shake and each kind of sensors such as position, practical horizontal minute is stated as follows.2.1 pressure sensorsPressure sensor applies mainly in the transmission system of automobile, detection engine breath negative pressure, atmosphere, engine hydraulic pressure and brake hydraulic etc.. Now, already practical product has membrane to suit - differential transformer or sensor and semiconductor type sensor with electrostatic allow type sensor. In which, it is biggest that the semiconductor type application of pressure sensor measure , it is ten millions that whole world produce per year quantity to reach, market possesses rate, have reached 70%.2.2 temperature sensorsEach automobile assembly of temperature sensor major detection engine and automobile and the temperature that enters waste gas, cooling fluid, oil, fuel air mixture and the air in engine.Nowadays, on general automobile usually, need the temperature sensors more than 10. Practical product has thermistor and gas temperature sensor. Now, abroad, it is thirty-four millions that automobile temperature sensor produce per year quantity to reach.2.3 revolving sensorsRevolving sensor is used in detection angle of bend, the angle of airflow control, engine revolving speed and speed mainly. Now its already practical product measure scope is 0 ~360 degrees, belowprecision 0.5, measure angle of bend to reach 0.1, major type has electromagnetism type and magneto resistive type with suddenly Er element type and optical type etc..2.4 gas sensorsIn automobile engine system, gas sensor is used in detection air purification and control exhaust composition mainly. In various exhaust control systems apply oxygen sensor extensively .the hear resistance of automobile exhaust sensor can higher, now already practical gas sensor have oxidize mainly oxygen sensor and the oxygen sensor of titanium oxide.2.5 air flow transducersAutomobile air flow transducer determines the combustion condition of engine mainly with engine control system and control leave empty burn than with start light a fire etc.. Now, already practical product has revolving board type , blocks the flowmeters such as the door type of eddy current, hot membrane type and the type of hot line.2.6 speed sensorsOn road, measure automobile speed , travel distance and the acceleration for automobile and brake with slide etc. detection , normally with " 5 ship instruments ", can satisfy the low measure requirement of middling speed better, but speed higher , measure error is greater. Therefore, the Japanese, German priority of our country is studied successfully not contact photoelectric speed sensor.2.7 shake sensorShake sensor use 10 automobile engine control ignition systems mainly in, realize to do not have shake working state, insurable certificate engine operates with economic norms and the power of biggest possibility. Now, abroad, already practical product has piezoelectricity type and the type sensor of magnetic induction.2.8 position sensorsPosition sensor is used in the distance of arrival destination and the location of detection automobile mainly. Now, already practical product has electromagnetism type and gyroscope type sensor two types.3 automobile sensor markets foreseeAlong with the quick development of auto industry, sensor has become automobile electronic pillar estate. According to market research, worldwide automobile sensor market is 3,800,000,000 dollars, in year, increase rate reaches 13%. In which, American automobile sensor market is 8,400,000,000 dollars in the beginning of 90 decade; annual increase rate is 154%. Japan is 8.300000000 dollars in the beginning of 90 decade, the end of 90 decade will break through 1,300,000,000 dollars, in the future most have potential will be speed sensor, position sensor, the gyroscope of optical cable and the sensor of terrestrial magnetism. The annual increase rate of above sensor will reach 22%, total sale will reach 4.900000000 dollars. Until 2000, have automatic control, identify barrier function, as well as the intelligent automobile that has definite position and communication function will reach practical melt. It produces per year quantity, will use 150 to 200 sensors for 1,500,000, each automobile.In a word ,Before automobile field is sensor mouth, and in the future, the most important market and that most has potential has development future very much. The automobile work industrial pillar as 90 decade as well as 21 century is industrial , just dynasty electricity melt safely , comfortable direction development, the various types of plenty of demands automobile sensor, develop various automobile sensors vigorously will become the overall realization of auto industry electronic fight goal.译文1汽车传感器技术现代电子控制技术对具有先进发动机控制系统、传动系统、调节系统以及行驶引导系统的汽车的性能起着决定性作用。
中英文资料外文翻译文献SHT11/71传感器的温湿度测量Assist.Prof.Grish Spasov,PhD,BSc Nikolay KakanakovDepartment of Computer Systems,Technical University-branch Plovdiv,25,”Tzanko Djustabanov”Str.,4000Plovdiv,Bulgaria,+35932659576, E-mail:gvs@tu-plovdiv.bg,kakanak@tu-plovdiv.bg 关键词:温湿度测量,智能传感器,分布式自动测控这篇论文阐述了智能传感器的优点,介绍了SHT11/71温湿度传感器(产自盛世瑞公司)。
该传感器是一种理想的对嵌入式系统提供环境测量参数的传感器。
常规的应用时将SHT11/71放于实际的工作环境当中。
应用于分布式的温湿度监测系统。
使用单片机与集成网络服务器来实现对传感器的信息交流与关系。
这个应用是可实现与测试的。
1.介绍温湿度的测量控制对于电器在工业、科学、医疗保健、农业和工艺控制过程都有着显著地意义。
温湿度这两种环境参数互相影响,因为这至关重要的一点,在一些应用中他们是必须并联测量的。
SHT11/71是利用现代技术把温度、湿度测量元件、放大器、A/D转换器、数字接口、校验CRC计算逻辑记忆模块和核心芯片集成到一个非常小的尺寸上[1][3]。
采用这种智能传感器可以缩短产品开发时间和成本。
整合入传感器模数转换和放大器的芯片使开发人员能够优化传感器精度和长期问的的元素。
并不是全结合形式的数字逻辑接口连通性管理的传感器。
这些优点可以减少整体上市时间,甚至价格[1][3]。
本文以SHT11/71(产自盛世瑞公司)智能传感器为例,介绍他的优势和测量程序给出一个实用实例来说明该工作的实现条件。
这个应用时可行可测试的。
2.智能传感器——SHT11/71SHT11/71是一个继承了温度和湿度组建,以及一个多元化校准数字器的芯片。
中英文资料对照外文翻译Basic knowledge of transducersA transducer is a device which converts the quantity being measured into an optical, mechanical, or-more commonly-electrical signal. The energy-conversion process that takes place is referred to as transduction.Transducers are classified according to the transduction principle involved and the form of the measured. Thus a resistance transducer for measuring displacement is classified as a resistance displacement transducer. Other classification examples are pressure bellows, force diaphragm, pressure flapper-nozzle, and so on.1、Transducer ElementsAlthough there are exception ,most transducers consist of a sensing element and a conversion or control element. For example, diaphragms,bellows,strain tubes and rings, bourdon tubes, and cantilevers are sensing elements which respond to changes in pressure or force and convert these physical quantities into a displacement. This displacement may then be used to change an electrical parameter such as voltage, resistance, capacitance, or inductance. Such combination of mechanical and electrical elements form electromechanical transducing devices or transducers. Similar combination can be made for other energy input such as thermal. Photo, magnetic and chemical,giving thermoelectric, photoelectric,electromaanetic, and electrochemical transducers respectively.2、Transducer SensitivityThe relationship between the measured and the transducer output signal is usually obtained by calibration tests and is referred to as the transducer sensitivity K1= output-signal increment / measured increment . In practice, the transducer sensitivity is usually known, and, by measuring the output signal, the input quantity is determined from input= output-signal increment / K1.3、Characteristics of an Ideal TransducerThe high transducer should exhibit the following characteristicsa) high fidelity-the transducer output waveform shape be a faithful reproduction of the measured; there should be minimum distortion.b) There should be minimum interference with the quantity being measured; the presence of the transducer should not alter the measured in any way.c) Size. The transducer must be capable of being placed exactly where it is needed.d) There should be a linear relationship between the measured and the transducer signal.e) The transducer should have minimum sensitivity to external effects, pressure transducers,for example,are often subjected to external effects such vibration and temperature.f) The natural frequency of the transducer should be well separated from the frequency and harmonics of the measurand.4、Electrical TransducersElectrical transducers exhibit many of the ideal characteristics. In addition they offer high sensitivity as well as promoting the possible of remote indication or mesdurement. Electrical transducers can be divided into two distinct groups:a) variable-control-parameter types,which include:i)resistanceii) capacitanceiii) inductanceiv) mutual-inductance typesThese transducers all rely on external excitation voltage for their operation.b) self-generating types,which includei) electromagneticii)thermoelectriciii)photoemissiveiv)piezo-electric typesThese all themselves produce an output voltage in response to the measurand input and their effects are reversible. For example, a piezo-electric transducer normally produces an output voltage in response to the deformation of a crystalline material; however, if an alternating voltage is applied across the material, the transducer exhibits the reversible effect by deforming or vibrating at the frequency of the alternating voltage.5、Resistance TransducersResistance transducers may be divided into two groups, as follows:i) Those which experience a large resistance change, measured by using potential-divider methods. Potentiometers are in this group.ii)Those which experience a small resistance change, measured by bridge-circuit methods. Examples of this group include strain gauges and resistance thermometers.5.1 PotentiometersA linear wire-wound potentiometer consists of a number of turns resistance wire wound around a non-conducting former, together with a wiping contact which travels over the barwires. The construction principles are shown in figure which indicate that the wiperdisplacement can be rotary, translational, or a combination of both to give a helical-type motion. The excitation voltage may be either a.c. or d.c. and the output voltage is proportional to the input motion, provided the measuring device has a resistance which is much greater than the potentiometer resistance.Such potentiometers suffer from the linked problem of resolution and electrical noise. Resolution is defined as the smallest detectable change in input and is dependent on thecross-sectional area of the windings and the area of the sliding contact. The output voltage is thus a serials of steps as the contact moves from one wire to next.Electrical noise may be generated by variation in contact resistance, by mechanical wear due to contact friction, and by contact vibration transmitted from the sensing element. In addition, the motion being measured may experience significant mechanical loading by the inertia and friction of the moving parts of the potentiometer. The wear on the contacting surface limits the life of a potentiometer to a finite number of full strokes or rotations usually referred to in the manufacture’s specification as the ‘number of cycles of life expectancy’, a typical value being 20*1000000 cycles.The output voltage V0 of the unload potentiometer circuit is determined as follows. Let resistance R1= xi/xt *Rt where xi = input displacement, xt= maximum possible displacement, Rt total resistance of the potentiometer. Then output voltage V0= V*R1/(R1+( Rt-R1))=V*R1/Rt=V*xi/xt*Rt/Rt=V*xi/xt. This shows that there is a straight-line relationship between output voltage and input displacement for the unloaded potentiometer.It would seen that high sensitivity could be achieved simply by increasing the excitation voltage V. however, the maximum value of V is determined by the maximum power dissipation P of the fine wires of the potentiometer winding and is given by V=(PRt)1/2 .5.2 Resistance Strain GaugesResistance strain gauges are transducers which exhibit a change in electrical resistance in response to mechanical strain. They may be of the bonded or unbonded variety .a) bonded strain gaugesUsing an adhesive, these gauges are bonded, or cemented, directly on to the surface of the body or structure which is being examined.Examples of bonded gauges arei) fine wire gauges cemented to paper backingii) photo-etched grids of conducting foil on an epoxy-resin backingiii)a single semiconductor filament mounted on an epoxy-resin backing with copper or nickel leads.Resistance gauges can be made up as single elements to measuring strain in one direction only,or a combination of elements such as rosettes will permit simultaneous measurements in more than one direction.b) unbonded strain gaugesA typical unbonded-strain-gauge arrangement shows fine resistance wires stretched around supports in such a way that the deflection of the cantilever spring system changes the tension in the wires and thus alters the resistance of wire. Such an arrangement may be found in commercially available force, load, or pressure transducers.5.3 Resistance Temperature TransducersThe materials for these can be divided into two main groups:a) metals such as platinum, copper, tungsten, and nickel which exhibit and increase in resistance as the temperature rises; they have a positive temperature coefficient of resistance.b) semiconductors, such as thermistors which use oxides of manganese, cobalt, chromium, or nickel. These exhibit large non-linear resistance changes with temperature variation and normally have a negative temperature coefficient of resistance.a) metal resistance temperature transducersThese depend, for many practical purpose and within a narrow temperature range, upon the relationship R1=R0*[1+a*(b1-b2)] where a coefficient of resistance in ℃-1,and R0 resistance in ohms at the reference temperature b0=0℃ at the reference temperature range ℃.The international practical temperature scale is based on the platinum resistance thermometer, which covers the temperature range -259.35℃ to 630.5℃.b) thermistor resistance temperature transducersThermistors are temperature-sensitive resistors which exhibit large non-liner resistance changes with temperature variation. In general, they have a negative temperature coefficient. For small temperature increments the variation in resistance is reasonably linear; but, if large temperature changes are experienced, special linearizing techniques are used in the measuring circuits to produce a linear relationship of resistance against temperature.Thermistors are normally made in the form of semiconductor discs enclosed in glass vitreous enamel. Since they can be made as small as 1mm,quite rapid response times are possible.5.4 Photoconductive CellsThe photoconductive cell , uses a light-sensitive semiconductor material. The resistance between the metal electrodes decrease as the intensity of the light striking the semiconductor increases. Common semiconductor materials used for photo-conductive cells are cadmium sulphide, lead sulphide, and copper-doped germanium.The useful range of frequencies is determined by material used. Cadmium sulphide is mainly suitable for visible light, whereas lead sulphide has its peak response in the infra-red regionand is, therefore , most suitable for flame-failure detection and temperature measurement. 5.5 Photoemissive CellsWhen light strikes the cathode of the photoemissive cell are given sufficient energy to arrive the cathode. The positive anode attracts these electrons, producing a current which flows through resistor R and resulting in an output voltage V.Photoelectrically generated voltage V=Ip.RlWhere Ip=photoelectric current(A),and photoelectric current Ip=Kt.BWhere Kt=sensitivity (A/im),and B=illumination input (lumen)Although the output voltage does give a good indication of the magnitude of illumination, the cells are more often used for counting or control purpose, where the light striking the cathode can be interrupted.6、Capacitive TransducersThe capacitance can thus made to vary by changing either the relative permittivity, the effective area, or the distance separating the plates. The characteristic curves indicate that variations of area and relative permittivity give a linear relationship only over a small range of spacings. Thus the sensitivity is high for small values of d. Unlike the potentionmeter, the variable-distance capacitive transducer has an infinite resolution making it most suitable for measuring small increments of displacement or quantities which may be changed to produce a displacement.7、Inductive TransducersThe inductance can thus be made to vary by changing the reluctance of the inductive circuit. Measuring techniques used with capacitive and inductive transducers:a)A.C. excited bridges using differential capacitors inductors.b)A.C. potentiometer circuits for dynamic measurements.c) D.C. circuits to give a voltage proportional to velocity for a capacitor.d) Frequency-modulation methods, where the change of C or L varies the frequency of an oscillation circuit.Important features of capacitive and inductive transducers are as follows:i)resolution infiniteii) accuracy+- 0.1% of full scale is quotediii)displacement ranges 25*10-6 m to 10-3miv) rise time less than 50us possibleTypical measurands are displacement, pressure, vibration, sound, and liquid level.8、Linear Variable-differential Ttransformer9、Piezo-electric Transducers10、Electromagnetic Transducers11、Thermoelectric Transducers12、Photoelectric Cells13、Mechanical Transducers and Sensing Elements传感器的基础知识传感器是一种把被测量转换为光的、机械的或者更平常的电信号的装置。
Development of Sensor New Technology Sensor is one kind component which can transform the physical quantity, chemistry quantity and the biomass into electrical signal. The output signal has the different forms like the voltage, the electric current, the frequency, the pulse and so on, which can satisfy the signal transmission, processing, recording, and demonstration and control demands. So it is the automatic detection system and in the automatic control industry .If automatic Technology is used wider, then sensor is more important. In information age, the information industry includes information gathering, transmission, process three parts, namely sensor technology, communication, computer technology. Because of ultra large scale integrated circuit’s rapi d development after having been developed Modern computer technology and communication, not only requests sensor precision reliability, speed of response and gain information content request more and more high but also requests its cost to be inexpensive. The obvious traditional sensor is eliminated gradually because of the function, the characteristic, the volume, the cost and so on. As world develop many countries are speeding up to the sensor new technology’s research and the development, and all has obtained the enormous breakthrough. Now the sensor new technology development mainly has following several aspects:Using the physical phenomenon, the chemical reaction, the biological effect as the sensor principle therefore the researches which discovered the new phenomenon and the new effect are the sensor technological improving ways .it is important studies to developed new sensor’s the foundation. Japanese Sharp Corporation uses the superconductivity technology to develop successfully the high temperature superconductivity magnetic sensor and get the sensor technology significant breakthrough. Its sensitivity is so high and only inferior in the superconductivity quantum interference component. Its manufacture craft is far simpler than the superconductivity quantum interference component. May use in magnetism image formation technology. So it has the widespread promoted value.Using the immune body and the antigen meets one another compound when the electrode surface. It can cause the electrode potential change and use this phenomenon to be possible to generate the immunity sensor. The immunity sensor makes with this kind of immune body may to some organism in whether has this kind of ant original work inspection. Like may inspect somebody with the hepatitis virus immune body whether contracts the hepatitis, plays to is fast, the accurate role. The US UC sixth branch has developed this kind of sensor.The sensor material is the important foundation for sensor technology, because the materials science is progressive and the people may make each kind of new sensor For example making the temperature sensor with the high polymer thin film; The optical fiber can make the pressure, the current capacity, the temperature, the displacement and so on the many kinds of sensors; Making the pressure transmitter with the ceramics. The high polymer can become the proportion adsorption and the release hydrogen along with the environment relative humidity size. The high polymer electricity lies between the constant to be small, the hydrogen can enhance the polymer the coefficient of dialectical loss. Making the capacitor the high polymerdielectric medium, determines the electric capacity cape city the change, then obtains the relative humidity. Making the plasma using this principle to gather the legitimate polystyrene film temperature sensor below, it has the characteristic.Measured the wet scope is wide; The temperature range is wide, may reach -400 ℃ ~ +1,500 ℃; The speed of response is quick, is smaller than 1S; The size is small, may use in the small space measuring wet; The temperature coefficient is small.The ceramic electric capacity type pressure transmitter is one kind does not have the intermediary fluid the dry type pressure transmitter. Uses the advanced ceramic technology, the heavy film electronic technology, its technical performance is stable, the year drifting quantity is smaller than 0.1%F.S, warm floats is smaller than ±0.15%/10K, anti- overloads strongly, may reach the measuring range several hundred times. The survey scope may from 0 to 60mpa.German E+H Corporation and the American Kahlo Corporation product is at the leading position.The optical fiber application is send the material significant breakthrough, its uses in most early the optical communication techniques. In the optical communication use discovered works as environmental condition change and so on the temperature, pres-sure, electric field, magnetic field, causes the fiber optic transmission light wave intensity, the phase, the frequency, change and so on the polarization condition, the survey light wave quantity change, may know causes these light wave physical quantity the and so on quantitative change temperature, pressure ,electric field, magnetic field size, uses these principles to be possible to develop the optical fiber sensor. The optical fiber sensor and the traditional sensor compare has many characteristics: Sensitivity high, the structure simple, the volume small, anti-corrosive, the electric insulation good, the path of rays may be curving, be advantageous for the realization telemeter and so on. Optical fiber sensor Japan is in the advanced level. Like Idec Izumi Corporation and Sun x Corporation. The optical fiber send receiver and the integrated path of rays technology unify, acce lerates the optical fiber sensor technology development. Will integrate the path of ray’s component to replace the original optics part and the passive light component; enable the optical fiber sensor to have the high band width, the low signal processing voltage, the reliability high, the cost will be low.In semiconductor technology processing method oxygenation, the photo etc hang, the proliferation, the deposition, the plane electron craft, various guides corrosion and steams plates, the sputtering thin film and so on, these have all introduced to the sensor manufacture. Thus has produced each kind of new sensor, like makes the silicon micro sensor using the semiconductor technology, makes the fast response using the thin film craft the gas to be sensitive, the wet sensitive sensor, the use sputtering thin film craft system pressure transmitter and so on..The Japanese horizontal river company uses various guides’corrosion technology to carry on the high accuracy three dimensional processing; the system helps the silicon resonance type pressure transmitter. The core partially presses two resonant Liang by the feeling which above the silicon diaphragm and the silicon diaphragm manufactures to form, two resonant Liang's frequency differencecorrespondence different pressure, measures the pressure with the frequency difference method, may eliminate the error which factor and so on ambient temperature brings. When ambient temperature change, two resonant Liang frequencies and the amplitude variation are same, after two frequency differences, its same change quantity can counterbalance mutually. It’s survey most high accuracy may reach 0.01%FS.American Silicon Microstructure Inc.(SMI) the company develops a series of low ends, linear in 0.1% to 0.In 65% scope silicon micro pressure transmitter, the lowest full measuring range is 0.15psi (1KPa), it makes take the silicon as the material, has the unique three dimensional structure, the light slight machine-finishing, makes the wheat stone bridge many times with the etching on the silicon diaphragm, when above silicon chip stress, it has the distortion, the resistance produces presses the anti- effect but to lose the bridge balance, the output and the pressure becomes the proportion the electrical signal.Such silicon micro sensor is the front technology which now the sensor develops, Its essential feature is the sensitive unit volume is a micron magnitude, Is the traditional sensor several dozens, several 1%. In aspect and so o n industry control, aerospace domain, biomedicine has the vital role, like on the airplane the use may reduce the airplane weight, reduces the energy. Another characteristic is can be sensitive is small surveyed, may make the blood pressure pressure transmitter.The Chinese aviation main corporation Beijing observation and control technical research institute, the development CYJ series splashes thanks the membrane pressure transmitter is uses the ion sputtering craft to process the metal strain gauge, it has over come the nonmetallic strain gauge easily the temperature influence insufficiency, has the high stability, is suitable in each kind of situation, is measured the medium scope widely, but also overcame the tradition lowly to glue the precision which the type brought, sluggish big, shortcoming and so on slow change, had the precision high, the re-liability is high, the volume small characteristic, widely used in domain and so on aviation, petroleum, chemical industry, medical service.Integrates the sensor the superiority is the traditional sensor is unable to achieve, it is a simple sensor not merely, it in at the same time the auxiliary circuit part and send the part will integrate on together the chip, will cause it to have the calibration, to compensate, from the diagnosis and the network correspondence function, it might reduce the cost, the gain in yield, this kind of blood pressure sensor which American LUCAS, NOV ASENSOR Corporation will develop, each week will be able to produce 10,000.The intellectualized sensor is one kind of belt microprocessor sensor, is achievement which the microcomputer and the sensor unifies, it has at the same time the examination, the judgment and the information processing function, compares with the traditional sensor has very many characteristics:Has the judgment and the information processing function, can carry on the revision, the error to the observed value compensates, thus enhancement measuring accuracy; May realize the multi-sensor multi parameters survey; Has from the diagnosis and from the calibration function, enhances the reliability; The survey datamay deposit and withdraw, easy to operate; Has the data communication interface, can and the microcomputer direct communication.The sensor, the signal adjustment electric circuit, the monolithic integrated circuit integration forms ultra large-scale integrated on a chip the senior intelligence sensor. American HONY WELL Corporation ST-3000 intelligence sensor, the chip size only then has 3×4×2mm3, uses the semiconductor craft, makes CPU, EPROM, the static pressure, the differential pressure, the temperature on the identical chip and so on three kind of sensitive units.The intellectualized sensor research and the development, US is at the leading position. American Space Agency when development spaceship called this kind of sensor for the clever sensor (Smart Sensor), on the spaceship this kind of sensor is extremely important. Our country in this aspect research and development also very backward mainly is because our country semiconductor integrated circuit technological level is limited.The sensor’s development is changing day after day since especially the 80's humanities have entered into the high industrialization the information age, sensor techno-logy to renewal, higher technological development. US, Japan and so on developed country sensor technological development quickest, our country because the foundation is weak, the sensor technology compares with these developed countries has the big disparity. Therefore, we should enlarge to the sensor engineering research, the development investment, causes our country sensor technology and the foreign disparity reduces, promotes our country instrument measuring appliance industry and from the technical development.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。