电容式传感器中英文翻译资料毕业设计用
红外传感器论文中英文资料对照外文翻译
中英文资料对照外文翻译外文资料Moving Object Counting with an Infrared Sensor NetworkBy KI, Chi KeungAbstractWireless 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 of applications, 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 nowadays including 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, somequasi-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 of applications, 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 constraints in 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 incomingdata 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 need to 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 environmen t 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 renewtheir energy from solar to vibration energy. Two major power saving policies used are Dynamic 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 levels depending 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 sensor network, 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作者KI, Chi Keung摘要无线传感器网络(WSN)已成为最近的一个研究热点。
光学传感器毕业论文中英文文献及翻译
英文文献及中文翻译一种精确测量倾斜角度的光学传感器摘要本文主要介绍了一种新型光学传感器，它可以同时准确地测量倾斜角或两轴倾斜角度。
这种传感器是基于激光干涉原理，因此具有很高的精度。
设计制作了一个传感器的模型来论证这个新的方法，这是一个光电传感器,传感器中没有移动的部分。
由正交于铅垂面的流动水平面提供参考面。
传感器和绝对水平面之间的角度随着被测量的物体倾斜而改变，这些变化反映在条纹图案的中心位置的转移方式。
不同的干涉条纹的中心位置随倾斜角的变化而改变。
干涉条纹图案进行记录和处理，转化为两轴、水平和垂直倾斜角度。
当使用1024*1024像素的传感器时，测量范围为700弧秒，其精度可高达+/ - 1弧秒。
关键词：倾斜角度传感器，倾斜仪，激光干涉I 介绍市场上目前有几种类型的商业倾斜角度测量传感器。
有些是角度传感器，有些是倾斜仪，它们的工作原理不同。
电解液体、电容和钟摆是现在大多数倾斜角度传感器和倾斜仪的三个主要工作原理。
在这里，我们提出了一种新的光学方法，建立了一个用激光、光学元件和图像传感器的光电传感器，它可以同时做精确的倾斜角度测量，不需要进行机械的移动，其工作原理是基于光学干涉，相干激光作为光源。
光线通过一个装满液态油的玻璃油盒。
由正交于铅垂面的流动水平面提供参考面。
当激光束穿过油箱有两束光线反射回来，一束是液体的表面产生的，另一束是容器玻璃产生的，干涉条纹就是由这两条光线形成的，条纹图案将随着倾斜角度的变化产生相应的变化，条纹图案采集和处理后将反映倾斜角度信息，光学工作原理使它不受磁场的影响。
该传感器可以同时测量两轴倾角。
流动的水平面确保了参考面是一个绝对的水平面。
高灵敏度光学干涉测量原理，保证了较高的精度。
II 原理图1说明了工作原理示意图，O点是光线扩大镜头的焦点，O点可以看作是点光源，它发出球面波。
由于地球重力的影响，液体油面始终保持水平，因此用油面作为参考平面。
该容器是玻璃材料的。
当传感器被放在目标表面时，其底部表面将连同目标对象一起倾斜。
传感器技术论文中英文对照资料外文翻译文献
传感器技术论文中英文对照资料外文翻译文献Development of New Sensor TechnologiesSensors are devices that can convert physical。
chemical。
logical quantities。
etc。
into electrical signals。
The output signals can take different forms。
such as voltage。
current。
frequency。
pulse。
etc。
and can meet the requirements of n n。
processing。
recording。
display。
and control。
They are indispensable components in automatic n systems and automatic control systems。
If computers are compared to brains。
then sensors are like the five senses。
Sensors can correctly sense the measured quantity and convert it into a corresponding output。
playing a decisive role in the quality of the system。
The higher the degree of n。
the higher the requirements for sensors。
In today's n age。
the n industry includes three parts: sensing technology。
n technology。
and computer technology。
电气类(外文翻译)英文电容式传感器操作capacitive-sensor-operation-毕业论
Capacitive Sensor OperationPart 1: The BasicsPart 1 of this two-part article reviews the concepts and theory of capacitive sensing to help to optimize capacitive sensor performance. Part 2 of this article will discuss how to put these concepts to work.Noncontact capacitive sensors measure the changes in an electrical property called capacitance. Capacitance describes how two conductive objects with a space between them respond to a voltage difference applied to them. A voltage applied to the conductors creates an electric field between them, causing positive and negative charges to collect on each objectCapacitive sensors use an alternating voltage that causes the charges to continually reverse their positions. The movement of the charges creates an alternating electric current that is detected by the sensor. The amount of current flow is determined by the capacitance, and the capacitance is determined by the surface area and proximity of the conductive objects. Larger and closer objects cause greater current than smaller and more distant objects. Capacitance is also affected by the type of nonconductive material in the gap between the objects. Technically speaking, the capacitance is directly proportional to the surface area of the objects and the dielectric constant of the material between them, and inversely proportional to the distance between them as shown.:In typical capacitive sensing applications, the probe or sensor is one of the conductive objects and the target object is the other. (Using capacitive sensors to sense plastics and other insulators will be discussed in the second part of this article.) The sizes of the sensor and the target are assumed to be constant, as is the material between them. Therefore, any change in capacitance is a result of a change in the distance between the probe and the target. The electronics are calibrated to generate specific voltage changes for corresponding changes in capacitance. These voltages are scaled to represent specific changes in distance. The amount of voltage change for a given amount of distance change is called the sensitivity. A common sensitivity setting is 1.0 V/100 µm. That means that for every 100 µm change in distance, the output voltage changes exactly 1.0 V. With this calibration, a 2 V change in the output means that the target has moved 200 µm relative to the probe.Focusing the Electric FieldWhen a voltage is applied to a conductor, the electric field emanates from every surface. In a capacitive sensor, the sensing voltage is applied to the sensing area of the probe. For accurate measurements, the electric field from the sensing area needs to be contained within the space between the probe and the target. If the electric field is allowed to spread to other items—or other areas on the target—then a change in the position of the other item will be measured as a change in the position of the target. A technique called "guarding" is used to prevent this from happening. To create a guard,the back and sides of the sensing area are surrounded by another conductor that is kept at the same voltage as the sensing area itself. When the voltage is applied to the sensing area, a separate circuit applies the exact same voltage to the guard. Because there is no difference in voltage between the sensing area and the guard, there is no electric field between them. Any other conductors beside or behind the probe form an electric field with the guard instead of with the sensing area. Only the unguarded front of the sensing area is allowed to form an electric field with the target.DefinitionsSensitivity indicates how much the output voltage changes as a result of a change in the gap between the target and the probe. A common sensitivity is 1 V/0.1 mm. This means that for every 0.1 mm of change in the gap, the output voltage will change 1 V. When the output voltage is plotted against the gap size, the slope of the line is the sensitivity.A system's sensitivity is set during calibration. When sensitivity deviates from the ideal value this is called sensitivity error, gain error, or scaling error. Since sensitivity is the slope of a line, sensitivity error is usually presented as a percentageof slope, a comparison of the ideal slope with the actual slope.Offset error occurs when a constant value is added to the output voltage of the system. Capacitive gauging systems are usually "zeroed" during setup, eliminating any offset deviations from the original calibration. However, should the offset error change after the system is zeroed, error will be introduced into the measurement. Temperature change is the primary factor in offset error.Sensitivity can vary slightly between any two points of data. The accumulated effect of this variation is called linearity erro. The linearity specification is the measurement of how far the output varies from a straight line.To calculate the linearity error, calibration data are compared to the straight line that would best fit the points. This straight reference line is calculated from the calibration data using least squares fitting. The amount of error at the point on the calibration line furthest away from this ideal line is the linearity error. Linearity error is usually expressed in terms of percent of full scale (%/F.S.). If the error at the worst point is 0.001 mm and the full scale range of the calibration is 1 mm, the linearity error will be 0.1%.Note that linearity error does not account for errors in sensitivity. It is only a measure of the straightness of the line rather than the slope of the line. A system with gross sensitivity errors can still be very linear.Error band accounts for the combination of linearity and sensitivity errors. It is the measurement of the worst-case absolute error in the calibrated range. The error band is calculated by comparing the output voltages at specific gaps to their expected value. The worst-case error from this comparison is listed as the system's error band. In Figure 7, the worst-case error occurs for a 0.50 mm gap and the error band (in bold)Bandwidth is defined as the frequency at which the output falls to –3 dB, a frequency that is also called the cutoff frequency. A –3 dB drop in the signal level is an approximately 30% decrease. With a 15 kHz bandwidth, a change of ±1 V at low frequency will only produce a ±0.7 V change at 15 kHz. Wide-bandwidth sensors can sense high-frequency motion and provide fast-responding outputs to maximize the phase margin when used in servo-control feedback systems; however,lower-bandwidth sensors will have reduced output noise which means higher resolution. Some sensors provide selectable bandwidth to maximize either resolution or response time.Resolution is defined as the smallest reliable measurement that a system can make. The resolution of a measurement system must be better than the final accuracy the measurement requires. If you need to know a measurement within 0.02 µm, then the resolution of the measurement system must be better than 0.02 µm.The primary determining factor of resolution is electrical noise. Electrical noise appears in the output voltage causing small instantaneous errors in the output. Even when the probe/target gap is perfectly constant, the output voltage of the driver has some small but measurable amount of noise that would seem to indicate that the gap is changing. This noise is inherent in electronic components and can be minimized, but never eliminated.If a driver has an output noise of 0.002 V with a sensitivity of 10 V/1 mm, then it has an output noise of 0.000,2 mm (0.2 µm). This means that at any instant in time, the output could have an error of 0.2 µm.The amount of noise in the output is directly related to bandwidth. Generally speaking, noise is distributed over a wide range of frequencies. If the higher frequencies are filtered before the output, the result is less noise and better resolution (Figures 8, 9). When examining resolution specifications, it is critical to know at what bandwidth the specifications apply.Capacitive Sensor Operation Part 2: System Optimization Part 2 of this two-part article focuses on how to optimize the performance of your capacitive sensor, and to understand how target material, shape, and size will affect the sensor's response.Effects of Target SizeThe target size is a primary consideration when selecting a probe for a specific application. When the sensing electric field is focused by guarding, it creates a slightly conical field that is a projection of the sensing area. The minimum targetdiameter is usually 130% of the diameter of the sensing area. The further the probe is from the target, the larger the minimum target size.Range of MeasurementThe range in which a probe is useful is a function of the size of the sensing area. The greater the area, the larger the range. Because the driver electronics are designed for a certain amount of capacitance at the probe, a smaller probe must be considerably closer to the target to achieve the desired amount of capacitance. In general, the maximum gap at which a probe is useful is approximately 40% of the sensing area diameter. Typical calibrations usually keep the gap to a value considerably less than this. Although the electronics are adjustable during calibration, there is a limit to the range of adjustment.Multiple Channel SensingFrequently, a target is measured simultaneously by multiple probes. Because the system measures a changing electric field, the excitation voltagefor each probe must be synchronized or the probes will interfere with each other. If they were not synchronized, one probe would be trying to increase the electric field while another was trying to decrease it; the result would be a false reading. Driver electronics can be configured as masters or slaves; the master sets the synchronization for the slaves in multichannel systems.Effects of Target MaterialThe sensing electric field is seeking a conductive surface. Provided that the target is a conductor, capacitive sensors are not affected by the specific target material; they will measure all conductors—brass, steel, aluminum, or salt water—as the same. Because the sensing electric field stops at the surface of the conductor, target thickness does not affect the measurement。
08湿度传感器系统毕业论文中英文资料外文翻译文献
湿度传感器系统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 determined accuracy.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:=(E-S)*(1-e)+SRH-t（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。
传感器外文翻译文献
传感器外文翻译文献(文档含中英文对照即英文原文和中文翻译)译文：传感器的基础知识传感器是一种将能量转化为光的、机械的或者更为普遍的电信号，这种能量转换发生的过程称之为换能作用。
按照能量转换的复杂程度和控制方式，传感器被分为不同的等级，用来测量位移的电阻式传感器被分类为电阻式位移传感器，其他的分类诸如压力波纹管、压力膜和压力阀等。
1、传感器元件大多数的传感器是由感应元件，转换元件、控制元件、当然也有例外，例如：震动膜、.波纹管、应力管和应力环、低音管和悬臂都是敏感元件。
对物理量作出反应，将物理的压力和力转换为位移，这些转换量可以被用作电参数，如电压、电阻、电容或者感应系数。
机械式和电子式元件合并形成机电式传感设备或传感器。
相似量的结合可以作为能量输入例如：热的、光的、磁的、化学的相互结合产生的热电式、光电式、电磁式和电化学式传感器。
2、传感器灵敏度通过校正测量系统获得的被测物理量和传感器输出信号的关系叫做传感器灵敏度K1=输出信号增量∕被测量的增量，实际上，传感器的灵敏度是已知的通过测量输出信号，输入量由下式决定，输入量=输出信号的增量∕k1。
3、理想传感器的性能特点：a)高保真性：传感器的输出波形式对被测量的真实展现，并且失真很小。
b)被测量干扰最小，任何情况下传感器的精度不能改变。
c)尺寸：必须将传感器正确的放在所需要的场所。
d)被测量和传感器信号之间要有线性关系。
e)传感器对外部变换由很小的灵敏度,例如：压力传感器常常受到外部震动和环境温度的影响f)传感器的固有频率应能够避开被测量的频率和谐波。
4、电传感器电传感器由很多理想特性，它们不仅实现远程测量和显示，还能提供高灵敏度。
电传感器可分为如下两大类。
这些传感器依靠外界电压刺激来工作。
A、变参数型包括：ⅰ）电阻式ⅱ）电容式ⅲ）感应式ⅳ）自感应式ⅴ）互感应式B、自激型包括:ⅰ)电磁式；ⅱ）热电式ⅲ）光栅式；ⅳ）压电式。
这些传感器都是自己产生输出电压来反映被测量的输入并且这些过程是可逆的;例如，一般的电子传感器通常能产生出输出电压来反映晶体材料的性能，.然而，如果在材料上加一个自变电压，传感器可以通过变形或与变电压同频率的振动来体现可逆效应。
传感器外文翻译
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。
中英文文献翻译—基于电容传感器的塑膜厚度检测系统的研究
基于电容传感器的塑膜厚度检测系统的研究摘要:采用非接触式电容传感器、电涡流传感器组合系统获取检测信号,利用基于LabVIEW软件平台的计算机实现对塑料薄膜进行在线检测的工作原理,整个系统由测试单元、电机驱动单元、数据采集与处理单元组成。
由于测试单元采用了电容、电涡流组合传感系统,信号的后续处理由基于LabVIEW软件平台的计算机自动完成,速了测量过程。
采用本系统取代传统的千分尺测量方法,可以使塑料薄膜厚度测量以完全智能的、实时的、非接触的方式进行精确测量。
最后,通过比较组合测量系统与千分尺测量的测试结果,证明了该系统具有较高的精度,良好的可靠性与可行性。
关键词:塑料薄膜;厚度测量;组合传感系统;在线测量中图分类号:TP212. 1 ; TP216 文献标识码:A文章编号:1004 - 1699 (2005) 01 - 0116 - 04目前，塑膜在塑料产品中占有一定的比例。
它们广泛应用于许多领域，比如农业、运输、医学治疗、环境保护和建筑业。
在制造过程中，膜厚是评估产品性质的重要规范。
一般而言，如果一卷中膜厚度的差异大于膜厚度的10%，它将被认为是不合格品。
膜的厚度和一致性直接影响产品的物理属性和机械性能。
在使用中，它们也直接影响使用功能、寿命和抵制外部力量的能力。
另外，塑膜经常以卷分布。
不同卷之间的厚度差异影响使用范围。
这联系到公司和顾客间的利益。
因此，对塑膜的厚度作出精确的测量是很有必要的。
全球有几种可行的方法来测量膜厚，例如机械测定法和重量分析测量法[1]。
传统的测量方法是用千分尺来精确测量，并对成品进行抽样检查，因此测量误差和阅读误差是不可避免的。
对于一片厚度远小于100mm的膜来说，测量精确度很低。
随着工农制造业对塑膜的增长需求，传统的测量方法几乎不能满足发展的需要。
在这种情况下，塑膜厚度在线检测发展了。
主要用于测量和监控低密度浇铸膜和聚丙烯浇铸膜。
就如我们所知，膜由同样的材料和同样的工艺制造而成，因此通过上述方法制造的膜的密度是一致的，我们能等距离不间断地测出日常用膜的宽度为1.4 m。
机械毕业设计英文外文翻译87传感器与现代汽车电子
附录附录1Sensor and the modern automobile electron modern automobile electron from the electronic primary device which applies to the vehicle in the electronic system construction entered one the new stage which has essential to enhance.One of in which most representative core components is the sensor.First, the automobile electron holds controls mentions with the safety systemFirst, the automobile electron holds controls mentions our country automobile industry growth with the safety system to be in the last few years rapid, the development tendency is very fierce.Therefore commented appeared some expert's forecast: The automobile industry has the possibility to surpass the IT industry, becomes one of Chinese national economymost important pillar industries.Actually, the automobile industry growth will certainly to contain with the automobile industry correlation IT industry growth.For example, although at present only occupies about 10%-15% in our country steam product neutron productand the technical price value content, but the overseas automobile neutron product and the technical value content approximately is equally 22%, in the upscale passenger vehicle the automobile electron has accounted for above 30%, moreover this proportion in, unceasingly the fast growth, anticipated very quick will also achieve 50%.The electronic information technology already became the new generation of automobile development direction the leading factor, the automobile (vehicle) the power performance, manoeuvring could, the safety performance and the comfortable performance and so on each aspect improvement and raisehigh, all will rely on the mechanical system and the structure and the electronic products, the information technology perfect union.The automobile engineering expert pointed out that,The electronic technology development has caused the automobile product the concept to have the deep transformation.This also is the recent electronic information industrial field to one of automobile electron unprecedented attentionreasons.But, must point out, except some vehicles in the sound, the video frequency equipment, Che Yong corresponds, the guidance system, as well as the vehicle carries vehicles and so on in work system, network system the electronic installation essence changes few outside .The modern automobile electron from the electronic primary device which applies (including sensor, actuator, micro electric circuit and so on) to the vehicle in the electronic system construction entered one the new stage which has essential to enhance.One of in which most representative core components is the intelligent sensor (intelligent actuator, intelligence changes delivers).In fact, the automobile electron has already experienced several development phases: Electric circuit monitor control builds which from the separation electron primary device, passed through the electronic primary device or the module adds the microprocessor to construct respectively independent, special-purpose, semiautomatic and automatic holds controls the system, now already enters has used the high speed main line (at present to have 5 kind of above main lines to develop use at least)In unification exchange automobile movement each kind of electronic equipment and system data, realization synthesis, intelligent regulation new stage.The new automobile electron system is composed by each electronic control unit (ECU), may hold independently controls, simultaneously can coordinate to the whole movement optimum condition.For example for causes the engine to be at the best active status, needs from the inspiration cylinder air flow, the manifold pressure determination start, Again according to work link boundary parameters and so on the water temperature, air temperature calculates the basic distributive value, meanwhile must through the damper position transducer examination damper opening, the definite engine operating mode, then the control, the adjustment best distributive value, finally also need through the crank angular speed sensor monitor crank corner and the engine speed, finally calculates and sends out the best ignition opportunity the instruction.This engine fuel injection system and the ignition integrated control systemalso may with combinations and so on exhaust gas discharge supervisory system and starting system, constructs Cheng Keshi the motor car engine power and the torque maximization, but simultaneously fuel oil consumption and exhaust gas discharge minimizing intelligent system.Also may lift a safe driving aspect the example, stemming from steady, safe driving need, only aims at four wheels to hold controls, and installed the braking besides the application massive pressure transmitter to guard against generally hugs installs (ABS) deadly, many passenger vehicles, including the domestically produced vehicle, additionally built electronic power distribution system (EBD), ABS+EBD to be possible time the maximum limit safeguard sleet weather driving stability.Presently in, the domestic and foreign some automobiles further has installed emergency brake servosystem (EBA), this system when has the emergency case, the automatic detection driver steps on when the brake pedal the speed and dynamics, and sentence break the emergency brake dynamics is whether enough, if the need, can increase the braking force automatically.The EBA automatic control movement must (e.g. 1/1000000 seconds levels) in complete in the extremely short time.This system can cause the 200km/h high speed travel vehicles the brake skidding distance to reduce the extremely precious more than 20 rice.Also has in view of the wheel monitors each wheel to be opposite separately in the vehicle speed rotational speed, then matches the power for each wheel balance minute, guaranteed each turn has good under the bad road surface condition stresses ability balanced “the electronic force of traction control” the (ETC) system and so on.Two examples enumerates which from above may see clearly, automobile development to automobile electron some basic requests:1. electrons hold control the system the movement to have fast, to be correct, to be reliable.The sensor (+ recuperates electric circuit) + the microprocessor, then (+ power enlargement electric circuit) + the actuator technical way already no longer could satisfy the modern automobile again through the microprocessor the request, needed through the hardware integration, the direct exchange data and the simplification electric circuit, and enhances the intellectualized degree to guarantee the control unit movement the accuracy, the reliability and the timeliness.2. present nearly all automobile mechanism part all already electronic installation control, but in the automobile chassis space is limited, the component system space is extremely limited.The ideal situation is certainly, the electronic control unit should and the control portion close union, is formed a whole.Therefore the component and the electric circuit microminiaturization, the integration may not avoid path.3. electronic control unit must have the enough intellectualized degree.Take the security aerocyst as the example, it in the critical moment must have to be able prompt, the instant to open correctly, but in the extremely majority time the aerocyst is place in the standby condition, therefore security aerocyst ECU must have self-checking, from the maintenance ability, confirmed unceasingly the aerocyst system may operate normally the reliability, guarantees the movement “surefire”.4. automobile each kind of function parts all have respective movement, hold control the characteristic, and, speaking of the electronic products, mostly is in the very severe movement environment, moreover various.Such as time active status high temperature, time static standby low temperature,highly concentrated oil steam and activeness (toxicity) gas, as well as high speed movement and high strength impact and vibration and so on.Therefore, the electronic primary device and the electric circuit musthave to have high stable, the anti-environment and auto-adapted, from compensation adjustment ability.5. is similarly important with the above request, even sometimes is the crucial condition is, the automobile electronic control unit uses the electronic primary device, the module must have to be able the large-scale industry production, and can cost reduction to the degree which may accept.A slightly sensor and the intelligent sensor is this aspect model.Not only for example the intelligence acceleration instrument, it can satisfy the modern automobile well each need, moreover because may in the integrated circuit standard silicon craft on-line volume production, the production cost be low (several US dollars to several or several dozens US dollars), therefore had found own biggest application market in the automobile industry, counter- has come also powerfully to promote the automobile industry electronic informationization.Two sensors: The micro sensor and the integrated circuit fuse new generation of electronic deviceThe micro sensor, the intelligent sensor is the emerging technology which only then starts to develop rapidly in recent years.The technical name at present uses which in our country's publication magazine quite is also ambiguous, still generally called it the sensor, or induces ambiguously into the automobile semiconductor device, also has the intelligent sensor (or intelligent actuator, intelligent transmitting instrument) and the micro systemMEMS and so on has all belonged to MEMS (microcomputer electrical system series) under the name.Here introduces in the current some European and American monograph the commonly used technical noun definition and the technical connotation.Intelligent sensor and modern automobile electronFirst must explain, in the overwhelming majority situation, the sensor which in this article size title and the full text said has made a general reference actually three big kind of components: Transforms the electromagnetics signal output the non-electricity input parameter the sensor; Transforms the non-electricity parameter output the electricity signal the actuator; As well as both can serve as the sensor and to be able to serve as the actuator many,in which is transforms one kind of electromagnetics parameter form Cheng Ling one kind of electromagnetics parameter shape output the transmitting instrumentMeant that, about the micro sensor, the intelligent sensor technical characteristic may expand analogizes the micro actuator, the micro transmitting instrument - sensor (or execution, either transmitting instrument) in the physical criterion to have a physical size to be equal to or to be smaller than at least an Asian millimeter magnitude.The micro sensor is not a product which traditional sensor simple physics reduces, but is based on partly leads the body processing technology the new generation of component:Sometimes therefore also is called the silicon to pass on the feeling.May use the similar definition and the technical characteristic analogy describes the micro actuator and the micro transmitting instrument.It is composed by two chips, one has from the examination ability accelerometer unit (micro acceleration instrument), together is in addition the micro sensor and the microprocessor (MCU) connection electric circuit and MCU.This is one kind compared the early time (around 1996), but already quite practical component, available in automobile self-braking and suspension system, because and the micro accelerometer had the self-checking ability Also available in security aerocyst.From this time on in the example may see clearly, not only the micro sensor superiority is the volume reduction, lies in can conveniently and the integrated circuit combination and the scale production.Should refer, uses this kind oftwo piece of solution to be possible to reduce the design cycle, reduces the development preliminary small batch trial production the cost.But to the practical application and the market, the single chip solution may take obviously, the production cost is lower, the application value is higher.The sensor (Smart Sensor), the intelligent actuator and the intelligent transmitting instrument - micro sensor (or micro actuator, either micro transmitting instrument) and its part or processes the component, the processing electric circuit integration completely on a chip component (e.g. the above micro accelerometer single chip solution).Therefore the intelligent sensor has certain biological modelling ability, like fuzzy logic operation, initiative distinction environment, automatic accent entire and compensation adaptation environment abilityFrom diagnosis, from maintenance and so on.Obviously, produces andreduces the production cost stemming from the scale the request, the intelligent sensor design concept, the choice of material and the production craft musthave to have as far as po ssible and the integrated circuit standard silicon plane craft is consistent.May throw in front of the piece in the normal technical process, either in flow, after either the craft completes increases some special need the working procedure, but should not too be many.In a seal, a micro mechanical pressure transmitter and simulation user connection, 8 mold - number switch (SAR), microprocessor (Motorola 69HC08), memory and serial interface (SPI) and so on integrations on a chip.Its front end silicon pressure transmitter uses the body silicon tiny processing technology manufacture.The preparation silicon pressure transmitter working procedure already may arrange in to integrate the CMOS electric circuit craft flows in front of the regulation, also may in afterThis kind of intelligence pressure transmitter technology and market all already mature, has widely used in all kinds of pressure survey and the control unit which the automobile (vehicle) needs, such as in front of each kind of air gage, spray nozzle collection class cavity pressure, waste gas exhaust pipe, fuel oil, tire, hydraulic gear and so on.The intelligence pressure transmitter application is very broad, does not limit to the automobile industry.At present, the production intelligence pressure transmitter manufacturer many, the market commodity variety also very have been many, already appeared the keen competition.The result is the intelligence pressure transmitter volume getting smaller, needs outside along with it control unit to encircle the connector and the discrete component are more and more few, but the function and the performance more and more are actually strong, moreover the production cost reduces very quickly (the present is approximately several US dollars).While convenient needs said, in some Chinese material, in particular in some product tendentious material, generally (either device) and Intelligent sensor (or device) all callsSmart Sensor it the intelligent sensor,But these only can respond the environmental variation simply, makes some corresponding compensations, the adjustment active status, specially does not need to integrate placethe principle component, its knowledge rank too is low, should not belong to the intelligent component category generally.Believed the majority readers can contact frequently, most drew close to the life the intelligent sensor possibly to have to be uses in the camera, the digital camera, the camera, in the handset photograph CCD image sensor. This is a situation which one kind of non-intelligence sensor not is, because in the CCD array each silicon unit transforms by the light the electrical signalis extremely weak, must direct and prompt shifting checks, and processes transforms the standard the imageform signal.Also has complex someThe electron and optics which in, on the upscale long focus (IOX) optics enlargement numerical code camera and the camera equips guard against shake the system, specially in high end product trueoptics guard against shake the system.Its core is the two axle to either 3 axial micro accelerometers or the micro gyroscope, monitors the fuselage through it the vibration, and converts the lens each axial displacement quantity, then actuates in the lensthe invariable angle lens migration, makes the optical system the refraction path of rays to maintain stably.Micro system (Microsystem) and MEMS (microcomputer electrical system series) - by the micro sensor, microelectronics electric circuit (signal processing, control circuit, correspondence meets and so on) and the micro actuator constitutes a three level of levelassociation system, the integration calls it on a chip component the micro system.If has the mechanical linkage or the machinery implementing agency and so on the micro mechanical part instrument calls it MEMS.MEMS chip left side gives prepares the basic processing technology which the MEMS chip needs.Its right flank enumerates for the main application domain.Very obvious, the MEMS best solution also is selects with the silicon laborskill compatible material and the physical effect, the design idea and the technical process, also namely uses the method which the conventional standard the CMOS craft and two-dimensional, the three dimensional tiny processing technology unifies, in which also includes the micro mechanicalstructural element the manufacture.The micro sensor logical development extends is the intelligent sensor, the intelligent sensor extends is naturally the micro system and the MEMS, MEMS further development is can receive, the resolution outside signal and the instructionindependently, then can independent Now, develops successful, and had the commercial product MEMS variety already many, covering shown in Figure 4 each big domain.In which of one of including entire smooth correspondence and entire light computer key components two-dimensional, three dimensional MEMS light switch.Through control chip on micro reflector array, realization light input/output overlapping interconnection.This is the present entire light exchange technology mature preferred plan.In the market may buy the MEMS light switch has amounted to1296 groups, the switch switching time is approximately 20ms.The micro machinery (also is called a nanometer machinery) then still was at the development experimental stage, but had many very important laboratory product emergence, like famous nanometer electrical machinery, micro insect, micro helicopter and submarine and so on.The technical industrial field believed generally that, they will develop successful and the investment practical application have the profound influence to the industrial technology and the quality of life.附录2传感器与现代汽车电子现代汽车电子从所应用的电子元器件到车内电子系统的架构均已进入了一个有本质性提高的新阶段。
传感器技术外文文献及中文翻译
Sensor technologyA sensor is a device which produces a signal in response to its detecting or measuring a property ,such as position , force , torque ，pressure , temperature ，humidity , speed ，acceleration ，or vibration 。
Traditionally ，sensors （such as actuators and switches )have been used to set limits on the performance of machines .Common examples are (a）stops on machine tools to restrict work table movements ,(b) pressure and temperature gages with automatics shut-off features ，and （c）governors on engines to prevent excessive speed of operation . Sensor technology has become an important aspect of manufacturing processes and systems 。
It is essential for proper data acquisition and for the monitoring ，communication ，and computer control of machines and systems 。
Because they convert one quantity to another , sensors often are referred to as transducers .Analog sensors produce a signal , such as voltage ,which is proportional to the measured quantity .Digital sensors have numeric or digital outputs that can be transferred to computers directly 。
传感器技术4-电容式传感器-中英对照
C AC 0 C BC 0
0 r (工作原理、结构及特性
对图(b)有
C AC 0 C BC 0
0 r lr 0
(4-18)
上两式中 α ——初始位置时一组极板相 互覆盖有效面积所包的角度(或所对的圆心 角)；δ 0、ε r同前。 当动极板C随角位移(Δα)输入而摆动时 两组电容值一增一减，差动输出。
2
4.1 工作原理、结构及特性
由式(4-9)可见, δ0的减小会导致非线性误差增大；δ0过小 还可能引起电容器击穿(break down)或短路(short circuit)。 为此，极板间可采用高介电常数(permittivity)的材料(云母 (Mica)、塑料膜(plastic film)等)作介质，如图4.4所示。设 两种介质的相对介电质常数为εr1 (空气：εr1＝1)、εr2， 相应的介质厚度为δ1、δ2，则有
4.1 工作原理、结构及特性
若电介质(dielectric)1为空气(εr1＝1)，当ｌ＝0时传感器的初 始电容为：
C0 0 r l 0 b0 / 0
当介质2进入极间ｌ后引起电容的相对变化为
C C C 0 r 2 1 l C0 C0 l0
4.1 工作原理、结构及特性
4.1.1 变极距型电容传感器
图4-1为这种传感器的原理图。当传感器的εr和A为常数，初 始极距为δ0 ，由式(4-1)可知其初始电容量C0为
C0 0 r A / 0
(4-2)
图4.1 变极距型电容传感器原理图
4.1 工作原理、结构及特性
4.1 工作原理、结构及特性
图4-7 变面积型差动式结构 (a)扇形平板结构；(b)柱面板结构
传感器——通信电子工程类中英文翻译、外文翻译
What is a smart sensorOne of the biggest advances in automation has been the development and spread of smart sensors. But what exactly is a "smart" sensor? Experts from six sensor manufacturers define this term.A good working "smart sensor" definition comes from Tom Griffiths, product manager, Honeywell Industrial Measurement and Control. Smart sensors, he says, are "sensors and instrument packages that are microprocessor driven and include features such as communication capability and on-board diagnostics that provide information to a monitoring system and/or operator to increase operational efficiency and reduce maintenance costs."No failure to communicate"The benefit of the smart sensor," says Bill Black, controllers product manager at GE Fanuc Automation, "is the wealth of information that can be gathered from the process to reduce downtime and improve quality." David Edeal, Temposonics product manager, MTS Sensors, expands on that: "The basic premise of distributed intelligence," he says, is that "complete knowledge of a system, subsystem, or component's state at the right place and time enables the ability to make 'optimal' process control decisions."Adds John Keating, product marketing manager for the Checker machine vision unit at Cognex, "For a (machine vision) sensor to really be 'smart,' it should not require the user to understand machine vision."A smart sensor must communicate. "At the most basic level, an 'intelligent' sensor has the ability to communicate information beyond the basic feedback signals that are derived from its application." saysEdeal. This can be a HART signal superimposed on a standard 4-20 mA process output, a bus system, or wireless arrangement. A growing factor in this area is IEEE 1451, a family of smart transducer interface standards intended to give plug-and-play functionality to sensors from different makers.Diagnose, programSmart sensors can self-monitor for any aspect of their operation, including "photo eye dirty, out of tolerance, or failed switch," says GE Fanuc's Black. Add to this, says Helge Hornis, intelligent systems manager, Pepperl+Fuchs, "coil monitoring functions, target out of range, or target too close." It may also compensate for changes in operating conditions. "A 'smart' sensor," says Dan Armentrout, strategic creative director, Omron Electronics LLC, "must monitor itself and its surroundings and then make a decision to compensate for the changes automatically or alert someone for needed attention."Many smart sensors can be re-ranged in the field, offering "settable parameters that allow users to substitute several 'standard' sensors," says Hornis. "For example, typically sensors are ordered to be normally open (NO) or normally closed (NC). An intelligent sensor can be configured to be either one of these kinds."Intelligent sensors have numerous advantages. As the cost of embedded computing power continues to decrease, "smart" devices will be used in more applications. Internal diagnostics alone can recover the investment quickly by helping avoid costly downtime.Sensors: Getting into PositionAs the saying goes, 'No matter where you go, there you are.' Still, most applications require a bit more precision and repeatability than that, so here's advice on how to select and locate position sensors.The article contains online extra material.What's the right position sensor for a particular application? It depends on required precision, repeatability, speed, budget, connectivity, conditions, and location, among other factors. You can bet that taking the right measurement is the first step to closing the loop on any successful application.Sensor technologies that can detect position are nearly as diverse as applications in providing feedback for machine control and other uses. Spatial possibilities are linear, area, rotational, andthree-dimensional. In some applications, they're used in combination. Sensing elements are equally diverse.Ken Brey, technical director, DMC Inc., a Chicago-based system integrator, outlined some the following position-sensing options.Think digitallyFor digital position feedback:∙Incremental encoders are supported by all motion controllers; come in rotary and linear varieties and in many resolutions; are simulated by many other devices; and require a homing process to reference the machine to a physical marker, and when power is turned off.∙Absolute encoders are natively supported by fewer motion controllers; can be used by all controllers that have sufficient available digital inputs; report a complete position within theirrange (typically one revolution); and do not require homing.∙Resolvers are more immune to high-level noise in welding applications; come standard on some larger motors; simulate incremental encoders when used with appropriate servo amps; and can simulate absolute encoders with some servo amps.∙Dual-encoder feedback, generally under-used, is natively supported by most motion controllers; uses one encoder attached to the motor and another attached directly to the load; and is beneficial when the mechanical connection between motor and load is flexible or can slip.∙Vision systems , used widely for inspection, can also be used for position feedback. Such systems locate objects in multiple dimensions, typically X, Y, and rotation; frequently find parts ona conveyor; and are increasing in speed and simplicity.A metal rolling, stamping, and cut-off application provides an example of dual-encoder feedback use, Brey says. 'It required rapid and accurate indexing of material through a roll mill for a stamping process. The roll mill creates an inconsistent amount of material stretch and roller slip,' Brey explains.'By using the encoder on the outgoing material as position feedback and the motor resolver as velocity feedback in a dual-loop configuration, the system was tuned stable and a single index move provided an accurate index length. It was much faster and more accurate than making a primary move, measuring the error, then having to make a second correction move,' he says.Creative, economicalSam Hammond, chief engineer, Innoventor, a St. Louis, MO-area system integrator, suggests that the application's purpose should guide selection of position sensors; measurements and feedback don't have to be complex. 'Creative implementations can provide simple, economical solutions,' he says. For instance, for sequencing, proximity sensors serve well in many instances.Recent sensor applications include the AGV mentioned in lead image and the following.∙In a machine to apply the top seals to tea containers, proximity and through-beam sensors locate incoming packages. National Instruments vision system images are processed to find location ofa bar code on a pre-applied label, and then give appropriate motorcommands to achieve the desired position (rotation) setting to apply one of 125 label types. Two types of position sensors were used. One was a simple inductive proximity sensor, used to monitor machine status to ensure various motion components were in the right position for motion to occur. The camera also served as a position sensor, chosen because of its multi purpose use, feature location, and ability to read bar codes.∙ A progressive-die stamping machine operates in closed loop. A linear output proximity sensor provides control feedback for optimizing die operation; a servo motor adjusts die position in the bend stage. A linear proximity sensor was selected to give a dimensional readout from the metal stamping operation; data are used in a closed-loop control system.∙Part inspection uses a laser distance measurement device to determine surface flatness. Sensor measures deviation in return beams, indicating different surface attributes to 10 microns insize. An encoder wouldn't have worked because distance was more thana meter. Laser measurement was the technology chosen because it hadvery high spatial resolution, did not require surface contact, and had a very high distance resolution.An automotive key and lock assembly system uses a proximity sensor for detecting a cap in the ready position. A laser profile sensor applied with a robot measures the key profile.What to use, where?Sensor manufacturers agree that matching advantages inherent to certain position sensing technologies can help various applications.David Edeal, product marketing manager, MTS Sensors Div., says, for harsh factory automation environments, 'the most significant factors even above speed and accuracy in customer's minds are product durability and reliability. Therefore, products with inherently non-contact sensing technologies (inductive, magnetostrictive, laser, etc.) have a significant advantage over those that rely on physical contact (resistive, cable extension, etc.)'Other important factors, Edeal says, are product range of use and application flexibility. 'In other words, technologies that can accommodate significant variations in stroke range, environmental conditions, and can provide a wide range of interface options are of great value to customers who would prefer to avoid sourcing a large variety of sensor types. All technologies are inherently limited with respect to these requirements, which is why there are so many options.'Edeal suggest that higher cost of fitting some technologies to a certain application creates a limitation, such as with linear variabledifferential transformers. 'For example, LVDTs with stroke lengths longer than 12 inches are rare because of the larger product envelope (about twice the stroke length) and higher material and manufacturing costs. On the other hand, magnetostrictive sensing technology has always required conditioning electronics. With the advent of microelectronics and the use of ASICs, we have progressed to a point where, today, a wide range of programmable output types (such as analog, encoder, and fieldbus) are available in the same compact package. Key for sensor manufacturers is to push the envelope to extend the range of use (advantages) while minimizing the limitations (disadvantages) of their technologies.'Listen to your appDifferent sensor types offer distinct advantages for various uses, agrees Tom Corbett, product manager, Pepperl+Fuchs. 'Sometimes the application itself is the deciding factor on which mode of sensing is required. For example, a machine surface or conveyor belt within the sensing area could mean the difference between using a standard diffused mode sensor, and using a diffused mode sensor with background suppression. While standard diffused mode models are not able to ignore such background objects, background suppression models evaluate light differently to differentiate between the target surface and background surfaces.'Similarly, Corbett continues, 'a shiny target in a retro-reflective application may require use of a polarized retro-reflective model sensor. Whereas a standard retro-reflective sensor could falsely trigger when presented with a shiny target, a polarized retro-reflective model uses a polarizing filter to distinguish the shiny target from the reflector.'MTS' Edeal says, 'Each technology has ideal applications, which tend to magnify its advantages and minimize its disadvantages. For example, inthe wood products industry, where high precision; varied stroke ranges; and immunity to high shock and vibration, electromagnetic interference, and temperature fluxuations are critical, magnetostrictive position sensors are the primary linear feedback option. Likewise, rotary optical encoders are an ideal fit for motor feedback because of their packaging, response speed, accuracy, durability, and noise immunity. When applied correctly, linear position sensors can help designers to ensure optimum machine productivity over the long haul.'Thinking broadly first, then more narrowly, is often the best way to design sensors into a system. Edeal says, 'Sensor specifications should be developed by starting from the machine/system-level requirements and working back toward the subsystem, and finally component level. This is typically done, but what often happens is that some system-level specifications are not properly or completely translated back to component requirements (not that this is a trivial undertaking). For example, how machine operation might create unique or additional environmental challenges (temperature, vibration, etc.) may not be clear without in-depth analysis or past experience. This can result in an under-specified sensor in the worst situation or alternatively an over-specified product where conservative estimates are applied.'Open or closedEarly in design, those involved need to decide if the architecture will be open-loop or closed-loop. Paul Ruland, product manager, AutomationDirect, says, 'Cost and performance are generally the two main criteria used to decide between open-loop or closed-loop control in electromechanical positioning systems. Open-loop controls, such as stepping systems, can often be extremely reliable and accurate when properly sized for the system. The burden of tuning a closed-loop systemprior to operation is not required here, which inherently makes it easy to apply. Both types can usually be controlled by the same motion controller. A NEMA 23 stepping motor with micro-stepping drive is now available for as little as $188, compared to an equivalent servo system at about $700.'Edeal suggests, 'Control systems are created to automate processes and there are many good examples of high-performance control systems that require little if any feedback. However, where structural system (plant) or input (demand or disturbance) changes occur, feedback is necessary to manage unanticipated changes. On the process side, accuracy—both static and dynamic—is important for end product quality, and system stability and repeatability (robustness) are important for machine productivity.'For example,' Edeal says, 'in a machining or injection molding application, the tool, mold or ram position feedback is critical to the final dimension of the fabricated part. With rare exceptions, dimensional accuracy of the part will never surpass that of the position sensor. Similarly, bandwidth (response speed) of the sensor may, along with response limitations of the actuators, limit production rates.'Finally, a sensor that is only accurate over a narrow range of operating conditions will not be sufficient in these types of environments where high shock and vibration and dramatic temperature variations are common.'The latestWhat are the latest position sensing technologies to apply to manufacturing and machining processes and why?Ruland says, 'Some of the latest developments in positioning technologies for manufacturing applications can be found in even the simplest ofdevices, such as new lower-cost proximity switches. Many of these prox devices are now available for as little as $20 and in much smaller form factors, down to 3 mm diameter. Some specialty models are also available with increased response frequencies up to 20 kHz. Where mounting difficulties and cost of an encoder are sometimes impractical, proximity switches provide an attractive alternative; many position control applications can benefit from increased performance, smaller package size, and lower purchase price and installation cost.'Corbett concurs. 'Photoelectric sensors are getting smaller, more durable, and flexible, and are packed with more standard features than ever before. Some new photoelectrics are about half the size of conventional cylindrical housings and feature welded housings compared with standard glued housings. Such features are very desirable in manufacturing and machining applications where space is critical and durability is a must. And more flexible connectivity and mounting options—side mount or snout mount are available from the same product—allow users to adapt a standard sensor to their machine, rather than vice versa.'Another simple innovation, Corbett says, is use of highly visible,360-degree LED that clearly display status information from any point of view. 'Such enhanced LED indicates overload and marginal excess gain, in addition to power and output. Such sensors offer adjustable sensitivity as standard, but are available with optional tamperproof housings to prevent unauthorized adjustments.'Photoelectric SensorsPhotoelectric sensors are typically available in at least nine or more sensing modes, use two light sources, are encapsulated in three categories of package sizes, offer five or more sensing ranges, and can be purchasedin various combinations of mounting styles, outputs, and operating voltages. It creates a bewildering array of sensor possibilities and a catalog full of options.This plethora of choices can be narrowed in two ways: The first has to do with the object being sensed. Second involves the sensor's environment.Boxed inThe first question to ask is: What is the sensor supposed to detect? "Are we doing bottles? Or are we detecting cardboard boxes?" says Greg Knutson, a senior applications engineer with sensor manufacturer Banner Engineering.Optical properties and physical distances will determine which sensing mode and what light source work best. In the case of uniformly colored boxes, for example, it might be possible to use an inexpensive diffuse sensor, which reflects light from the box.The same solution, however, can't be used when the boxes are multicolored and thus differ in reflectivity. In that case, the best solution might be an opposed or retroreflective mode sensor. Here, the system works by blocking a beam. When a box is in position, the beam is interrupted and the box detected. Without transparent boxes, the technique should yield reliable results. Several sensors could gauge boxes of different heights.Distance plays a role in selecting the light source, which can either be an LED or a laser. LED is less expensive. However, because LED are a more diffuse light source, they are better suited for shorter distances. A laser can be focused on a spot, yielding a beam that can reach long distances. Tight focus can also be important when small features have tobe sensed. If a small feature has to be spotted from several feet, it may be necessary to use a laser.Laser sensors used to cost many times more than LED. That differential has dropped with the plummeting price of laser diodes. There's still a premium for using a laser, but it's not as large as in the past.Environmental challengesOperating environment is the other primary determining factor in choosing a sensor. Some industries, such food and automotive, tend to be messy, dangerous, or both. In the case of food processing, humidity can be high and a lot of fluids can be present. Automotive manufacturing sites that process engines and other components may include grit, lubricants, and coolants. In such situations, the sensor's environmental rating is of concern. If the sensor can't handle dirt, then it can't be used. Such considerations also impact the sensing range needed because it may be necessary to station the sensor out of harm's way and at a greater distance than would otherwise be desirable. Active alarming and notification may be useful if lens gets dirty and signal degrades.Similar environmental issues apply to the sensor's size, which can range from smaller than a finger to something larger than an open hand. A smaller sensor can be more expensive than a larger one because it costs more to pack everything into a small space. Smaller sensors also have a smaller area to collect light and therefore tend to have less range and reduced optical performance. Those drawbacks have to be balanced against a smaller size being a better fit for the amount of physical space available.Sensors used in semiconductor clean room equipment, for example, don't face harsh environmental conditions, but do have to operate in tight spaces. Sensing distances typically run a few inches, thus the sensorstend to be small. They also often make use of fiber optics to bring light into and out of the area where changes are being detected.Mounting, pricingAnother factor to consider is the mounting system. Frequently, sensors must be mechanically protected with shrouds and other means. Such mechanical and optical protection can cost more than the sensor itself—a consideration for the buying process. If vendors have flexible mounting systems and a protective mounting arrangement for sensors, the products could be easier to implement and last longer.List prices for standard photoelectric sensors range from $50 or so to about $100.Laser and specialty photoelectric sensors cost between $150 and $500. Features such as a low-grade housing, standard optical performance, and limited or no external adjustments characterize the lower ends of each category. The higher end will have a high-grade housing, such as stainless steel or aluminum, high optical performance, and be adjustable in terms of gain or allow timing and other options. Low-end products are suitable for general applications, while those at the higher end may offer application-specific operation at high speed, high temperature, or in explosive environments.Finally, keep in mind that one sensing technology may not meet all of the needs of an application. And if needs change, a completely different sensor technology may be required. Having to switch to a new approach can be made simpler if a vendor offers multiple technologies in the same housing and mounting footprint, notes Ed Myers, product manager at sensor manufacturer Pepperl+Fuchs. If that's the case, then one technology can be more easily swapped out for another as needs change.译文什么是智能传感器自动化领域所取得的一项最大进展就是智能传感器的发展与广泛使用。
英文文献翻译--温度传感器简单集成电路的设计
XX 大学毕业设计(论文)外文资料翻译学院：系（专业）：电子信息工程姓名：学号：外文出处：Jay Scolio，Maxim Integrated ProductsInc.(用外文写)附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文温度传感器简单集成电路的设计当选择一个温度传感器的时候,将不再限制在模拟输出或数字输出装置。
与你系统需要相匹配的传感器类型现在有很大的选择空间。
市场上供应的所有温度感应器都是模拟输出。
热电阻， RTDs 和热电偶是另一种输出装置,矽温度感应器。
在多数的应用中，这些模拟输出装置在有效输出时需要一个比较器 , ADC, 或一个扩音器。
因此，当更高技术的集成变成可能的时候,有数字接口的温度传感器变成现实。
这些集成电路被以多种形式出售,从超过特定的温度时才有信号简单装置,到那些报告远的局部温度提供警告的装置。
现在不只是在模拟输出和数字输出传感器之间选择，还有那些应该与你的系统需要相匹配的更广阔的感应器类型的选择。
温度传感器的类型：图 1：传感器和集成电路制造商提供的四种温度传感器在图1中举例说明四种温度感应器类型。
一个理想模拟传感器提供一个完全线性的功能输出电压（A）。
在传感器(B)的数字I/O类中, 温度数据通常通过一个串行总线传给微控制器。
沿着相同的总线，数据由温度传感器传到微控制器,通常设定温度界限在引脚得数字输出将下降的时候。
当超过温度界限的时候，报警中断微控制器。
这个类型的装置也提供风扇控制。
"模拟正量"传感器(C)被应用在多种类型的数字输出上。
当超过特定温度的时候 , V OUT 对温度曲线是一个数字输出。
在这情况，增加到模拟温度传感器的"正信号"只不过是一个比较器和参考电压。
其他的类型"正信号"部分在以频率和方波的形式储存以后被延迟,这些将会在以后讨论。
系统监视器(D)是四种类型当中最复杂的集成电路。
传感器的基础知识论文中英文资料对照外文翻译
传感器的根底知识论文中英文资料对照外文翻译英文文献翻译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. Theenergy-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 Elements Although 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.1英文文献翻译d) There should be a linear relationship between the measured and the transducer signal. e) The transducer should have minimum sensitivity to external effects, pressuretransducers,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)resistance ii) capacitance iii) inductanceiv) mutual-inductance typesThese transducers all rely on external excitation voltage for their operation. b) self-generating types,which include i) electromagnetic ii)thermoelectric iii)photoemissive iv)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 wiper2英文文献翻译displacement 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 the cross-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,3英文文献翻译or a combination of elements such as rosettes will permit simultaneous measurements in more than one direction. b) unbonded strain gauges A 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 ℃.℃℃. b) thermistor resistance temperature transducersThermistors are temperature-sensitive resistors which exhibit large non-liner resistance changes with temperature variation. In general, theyhave 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 Cells The 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 region4英文文献翻译and 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.B Where 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 controlpurpose, 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 producea 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 quoted iii)displacement ranges 25*10-6 m to 10-3m iv) rise time less than 50us possibleTypical measurands are displacement, pressure, vibration, sound, and liquid level. 8、 Linear Variable-differential Ttransformer 9、Piezo-electric Transducers5。
传感器技术论文中英文对照资料外文翻译文献
传感器技术论文中英文对照资料外文翻译文献中英文对照资料外文翻译文献附件1:外文资料翻译译文传感器新技术的发展传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。
输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。
如果把计算机比作大脑，那么传感器则相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。
自动化程度越高，系统对传感器要求越高。
在今天的信息时代里，信息产业包括信息采集、传输、处理三部分，即传感技术、通信技术、计算机技术。
现代的计算机技术和通信技术由于超大规模集成电路的飞速发展，而已经充分发达后，不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高，还要求其成本低廉且使用方便。
显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。
世界许多发达国家都在加快对传感器新技术的研究与开发，并且都已取得极大的突破。
如今传感器新技术的发展，主要有以下几个方面:利用物理现象、化学反应、生物效应作为传感器原理，所以研究发现新现象与新效应是传感器技术发展的重要工作，是研究开发新型传感器的基础。
日本夏普公司利用超导技术研制成功高温超导磁性传感器，是传感器技术的重大突破，其灵敏度高，仅次于超导量子干涉器件。
它的制造工艺远比超导量子干涉器件简单。
可用于磁成像技术，有广泛推广价值。
利用抗体和抗原在电极表面上相遇复合时，会引起电极电位的变化，利用这一现象可制出免疫传感器。
用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。
如用肝炎病毒抗体可检查某人是否患有肝炎，起到快速、准确作用。
美国加州大学巳研制出这类传感器。
传感器材料是传感器技术的重要基础，由于材料科学进步，人们可制造出各种新型传感器。
例如用高分子聚合物薄膜制成温度传感器;光导纤维能制成压力、流量、温度、位移等多种传感器;用陶瓷制成压力传感器。
传感器温湿度测量中英文资料外文翻译文献
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。
毕业设计说明书英文文献中文翻译1
利用声学矢量传感器阵列对连贯的信号进行二维DOA估计摘要在本文中,我们提出了两种新的方法来评估的二维波达方向(DOA)的窄带一致(或高度相关)信号通过一个l型的声学矢量传感器阵列。
我们的去除信号的相干性并利用互相关矩阵重构信号子空间,ESPRIT和传播算子的方法是用于估计方位和俯仰角。
ESPRIT 技术是基于几何形状转移不变性和传播算子的方法是基于分区的互相关矩阵。
传播算子的方法计算效率高,而且只需要线性操作。
此外,ESPRIT的方法不需要任何特征分解或奇异值分解。
这两种技巧是直接的方法,不需要任何二维估计方位和仰角的迭代搜索。
给出仿真结果证明该方法的性能。
爱思唯尔B.V. 2011 保留所有权利。
关键词:来波方向角估计互相关相干信号声学矢量传感器阵列1 介绍近年来,声学矢量传感器阵列信号处理在水下信号处理的领域已经引起了越来越多的关注。
一个声学矢量传感器在空间一点测量压力和声空间粒子速度而传统的压力传感器只能提取压力的信息。
主要利用这些向量传感器比传统的标量传感器是他们可以更好地利用可用的声学信息;因此,它们应该比标量(压力)传感器数组计算精确。
因此应该允许矢量传感器在保持性能的同时使用更小的数组孔。
声学矢量传感器模型首次引入信号处理领域是在文献[1]总。
自那时以来,许多先进的压力传感器阵列技术适应声学矢量传感器阵列[2 - 4]。
各类不同的设计技术的声学矢量传感器如今在商业运用[5]。
矢量传感器技术已在水下环境使用了几十年,并吸引了对水下振源位置的问题的注意。
大多数的高分辨率波达方向估计方法如MUSIC[6、7]和ESPRIT[8、9]，当信号不相关时，已被证明是有效的。
当信号源连贯或高度相关时,例如,在多径传播或在军事场景,包含智能干扰系统,这些技术的性能却大幅降低。
在此情况下,协方差矩阵的秩一般都小于信源的数量。
要克服这种不利的方面,去相关技术，如Kozickand Kassam[13]研发的空间平滑(SS)[10-12]技术,特征向量平滑(ES)[14、15]，而且没有特征分解(SUMWE) [16]的计算效率方法已经被认可,然而,这些技术只适合某些阵列配置,例如,均匀间隔的线性阵列。
电容式传感器的外文文献翻译、中英文翻译、外文翻译
参考资料原文：Capacitive sensors and the main features of the basic concepts: The measured volume of the machinery, such as displacement, pressure change is converted to the sensor capacitance. It is the sensitive part of the capacitor with variable parameters. Its most common form is composed of two parallel electrodes, a very inter-air as the medium of the capacitor, if the neglect edge effects, the capacitance for the capacitor plate ε A / δ, where εis a very inter-medium dielectric constant, A two electrode effective area covered by each other, δ is the distance between two electrodes. δ, A, εone of the three parameters will lead to the change in capacitance changes can be used for measurement. Therefore capacitive sensors can be divided into polar distance change type, change type size, media type three types of changes.Most from the changes in small type generally used to measure the linear displacement, or as a result of force, pressure, vibration caused by changes in polar distance (see capacitive pressure sensors). Change type size generally used to measure the angular displacement or linear displacement larger. Changes in media type commonly used in level measurement and a variety of media, temperature, density, humidity measurement. The advantage of the sensor capacitor structure is simple, inexpensive, high sensitivity,过载能力strong, good dynamic response and high temperature, radiation, vibration and other adverse conditions of strong adaptability and strong. The disadvantage is that there are non-linear output, parasitic capacitance and the distributed capacitance on the sensitivity and accuracy the impact of larger and more complex circuits, such as connectivity. Since the late 70s, with the development of integrated circuit technology, a packaging and micro-measuring instrument with capacitive sensors.This new type of distributed capacitance sensors can greatly reduce the impact to overcome the inherent drawbacks. Capacitive sensor is a very wide use, a great potential for development of the sensor.Capacitive sensor working principle：Capacitive sensor surface of the induction of two coaxial metal electrode composition, much like "open" capacitor electrode, the two electrodes form a capacitor, in series with the RC oscillation circuit. Power when connected, RC oscillator is notoscillating, when a goal of moving around electrical capacitor, the capacitor capacity increased, the oscillator to start oscillation. Circuit after the passage of the deal, will be two kinds of vibration and vibration signals into switching signals, which played a detection purpose of the existence of any objects. The sensor can detect metal objects, but also to detect non-metallic objects, metal objects can move away from the largest, non-metallic objects on the decision to move away from the dielectric constant material, the greater the dielectric constant materials, the availability of action the greater distance.Application of capacitive sensors：Capacitive sensor can be used to measure linear displacement, angular displacement, vibration amplitude, especially suitable for measuring high-frequency vibration amplitude, precision rotary axis accuracy, acceleration and other mechanical parameters. Pole-changing type of application from a smaller displacement in the measurement range to several hundred microns in 0.01m, precision can reach 0.01m, a resolution of up to 0.001m. Change type size larger displacement can be measured, for the zero-range a few millimeters to a few hundred mm, 0.5 percent better than the linear resolution of 0.01 ~ 0.001m. Capacitive angular displacement sensor point of view and the dynamic range to a few degrees, a resolution of about 0.1 "up to the stability of the zero angle-second, widely used in precision angle measurement, such as for high-precision gyroscopes and accelerometers tilting . capacitive measurement sensor can measure the peak amplitude for the 0 ~ 50m, a frequency of 10 ~ 2kHz, sensitivity is higher than 0.01m, non-linear error of less than 0.05m.Capacitive sensor can also be used to measure pressure, differential pressure, level, surface, composition content (such as oil, the water content of food), non-metallic coating materials, such as film thickness, dielectric measurements of humidity, density, thickness, etc., in the automatic detection and control systems are also often used as a location signal generator. Capacitive differential pressure sensor measuring range up to 50MPa, an accuracy of ± 0.25% ~ ± 0.5%. Capacitive sensor for measuring range of the thickness of a few hundred microns, resolution of up to 0.01m. Capacitive Proximity Switches can not only detect metal, but also can detect plastic, wood,paper, and other dielectric liquids, but can not achieve the ultra-small, the movement distance of about 10 ~ 20mm. Electrostatic capacitive level switch is widely used in detection is stored in the tank, hopper, such as the location of containers in a variety of objects of a mature product. When the capacitive sensor measuring metal surface conditions, from the size, vibration amplitude is often used very variable from unilateral type, when the measured object is a capacitor electrode, and the other electrode in the sensor inside. This type of sensor is a non-contact measurement, dynamic range is relatively small, about a few millimeters is about the precision of more than 0.1m, a resolution of 0.01 ~ 0.001m.译文：电容式传感器的基本概念及主要特点:把被测的机械量，如位移、压力等转换为电容量变化的传感器。
MEMS电容式加速度传感器课程设计报告(英文版)
A Novel Design of Capacitively-sensed In-plane Accelerometer in Wafer-bonded Deep-RIE Silicon Process[Abstract]This article introduces a new MEMS design of capacitively-sensed in-plane accelerometer using wafer-bonding DIRE silicon process, Including the complete silicon wafer etching process, the internal mechanical structure of the accelerometer, chip packaging, overall physical simulation modeling and readout circuit.[Key Word]DRIE;Capacitive; Accelerometer1.IntroductionWith the rapid development of silicon micromachining technology (MEMS), various devices based on MEMS technology have also emerged. Currently, there are various types of MEMS sensors which have been widely used, the commonly used ones like pressure sensors, acceleration sensors, optical switches, etc. have the characteristics of small size, light weight, low cost, low power consumption, and high reliability. Besides of the compatible fabricating process, it is easy to realize digitization, intelligent and mass production. MEMS sensors have attracted wide attention in the fields of automobile, medicine, navigation and control, biochemical analysis and industrial inspection. The principle of the acceleration sensor varies with its application, including piezoresistive, capacitive, piezoelectric, resonant, etc. Capacitive acceleration sensors are widely used in industrial fields, such as engines, CNC lathes and so on. It has a simple circuit structure, a wide frequency range of about 0 to 450 Hz, linearity less than 1%, high sensitivity, stable output, small temperature drift, small measurement error, steady-state response, low output impedance, and the relationship between output power and vibration acceleration. The mathematical formula is simple, convenient, easy to calculate and equips other advantages, and has high practical application value. In this article we will focus on the introduction of the new type of capacitive accelerometer and related information.2.PrincipleThe basic principle of a capacitive sensor is to measure the effect of physical displacement on the capacitance or electric field.Based on this principle, in addition to measuring acceleration, we can also measure pressure, angular velocity, flow, and humidity.First, we use the parallel plate capacitor to roughly describe its working principle.These three motions (changeable area, changeable spacing, changeable medium) cause the change of capacitance, as shown in fig.1, can be described by a basic equation:C=ε0εr Ad(2−1)Fig.1.Typical parallel plate reaction with three different kinds of motionsWhere ε0and εr are the dielectric constant of air and the relative dielectric constantof the medium, respectively. A is direct area and d is the distance between two plates. Let ε=ε0εr, when the displacement of one plate is vertical (fig.1), indicating A is constant,C=εAd−x(2−2)Differentiate (1-2) then we can get variation of capacitance with spacing:dC(x) dx =εA(d−x)2(2−3)From (1-3) we acknowledge that the capacitance of the parallel plates has a strong nonlinear relationship with spacing-changing motion, giving same x, if d is smaller, changing rate will be higher, which means higher sensitivity for plate motion. While the maximum displacement of plate is limited, for the reason of pull-down effect, we must use improved readout circuit to measure the sensor output.The second method to change capacitance is changing the direct area, at this time x is horizontal displacement,C(x)=εb(L0−x)d(2−4)Differentiate it, we getdC(x) dx =−εbd(2−5)It is obviously that capacitance has a proportional relationship with displacement x, b is the depth, meanwhile, the sensitivity is constant, however, this kind of motion is seldom used in parallel plate capacitive sensor, more often in comb-like capacitive sensor, as shown in fig.2, in this case, the flange effect cannot be neglected, hence complicated calculation. The result is only theoretical, the sensitivity is not constant all the time.b-like capacitive senor, applied a fixed voltage value, the relative motion leads to capacitance change.The third method is changing the dielectric, in this situationC=ε0εr(L−x)b+ε0bxd(2−6)Medium-change type is often used for object position measurement and temperature, density, humidity determination of various media, area-change type is usually used for angular displacement or larger linear displacement, for measuring acceleration, placing-change type is more convenient, which is often used for measuring small linear displacement caused by force, pressure, vibration and so on. This article will introduce a new design of capacitive accelerometer based on spacing-changing parallel plates capacitor, using novel processing technique and add new elements tothis device.3. Mechanical modelTo be simple, the structure can be equivalent to a work mass, a cantilever beam and two electrodes, the cantilever bends due to the acceleration exerted on the mass, after that the capacitance will change. The flat capacitive acceleration sensor is basically made of three silicon chips bonded, as fig.3 shows. The cantilever beam and the mass are etched on the middle silicon wafer by DRIE processing technology, and two flat plate capacitors are connected in series on the upper and lower surfaces of the mass block and the surface electrodes on the upper and lower silicon wafers respectively. Fig.3. A schematic diagram of the structure of a capacitiveaccelerometer, including a cantilever beam, a mass, and two platecapacitors connected in series.Fig.4. When the mass moves under the action of acceleration, the measurement sensitivity can be improved by means of differential connection.When the mass moves under the action of acceleration, the changes in the two capacitors are exactly opposite, and the sensitivity can be doubled by differential connection, meanwhile, greatly improved signal-to-noise ratio.Fig.5. The equivalent diagram of the differential capacitorIn static state, the mass is in a balanced position, the two differential capacitors are equal, at this time,C 1=C 2=C 0=εA 0(3−1) when accelerating, the inertial force caused by the acceleration of the mass produces displacement x, and the gap between the two differential capacitors becomes{ C 1=εAd 0−x C 2=εA d 0+x (3−2) So the total capacitance change isΔC =C,−C 2=2C 0x 0(3−3) The capacitive acceleration sensor can be regarded as a mass-spring-damping system from a mechanical point of view, and the acceleration forms an inertial force on the system through the mass(fig,6).Fig.6.capacitive accelerometer equivalent diagramAccording to Newton's second law, for this mechanical model, the following second-order differential equations can be written:m d2xdt2+Ddxdt+kx=ma (3−4)And the spring can be replaced by cantilever, if only consider the stiffness coefficient of elastic structure, according to structure mechanics, we haveK=3EIL3(3−5)Perform the Laplace transform under zero initial conditions by the above formula, (ms2+Ds+K)X(s)=mA(s) (3−6) Therefore, the acceleration can be used as the input variable, and the displacement of the mass relative to the shell is the output variable; the transfer function isG(s)=X(s)A(s)=mms2+Ds+K(3−7)Undamped natural frequency isω0=√Km(3−8) The transfer function can be rewritten asC(s)=1s2+ω0Q s+ω02(3−9)The relationship between Q-factor and damping ratio isQ=1(3−10)The damping ratio of the sensor isζ=D21√Km−11)Thus, the critical damping, when ζ=1,D cr=2√Km (3−12)4.StructureThis capacitive acceleration sensor is composed of three-part silicon crystal discs, and the middle layer is a movable capacitor plate made of double-layer SOI silicon wafers.As shown in Fig.7, the middle movable capacitor plate is supported by eight bending elastic connecting beams, sandwiched between two fixed capacitor plates on the upper and lower layers.Fig.7.Structural layout of capacitive acceleration sensorThe choice of basic structure depends on the range, rigid constraints, elastic constraints, resonance frequency constraints, the design of the elastic beam is a very critical part in the MEMS accelerometer, and its structure directly affects the parameters such as the range, resolution, lateral sensitivity, and high overload resistance of the sensor. This article will use serpentine beam (as shown in fig.7), while in simulation we use cantilever as sample, which is easily-perform, intuitive and lower stiffness.5.FabricationThe processes of capacitive MEMS accelerometers generally use: surface process, bulk silicon process, LIGA process and SOI+DRIE process, etc.Surface technology is a micro-technology developed on the basis of the integrated circuit planar technology, and only performs single-sided lithography. It uses the sequential deposition and selective etching of different materials on the silicon plane to form various microstructures. It mainly includes sacrificial layer deposition, sacrificial layer etching, structural layer deposition, structural layer etching, sacrificial layer removal (release structure). Finally, the structural material is suspended above the substrate to form a 2D or 3D structure of various shapes.The bulk silicon process refers to the process of etching the silicon substrate along the thickness direction of the silicon substrate, including wet etching and dry etching, and is an important method to realize the three-dimensional structure. In order to form a complete microstructure, bonding technology is often used on the basis of processing, combining silicon bonding technology with bulk silicon processing methods. The microstructure of silicon is formed through multiple masking, single-sided or double-sided lithography and anisotropic etching, and then the relevant parts are precisely aligned and bonded into a whole. The process of bulk silicon processing is more complicated than that of silicon surface processing, withlarge volume and high cost.The SO1+DRIE process is an extension and development of the bulk silicon process. The use of silicon-on-insulator (SOI) to fabricate single-crystal silicon three-dimensional microstructures has been an extremely rapid method in recent years. Almost all methods of manufacturing microstructures using SOI+DRIE (deep reactive ion etching) to deeply etch single crystal silicon. Depending on the structure, performance requirements, front structure release and back structure release can be used.Bonding + DRIE process is able to accurately control the thickness of the structure, meanwhile, realize the structure of larger volume and mass. However, this technology has the problem of dielectric filling, which increases the difficulty of the process. The RIE-lag and lateral etching phenomena are obvious. This fabrication is based on deep-RIE process to realize the structure of capacitive accelerometer.The selected process is n-type (100), two layers of mirror-surface bonding silicon crystal layer, the processing layer thickness is 800 ± 25μm, the device layer thickness is 30μm, the oxide layer thickness is 2μm, the crystal orientation of <110>, the patterned mask should be is 1.5μm and 3μm respectively. Silica is used as an insulating layer between the two layers.The specific steps are shown in Figure 8.(a) Determine the capacitance distance between the upper and lower plates(b) First etch the partially recessed area at the bottom, and deposit metal electrodes on it to achieve vertical detection and driving(c) Use DRIE etching until the SiO2 buried layer stops(d) Use HF to remove the SiO2 layer. The new oxide layer will be regenerated on both sides. Continue to etch with DRIE until the SiO2 layer is completely removed. Apply photoresist on both sides as the beam structure etched by DRIE.(e) After removing the photoresist Both sides are oxidized again to form SiO2, and then covered with EVG-100(f) etch with the remaining photoresist and then remove the photoresist(g) etc. The etching is completed, and a symmetric beam structure is formed(h) using a symmetric structure Confirm the position of the middle beam(i) the upper and lower two layers form a 2μm SiO2 symmetric oxide layer to isolate the upper, middle and lower three layers(j) and then connect the upper and lower layers through the beam structure intermediate layer(k) to control the bonding temperature of 480°C and then at 1100 °C Save for one hour.Fig.8.The fabrication steps for capacitive accelerometer6.SimulationIn this simplified simulation model we calculate the mass displacement in different acceleration and different voltage, fig.9 and fig.10 are the geometry structure of the beam. It is obvious that when acceleration exerted, the displacement can be easily seen.Fig.9.cantilever beam connection Fig.10.L-shape beam connectionFig.11.The simulation steps of modeling, including electric potential and offset displacement(using COMSOL finite elementanalysis software)7.Readout circuit.The readout circuit is composed of several parts, after the signal is input to the Venturi bridge sinusoidal oscillator, the RC circuit of the operational amplifier is used for sinusoidal oscillation and the amplitude is automatically stabilized, and then the voltage is adjusted by the transformer, reverse amplified, it passed through phase sensitive detection, low-pass filter conversion, a then input into the single-chip microcomputer, as shown in fig.12.The sub-circuits are following(fig.13),Stable amplitude Venturi oscillator circuit Reverse amplificationPhase sensitive detector Low-pass active circuitFig.13.the readout circuit components8.ConclusionThis article introduce a new design of capacitive accelerometer, based on silicon bonding and DIRE process, we decide the geometric feature of capacitive accelerometer, besides perform finite element simulation for stress analysis. In theory, we made a mathematical demonstration of differential capacitance and force, and obtained the relationship between acceleration and readout capacitance value, and deduced the critical damping equation to enable it to work under optimal conditions. We describe the specific wafer processing and fabrication process in detail. Meanwhile we compare this design with other types of capacitive accelerometer sensors, and show the using potential, it can be foreseen that MEMS sensors have a bright future.Reference[1] YUFIN S A. Geoecology and computers：proceedings of the Third International Conference on Advances of Computer Methods in Geotechnical and Geoenvironmental Engineering, Moscow, Russia, February 1-4,2000[C].Rotterdam：A. A. Balkema,2000.[2]JC Lotters, et al. Design. fabrication and characterization of a highly symmetrical capacitive triaxial accelerometer. Sens Actuators A,1998,66:205-212[3]J Melin, et al. A low-pressure encapsulated deep reactive ion etched resonant pressure sensor electrically excited and detected using “burst” technology, JMM, 2000,10:209-217[4]R Nadal-Guardia, et al. AC transfer function of electrostatic capacitive sensors based on the 1-D equivalent model: application to Silicon microphones. J MEMS,2003,12(6):972-978[5]K S Chen.et al. Effect of process parameters on the surface morphology and mechanical performance of silicon structures after deep reactive ion etching (DRIE), IEEE J, MEMS, 2002,11(3):264-275[6]Y L Chao, et al. Ammonium hydroxide effect on low-temperature wafer bonding energy enhancement, Electrochem. Solid-State Lett. 8, G74,2005[7]N Miki, et al. Multi-stack silicon-direct wafer bonding for 3D MEMS manufacturing, Sensors and Actuators A 2003:103,194-201[8] MARK V P．Interface circuit for capacitive accelerometer．Sensors ＆Actuators，1989,17:629-637[9]BERNHARD B．Electronics for micro-machined inertial sensors. Solid State Sensors and Actuators，1997(2):1169-1172[10]Leea GHY et al. Develop and analysis of the vertical capacitive accelerometer. Sens Actuators,2005,A119:8-18。
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Capacitive Sensor Operation Part 1: The BasicsPart 1 of this two-part article reviews the concepts and theory of capacitive sensing to help to optimize capacitive sensor performance. Part 2 of this article will discuss how to put these concepts to work.Noncontact capacitive sensors measure the changes in an electrical property called capacitance. Capacitance describes how two conductive objects with a space between them respond to a voltage difference applied to them. A voltage applied to the conductors creates an electric field between them, causing positive and negative charges to collect on each objectCapacitive sensors use an alternating voltage that causes the charges to continually reverse their positions. The movement of the charges creates an alternating electric current that is detected by the sensor. The amount of current flow is determined by the capacitance, and the capacitance is determined by the surface area and proximity of the conductive objects. Larger and closer objects cause greater current than smaller and more distant objects. Capacitance is also affected by the type of nonconductive material in the gap between the objects. Technically speaking, the capacitance is directly proportional to the surface area of the objects and the dielectric constant of the material between them, and inversely proportional to the distance between them as shown.:In typical capacitive sensing applications, the probe or sensor is one of the conductive objects and the target object is the other. (Using capacitive sensors to sense plastics and other insulators will be discussed in the second part of this article.) The sizes of the sensor and the target are assumed to be constant, as is the material between them. Therefore, any change in capacitance is a result of a change in the distance between the probe and the target. The electronics are calibrated to generate specific voltage changes for corresponding changes in capacitance. These voltages are scaled to represent specific changes in distance. The amount of voltage change for a given amount of distance change is called the sensitivity. A common sensitivity setting is 1.0 V/100 µm. That means that for every 100 µm change in distance, the output voltage changes exactly 1.0 V. With this calibration, a 2 V change in the output means that the target has moved 200 µm relative to the probe.Focusing the Electric FieldWhen a voltage is applied to a conductor, the electric field emanates from every surface. In a capacitive sensor, the sensing voltage is applied to the sensing area of the probe. For accurate measurements, the electric field from the sensing area needs to be contained within the space between the probe and the target. If the electric field is allowed to spread to other items—or other areas on the target—then a change in the position of the other item will be measured as a change in the position of the target. A technique called "guarding" is used to prevent this from happening. To create a guard, the back and sides of the sensing area are surrounded by another conductor that is kept at the same voltage as the sensing area itself. When the voltage is applied to the sensing area, a separate circuit applies the exact same voltage to the guard. Because there is no difference in voltage between the sensing area and the guard, there is no electric field between them. Any other conductors beside or behind the probe form an electric field with the guard instead of with the sensing area. Only the unguarded front of the sensing area is allowed to form an electric field with the target.DefinitionsSensitivity indicates how much the output voltage changes as a result of a change in the gap between the target and the probe. A common sensitivity is 1 V/0.1 mm. This means that for every 0.1 mm of change in the gap, the output voltage will change 1 V. When the output voltage is plotted against the gap size, the slope of the line is the sensitivity.A system's sensitivity is set during calibration. When sensitivity deviates from the ideal value this is called sensitivity error, gain error, or scaling error. Since sensitivity is the slope of a line, sensitivity error is usually presented as a percentage of slope, a comparison of the ideal slope with the actual slope.Offset error occurs when a constant value is added to the output voltage of the system. Capacitive gauging systems are usually "zeroed" during setup, eliminating any offset deviations from the original calibration. However, should the offset error change after the system is zeroed, error will be introduced into the measurement. Temperature change is the primary factor in offset error.Sensitivity can vary slightly between any two points of data. The accumulated effect of this variation is called linearity erro. The linearity specification is the measurement of how far the output varies from a straight line.To calculate the linearity error, calibration data are compared to the straight line that would best fit the points. This straight reference line is calculated from the calibration data using least squares fitting. The amount of error at the point on the calibration line furthest away from this ideal line is the linearity error. Linearity error is usually expressed in terms ofpercent of full scale (%/F.S.). If the error at the worst point is 0.001 mm and the full scale range of the calibration is 1 mm, the linearity error will be 0.1%.Note that linearity error does not account for errors in sensitivity. It is only a measure of the straightness of the line rather than the slope of the line. A system with gross sensitivity errors can still be very linear.Error band accounts for the combination of linearity and sensitivity errors. It is the measurement of the worst-case absolute error in the calibrated range. The error band is calculated by comparing the output voltages at specific gaps to their expected value. The worst-case error from this comparison is listed as the system's error band. In Figure 7, the worst-case error occurs for a 0.50 mm gap and the error band (in bold) is –0.010.Gap (mm)Expected Value (VDC)Actual Value VDC)Error (mm) 0.50 –10.000 –9.800 –0.0100.75 –5.000 –4.900 –0.0051.00 0.000 0.000 0.0001.25 5.000 5.000 0.0001.50 10.000 10.100 0.005Figure 7. Error valuesBandwidth is defined as the frequency at which the output falls to –3 dB, a frequency that is also called the cutoff frequency. A –3 dB drop in the signal level is an approximately 30% decrease. With a 15 kHz bandwidth, a change of ±1 V at low frequency will only produce a ±0.7 V change at 15 kHz. Wide-bandwidth sensors can sense high-frequency motion and provide fast-responding outputs to maximize the phase margin when used in servo-control feedback systems; however, lower-bandwidth sensors will have reduced output noise which means higher resolution. Some sensors provide selectable bandwidth to maximize either resolution or response time.Resolution is defined as the smallest reliable measurement that a system can make. The resolution of a measurement system must be better than the final accuracy the measurement requires. If you need to know a measurement within 0.02 µm, then the resolution of the measurement system must be better than 0.02 µm.The primary determining factor of resolution is electrical noise. Electrical noise appears in the output voltage causing small instantaneous errors in the output. Even when theprobe/target gap is perfectly constant, the output voltage of the driver has some small butmeasurable amount of noise that would seem to indicate that the gap is changing. This noise is inherent in electronic components and can be minimized, but never eliminated.If a driver has an output noise of 0.002 V with a sensitivity of 10 V/1 mm, then it has an output noise of 0.000,2 mm (0.2 µm). This means that at any instant in time, the output could have an error of 0.2 µm.The amount of noise in the output is directly related to bandwidth. Generally speaking, noise is distributed over a wide range of frequencies. If the higher frequencies are filtered before the output, the result is less noise and better resolution (Figures 8, 9). When examining resolution specifications, it is critical to know at what bandwidth the specifications apply.Capacitive Sensor Operation Part 2: System OptimizationPart 2 of this two-part article focuses on how to optimize the performance of your capacitive sensor, and to understand how target material, shape, and size will affect the sensor's response.Effects of Target SizeThe target size is a primary consideration when selecting a probe for a specific application. When the sensing electric field is focused by guarding, it creates a slightly conical field that is a projection of the sensing area. The minimum target diameter is usually 130% of the diameter of the sensing area. The further the probe is from the target, the larger the minimum target size.Range of MeasurementThe range in which a probe is useful is a function of the size of the sensing area. The greater the area, the larger the range. Because the driver electronics are designed for a certain amount of capacitance at the probe, a smaller probe must be considerably closer to the target to achieve the desired amount of capacitance. In general, the maximum gap at which a probe is useful is approximately 40% of the sensing area diameter. Typical calibrations usually keep the gap to a value considerably less than this. Although the electronics are adjustable during calibration, there is a limit to the range of adjustment.Multiple Channel SensingFrequently, a target is measured simultaneously by multiple probes. Because the system measures a changing electric field, the excitation voltagefor each probe must be synchronized or the probes will interfere with each other. If they were not synchronized, one probe would be trying to increase the electric field while another was trying to decrease it; the result wouldbe a false reading. Driver electronics can be configured as masters or slaves; the master sets the synchronization for the slaves in multichannel systems.Effects of Target MaterialThe sensing electric field is seeking a conductive surface. Provided that the target is a conductor, capacitive sensors are not affected by the specific target material; they will measure all conductors—brass, steel, aluminum, or salt water—as the same. Because the sensing electric field stops at the surface of the conductor, target thickness does not affect the measurement中文翻译电容式传感器操作第一部分：基础 这篇文章的第一部分回顾了电容式传感器的概念和理论来帮助我们优化电容式传感器的性能。