改进的红外测温传感系统的移动设备 毕业论文外文翻译

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电容式传感器的外文文献翻译、中英文翻译、外文翻译

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。

红外传感器论文中英文资料对照外文翻译

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。

温度控制系统论文中英文资料对照外文翻译

温度控制系统论文中英文资料对照外文翻译

温度控制系统论文中英文资料对照外文翻

本文将介绍温度控制系统的关键技术,涉及环境温度探测、数
据处理、控制策略等内容。

以下是部分资料的中英文对照外文翻译。

环境温度探测
中文资料
传感器是环境温度控制系统的关键组件之一。

目前市场上主流
的温度传感器有热敏电阻、热电偶、红外线传感器等。

温度控制系
统还需要考虑传感器的输出精度和响应速度等因素。

英文资料
数据处理
中文资料
数据处理是温度控制系统的核心部分。

常用的数据处理方法有滤波、线性化处理、校准等。

数据处理的目的是提高控制精度和稳定性。

英文资料
控制策略
中文资料
控制策略主要包括开环控制和闭环控制。

其中,闭环控制具有更高的控制精度和稳定性,但需要采集反馈信号、进行数据处理等多个步骤。

英文资料
Control strategies mainly include open-loop control and closed-loop control. Among them, closed-loop control has higher control accuracy and stability, but requires multiple steps such as collecting feedback signals and data processing.。

红外遥控系统毕业论文中英文资料对照外文翻译文献

红外遥控系统毕业论文中英文资料对照外文翻译文献

中英文资料对照外文翻译文献红外遥控系统摘要目前红外数据通信技术是在世界范围内被广泛应用的一种无线连接技术,它也可以被许多软硬件平台所支持。

红外收发器产品具有成本低,体积小,传输速率快,点对点传输安全性好,不受电磁干扰等特点,可使得信息在几个不同产品器件之间快速、便捷、安全地交换与传输。

红外数据通信技术在短距离无线传输领域内有着十分显著的优势,红外遥控收发系统的设计和存在具有非常高的运用价值。

目前,红外收发器产品在便携式产品中的应用潜力很大。

全世界约有1亿5千万台设备和仪器是采用红外数据通信技术的,在电子产品、工业设备、医疗设备等领域内使用范围很广。

几乎所有笔记本电脑、手机都配置红外收发器接口。

伴随着红外数据传输技术的愈发成熟、生产和使用成本下降,红外收发器在短距离通讯领域内将会得到更加广泛的应用。

设计这个系统的目的是用红外线作为传输媒介来传输操作者或用户的操作信息和指令,然后由接收器电路翻译出原信号,主要是利用编码芯片和解码芯片对信号进行调制解调,这其中,编码芯片用的是台湾生产的PT2262,解码芯片是PT2272。

它们的主要工作原理是:通过编码键盘可以为PT2262提供输入信息,PT2262对输入的信息进行编码并加载到38KHZ 的载波上并调制红外发射二极管,再将其辐射到空间,然后再由接收系统接收信号并解调出原始的信息内容,由PT2272对原信号进行解码,从而驱动相应的电路完成用户的操作指令和操作要求。

关键字:红外线;编码;解码;LM386;红外收发器。

1 绪论1.1 课题研究的背景及意义目前,在世界范围内,红外数据通信技术是被广泛使用的一种无线连接技术,被许多的硬件和软件平台所支持。

是一种通过数据脉冲与红外脉冲之间的相互转换实现无线数据收发的技术。

红外收发器产品具有成本低,体积小,传输速率快,点对点传输安全性好,不受电磁干扰等特点,可使得信息在几个不同产品器件之间快速、便捷、安全地交换与传输。

智能红外传感器中英文对照外文翻译文献

智能红外传感器中英文对照外文翻译文献

外文翻译中英文对照翻译智能红外传感器跟上不断发展的工艺技术对工艺工程师来说是一向重大挑战。

再加上为了保持目前迅速变化的监测和控制方法的过程的要求,所以这项任务已变得相当迫切。

然而,红外温度传感器制造商正在为用户提供所需的工具来应付这些挑战:最新的计算机相关的硬件、软件和通信设备,以及最先进的数字电路。

其中最主要的工具,不过是新一代的红外温度计---智能传感器。

今天新的智能红外传感器代表了两个迅速发展的结合了红外测温和通常与计算机联系在一起的高速数字技术的科学联盟。

这些文书被称为智能传感器,因为他们把微处理器作为编程的双向收发器。

传感器之间的串行通信的生产车间和计算机控制室。

而且因为电路体积小,传感器因此更小,简化了在紧张或尴尬地区的安装。

智能传感器集成到新的或现有的过程控制系统,从一个新的先进水平,在温度监测和控制方面为过程控制方面的工程师提供了一个直接的好处。

1 集成智能传感器到过程线同时广泛推行的智能红外传感器是新的,红外测温已成功地应用于过程监测和控制几十年了。

在过去,如果工艺工程师需要改变传感器的设置,它们将不得不关闭或者删除线传感器或尝试手动重置到位。

当然也可能导致路线的延误,在某些情况下,是十分危险的。

升级传感器通常需要购买一个新单位,校准它的进程,并且在生产线停滞的时候安装它。

例如,某些传感器的镀锌铁丝厂用了安装了大桶的熔融铅、锌、和/或盐酸并且可以毫不费力的从狭窄小道流出来。

从安全利益考虑,生产线将不得不关闭,并且至少在降温24小时之前改变和升级传感器。

今天,工艺工程师可以远程配置、监测、处理、升级和维护其红外温度传感器。

带有双向RS - 485接口或RS - 232通信功能的智能模型简化了融入过程控制系统的过程。

一旦传感器被安装在生产线,工程师就可以根据其所有参数来适应不断变化的条件,一切都只是从控制室中的个人电脑。

举例来说,如果环境温度的波动,或程序本身经历类型、厚度、或温度的改变,所有过程工程师需要做的是定制或恢复保存在计算机终端的设置。

红外遥控系统中英文对照外文翻译文献

红外遥控系统中英文对照外文翻译文献

中英文对照翻译(文档含英文原文和中文翻译)Infrared Remote And Chips Are IntroducedPeople's eyes can see the visible wavelength from long to short according to the arrangement, in order to red, orange, yellow, green, green, blue, violet. One of the red wavelengths for 0.62 ~ 0.76 muon m, Purple is 0.38 wavelength range ~ muon m. Purple is shorter than the wavelength of light called ultraviolet ray, red wavelengths of light is longer than that of infrared light. Infrared remote control is to use wavelength for 0.76 ~ 1.5 muon m between the near infrared to transfer control signal.Commonly used infrared remote control system of general points transmit and receive two parts. The main component part for the launch of infrared light emitting diode. It is actually a special light emitting diode, due to its internal material differs from ordinary light emitting diode, resulting in its ends on certain voltage, it is a rather infrared light. Use of infrared light emitting diode the infrared wavelengths, for 940nm appearance and ordinary, just the same light emitting diode five different colors. Infrared light emitting diode generally have black and blue, transparent three colors. Judgement of infrared light emitting diode and judgment method, using a multimeter to ordinary diode electric block measure of infrared light emitting diode, reverse resistance. The infrared light emitting diode luminescence efficiency to use special instrument to measure precise, and use only spare conditions to pull away from roughly judgement. Receiving part of infrared receiving tube is a photosensitive diode.In actual application of ir receiving diode to reverse bias, it can work normally, i.e., the infrared receiving circuit application in diode is used to reverse, higher sensitivity. Infrared receiving diode usually have two round and rectangular. Due tothe power of infrared light emitting diode (or less commonly 100mW), so ir receiving diode received signals is weak, so will increase high-gain ones.the amplifier circuit.In common CX20106A, etc PC1373H muon infrared receiving special amplifier circuit. In recent years both amateur or formal products, mostly using infrared receiving head finished. The head of infrared receiving product packages generally has two kinds: one kind USES sheet shielding, A kind of plastic packaging. There are three pin, namely the power is (VDD), power negative (GND) and data output (VO or OUT). Infrared receiving head foot arrangement for types varied, manufacturer's instructions. Finished the advantages of infrared receiving head is not in need of sophisticated debugging and shell screen, use rise as a transistor, very convenient. But when used in the infrared receiving attention finished first carrier frequency.Infrared remote common carrier frequency for 38kHz, this is transmitted by using 455kHz TaoZhen to decide. At the launch of crystals were integer frequency, frequency coefficients, so commonly 12, so 455kHz ÷12 hundredth kHz 38kHz hundredth 379,000. Some remote control system adopts 36kHz, 56kHz, etc, general 40kHz launched by the crystals of oscillation frequency to decide.Infrared remote characteristic is not influence the surrounding environment and does not interfere with other electric equipment. Due to its cannot penetrate walls, so the room can use common household appliance of remote control without mutual interference, Circuit testing is simple, as long as given circuit connection, generally does not need any commissioning can work, Decoding easily, can undertake multiple remote control. Because each manufacturer produces a great deal of infrared remote application-specific integrated circuit, when need press diagram suo ji. Therefore, the infrared remote now in household appliances, indoor close (less than 10 meters) in the remote control is widely used.Multiple infrared remote control system of infrared emission control buttons, there are many parts general representative of different control function. When pressed a button, correspondingly in the receiver with different output.Receiving the output state can be roughly divided into pulse, level, self-locking and interlock, data five forms. "The pulse output is according to launch" when the button, the receiver output terminals output corresponding "effective", a pulse width 100ms in general. "Level" refers to the output launch press button, the receiver output corresponding output level ", "effective transmit to loosen the receiver" level "disappears. This "effective pulse" and "effective", may be of high level is low, andmay also depend on the output corresponding static state, such as feet for low, static "high" for effective, As for the static, "low" high effective. In most cases, "high" for effective. "Since the lock" refers to launch the output of each time you press the button, a receiver output corresponding change, namely originally a state for high level into a low level, originally for low level into high level. The output power switch and mute as control etc. Sometimes also called the output form for "invert". "The interlock" refers to multiple outputs each output, at the same time only one output. The TV sets of this case is selected, the other is like the light and sound input speed, etc."Data" refers to launch the output some key, use a few output form a binary number, to represent different keystroke.Normally, the receiver except a few data output, but also a "valid" output data, so the timely to collect data. This output form with single-chip microcomputer or are commonly used interface. In addition to the above output form outside, still have a "latch" and "temporary" two forms. The so-called "latch" refers to launch the output signal of each hair, the receiver output corresponding ", "new store until you receive signals. "Temporary" output and the introduction of "level" output is similar.Remote distance (Remote Control effect of RF Remote Control distance) are the major factors as follows:1, launched in power transmission power: while distance, but great power consumption, easy to generate interference,2 and receiving the receiver sensitivity, receiving, remote distance increased sensitivity to improve, but easy to cause disturbance maloperation or abuse, 3, antenna, using linear antenna, and parallel, remote distance, but occupies a large space, in use the antenna spin, pull can increase the remote distance,4 and the higher height: antenna, remote farther, but by objective conditions,5 and stop: current use of wireless remote use of UHF band stipulated by the state, the propagation characteristics of approximate linear transmission, light, small, transmitters and receivers diffraction between such as walls are blocking will greatly discounted remote distance, if is reinforced concrete walls, due to the absorption effect conductor, radio waves.Considering the design of hardware volume small to be embedded in the remote control, so we chose 20 foot single-chip chip AT89C2051. Below is the introduction of the function.1) AT89C2051 internal structure and performanceAT89C2051 is a byte flash 2K with programmable read-only memory can be erased EEPROM (low voltage, high performance of eight CMOS microcomputer. It adopts ATMEL of high-density non-volatile storage technology manufacturing and industrial standard MCS - 51 instruction set and lead. Through the combination of single chip in general CPL1 and flash memory, is a strong ATMEL AT89C2051 microcomputer, its application in many embedded control provides a highly flexible and low cost solutions. The compatible with 8051 AT89C2051 is CHMOS micro controller, the Flash memory capacity for 2KB. And CHMOS 80C51 process, have two kinds of leisure and power saving operation mode. The performance is as follows:8 CUP, 2KB Flash memory,Working voltage range 2.7-6V, 128KB data storage,The static working way: 0-24MHz, 15 root input/output line,A programmable serial, 2 a 16-bit timing/counters,There is a slice of inside precision simulation comparator, 5 the interrupt sources, 2 priority.Programmable serial UART channel, Directly LED driver output,The internal structure of AT89C2051 is shown in figure 1.Figure 1 AT89C2051 interior structure2) AT89C2051 chip pin and functionIn order to adapt to the requirement of intelligent instrument, embedded in the chip foot AT89C2051 simplified configuration, as shown in figure b. The major changes to: (1) the lead foot from 20 to 40 wires, (2) increased a simulated comparator.AT89C2051 pin function:1 the Vcc: voltage.2 to GND.3 P1 mouth: P1 mouth is an 8-bit two-way I/O port. P1.2 ~ P1.7 mouth pin the internal resistance provides. P1.0 and P1.1 requirements on the external pull-up resistors. P1.0 and P1.1 also separately as piece inside precision simulationDiagram b AT89C2051 foot figurecomparator with input (AIN0) and reversed-phase input (AIN1). Output buffer can absorb the P1 mouth 20mA current and can directly LED display driver. When P1 mouth pin into a "1", can make its input. When the pin P1.2 ~ P1.7 as input and external down, they will be for the internal resistance and flow current (IIL). In flash P1 mouth during the procedure and program code data receiving calibration.4 P3: the P3.0 ~ P3.5 P3, P3.7 is the internal resistance with seven two-way I / 0 lead. P3.6 for fixed inputs piece inside the comparator output signal and it as a general I/O foot and inaccessible. P3 mouth buffer can absorb 20mA current. When P3 mouth pin into "1", they are the internal resistance can push and input. As input, and the low external P3 mouth pin pull-up resistors and will use current (IIL) outflow. P3 mouth still used to implement the various functions, such as AT89C2051 shown in table 1. P3 mouth still receive some for flash memory programming and calibration ofRST/VPP (RXD)P3.0 (TXD)P3.1 XTAL2 XTAL1 (INT0)P3.2 (INT1)P3.3 (T0)P3.4 (T1)P3.5GND VCC P1.7 P1.6 P1.5 P1.4 P1.3 P1.2 P1.1(AIN1) P1.0(AIN0) P3.7program control signals.P3 mouth function as is shown in table 1.5 RST: reset input. RST once, all into high level I/O foot will reset to "1". When the oscillator is running, continuous gives RST pin two machine cycle of high level can finish reset. Each machine cycle to 12 oscillator or clock cycle.6 XTAL1: as the oscillator amplifier input and inverse internal clock generator input.7. XTAL2: as the oscillator reversed-phase the amplifier's output.3) the software and hardware constraints. AT89C2051Due to the foot of the chip AT89C2051, no set limits of external storage interface, so, for external memory read/write instructions as MOVX etc.Due to 2KB ROM, so, the space to jump instruction should pay attention to the destination address range (transfer 000H - 7FFH), beyond the range of addresses, will not meet wrong results. The scope of data storage is 00H (7FH -- when stack manipulation), also should be noticed.The input signal is simulated by the original P3.6 foot into the microcontroller, so the original P3.6 footUnable to external use. Simulation comparator can compare two simulation, if the size of the voltage external A D/A converter and its output as A comparator analog input, and by simulating the comparator another input voltage to be measured, through the introduction of the software method can realize the A/D conversion.4 the Flash memory AT89C2051)Provide a 2KB of single-chip AT89C2051 in Flash memory chips, which allows the online program to modify or use special programming programming.A). Flash memory encryptionAT89C2051 SCM has 2 encryption, can programming (P) or programming (U) to obtain different encryption functionality. Encryption functionality table as shown in table 1-1.Encrypt a content erased only through chips to erase operation.B). Flash memory programming and procedures(1) the piece inside chip AT89C2051 Flash memory programming model as shown in table 1-2.Table 1-2 AT89C2051 microcontroller programming model. Note: (1) the counters RESET at an EPROM inside the rising edge, and 000H RESET to XTAL1 by foot is executed, pulse count,(2) pieces of 10ms to erase PROG pulse,(3 )during the programming P3.1 pulled low RDY/BSY instructions.C).A T89C2051 SCM in Flash memory chips programming steps are as follows:1. in the sequence is the VCC GND pin, add working voltage, XTAL1 pin RESET, receiving GND pin, other than the above time, waiting for 10ms,2. In P3.2 pin RESET, heightening level,3. In P3.3, P3.4, P3.5, P3.7 pin; add model multilevel4. P1.0 P1.7 -- for the 000H unit add data bytes,5. RESET to increase the 12V activation programming,6. P3.2 jump to a one byte programming or encryption,7. calibration has been programming, data from 12V to RESET logic level "H" and setP3.3 P3.7 -- for the correct level, and can output data in P1 mouth,Figure c programming circuit Figure d calibration circuit8.For the next addresses) in the unit XTAL1 byte programming, a pulse, make address counter add 1, in mouth add programming data P1.Repeat step 1-8 complete the whole -- 2KB programming.Electricity is XTAL1 Settings: in order to "L" RESET, and float empty other I/O foot, close the VCC power.(3) programming and calibration circuit figure c, d.Explanation:(1) P3.1 during programming instructions to be low RDY/BSY,(2) single erasing the PROG 10ms need,(3) internal EEPROM address counter on the rising edge RESET, and 000H RESET to XTAL1 by foot pulses are executed.Along with the rapid development of science and technology, human society has undergone earth-shaking changes. Make our life more colorful. In these changes, the remote control technology has been widely permeates TV, aerospace, military, sports and other production, all aspects of life. From the broad sense, all equipped with electric locomotive facility or electrical switches, if feel some necessary, can consider to improve existing with remote control device, the operation fixed switch to realize the remote operation of the original equipment, stop, the variable, etc. Function. switch, for example, can be used to control the electric control switch the light switch, We design the infrared remote control system to realize the opponent switch quantity control. Infrared remote characteristic is not influence the surrounding environment and does not interfere with other electric equipment. Due to its cannot penetrate walls, so the room can use common household appliance of remote controlwithout mutual interference, Circuit testing is simple, as long as given circuit connection, generally does not need any commissioning can work, Decoding easily, can undertake multiple remote control.红外遥控及芯片介绍红外遥控及芯片介绍人的眼睛能看到的可见光按波长从长到短排列,依次为红、橙、黄、绿、青、蓝、紫。

智能红外传感器外文文献翻译中英文

智能红外传感器外文文献翻译中英文

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

红外传感器网络文献翻译

红外传感器网络文献翻译

红外传感器网络文献翻译随着物联网技术的不断发展,传感器网络正在变得越来越重要。

利用传感器网络可以收集大量数据,并通过远距离的通信手段将这些数据传回控制中心,以便对环境进行监测和控制。

红外传感器是一种常用的传感器,可用于监测多种物质,例如温度、湿度、气体、颜色等。

近年来,红外传感器网络在物联网领域中受到了越来越多的关注。

本文翻译自论文《基于红外传感器网络的室内定位及其应用研究》,该论文系统地介绍了基于红外传感器网络的室内定位技术及其应用。

以下是摘自论文的翻译内容。

1. 引言传统的室内定位技术主要依赖于GPS等卫星定位系统,但室内因为多因素的干扰,GPS的定位精度较低。

基于红外传感器网络的室内定位技术具有定位精度高、成本低等优势,越来越受到研究者和工程师的广泛关注。

2. 红外传感器网络概述红外传感器是一种利用热辐射原理进行物体探测的传感器。

红外传感器网络是一种通过红外传感器节点相互通信的无线传感器网络。

红外传感器网络由多个节点组成,每个节点都有一个红外传感器。

这些节点通过无线信道通信,并将监测到的数据传输到控制中心。

控制中心可以对这些数据进行处理,并进行相应的控制操作。

3. 红外传感器节点设计红外传感器节点由红外传感器、微处理器和无线通信模块组成。

其中,红外传感器负责监测环境中的温度、湿度、气体、颜色等各种参数;微处理器负责对传感器采集的数据进行处理,并进行通信协议的处理;无线通信模块负责传输数据到控制中心。

4. 室内定位算法室内定位是指在室内环境中对人或物体进行准确定位的技术。

基于红外传感器网络的室内定位技术主要依赖于测距算法和信号滤波算法。

红外传感器节点发送的信号经过接收器后,信号会有一定的衰减,这就需要进行距离测量。

测距算法主要有三种:TOA(Time of Arrival)、TDOA(Time Difference of Arrival)和RSS(Received Signal Strength)。

红外传感器网络文献翻译

红外传感器网络文献翻译

单位代码01学号分类号TNO密级文献翻译红外传感器网络院(系)名称信息工程学院专业名称电子信息工程学生姓名指导教师2013年3月28日黄河科技学院毕业设计(文献翻译)第1页红外传感器网络摘要:无线传感器网络(WSN)已成为最近的一个研究热点。

无线传感器网络在大范围的领域得到应用,主要应用于商业、军事以及住宅,创造了巨大的效益。

在这个项目中,我们设计了一个计数系统,这个系统部署在交通控制、资源管理和人力的流量控制之中,用于追踪检测区以及相应的移动方向。

我们的设计是基于自制的红外传感模块板,用于无线传感器网络之间的联系。

我们的系统设计包括红外传感模块设计、传感器节点通讯、系统聚类、建筑和部署。

我们进行了一系列的计数实验来评估系统的性能,论证了高效率的移动对象的有效性。

关键词:红外辐射,无线传感器节点1 介绍红外红外辐射是指波长在可见光与无线电波之间的部分电磁辐射。

现在红外线已经被广泛应用,包括数据通讯、夜视装置,物件追踪等等。

由于它容易产生并且受到电磁波的干扰很少,在红外数据通信中,人们通常使用红外线。

把电视遥控器作为一个例子, 在每个人的家里可以被发现。

当按钮被推后,红外遥控系统利用红外发光二极管(led)散发出红外(红外线)信号。

按钮被推后,不同模式显示相应的按钮脉冲。

在不受干扰的情况下,允许控制多种电器比如电视机、录像机、有线电视盒,系统通常有序言和一个地址进行同步识别来源的接收机的位置和红外信号。

为了编码数据,系统通常用不同脉冲的宽度(脉宽调制)或宽度之间的间隔空间调制脉冲(脉冲)。

另一种受欢迎的系统:双相编码,利用信号转换来传递信息。

在载波频率中,实际上每个脉冲都是一阵红外。

“高”的含义是一阵红外能量载波频率和“低”体现了一种不在红外能量。

这没有编码标准。

然而,许多家庭使用他们自己的一些quasi-standards专有的编码系统的娱乐设备,确实存在。

这些包括RC-5、RC -(六)、REC-80。

DS18B20数字式温度传感器毕业论文中英文资料外文翻译文献

DS18B20数字式温度传感器毕业论文中英文资料外文翻译文献

中英文资料外文翻译文献The introduction to The DS18B201. DESCRIPTIONThe DS18B20 digital thermometer provides 9-bit to 12-bit Celsius temperature measurements and has an alarm function with nonvolatile user programmable upper and lower trigger points. The DS18B20 communicates over a 1-Wire bus that by definition requires only one data line for communication with a central microprocessor. It has an operating temperature range of -55°C to +125°C and is accurate to ±0.5°C over the range of -10°C to +85°C. In addition, the DS18B20 can derive power directly from the data line (“parasite power”), eliminating the need for an external power supply.Each DS18B20 has a unique 64-bit serial code, which allows multiple DS18B20s to function on the same 1-Wire bus. Thus, it is simple to use one microprocessor to control many DS18B20s distributed over a large area. Applications that can benefit from this feature include HV AC environmental controls, temperature monitoring systems inside buildings, equipment, or machinery, and process monitoring and control systems.2.FEATURES●Unique 1-Wire® Interface Requires Only One Port Pin for Communication●Each Device has a Unique 64-Bit Serial Code Stored in an On-Board ROM●Multi-drop Capability Simplifies Distributed Temperature-Sensing Applications ●Requires No External Components●Can Be Powered from Data Line; Power Supply Range is 3.0V to 5.5V1●Measures Temperatures from -55°C to +125°C (-67°F to +257°F)●±0.5°C Accuracy from -10°C to +85°C●Thermometer Resolution is User Selectable from 9 to 12 Bits●Converts Temperature to 12-Bit Digital Word in 750ms (Max)●User-Definable Nonvolatile (NV) Alarm Settings●Alarm Search Command Identifies and Addresses Devices Whose Temperature isOutside Programmed Limits●Software Compatible with the DS1822●Applications Include Thermostatic Controls, Industrial Systems, ConsumerProducts, Thermometers, or Any Thermally Sensitive System3.OVERVIEWFigure 1 shows a block diagram of the DS18B20, and pin descriptions are given in the Pin Description table. The 64-bit ROM stores the device’s unique serial code. The scratchpad memory contains the 2-byte temperature register that stores the digital output from the temperature sensor. In addition, the scratchpad provides access to the 1-byte upper and lower alarm trigger registers (TH and TL) and the 1-byte configuration register. The configuration register allows the user to set the resolution of the temperature to-digital conversion to 9, 10, 11, or 12 bits. The TH, TL, and configuration registers are nonvolatile (EEPROM), so they will retain data when the device is powered down.The DS18B20 uses Maxim’s exclusive 1-Wire bus protocol that implements bus communication using one control signal. The control line requires a weak pull up resistor since all devices are linked to the bus via a 3-state or open-drain port (the DQ pin in the case of the DS18B20). In this bus system, the microprocessor (the master device) identifies and addresses devices on the bus using each device’s unique 64-bit code. Because each device has a unique code, the number of devices that can be addressed on one DS18B20 bus is virtually unlimited. The 1-Wire bus protocol, including detailed explanations of the commands and “time slots,” is covered in the21-Wire Bus System section.Another feature of the DS18B20 is the ability to operate without an external power supply. Power is instead supplied through the 1-Wire pull up resistor via the DQ pin when the bus is high. The high bus signal also charges an internal capacitor (CPP), which then supplies power to the device when the bus is low. This method of deriving power from the 1-Wire bus is referred to as “parasite power.” As an alternative, the DS18B20 may also be powered by an external supply on VDD.Figure 1.DS18B20 Block Diagram4.OPERATION—MEASURING TEMPERATURThe core functionality of the DS18B20 is its direct-to-digital temperature sensor. The resolution of the temperature sensor is user-configurable to 9, 10, 11, or 12 bits, corresponding to increments of 0.5°C, 0.25°C, 0.125°C, and 0.0625°C, respectively. The default resolution at power-up is 12-bit. The DS18B20 powers up in a low-power idle state. To initiate a temperature measurement and A-to-D conversion, the master must issue a Convert T [44h] command. Following the conversion, the resulting thermal data is stored in the 2-byte temperature register in the scratchpad memory and the DS18B20 returns to its idle state. If the DS18B20 is powered by an external supply, t he master can issue “read time slots” (see the 1-Wire Bus System section) after the Convert T command and the DS18B20 will respond by transmitting 0 while the temperature conversion is in progress and 1 when the conversion is done. If the3DS18B20 is powered with parasite power, this notification technique cannot be used since the bus must be pulled high by a strong pull up during the entire temperature conversion.The DS18B20 output temperature data is calibrated in degrees Celsius; for Fahrenheit applications, a lookup table or conversion routine must be used. The temperature data is stored as a 16-bit sign-extended two’s complement number in the temperature register (see Figure 2). The sign bits (S) indicate if the temperature is positive or negative: for positive numbers S = 0 and for negative numbers S = 1. If the DS18B20 is configured for 12-bit resolution, all bits in the temperature register will contain valid data. For 11-bit resolution, bit 0 is undefined. For 10-bit resolution, bits 1 and 0 are undefined, and for 9-bit resolution bits 2, 1, and 0 are undefined. Table 1 gives examples of digital output data and the corresponding temperature reading for 12-bit resolution conversions.5.64-BIT LASERED ROM CODEEach DS18B20 contains a unique 64–bit code (see Figure 3) stored in ROM. The least significant 8 bits of the ROM code contain the DS18B20’s 1-Wire family4code: 28h. The next 48 bits contain a unique serial number. The most significant 8 bits contain a cyclic redundancy check (CRC) byte that is calculated from the first 56 bits of the ROM code. The 64-bit ROM code and associated ROM function control logic allow the DS18B20 to operate as a 1-Wire device using the protocol detailed in the 1-Wire Bus System section.Figure 3.64-Bit Lasered ROM Code6.MEMORYThe DS18B20’s memory is organized as shown in Figure 4. The memory consists of an SRAM scratchpad with nonvolatile EEPROM storage for the high and low alarm trigger registers (TH and TL) and configuration register. Note that if the DS18B20 alarm function is not used, the TH and TL registers can serve as general-purpose memory.Byte 0 and byte 1 of the scratchpad contain the LSB and the MSB of the temperature register, respectively. These bytes are read-only. Bytes 2 and 3 provide access to TH and TL registers. Byte 4 contains the configuration register data. Bytes 5, 6, and 7 are reserved for internal use by the device and cannot be overwritten. Byte 8 of the scratchpad is read-only and contains the CRC code for bytes 0 through 7 of the scratchpad. The DS18B20 generates this CRC using the method described in the CRC Generation section.Data is written to bytes 2, 3, and 4 of the scratchpad using the Write Scratchpad [4Eh] command; the data must be transmitted to the DS18B20 starting with the least significant bit of byte 2. To verify data integrity, the scratchpad can be read (using the Read Scratchpad [BEh] command) after the data is written. When reading the scratchpad, data is transferred over the 1-Wire bus starting with the least significant bit of byte 0. To transfer the TH, TL and configuration data from the scratchpad to EEPROM, the master must issue the Copy Scratchpad [48h] command.57.CONFIGURATION REGISTERByte 4 of the scratchpad memory contains the configuration register, which is organized as illustrated in Figure 5. The user can set the conversion resolution of the DS18B20 using the R0 and R1 bits in this register as shown in Table 2. The power-up default of these bits is R0 = 1 and R1 = 1 (12-bit resolution). Note that there is a direct tradeoff between resolution and conversion time. Bit 7 and bits 0 to 4 in the configuration register are reserved for internal use by the device and cannot be overwritten.68.1-WIRE BUS SYSTEMThe 1-Wire bus system uses a single bus master to control one or more slave devices. The DS18B20 is always a slave. When there is only one slave on the bus, the system is referred to as a “single-drop” system; the system is “multi-drop” if there are multiple slaves on the bus. All data and commands are transmitted least significant bit first over the 1-Wire bus. The following discussion of the 1-Wire bus system is broken down into three topics: hardware configuration, transaction sequence, and1-Wire signaling (signal types and timing).9.TRANSACTION SEQUENCEThe transaction sequence for accessing the DS18B20 is as follows:Step 1. InitializationStep 2. ROM Command (followed by any required data exchange)Step 3. DS18B20 Function Command (followed by any required data exchange)It is very important to follow this sequence every time the DS18B20 is accessed, as the DS18B20 will not respond if any steps in the sequence are missing or out of order. Exceptions to this rule are the Search ROM [F0h] and Alarm Search [ECh] commands. After issuing either of these ROM commands, the master must return to Step 1 in the sequence.(1)INITIALIZATIONAll transactions on the 1-Wire bus begin with an initialization sequence. The initialization sequence consists of a reset pulse transmitted by the bus master followed by presence pulse(s) transmitted by the slave(s). The presence pulse lets the bus master know that slave devices (such as the DS18B20) are on the bus and are ready to operate.(2)ROM COMMANDS7After the bus master has detected a presence pulse, it can issue a ROM command. These commands operate on the unique 64-bit ROM codes of each slave device and allow the master to single out a specific device if many are present on the 1-Wire bus. These commands also allow the master to determine how many and what types of devices are present on the bus or if any device has experienced an alarm condition. There are five ROM commands, and each command is 8 bits long. The master device must issue an appropriate ROM command before issuing a DS18B20 function command.1.SEARCH ROM [F0h]When a system is initially powered up, the master must identify the ROM codes of all slave devices on the bus, which allows the master to determine the number of slaves and their device types. The master learns the ROM codes through a process of elimination that requires the master to perform a Search ROM cycle (i.e., Search ROM command followed by data exchange) as many times as necessary to identify all of the slave devices. If there is only one slave on the bus, the simpler Read ROM command can be used in place of the Search ROM process.2.READ ROM [33h]This command can only be used when there is one slave on the bus. It allows the bus master to read the slave’s 64-bit ROM code without using the Search ROM procedure. If this command is used when there is more than one slave present on the bus, a data collision will occur when all the slaves attempt to respond at the same time.3.MATCH ROM [55h]The match ROM command followed by a 64-bit ROM code sequence allows the bus master to address a specific slave device on a multi-drop or single-drop bus. Only the slave that exactly matches the 64-bit ROM code sequence will respond to the function command issued by the master; all other slaves on the bus will wait for a reset pulse.84.SKIP ROM [CCh]The master can use this command to address all devices on the bus simultaneously without sending out any ROM code information. For example, the master can make all DS18B20s on the bus perform simultaneous temperature conversions by issuing a Skip ROM command followed by a Convert T [44h] command. Note that the Read Scratchpad [BEh] command can follow the Skip ROM command only if there is a single slave device on the bus. In this case, time is saved by allowing the master to read from the slave without sending the device’s 64-bit ROM code. A Skip ROM command followed by a Read Scratchpad command will cause a data collision on the bus if there is more than one slave since multiple devices will attempt to transmit data simultaneously.5.ALARM SEARCH [ECh]The operation of this command is identical to the operation of the Search ROM command except that only slaves with a set alarm flag will respond. This command allows the master device to determine if any DS18B20s experienced an alarm condition during the most recent temperature conversion. After every Alarm Search cycle (i.e., Alarm Search command followed by data exchange), the bus master must return to Step 1 (Initialization) in the transaction sequence.(3)DS18B20 FUNCTION COMMANDSAfter the bus master has used a ROM command to address the DS18B20 with which it wishes to communicate, the master can issue one of the DS18B20 function commands. These commands allow the master to write to and read from the D S18B20’s scratchpad memory, initiate temperature conversions and determine the power supply mode.1.CONVERT T [44h]This command initiates a single temperature conversion. Following the conversion, the resulting thermal data is stored in the 2-byte temperature register in9the scratchpad memory and the DS18B20 returns to its low-power idle state. If the device is being used in parasite power mode, within 10µs (max) after this command is issued the master must enable a strong pull up on the 1-Wire bus. If the DS18B20 is powered by an external supply, the master can issue read time slots after the Convert T command and the DS18B20 will respond by transmitting a 0 while the temperature conversion is in progress and a 1 when the conversion is done. In parasite power mode this notification technique cannot be used since the bus is pulled high by the strong pull up during the conversion.2.READ SCRATCHPAD [BEh]This command allows the master to read the contents of the scratchpad. The data transfer starts with the least significant bit of byte 0 and continues through the scratchpad until the 9th byte (byte 8 – CRC) is read. The master may issue a reset to terminate reading at any time if only part of the scratchpad data is needed.3.WRITE SCRATCHPAD [4Eh]This comm and allows the master to write 3 bytes of data to the DS18B20’s scratchpad. The first data byte is written into the TH register (byte 2 of the scratchpad), the second byte is written into the TL register (byte 3), and the third byte is written into the configuration register (byte 4). Data must be transmitted least significant bit first. All three bytes MUST be written before the master issues a reset, or the data may be corrupted.4.COPY SCRATCHPAD [48h]This command copies the contents of the scratchpad TH, TL and configuration registers (bytes 2, 3 and 4) to EEPROM. If the device is being used in parasite power mode, within 10µs (max) after this command is issued the master must enable a strong pull-up on the 1-Wire bus.5.RECALL E2 [B8h]This command recalls the alarm trigger values (TH and TL) and configuration10data from EEPROM and places the data in bytes 2, 3, and 4, respectively, in the scratchpad memory. The master device can issue read time slots following the Recall E2command and the DS18B20 will indicate the status of the recall by transmitting 0 while the recall is in progress and 1 when the recall is done. The recall operation happens automatically at power-up, so valid data is available in the scratchpad as soon as power is applied to the device.6.READ POWER SUPPL Y [B4h]The master device issues this command followed by a read time slot to determine if any DS18B20s on the bus are using parasite power. During the read time slot, parasite powered DS18B20s will pull the bus low, and externally powered DS18B20s will let the bus remain high.10.WIRE SIGNALINGThe DS18B20 uses a strict 1-Wire communication protocol to ensure data integrity. Several signal types are defined by this protocol: reset pulse, presence pulse, write 0, write 1, read 0, and read 1. The bus master initiates all these signals, with the exception of the presence pulse.(1)INITIALIZATION PROCEDURE—RESET AND PRESENCE PULSES All communication with the DS18B20 begins with an initialization sequence that consists of a reset pulse from the master followed by a presence pulse from the DS18B20. This is illustrated in Figure 6. When the DS18B20 sends the presence pulse in response to the reset, it is indicating to the master that it is on the bus and ready to operate.During the initialization sequence the bus master transmits (TX) the reset pulse by pulling the 1-Wire bus low for a minimum of 480µs. The bus master then releases the bus and goes into receive mode (RX). When the bus is released, the 5kΩ pull-up resistor pulls the 1-Wire bus high. When the DS18B20 detects this rising edge, it waits 15µs to 60µs and then transmits a presence pulse by pulling the 1-Wire bus low11for 60µs to 240µs.TimingBus master pulling lowDS18B20 pulling lowResistor pullupFigure 6.Initialization Timing(2)READ/WRITE TIME SLOTSThe bus master writes data to the DS18B20 during write time slots and reads data from the DS18B20 during read time slots. One bit of data is transmitted over the 1-Wire bus per time slot.1.WRITE TIME SLOTSThere are two types of write time slots: “Write 1” time slots and “Write 0” time slots. The bus master uses a Write 1 time slot to write a logic 1 to the DS18B20 and a Write 0 time slot to write a logic 0 to the DS18B20. All write time slots must be a minimum of 60µs in duration with a minimum of a 1µs recovery time between individual write slots. Both types of write time slots are initiated by the master pulling the 1-Wire bus low (see Figure 7).To generate a Write 1 time slot, after pulling the 1-Wire bus low, the bus master must release the 1-Wirebus within 15µs. When the bus is released, the 5kΩ pull-up resistor will pull the bus high. To generate a Write 0 time slot, after pulling the 1-Wire bus low, the bus master must continue to hold the bus low for the duration of the time slot (at least 60µs).The DS18B20 samples the 1-Wire bus during a window that lasts from 15µs1213to 60µs after the master initiates the write time slot. If the bus is high during the sampling window, a 1 is written to the DS18B20. If the line is low, a 0 is written to the DS18B20.DS18B20Write Time SlotSTART OF SLOTVccBus master pulling low Resistor pullupFigure 7.DS18B20 Write Time Slot2.READ TIME SLOTSThe DS18B20 can only transmit data to the master when the master issues read time slots. Therefore, the master must generate read time slots immediately after issuing a Read Scratchpad [BEh] or Read Power Supply [B4h] command, so that the DS18B20 can provide the requested data. In addition, the master can generate read time slots after issuing Convert T [44h] or Recall E 2 [B8h] commands to find out the status of the operation.All read time slots must be a minimum of 60µs in duration with a minimum of a 1µs recovery time between slots. A read time slot is initiated by the master device pulling the 1-Wire bus low for a minimum of 1µs and then releasing the bus (see Figure 8). After the master initiates the read time slot, the DS18B20 will begin transmitting a 1 or 0 on bus. The DS18B20 transmits a 1 by leaving the bus high and transmits a 0 by pulling the bus low. When transmitting a 0, the DS18B20 will release the bus by the end of the time slot, and the bus will be pulled back to its high idle state by the pull up resister. Output data from the DS18B20 is valid for 15µs after the falling edge that initiated the read time slot. Therefore, the master must release thebus and then sample the bus state within 15µs from the start of the slot.VccBus master pulling lowResistor pullupDS18B20 pulling lowFigure 8.DS18B20 Read Time Slot1415DS18B20介绍1.说明DS18B20数字式温度传感器提供9位到12位的摄氏温度测量,并且有用户可编程的、非易失性温度上下限告警出发点。

温度传感器毕业论文中英文资料外文翻译文献

温度传感器毕业论文中英文资料外文翻译文献

中英文翻译英文文献原文Temperature Sensor ICs Simplify DesignsWhen you set out to select a temperature sensor, you are no longer limited to either an analog output or a digital output device. There is now a broad selection of sensor types, one of which should match your system's needs.Until recently, all the temperature sensors on the market provided analog outputs. Thermistors, RTDs, and thermocouples were followed by another analog-output device, the silicon temperature sensor. In most applications, unfortunately, these analog-output devices require a comparator, an ADC, or an amplifier at their output to make them useful.Thus, when higher levels of integration became feasible, temperature sensors with digital interfaces became available. These ICs are sold in a variety of forms, from simple devices that signal when a specific temperature has been exceeded to those that report both remote and local temperatures while providing warnings at programmed temperature settings. The choice now isn't simply between analog-output and digital-output sensors; there is a broad range of sensor types from which to choose.Classes of Temperature SensorsFour temperature-sensor types are illustrated in Figure 1. An ideal analog sensor provides an output voltage that is a perfectly linear function of temperature (A). In the digital I/O class of sensor (B), temperature data in the form of multiple 1s and 0s are passed to the microcontroller, often via a serial bus. Along the same bus, data are sent to the temperature sensor from the microcontroller, usually to set the temperature limit at which the alert pin's digital output will trip. Alert interrupts the microcontroller when the temperature limit has been exceeded. This type of device can also provide fan control.Figure 1. Sensor and IC manufacturers currently offer four classes of temperature sensors."Analog-plus" sensors (C) are available with various types of digital outputs. The V OUT versus temperature curve is for an IC whose digital output switches when a specific temperaturehas been exceeded. In this case, the "plus" added to the analog temperature sensor is nothing more than a comparator and a voltage reference. Other types of "plus" parts ship temperature data in the form of the delay time after the part has been strobed, or in the form of the frequency or the period of a square wave, which will be discussed later.The system monitor (D) is the most complex IC of the four. In addition to the functions provided by the digital I/O type, this type of device commonly monitors the system supply voltages, providing an alarm when voltages rise above or sink below limits set via the I/O bus. Fan monitoring and/or control is sometimes included in this type of IC. In some cases, this class of device is used to determine whether or not a fan is working. More complex versions control the fan as a function of one or more measured temperatures. The system monitor sensor is not discussed here but is briefly mentioned to give a complete picture of the types of temperature sensors available.Analog-Output Temperature SensorsThermistors and silicon temperature sensors are widely used forms of analog-output temperature sensors. Figure 2 clearly shows that when a linear relationship between voltage and temperature is needed, a silicon temperature sensor is a far better choice than a thermistor. Over a narrow temperature range, however, thermistors can provide reasonable linearity and good sensitivity. Many circuits originally constructed with thermistors have over time been updated using silicon temperature sensors.Figure 2. The linearity of thermistors and silicon temperature sensors, two popular analog-output temperature detectors, is contrasted sharply.Silicon temperature sensors come with different output scales and offsets. Some, for example, are available with output transfer functions that are proportional to K, others to °C or °F. Some of the °C parts provide an offset so that negative temperatures can be monitored using a single-ended supply.In most applications, the output of these devices is fed into a comparator or a n A/D converter to convert the temperature data into a digital format. Despite the need for these additional devices,thermistors and silicon temperature sensors continue to enjoy popularity due to low cost and convenience of use in many situations.Digital I/O Temperature SensorsAbout five years ago, a new type of temperature sensor was introduced. These devices include a digital interface that permits communication with a microcontroller. The interface is usually an I²C or SMBus serial bus, but other serial interfaces such as SPI are common. In addition to reporting temperature readings to the microcontroller, the interface also receives instructions from the microcontroller. Those instructions are often temperature limits, which, if exceeded, activate a digital signal on the temperature sensor IC that interrupts the microcontroller. The microcontroller is then able to adjust fan speed or back off the speed of a microprocessor, for example, to keep temperature under control.This type of device is available with a wide variety of features, among them, remote temperature sensing. To enable remote sensing, most high-performance CPUs include an on-chip transistor that provides a voltage analog of the temperature. (Only one of the transistor's two p-n junctions is used.) Figure 3 shows a remote CPU being monitored using this technique. Other applications utilize a discrete transistor to perform the same function.Figure 3. A user-programmable temperature sensor monitors the temperature of a remote CPU's on-chip p-n junction.Another important feature found on some of these types of sensors (including the sensor shown in Figure 3) is the ability to interrupt a microcontroller when the measured temperature falls outside a range bounded by high and low limits. On other sensors, an interrupt is generated when the measured temperature exceeds either a high or a low temperature threshold (i.e., not both). For the sensor in Figure 3, those limits are transmitted to the temperature sensor via the SMBus interface. If the temperature moves above or below the circumscribed range, the alert signal interrupts the processor.Pictured in Figure 4 is a similar device. Instead of monitoring one p-n junction, however, it monitors four junctions and its own internal temperature. Because Maxim's MAX1668 consumes a small amount of power, its internal temperature is close to the ambient temperature. Measuring the ambient temperature gives an indication as to whether or not the system fan is operating properly.Figure 4. A user-programmable temperature sensor monitors its own local temperature and the temperatures of four remote p-n junctions.Controlling a fan while monitoring remote temperature is the chief function of the IC shown in Figure 5. Users of this part can choose between two different modes of fan control. In the PWM mode, the microcontroller controls the fan speed as a function of the measured temperature by changing the duty cycle of the signal sent to the fan. This permits the power consumption to be far less than that of the linear mode of control that this part also provides. Because some fans emit an audible sound at the frequency of the PWM signal controlling it, the linear mode can be advantageous, but at the price of higher power consumption and additional circuitry. The added power consumption is a small fraction of the power consumed by the entire system, though.Figure 5. A fan controller/temperature sensor IC uses either a PWM- or linear-mode control scheme.This IC provides the alert signal that interrupts the microcontroller when the temperature violates specified limits. A safety feature in the form of the signal called "overt" (an abbreviated version of "over temperature") is also provided. If the microcontroller or the software were to lock up while temperature is rising to a dangerous level, the alert signal would no longer be useful. However, overt, which goes active once the temperature rises above a level set via the SMBus, is typically used to control circuitry without the aid of the microcontroller. Thus, in thishigh-temperature scenario with the microcontroller not functioning, overt could be used to shutdown the system power supplies directly, without the microcontroller, and prevent a potentially catastrophic failure.This digital I/O class of devices finds widespread use in servers, battery packs, and hard-disk drives. Temperature is monitored in numerous locations to increase a server's reliability: at the motherboard (which is essentially the ambient temperature inside the chassis), inside the CPU die, and at other heat-generating components such as graphics accelerators and hard-disk drives. Battery packs incorporate temperature sensors for safety reasons and to optimize charging profiles, which maximizes battery life.There are two good reasons for monitoring the temperature of a hard-disk drive, which depends primarily on the speed of the spindle motor and the ambient temperature: The read errors in a drive increase at temperature extremes, and a hard disk's MTBF is improved significantly through temperature control. By measuring the temperature within the system, you can control motor speed to optimize reliability and performance. The drive can also be shut down. In high-end systems, alerts can be generated for the system administrator to indicate temperature extremes or situations where data loss is possible.Analog-Plus Temperature Sensors"Analog-plus" sensors are generally suited to simpler measurement applications. These ICs generate a logic output derived from the measured temperature and are distinguished from digital I/O sensors primarily because they output data on a single line, as opposed to a serial bus.In the simplest instance of an analog-plus sensor, the logic output trips when a specific temperature is exceeded. Some of these devices are tripped when temperature rises above a preset threshold, others, when temperature drops below a threshold. Some of these sensors allow the temperature threshold to be adjusted with a resistor, whereas others have fixed thresholds.The devices shown in Figure 6 are purchased with a specific internal temperature threshold. The three circuits illustrate common uses for this type of device: providing a warning, shutting down a piece of equipment, or turning on a fan.Figure 6. ICs that signal when a temperature has been exceeded are well suited forover/undertemperature alarms and simple on/off fan control.When an actual temperature reading is needed, and a microcontroller is available, sensors that transmit the reading on a single line can be useful. With the microcontroller's internal counter measuring time, the signals from this type of temperature sensor are readily transformed to a measure of temperature. The sensor in Figure 7 outputs a square wave whose frequency is proportional to the ambient temperature in Kelvin. The device in Figure 8 is similar, but the period of the square wave is proportional to the ambient temperature in kelvins.Figure 7. A temperature sensor that transmits a square wave whose frequency is proportional to the measured temperature in Kelvin forms part of a heater controller circuit.Figure 8. This temperature sensor transmits a square wave whose period is proportional to the measured temperature in Kelvin. Because only a single line is needed to send temperature information, just a single optoisolator is required to isolate the signal path.Figure 9, a truly novel approach, allows up to eight temperature sensors to be connected on this common line. The process of extracting temperature data from these sensors begins when the microcontroller's I/O port strobes all the sensors on the line simultaneously. The microcontroller is then quickly reconfigured as an input in order to receive data from each of the sensors. The data are encoded as the amount of time that transpires after the sensors are strobed. Each of the sensors encodes this time after the strobe pulse within a specific range of time. Collisions are avoided by assigning each sensor its own permissible time range.Figure 9. A microcontroller strobes up to eight temperature sensors connected on a common line and receives the temperature data transmitted from each sensor on the same line.The accuracy achieved by this method is surprisingly high: 0.8°C is typical at room temperature, precisely matching that of the IC that encodes temperature data in the form of the frequency of the transmitted square wave. The same is true of the device that uses the period of the square wave.These devices are outstanding in wire-limited applications. For example, when a temperature sensor must be isolated from the microcontroller, costs are kept to a minimum because only one optoisolator is needed. These sensors are also of great utility in automotive and HVAC applications, because they reduce the amount of copper running over distances.Anticipated Temperature Sensor DevelopmentsIC temperature sensors provide a varied array of functions and interfaces. As these devicescontinue to evolve, system designers will see more application-specific features as well as new ways of interfacing the sensors to the system. Finally, the ability of chip designers to integrate more electronics in the same die area ensures that temperature sensors will soon include new functions and special interfaces.中文翻译温度传感器芯片简化设计当选择一个温度传感器时,将不再局限于模拟输出或数字输出设备。

红外遥控系统毕业论文外文文献翻译

红外遥控系统毕业论文外文文献翻译

Infrared Remote Control SystemAbstractRed outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique,drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos etc.characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage.Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application.The purpose that design this system is transmit customer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish customer’s operation demand.Keywords:Infrare dray;Code;Decoding;LM386;Redoutside transceiver1 Introduction1.1 research the background and significanceInfrared Data Communication Technology is the world wide use of a wireless connection technology, by the many hardware and software platforms supported. Is a data through electrical pulses and infrared optical pulse switch between the wireless data transceiver technology.Infrared transceiver products with low cost, small, fast transmission rate, the point-to-point transmission security, not subject to electromagnetic interference and other characteristics that can be achieved between the different products, rapid, convenient and safe exchange and transmission, In short distance wireless transmission have a very distinct advantage.Infrared transceiver products in the portable product of a great role. At present, the world's 150 million piece of equipment used infrared technology in electronic products and industrial equipment. medical equipment and other fields widely used. For example, 95% of the notebook computers on the installation of infrared transceiver interface the majority of the cell phone is also the allocation of infrared transceiver interface. With the exchange of quantitative data, infrared data communications will enable cell phone data transmission more convenient. With infrared data transmission technology matures, perfect, low costs, Infrared Transceiver in short distance communications will be more widely applied.This chapter first describes the infrared transceiver IC design issues to the background and significance. then briefed the infrared data communications technology features and applications, and infrared transceiver product characteristics, domestic and international situation and development trend of the last under infrared remote transceiver system in practical application to establish a task of design orientation.1.2 Infrared Remote ControlTransceiver SystemInfrared remote control system is divided into single-channel and multi-channel remote control. Only a command signal transmission channel, called single-channel remote control system; with more than two instructions signal transmission channel known as a multi-channel remote control system. Relatively simple single-channel remote control, in general, only a launcher directive Key receivers and only one circuit implementation. While in the receiving circuit to add more stable memory circuits that can be activated commands to launch a number of key, so that the receiver circuit multistable memory circuit repeatedly to change the state, to realize many of the functional control, But such a state of change is the order. If we are to achieve an arbitrary control, resort to the use of multi-channel remote control system. Multi-channel remote control can be realized by the object of arbitrary multi-function remote control. As for the choice of several routes and what control methods, according to the actual situation (such as object, operational requirements and cost accounting, etc.) to decide. General infrared remote transceiver system by infrared remote control transmitter signal coding, infrared remote control signal receivers and decoders (or decoder chip MCU) and the external circuit consisting of three parts. Signal transmitter remote control code used to generate pulses of infrared emission-driven output infrared remote control signal, receiver completion of the remote control signal amplification and detection, plastic and demodulation encoding pulse. Infrared remote control coded pulse is going to obtain a continuous serial binary code, and for most of the infrared transceiver system, This serial code as micro-controller of the remote control input signals from the internal CPU completion of the remote control instruction decoder, on the other infrared remote control transceivers, the designers of electronic products, The internal micro-controller of the remote control decoder directive is not accessible.Therefore, people are using infrared encoder / decoder chip and microcontroller developed various generic infrared remote transceiver system, In various equipment infrared signals between the transceiver.Remote transceiver system generally transmitters and receivers is composed of two parts. Launchers from the general direction keys, coded instructions circuit modulation circuit, driving circuit, firing circuit of several parts. When pressed a key, the directive coding circuit, in the corresponding instructions encoded signal, the encoder signal to the carrier modulation, Driven by the power amplifier circuit after circuit fired from the field after firing instructions coded modulation signals. General receiver by the receiving circuit, the amplifier circuit, demodulation circuits, instruction decoder circuit, driving circuit, circuit implementation of several parts. Receiving Circuit will launch vehicles have been coded modulation signal receiving instructions from, and to enlarge evacuation demodulation circuit. Demodulation circuit will have the coding modulation signal demodulation, namely, reduction of signal coding. The instruction decoder to the encoder signal decoding, Driven by the final circuit to drive the implementation of various instructions circuit to control the operation.1.3 infrared remote control transceiver product profiles 1.3.1 infrared remote control transceiver product structure and typeCurrently infrared transceiver in accordance with the mode of transmission rate and can be divided into four categories : Serial mode, the highest rate of 115.2 Kbps; medium-speed model : the highest rate of 0.567 Mbps and 1.152Mbps; High-speed mode : The maximum rate of 16 Mbps.Also according to the size chip power consumption can be divided into low-power consumption and standard two categories, low-power type normally used 3 V power supply, transmission distance closer to about 0 - 30cm, which is commonly used standard 5V power supply, transmission distance away at least 1mabove.1.3.2 infrared remote control transmitters of the status quo at home and abroadInfrared communication technology in the development stage and there are several infrared communication standards, between different standards for infrared equipment can not infrared communication. To have all the infrared equipment to interoperability in 1993 by more than 20 large manufacturers initiated the establishment of an Infrared Data Association (IRDA) unified the infrared communication standards , which is currently widely used in infrared data communication protocols and standards, also known as the IRDA standard.Since 1993 IRDA since the establishment of the Infrared Data Association members have developed to more than 150. IRDA standards of the industry has been widely recognized and supported. Has been developed with the infrared communications equipment have been as many as 100 species. IR module, installed capacity has reached 150 million sets. Although there is also a short distance wireless Bluetooth technology, But in infrared communication technology low cost and broad compatibility advantages, Infrared data communication in the future will still be a very long time inherent short-range wireless data communications fields play an important role.1.3.3 Infrared Transceiver product development trendIn various infrared transceiver products, although the transmission rate, transmission distance and other characteristics, But infrared transceiver products has been towards improving the transmission rate, increase the transmission distance and lower power consumption, expanding launch reception angle of development. In particular, as the technology development and maturity, the means of transmission is moving in the direction of point-to-multipoint. Therefore infrared remote control transceiver products have broader prospects for development.2 Infrared communication of knowledge2.1 infrared ray foundation knowledge2.1.1 infrared outlinedInfrared is actually a kind of electromagnetic wave. From the analysis of various natural component of the electromagnetic wave reflected spectrum is :-ray, x-ray, ultraviolet, visible, infrared, microwave and radio wave. From the viewpoint of form, and they did not seem to, but if the wavelength in descending order, and we will find him all the only visible light spectrum of the entire 0.38 μm - 0.76μm so long little area, and adjacent to the visible light and infrared (including the far infrared, mid-infrared and near infrared foreign) accounts for the spec trum of 0.76 μm - 1000μm of a major. Which micron wavelength range also includes UV, visible, near infrared, mid-infrared and far-infrared, microwave.From the above analysis shows that infrared is a very rich spectrum resources, it currently has in production, life, military, medical, and other aspects have been widely used, such as infrared heating, medical infrared, infrared communication, infrared camera, infrared remote control, and so on. Infrared remote control is the many applications of infrared part of the current household appliances widely used in TV remote control, VCR remote control, VCD remote control, high-fidelity audio remote control, are used infra-red remote control, It allows the control of these appliances have become very easy.2.1.2 infrared propertiesInfrared lies between visible light and microwave a wave, it is with certain clinical characteristics of the wave. In the near-infrared, visible light and its adjacent, it is visible in certain characteristics, such as straight-line transmission, reflection, refraction, scattering, diffraction, can be certainobjects and can be absorbed through the lens of their focusing. In the far-infrared region, owing to its neighboring microwave, it has some characteristics of microwave, If a strong penetrating power and can run through some opaque substances. Since in any object, natural profession, regardless of whether its own luminescence (referring to visible light), as long as the temperature is above absolute zero (-273 °C), moment will be kept around to infrared radiation. Only higher temperature of objects strong infrared radiation, low-temperature objects infrared radiation weaker. Therefore infrared feature is the greatest common in nature, it is called thermal radiation called thermal radiation. Infrared cameras, infrared night market pyroelectric infrared detectors and some other missiles aiming at is the use of this characteristic of infrared work.Infrared and visible light compared to another characteristic of a variety of colors. As the longest wavelength of visible light is a wavelength of the shortest times (780 nm-380 nm), So is called an octave. And infrared wavelength is the longest shortest wavelength of a times, and the longest wavelength infrared is the shortest wavelength of 10 times, that is, 10 octave. Therefore, if visible light can be expressed as seven colors, infrared may performance 70 colors, showing the rich colors. Infrared smoke through the good performance, which is also one of its features.Because not visible to the infrared, it has little effect on the environment. By the wave infrared rays than the long wavelength radio waves, infrared remote control will not affect the nearby radio equipment. Another wavelength of less than 1.5μm near infrared light, transparent atmosphere in the visible light transmission characteristics much better than, because it close to the visible edge of the red light, linear transmission, reflection, refraction and absorption material and the physical characteristics very similar to visible light. Therefore, it can be used with similar visible focusing lens and other opticaldevices. Because infrared remote control is not as remote as the radio through the barrier to control the object's ability to control, so in the design of household appliances infra-red remote control, wireless remote control as unnecessary, each set (transmitters and receivers) have different frequency or remote coding (Otherwise, wall will control or interference with neighbors household appliances), all similar products in the infrared remote control, The same can control the frequency or coding, and no remote control signal "drop." This universal infrared remote control provides a great convenience. Infrared to visible light, is very subtle and confidentiality, therefore, the security, Alert and other security devices have been widely used. Infrared remote control is simple in structure and easy, low-cost, anti-interference capability, high reliability are a number of advantages, is a close-up remote control, especially in indoor remote control optimized manner.2.1.3 infrared diode characteristicsInfrared is not visible, people here are not aware of. Electronic technology is used infrared light emitting diode (also known as the IR emission diode) to generate infrared. Infrared remote control transceiver is using near-infrared transmission control instructions 0.76μm wavelength of ~ 1. 5μm. Near-infrared remote control as a light source, because there infrared light emitting diodes and infrared receiving device (photodiode. Transistor and PV) and the luminescence peak wavelength of light by the general 0.8μm ~ 0. 94μm. in the near-infrared band, both of the spectrum is the coincidence to a good match, access to higher transmission efficiency and higher reliability. Commonly used infrared diode, and its shape is similar LED light emitting diodes, Its basic circuit shown in figure 2 -2. The triode plans for the switch, when the base added a driving signal, Transistor saturated conduction infrared LED D is also Wizard Lin k, issued infrared (near infrared about 0.93 μm). D.The pressure drop of about 1.4 V and the current general for 10-20mA. To adapt to the working voltage of the D loop resistance often as a series of infrared diode current limit resistance.When the circuit diagram of the infrared emission control corresponding to the controlled device, the control of the distance and D is proportional to the transmitting power. In order to increase the distance of infrared control, infrared diode D should work on the pulse state that work is the lifeblood of current. Because pulse light (optical modulation) the effective transmission distance and pulse is proportional to the peak current, only maximize peak current Ip, will increase the infrared distance. Ip increase is a way to reduce the pulse duty cycle, that is compressed pulse width τ some TV infrared remote control, its infrared luminescence of the pulse duty cycle of about 1/4-1/3; Some electrical products infrared remote control, its duty cycle of 1 / 10. Decreasing pulse duty cycle also enable low-power infrared LED distance of the greatly increased. Common infrared light emitting diodes, power is divided into small power (1 mW - 10mW). Chinese power (20mW - 50mW) and power (50mW - 100mW more) three categories. Use different power infrared LED, the allocation should be driven by the corresponding power control. Figure 2 -2 by the reflected infrared light-emitting diodes to make produce optical modulation, Drivers only need to add the control of a certain frequency pulse voltage.Infrared transmitter and receiver in the way the two kinds of straight, and the second is reflective. Luminescence pointed straight pipe and tube receiver placed in a relatively controlled and fired on the two ends, a certain distance away from the middle; Reflective means luminescent tube and pipe parallel with the receiving peacetime, without always receiving tube light, luminescence only in possession of the infrared light reflected fromencountered, the receiving tube received from the reflected infrared before work.2.2 infrared communication basic tenets2.2.1 infrared communication PrincipleCommunication is the use of infrared wavelength of 900 nm-infrared waves from 1000 to serve as an information carrier, through infrared technology between the two close communication and confidentiality of information transmitted. Infrared communication system structure include : part launcher, channel, the receiver part.Launcher source letter issued after the binary signal from the high-frequency modulated infrared LED sent, receiving device regard the reception of high-frequency signals from the infrared receiver tube after receiving further demodulation photoelectric conversion of the original information of a mass communication lose way. Afterwards the former Information received after receiving part of the drive circuit connected to the expected completion of the various functions. To which the modulation coding style pulse width modulation (by changing the pulse width modulated signal PWM) and pulse modulation time (through change the pulse train interval time between the modulation signal PPM) two.2.2.2 infrared communication system elements(1) Launches : Currently there is a infrared wireless digital communications system sources of information including voice, data, images. Its methods of work for the launch of the receiver can be divided into different layout LOS way (Light-of-Sight , intracardiac way), diffuse (diffuse) mode. LOS way directional, it has good channel characteristics such advantages, but the existence of a "shadow" effect. difficult to achieve roaming function. Roaming means the main features of non-directional, and easy to implementroaming function, but its channel quality is better sometimes LOS way. Transmission of signals required for a few of (the sampling was quantified), the general need for baseband modulation, transmission, modulation, sometimes signal source coding, the above-driven signals from photoelectric converter complete optical signal transmission. Infrared wireless digital communications system and its scope of work-for-fired power distribution, the quality of the communication. While using various methods to improve optical transmitter power, the other using spatial diversity, holographic films and so on so diffuse light for the launch of space optical power evenly distributed.(2) Channel : infrared wireless digital communication channel refers to the transmitters and receivers in the space between. Due to natural light and artificial light sources such as light signals in the context of intervention, and the source - Electrical Equipment, The optical noise and disturbances, infrared wireless digital communications in some occasions, poor quality, At this point needed to channel coding. Infrared wireless communication system, the optical signal reflection, light scattering and background noise and interference effects, Infrared wireless digital channel presence multi-path interference and noise, This is to improve the quality and access for high-speed applications should be addressed. Infrared wireless digital communication channel often used by the major optical components, optical filter, condenser, their role is : plastic, filter, depending on the field transformation, the band division, the lens can be used as launch-ray focusing, the use of optical filters filter out stray light, the use of optical lenses to expand the field of view receiver, able to make use of optical components for the link frequency division multiplexing, etc.. Infrared wireless communication channel optical noise : the natural noise (sunlight) and anthropogenic interference (fluorescent lighting). can be modulated by the transmission technology such as filters and adding to be addressed.(3) receivers : Channel optical signal from the optical receiver partially photoelectric conversion, In order to remove noise and intersymbol interference and other functions. Infrared wireless digital communications system receiver include optical receiver parts and follow-up sampling, filtering, judgment, quantity, balanced and decoding part. Infrared wireless optical receiver often used amplifier, and called for large-bandwidth, high gain, low noise and low noise, frequency response and channel impulse response matched. To be suppressed by low-frequency noise and human disturbance needs a band-pass filter. To obtain large optical receiver scope and instantaneous field of view, often using spherical optical lens.2.2.3 infrared communications featureWireless communications are a lot of ways, some using infrared communication with the following characteristics :• The high frequency, wave length, and fired the energy concentrated space propagation attenuation coefficient can ensure the effective signal transmission;• infrared is the invisible li ght, strong confidentiality and use it as an information carrier. device when there is no visual pollution, it does no harm to the human body;• dissemination without limitation, and there is no question of frequency interference with radio-wave pattern, not on the spectrum resources to the relevant authorities for the application and registration, easy to implement;• has a good point, when the transmission equipment and infrared receiver ports line up straight, deviation of not more than about 15 degrees when infrared devices running the best effect;• through infrared or not bypassed and objects, data transmission, optical path can not be blocked;• currently produce and receive infrared signals in the technology is relatively mature, components small size, low cost production of simple, easy to produce and modulation advantages.2.3 infrared communication code based on the knowledgeUsually, infrared remote control transmitters will signal (pulse binary code) modulation at 38 KHz carrier, After buffer amplified sent to the infrared light-emitting diodes, infrared signals into firing away. Pulse binary code in a variety of formats. One of the most commonly used code is PWM (pulse width modulation code) and the PPM code (Pulse Code Modulation). The former said in a pulse width, pulse indicated 0. The latter pulse width, but the width of code-not the same, the codes represent a bit - and the digits represent narrow 0.Remote coding pulse signal (PPM code as an example) are usually guided by the code, the system code, the anti-code system, a feature code, functional anti-code signal components. Guide the code name for the initial code, by the width of 9 ms and the margin width of 4.5 ms to the low-level components (different remote control systems in the low-level high width of a certain distinction), remote coding used to mark the beginning of pulsed signals. System identification code is also called code, which used to indicate the type of remote control system, in order to distinguish other remote-control system, prevent the remote control system malfunction. Functional code is also called scripts, which represents the corresponding control functions, Receiver of the micro-controller functions under the numerical code to complete the various functions operating. Anti-code system and function codes are anti-system code and the functional code against code Anti-code can be joined to the receiver synchronization transmission process leads to errors. In order to improve performance and reduce interference power consumption, The remote control will be coded pulse frequency of 38 KHz (for the cycle of 26.3 ms) of the carrier signal pulse reshuffle system (PAM), and then sentto the buffer amplified infrared LED, the remote control signal transmitter away.Address code and data codes are composed of different pulse width expressed that the two narrow pulse "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."Is the first part of a group a group of code, each code synchronization between separated. The plan is to enlarge the second half of a group code : a code from 12 AD (the address code plus data code For example, eight address code plus four data code), each with two AD-Pulse's : Pulse said the two "0"; 2 pulse width "1"; a narrow pulse width and pulse expressed an "F" is the code addresses "vacant."Realize fired at each fired at least four groups code, PT2272 only twice in a row to detect the same address code plus data code data will be the code "1" is driven The data should be output to drive margin and VT terminal for synchronous serial.红外遥控系统摘要红外数据通信技术是目前在世界范围内被广泛使用的一种无线连接技术,被众多的硬件和软件平台所支持。

外文翻译---改进的红外测温传感系统的移动设备

外文翻译---改进的红外测温传感系统的移动设备

附录AImproved infrared temperature sensing system for mobile devicesAbstractAn infrared (IR) temperature measurement systemconsists of not only a sensor module and electronics, but also an optomechanical system that guides IR radiation onto the sensor. The geometry and emissivity of the parts affects the reading, if the detector sees not only the target but parts of the measuring system itself. In normal industrial applications, the optics is designed so that the surfaces stabilize to the same temperature as the sensor.This allows the error caused by the device temperature to be easily calibrated away. The correction is valid for stationary conditions and usually near the calibration temperature, which is typically at room temperature.However, we show that if the sensor is embedded into a mobile (hand-held) device which has heat sources, such as power electronics, the normal conditions are no longer valid and the calibration fails. In order to improve infrared temperature sensing for mobile devices, the optics concept was studied and detailed design was performed. In addition, the optics performance was modelled and verified by measurement sensor prototyping. A calibration procedure noticing ope~a~ional temperature variations was applied. The repeatabIlIty of the implemented IR temperature sensor using on a correct transferred calibration curve was better than ±0.5 °C in an operational temperature range from +12.6 to +49.3 °C and target range from +10 to +90 °C.IntroductionTemperature is probably the most measured environmental parameter in the world. The global warming has dramatically increased the need of accurate temperature measurement of the environment. Temperature measurement is also required in numerous industrial and domestic applications. One important example is the temperature control of a microprocessor in a PC. Based on the temperature information produced by a thermistor both the microprocessor and the cooling system operation can be optimally controlled. Temperature control is also typically needed in household appliances, such as refrigerators, coffee makers and electric ovens. In addition, overheating protection is applied in several devices, such as motors and batteries. In consumer electronics, the main application is body thermometers, typically measured from the tympanic membrane in the ear. It is only natural to consider whether temperature sensing, which has such ubiquitous applications andgeneral interest, could be implemented in mobilehandheld devices such as mobile phones. ThermIstor-based temperature sensors exist in a variety of products,including wristwatches and also a few mobile phones. However, their performance is highly limited for a simple physical reason. If we put a thermistor inside a mobile device we are able to measure the temperature of a localis~d volume within the device case. However, this does not necessarily correlate at all with the real ambient temperature due to two main reasons. Thermal contact from the environment to the thermistor is weak, but thermal contact from the device itself to the thermistor is strong. In addition, mobile device can contain heat sources, such as power electronics, which easily increase the temperature within the device. Naturally, the heating effect is larger close to the heat sources, but heat conduction throughout the device affects all locations within the device. Locating the sensor outside the cover and isolating it from the rest of the device would improve sensor contact to the environment, but complete isolationis practically impossible to achieve. In addition, a sensor that locates outside the cover will still be vulnerable to heating from the user's hand.An alternative principle to implement a well performing environmental temperature measurement in mobile device application is infrared (IR) temperature sensing. IR sensing offers a non-contact method to measure temperature of targets due to the fact that all objects, which temperature is above absolute zero emit IR radiation. The target temperature sensing is based on the measurement of the emitted IR radiation from the object. The main advantages compared to thermistor based measurement are as follows. Thermal signal from the target can be amplified by optics and thermal signal from the device itself can be attenuated by an advantageous optical design and implementation.IR temperature sensingInfrared sensing is based on the fact that the intensity of infrared radiation emitted by a surface depends on its emperature, in the first approximation following Boltzmann's law. Since the field of view of the sensor has to be restricted in a practical mobile application the sensor also sees a surface which typically is not at the same temperature as the surface to be measured. In dealized conditions, this Narcissus effect can be calibrated away using an internal compensation circuit hat measures the temperature of the sensor element itself. A traditional optomechanical design for IR sensing, showing the Narcissus effect is shown in Fig. 1.Fig. 1. Traditional optomechanical design for IR sensing, showing the Narcissus effectAs one can see from Fig. 1 the tube is dominating the optical signal value seen by the detector, if the can is excluded as a commercial component. It is also important to notice that the lens used in the measurement system is producing an optical signal of a same order than the measurement target itself. This is due to the fact that lens material is not totally transparent, but it has absorption at the measurement band, which corresponds to the lens emittance at the equal band.The traditional method rests on two basic assumptions. The measuring device is in practice assumed to be stabilized (at room temperature), and there are assumed to be no internal sources of heat. The situation is very different, however, when the device operational temperature fluctuates strongly due to environmental temperature variation and/or internal heating. In a first approximation to measure the target temperature by its radiated IR power, the total radiance of an object depends on its emissivity and its temperaturein whichW= total radiance of the object (W/srxm2)ε= emissivityT = absolute temperature of the objectThe incident power is measured by the infrared detector. If the .emissivity of the target is known, the measurement should be quite accurate. Most natural objects have emissivities which are close to 0.95, and this value appears to be set as the default emissivity in all known commercial devices.It is important to notice from the equation 2 that the sensor temperature is typically assumed to be in ambient temperature or at least near to ambient temperature. Intypical mobile application use this assumption, however, is not valid. The factor K' includes the view angle or field-of-view (FOV) of the thermopile instrument. In order to obtain an improved spatial resolution at the target, it is necessary to restrict the field of view of the thermopile detector. Traditionally, this is done with a metal tube that has been painted black. The metal conducts heat quite quickly, and in normal circumstances quickly attains a constant temperature throughout the device.The target temperature is possible to determine through calibration, when the Ts is known. In most cases, Ts is measured at the sensor element, with the assumption that the sensor element corresponds well to the temperature of the whole optical system. In equilibrium conditions, the target temperature can thus be calculated by compensating with the measured sensor temperature.Measurements and modeling with traditional optics We tested some commercially available IR temperature sensors in actual use cases. Especially we wanted to see performance of the sensors in dynamic operational temperatures. In Table 1 performance of a traditional IR temperature sensor with heated optics is shown. Traditional sensor optical structure consisted of a blackened metal tube and a Fresnel lens made of IR transmitting polymer locating at the tube head. The Fresnel lens collects IR light from target and aims it to the thermopile detector located at the end of the tube.One can see from Table 1 that substantial difference between measurement reading and target reference value was noticed, when the lens was heated above the operational temperature of the system. A smaller error was also noticed, when the system operational temperature was O°C, which was 25 degrees below the definedTable 1. Performance of traditional IR temperature sensornominal operational temperature of the system. The system operational temperature was equal to the environmental temperature in the measurement. The used target in the measurement was an aluminum plate painted black and located on top of a Peltier element. The reference temperature was measured using a thermistor, which was attached to the target plate by a silicone.Narcissus effect in the commercial temperature sensor was suspected to be the main reason for the substantial measurement error. The Narcissus effect in the commercial system was modelled by ASAP optical simulation software. The purpose of the simulation was to find out how much optical signal is actually from the target compared to optical and mechanical structures of the measurement system. In order to get estimation of the actual emissivity values of the critical optical and optomechanical structures used in the commercial measurement unit, reflectivity (and transmissivity in some cases) of these structures were measured at wide optical band by Biorad Fourier Transform Infrared (FTIR) spectrometer. Average reflectivity (and transmissivity) at 8 ... 14 Jlm band were used to deduce the emissivity value in the optical simulations.Designs to improve system performanceNarcissus effect is clearly a very critical characteristic limiting the measurement performance of an IR temperature sensor. In order to improve performance the Narcissus effect has to be minimised by increasing the transmittance of optics and decreasing the relative amount of optical signal from the optomechanics. The field-of-view (FOV) of a Perkin-Elmer thermopile detector model TPS 333 for example is 100 degrees defined at the 50% relative response points. The wide FOV causes that the optomechanics of the measurement system can easily be seen by the detector. Use of reflective optics instead of refractive optics can provide higher optical transmittances through very high reflectivity surfaces. In addition, the reflective optics can be designed in such a way that there are only high reflectivity optical surfaces within the FOV of the detector. The high reflectivity of the surface corresponds to a low emissivity, which means that a low relative optical signal originates from the high reflectivity surface. In practice it is easier to achieve high optical transmittance through reflective optics at 8 to 14 Jlm band than with refractive optics. Gold and aluminium have high reflectivity from 8 to 14 Jlm band. Aluminium is more cost-efficient material than gold and therefore itsuse is advantageous in mobile applications. The average reflectivity of aluminium is over 97% from 8 to 14 Jlm.Reflector system preliminary specifications were as follows. Optics compatible with similar IR detectors used in commercially available sensors, collects light with object diameter to distance ratio of approximately 1:6 and maximum height of 10 mm for the whole optical structure. The nominal FOV for the IR temperature sensor was specified to 10 degrees defined by 50% relative intensity points. A parabolic reflector was designed on top of the TPS 333 thermopile detector to fulfil the FOV requirement. The parabolic shape was chosen because theshape was able to limit the sensor field of view to sufficiently narrow acceptance cone. Compound parabolic concentrator (CPC) and conical surfaces were also considered, but they were not able to limit the FOV adequately. The designed parabolic reflector and its dimensions are shown in Fig. 2.Fig. 2. Designed optical system and its dimensionsThe parabolic reflector surface is 9 mm long. Input aperture diameter is 4.9 mm and output aperture diameter is 1.56 mm. The output aperture is designed in such a way that it does not obscure any rays originating inside the FOV.附录B改进的红外测温传感系统的移动设备摘要一个红外线( IR )温度测量系统包括不仅是一个传感器模块和电子产品,而且是光学机械系统,红外辐射导游到传感器。

毕业论文之温度控制系统的设计外文翻译

毕业论文之温度控制系统的设计外文翻译

Design of the Temperature Control System Based on AT89C51ABSTRACTThe principle and functions of the temperature control system based on micro controller AT89C51 are studied, and the temperature measurement unit consists of the 1-Wire bus digital temperature sensor DS18B20. The system can be expected to detect the preset temperature, display time and save monitoring data. An alarm will be given by system if the temperature exceeds the upper and lower limit value of the temperature which can be set discretionarily and then automatic control is achieved, thus the temperature is achieved monitoring intelligently within a certain range. Basing on principle of the system, it is easy to make a variety of other non-linear control systems so long as the software design is reasonably changed. The system has been proved to be accurate, reliable and satisfied through field practice. KEYWORDS: AT89C51; micro controller; DS18B20; temperature1 INTRODUCTIONTemperature is a very important parameter in human life. In the modern society, temperature control (TC) is not only used in industrial production, but also widely used in other fields. With the improvement of the life quality, we can find the TC appliance in hotels, factories and home as well. And the trend that TC will better serve the whole society, so it is of great significance to measure and control the temperature. Based on the AT89C51 and temperature sensor DS18B20, this system controls the condition temperature intelligently. The temperature can be set discretionarily within a certain range. The system can show the time on LCD, and save monitoring data; and automatically control the temperature when the condition temperature exceeds the upper and lower limit value. By doing so it is to keep the temperature unchanged. The system is of high anti-jamming, high control precision and flexible design; it also fits the rugged environment. It is mainly used in people's life to improve the quality of the work and life. It is also versatile, so that it can be convenient to extend the use of the system. So the design is of profound importance. The general design, hardware design and software design of the system are covered.1.1 IntroductionThe 8-bit AT89C51 CHMOS microcontrollers are designed to handle high-speed calculations and fast input/output operations. MCS 51 microcontrollers are typically used for high-speed event control systems. Commercial applications include modems, motor-control systems, printers, photocopiers, air conditioner control systems, disk drives, and medical instruments. The automotive industry use MCS 51 microcontrollers in engine-control systems, airbags, suspension systems, and antilock braking systems (ABS). The AT89C51 is especially well suited to applications that benefit from its processing speed and enhanced on-chip peripheral functions set, such as automotive power-train control, vehicle dynamic suspension, antilock braking, and stability control applications. Because of these critical applications, the market requires a reliable cost-effective controller with a low interrupt latency response, ability to service the high number of time and event driven integrated peripherals needed in real time applications, and a CPU with above average processing power in a single package. The financial and legal risk of having devices that operate unpredictably is very high. Once in the market, particularly in mission critical applications such as an autopilot or anti-lock braking system, mistakes are financially prohibitive. Redesign costs can run as high as a $500K, much more if the fix means 2 back annotating it across a product family that share the same core and/or peripheral design flaw. In addition, field replacements of components is extremely expensive, as the devices are typically sealed in modules with a total value several times that of the component. To mitigate these problems, it is essential that comprehensive testing of the controllers be carried out at both the component level and system level under worst case environmental and voltage conditions. This complete and thorough validation necessitates not only a well-defined process but also a proper environment and tools to facilitate and execute the mission successfully. Intel Chandler Platform Engineering group provides post silicon system validation (SV) of various micro-controllers and processors. The system validation process can be broken into three major parts. The type of the device and its application requirements determine which types of testing are performed on the device.1.2 The AT89C51 provides the following standard features4Kbytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bittimer/counters, a five vector two-level interrupt architecture, a full duple ser-ial port, on-chip oscillatorand clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt sys -tem to continue functioning. The Power-down Mode saves the RAM contents but freezes the oscil–lator disabling all other chip functions until the next hardware reset.1.3Pin DescriptionVCC Supply voltage.GND Ground.Port 0:Port 0 is an 8-bit open-drain bi-directional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has internal pull ups. Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull ups are required during program verification.Port 1:Port 1 is an 8-bit bi-directional I/O port with internal pull ups. The Port 1 output buffers can sink/so -urce four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups. Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2:Port 2 is an 8-bit bi-directional I/O port with internal pull ups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull ups. Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX@DPTR). In this application, it uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register. Port 2 also receives the high-orderaddress bits and some control signals durin Flash programming and verification.Port 3:Port 3 is an 8-bit bi-directional I/O port with internal pull ups. The Port 3 output buffers can sink/sou -rce four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull ups.Port 3 also serves the functions of various special features of the AT89C51 as listed below:RST:Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROG:Address Latch Enable output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming. In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped duri-ng each access to external Data Memory. If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSEN:Program Store Enable is the read strobe to external program memory. When theAT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPP:External Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions. This pin alsreceives the 12-volt programming enable voltage (VPP) during Flash programming, for parts that require 12-volt VPP.XTAL1:Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2 :Output from the inverting oscillator amplifier. Oscillator CharacteristicsXTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shownin Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2.There are no requirements on the duty cycle of the external clock signal, since the input to the internal clocking circuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low time specifications must be observed. Idle Mode In idle mode, the CPU puts itself to sleep while all the on chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registers remain unchanged during this mode. The idle mode can be terminated by any enabled interrupt or by a hardware reset. It should be noted that when idle is terminated by a hard ware reset, the device normally resumes program execution, from where it left off, up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate the possibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle should not be one that writes to a port pin or to external memory.Power-down ModeIn the power-down mode, the oscillator is stopped, and the instruction that invokes power-down is the last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power-down mode is terminated. The only exit from power-down is a hardware reset. Reset redefines the SFRS but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize. The AT89C51 code memory array is programmed byte-by byte in either programming mode. To program any nonblank byte in the on-chip Flash Memory, the entire memory must be erased using the Chip Erase Mode.2 Programming AlgorithmBefore programming the AT89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figure 3 and Figure 4. To program the AT89C51, take the following steps.1. Input the desired memory location on the address lines.2. Input the appropriate data byte on the data lines. 3. Activate the correct combination of control signals. 4. Raise EA/VPP to 12V for the high-voltage programming mode. 5. Pulse ALE/PROG once to program a byte in the Flash array or the lock bits. The byte-write cycle is self-timed and typically takes nomore than 1.5 ms. Repeat steps 1 through 5, changing the address and data for the entire array or until the end of the object file is reached. Data Polling: The AT89C51 features Data Polling to indicate the end of a write cycle. During a write cycle, an attempted read of the last byte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated.2.1Ready/Busy:The progress of byte programming can also be monitored by the RDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY.Program Verify:If lock bits LB1 and LB2 have not been programmed, the programmed code data can be read back via the address and data lines for verification. The lock bits cannot be verified directly. Verification of the lock bits is achieved by observing that their features are enabled.2.2 Chip Erase:The entire Flash array is erased electrically by using the proper combination of control signals and by holding ALE/PROG low for 10 ms. The code array is written with all “1”s. The chip erase operation must be executed before the code memory can be re-programmed.2.3 Reading the Signature Bytes:The signature bytes are read by the same procedure as a normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7 must be pulled to a logic low. The values returned areas follows.(030H) = 1EH indicates manufactured by Atmel(031H) = 51H indicates 89C51(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programming2.4 Programming InterfaceEvery code byte in the Flash array can be written and the entire array can be erased by using the appropriate combination of control signals. The write operationcycle is self timed and once initiated, will automatically time itself to completion. A microcomputer interface converts information between two forms. Outside the microcomputer the information handled by an electronic system exists as a physical signal, but within the program, it is represented numerically. The function of any interface can be broken down into a number of operations which modify the data in some way, so that the process of conversion between the external and internal forms is carried out in a number of steps. An analog-to-digital converter(ADC) is used to convert a continuously variable signal to a corresponding digital form which can take any one of a fixed number of possible binary values. If the output of the transducer does not vary continuously, no ADC is necessary. In this case the signal conditioning section must convert the incoming signal to a form which can be connected directly to the next part of the interface, the input/output section of the microcomputer itself. Output interfaces take a similar form, the obvious difference being that here the flow of information is in the opposite direction; it is passed from the program to the outside world. In this case the program may call an output subroutine which supervises the operation of the interface and performs the scaling numbers which may be needed for digital-to-analog converter(DAC). This subroutine passes information in turn to an output device which produces a corresponding electrical signal, which could be converted into analog form using a DAC. Finally the signal is conditioned(usually amplified) to a form suitable for operating an actuator. The signals used within microcomputer circuits are almost always too small to be connected directly to the outside world”and some kind of interface must be used to translate them to a more appropriate form. The design of section of interface circuits is one of the most important tasks facing the engineer wishing to apply microcomputers. We have seen that in microcomputers information is represented as discrete patterns of bits; this digital form is most useful when the microcomputer is to be connected to equipment which can only be switched on or off, where each bit might represent the state of a switch or actuator. To solve real-world problems, a microcontroller must have more than just a CPU, a program, and a data memory. In addition, it must contain hardware allowing the CPU to access information from the outside world. Once the CPU gathers information and processes the data, it must also be able to effect change on some portion of the outside world. These hardware devices, called peripherals, are the CPU’s window to the outside.The most basic form of peripheral available on microcontrollers is the generalpurpose I70 port. Each of the I/O pins can be used as either an input or an output. The function of each pin is determined by setting or clearing corresponding bits in a corresponding data direction register during the initialization stage of a program. Each output pin may be driven to either a logic one or a logic zero by using CPU instructions to pin may be viewed (or read.) by the CPU using program instructions. Some type of serial unit is included on microcontrollers to allow the CPU to communicate bit-serially with external devices. Using a bit serial format instead of bit-parallel format requires fewer I/O pins to perform the communication function, which makes it less expensive, but slower. Serial transmissions are performed either synchronously or asynchronously.3 SYSTEM GENERAL DESIGNThe hardware block diagram of the TC is shown in Fig. 1. The system hardware includes the micro controller, temperature detection circuit, keyboard control circuit, clock circuit, Display, alarm, drive circuit and external RAM. Based on the AT89C51, the DS18B20 will transfer the temperature signal detected to digital signal. And the signal is sent to the micro controller for processing. At last the temperature value is showed on the LCD 12232F. These steps are used to achieve the temperature detection. Using the keyboard interface chip HD7279 to set the temperature value, using the micro controller to keep a certain temperature, and using the LCD to show the preset value for controlling the temperature. In addition, the clock chip DS1302 is used to show time and the external RAM 6264 is used to save the monitoring data. An alarm will be given by buzzer in time if the temperature exceeds the upper and lower limit value of the temperature.3.1 HARDWARE DESIGNA. Micro controllerThe AT89C51 is a low-power, high-performance CMOS 8-bit micro controller with 4K bytes of in-system programmable Flash memory. The device is manufactured using At mel’s high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pin out. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip, the At mel AT89C51 is a powerful micro controller which provides a highly-flexible and cost-effective solution to manyembedded control applications. Minimum system of the micro controller is shown in Fig. 2. In order to save monitoring data, the 6264 is used as an external RAM. It is a static RAM chip, low-power with 8K bytes memory.B. Temperature Detection CircuitThe temperature sensor is the key part in the system. The Dallas DS18B20 is used, which supports the 1-Wire bus interface, and the ON-BOARD Patented is used internally. All the sensor parts and the converting circuit are integrated in integrated circuit like a transistor [1]. Its measure range is -55℃~125 ℃, and the precision between -10℃~85℃is ±0.5℃[2 ,3]. The temperature collected by the DS18B20 is transmitted in the 1-Wire bus way, and this highly raises the system anti-jamming and makes it fit in situ temperature measurement of the rugged environment [4]. There are two power supply ways for the DS18B20. The first is external power supply: the first pin of the DS18B20 is connected to the ground; the second pin serves as signal wire and the third is connected to the power. The second way is parasite power supply [5]. As the parasite power supply will lead to the complexity of the hardware circuit, the difficulty of the software control and the performance degradation of the chip, etc. But the DS18B20(s) can be connected to the I/O port of the micro controller in the external power supply way and it is more popular. Therefore the external power supply is used and the second pin is connected to the pin P1.3 of the AT89S51. Actually, if there are multipoint to be detected, the DS18B20(s) can be connected to the 1-Wire bus. But when the number is over 8, there is a concern to the driving and the more complex software design as well as the length of the 1-Wire bus. Normally it is no more than 50m. To achieve distant control, the system can be designed in to a wireless one to breakthe length limit of the 1-Wire bus [6].C. LCD CircuitThe LCD 12232F is used, which can be used to show characters, temperature value and time, and supply a friendly display interface. The 12232F is a LCD with 8192 128×32 pixels Chinese character database and 128 16×8 pixels ASCII character set graphics. It mainly consists of row drive/column drive and 128×32 full lattice LCD with the function of displaying graphics as well as 7.5×2 Chinese characters. It is in a parallel or serial mode to connect to external CPU [7]. In order to economize the hardware resource, the 12232F should be connected to the AT89S51 in serial mode with only 4 output ports used. The LCD grayscale can be changed by adjustingthe variable resistor connected the pin Vlcd of the LCD. CLK is used to transmit serial communication clock. SID is used to transmit serial data. CS is used to enable control the LCD. L+ is used to control the LCD backlight power.D. Clock CircuitThe Dallas DS18B20 is used, which is a high performance, low-power and real-time clock chip with RAM. The DS18B20 serves in the system with calendar clock and is used to monitor the time. The time data is read and processed by the AT89C51 and then displayed by the LCD. Also the time can be adjusted by the keyboard. The DS18B20 crystal oscillator is set at 32768Hz, and the recommended compensation capacitance is 6pF. The oscillator frequency is lower, so it might be possible not to connect the capacitor, and this would not make a big difference to the time precision. The backup power supply can be connected to a 3.6V rechargeable battery.E. Keyboard Control CircuitThe keyboard interface in the system is driven by the HD7279A which has a +5V single power supply and which is connected to the keyboard and display without using any active-device. According to the basic requirements and functions of the system, only 6 buttons are needed. The system's functions are set by the AT89C51 receiving the entered data. In order to save the external resistor, the 1×6 keyboard is used, and the keyboard codes are defined as: 07H, 0FH, 17H, 1FH, 27H, 2FH. The order can be read out by reading the code instruction. HD7279A is connected to the AT89S51 in serial mode and only 4 ports are need. As shown in Fig. 6, DIG0~DIG5 and DP are respectively the column lines and row line ports of the six keys which achieve keyboard monitoring, decoding and key codes identification.F. Alarm CircuitIn order to simplify the circuit and convenient debugging, a 5V automatic buzzer is used in the alarm circuit [8]. And this make the software programming simplified. As shown in Fig. 7, it is controlled by the PNP transistor 9012 whose base is connected to the pin P2.5 of the AT89C51. When the temperature exceeds the upper and lower limit value, the P2.5 output low level which makes the transistor be on and then an alarm is given by the buzzer.G. Drive CircuitA step motor is used as the drive device to control the temperature. The four-phase and eight-beat pulse distribution mode is used to drive motor and thesimple delay program is used to handle the time interval between the pulses to obtain different rotational speed. There are two output states for the step motor. One: when the temperature is over the upper value, the motor rotates reversely (to low the temperature), while when lower than the lower limit value, the motor rotates normally (to raise the temperature); besides not equals the preset value. Two: when the temperature is at somewhere between the two ends and equals the preset value, the motor stops. These steps are used to achieve the temperature control. In addition, the motor speed can also be adjusted by relative buttons. As shown in Fig. 8, the code data is input through ports A11~A8 (be P2.3~P2.0) of the AT89C51 and inverted output by the inverter 74LS04. Finally it is amplified by the power amplifier 2803A to power the motor.3.2 SOFTW ARE DESIGNAccording to the general design requirement and hardware circuit principle of the system, as well as the improvement of the program readability, transferability and the convenient debugging, the software design is modularized. The system flow mainly includes the following 8 steps: POST (Power-on self-test), system initiation, temperature detection, alarm handling, temperature control, clock chip DS18B20 operation, LCD and keyboard operation. The main program flow is shown in Fig. 9. Give a little analysis to the above 8 tasks, it is easy to find out that the last five tasks require the real time operation. But to the temperature detection it can be achieved with timer0 timing 1 second, that is to say temperature detection occurs per second. The system initiation includes global variable definition, RAM initiation, special function register initiation and peripheral equipment initiation. Global variable definition mainly finishes the interface definition of external interface chip connected to the AT89C51, and special definition of some memory units. RAM initiation mainly refers to RAM processing. For example when the system is electrified the time code will be stored in the internal unit address or the scintillation flag will be cleared. The special function register initiation includes loading the initial value of timer and opening the interrupt. For example, when the system is electrified the timer is initialized. The peripheral equipment initiation refers to set the initial value of peripheral equipment. For example, when the system is electrified, the LCD should be initialized, the start-up display should be called, the temperature conversion command should be issued firstly and the clock chip DS18B20 should also be initialized. The alarm handling is mainly the lowering and the raising of temperature to make thetemperature remain with the preset range. When the temperature is between the upper and the lower limit value, it goes to temperature control handling, that is to say the temperature need to be raised or lowered according to the preset value. By doing so make the condition temperature equal to the preset value and hence to reach the temperature target.4 CONCLUSIONThe temperature control system has the advantages of friendly human-computer interaction interface, simple hardware, low cost, high temperature control precision (error in the range of ±1 ℃), convenience and versatility, etc. It can be widely used in the occasions with -55℃to 125℃range, and there is a certain practical value.。

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附录AImproved infrared temperature sensing system for mobile devicesAbstractAn infrared (IR) temperature measurement systemconsists of not only a sensor module and electronics, but also an optomechanical system that guides IR radiation onto the sensor. The geometry and emissivity of the parts affects the reading, if the detector sees not only the target but parts of the measuring system itself. In normal industrial applications, the optics is designed so that the surfaces stabilize to the same temperature as the sensor.This allows the error caused by the device temperature to be easily calibrated away. The correction is valid for stationary conditions and usually near the calibration temperature, which is typically at room temperature.However, we show that if the sensor is embedded into a mobile (hand-held) device which has heat sources, such as power electronics, the normal conditions are no longer valid and the calibration fails. In order to improve infrared temperature sensing for mobile devices, the optics concept was studied and detailed design was performed. In addition, the optics performance was modelled and verified by measurement sensor prototyping. A calibration procedure noticing ope~a~ional temperature variations was applied. The repeatabIlIty of the implemented IR temperature sensor using on a correct transferred calibration curve was better than ±0.5 °C in an operational temperature range from +12.6 to +49.3 °C and target range from +10 to +90 °C.IntroductionTemperature is probably the most measured environmental parameter in the world. The global warming has dramatically increased the need of accurate temperature measurement of the environment. Temperature measurement is also required in numerous industrial and domestic applications. One important example is the temperature control of a microprocessor in a PC. Based on the temperature information produced by a thermistor both the microprocessor and the cooling system operation can be optimally controlled. Temperature control is also typically needed in household appliances, such as refrigerators, coffee makers and electric ovens. In addition, overheating protection is applied in several devices, such as motors and batteries. In consumer electronics, the main application is body thermometers, typically measured from the tympanic membrane in the ear. It is only natural to consider whether temperature sensing, which has such ubiquitous applications andgeneral interest, could be implemented in mobile handheld devices such as mobile phones. ThermIstor-based temperature sensors exist in a variety of products,including wristwatches and also a few mobile phones. However, their performance is highly limited for a simple physical reason. If we put a thermistor inside a mobile device we are able to measure the temperature of a localis~d volume within the device case. However, this does not necessarily correlate at all with the real ambient temperature due to two main reasons. Thermal contact from the environment to the thermistor is weak, but thermal contact from the device itself to the thermistor is strong. In addition,mobile device can contain heat sources, such as power electronics, which easily increase the temperature within the device. Naturally, the heating effect is larger close to the heat sources, but heat conduction throughout the device affects all locations within the device. Locating the sensor outside the cover and isolating it from the rest of the device would improve sensor contact to the environment, but complete isolationis practically impossible to achieve. In addition, a sensor that locates outside the cover will still be vulnerable to heating from the user's hand.An alternative principle to implement a well performing environmental temperature measurement in mobile device application is infrared (IR) temperature sensing. IR sensing offers a non-contact method to measure temperature of targets due to the fact that all objects, which temperature is above absolute zero emit IR radiation. The target temperature sensing is based on the measurement of the emitted IR radiation from the object. The main advantages compared to thermistor based measurement are as follows. Thermal signal from the target can be amplified by optics and thermal signal from the device itself can be attenuated by an advantageous optical design and implementation.IR temperature sensingInfrared sensing is based on the fact that the intensity of infrared radiation emitted by a surface depends on its emperature, in the first approximation following Boltzmann's law. Since the field of view of the sensor has to be restricted in a practical mobile application the sensor also sees a surface which typically is not at the same temperature as the surface to be measured. In dealized conditions, this Narcissus effect can be calibrated away using an internal compensation circuit hat measures the temperature of the sensor element itself. A traditional optomechanical design for IR sensing, showing the Narcissus effect is shown in Fig. 1.Fig. 1. Traditional optomechanical design for IR sensing, showing the Narcissus effectAs one can see from Fig. 1 the tube is dominating the optical signal value seen by the detector, if the can is excluded as a commercial component. It is also important to notice that the lens used in the measurement system is producing an optical signal of a same order than the measurement target itself. This is due to the fact that lens material is not totally transparent, but it has absorption at the measurement band,which corresponds to the lens emittance at the equal band.The traditional method rests on two basic assumptions. The measuring device is in practice assumed to be stabilized (at room temperature), and there are assumed to be no internal sources of heat. The situation is very different, however, when the device operational temperature fluctuates strongly due to environmental temperature variation and/or internal heating. In a first approximation to measure the target temperature by its radiated IR power, the total radiance of an object depends on its emissivity and its temperature4W T εσ=in whichW= total radiance of the object (W/srxm2)ε= emissivity428K w/m 1067.5⋅⨯=-σ Stefan-Bolzmann constantT = absolute temperature of the objectThe incident power is measured by the infrared detector. If the .emissivity of the target is known, the measurement should be quite accurate. Most natural objects have emissivities which are close to 0.95, and this value appears to be set as the default emissivity in all known commercial devices.It is important to notice from the equation 2 that the sensor temperature is typically assumed to be in ambient temperature or at least near to ambient temperature. Intypical mobile application use this assumption, however, is not valid. The factor K' includes the view angle or field-of-view (FOV) of the thermopile instrument. In order to obtain an improved spatial resolution at the target, it is necessary to restrict the field of view of the thermopile detector. Traditionally, this is done with a metal tube that has been painted black. The metal conducts heat quite quickly, and in normal circumstances quickly attains a constant temperature throughout the device.The target temperature is possible to determine through calibration, when the Ts is known. In most cases, Ts is measured at the sensor element, with the assumption that the sensor element corresponds well to the temperature of the whole optical system. In equilibrium conditions, the target temperature can thus be calculated by compensating with the measured sensor temperature.Measurements and modeling with traditional opticsWe tested some commercially available IR temperature sensors in actual use cases. Especially we wanted to see performance of the sensors in dynamic operational temperatures. In Table 1 performance of a traditional IR temperature sensor with heated optics is shown. Traditional sensor optical structure consisted of a blackened metal tube and a Fresnel lens made of IR transmitting polymer locating at the tube head. The Fresnel lens collects IR light from target and aims it to the thermopile detector located at the end of the tube.One can see from Table 1 that substantial difference between measurement reading and target reference value was noticed, when the lens was heated above the operational temperature of the system. A smaller error was also noticed, when thesystem operational temperature was O°C, which was 25 degrees below the definedTable 1. Performance of traditional IR temperature sensornominal operational temperature of the system. The system operational temperature was equal to the environmental temperature in the measurement. The used target in the measurement was an aluminum plate painted black and located on top of a Peltier element. The reference temperature was measured using a thermistor, which was attached to the target plate by a silicone.Narcissus effect in the commercial temperature sensor was suspected to be the main reason for the substantial measurement error. The Narcissus effect in the commercial system was modelled by ASAP optical simulation software. The purpose of the simulation was to find out how much optical signal is actually from the target compared to optical and mechanical structures of the measurement system. In order to get estimation of the actual emissivity values of the critical optical and optomechanical structures used in the commercial measurement unit, reflectivity (and transmissivity in some cases) of these structures were measured at wide optical band by Biorad Fourier Transform Infrared (FTIR) spectrometer. Average reflectivity (and transmissivity) at 8 ... 14 Jlm band were used to deduce the emissivity value in the optical simulations.Designs to improve system performanceNarcissus effect is clearly a very critical characteristic limiting the measurement performance of an IR temperature sensor. In order to improve performance the Narcissus effect has to be minimised by increasing the transmittance of optics and decreasing the relative amount of optical signal from the optomechanics. The field-of-view (FOV) of a Perkin-Elmer thermopile detector model TPS 333 for example is 100 degrees defined at the 50% relative response points. The wide FOV causes that the optomechanics of the measurement system can easily be seen by the detector. Use of reflective optics instead of refractive optics can provide higher optical transmittances through very high reflectivity surfaces. In addition, the reflective optics can be designed in such a way that there are only high reflectivity optical surfaces within the FOV of the detector. The high reflectivity of the surface corresponds to a low emissivity, which means that a low relative optical signal originates from the high reflectivity surface. In practice it is easier to achieve high optical transmittance through reflective optics at 8 to 14 Jlm band than with refractive optics. Gold and aluminium have high reflectivity from 8 to 14 Jlm band. Aluminium is more cost-efficient material than gold and therefore itsuse is advantageous in mobile applications. The average reflectivity of aluminium is over 97% from 8 to 14 Jlm.Reflector system preliminary specifications were as follows. Optics compatiblewith similar IR detectors used in commercially available sensors, collects light with object diameter to distance ratio of approximately 1:6 and maximum height of 10 mm for the whole optical structure. The nominal FOV for the IR temperature sensor was specified to 10 degrees defined by 50% relative intensity points. A parabolic reflector was designed on top of the TPS 333 thermopile detector to fulfil the FOV requirement. The parabolic shape was chosen because the shape was able to limit the sensor field of view to sufficiently narrow acceptance cone. Compound parabolic concentrator (CPC) and conical surfaces were also considered, but they were not able to limit the FOV adequately. The designed parabolic reflector and its dimensions are shown in Fig. 2.Fig. 2. Designed optical system and its dimensionsThe parabolic reflector surface is 9 mm long. Input aperture diameter is 4.9 mm and output aperture diameter is 1.56 mm. The output aperture is designed in such a way that it does not obscure any rays originating inside the FOV.附录B改进的红外测温传感系统的移动设备摘要一个红外线(IR )温度测量系统包括不仅是一个传感器模块和电子产品,而且是光学机械系统,红外辐射导游到传感器。

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