专业英语unite16专题省名师优质课赛课获奖课件市赛课一等奖课件.ppt

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,本资料仅供参考，不能作为科学依据。谢谢,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,本资料仅供参考，不能作为科学依据。谢谢,UNIT 16,Transducers(Sensors),传感器,第1页,游戏很好玩，,工作原理是什么？,Wii,健身运动,第2页,触摸屏是怎么感知？,第3页,空隙,隔离点,保护膜内金属层,玻璃上电阻层,触摸屏结构,这里触摸屏就是一个传感器,第4页,摇摆你手机,使用者翻动手机选择“响铃”或“震铃”；摇摆手机变换不一样铃声和游戏；音乐和壁纸伴随人们动作而改变。,传感器,第5页,身边传感器,CCD,热敏电阻,传声器,温控器,第6页,力传感器,温度开关,第7页,试验室传感器,第8页,无线传感器结点,工业监测与控制,产品检测,天然气,压力监测,第9页,什么是传感器,狭义地定义：,能够将外界非,电,信号，按一定规律转换成,电,信号输出器件或装置。,温度改变,电阻值改变,热敏电阻,第10页,16.1 Introduction,A transducer is a device which converts the,quantity(量),being measured into an,optical(光学),mechanical,or more commonly-electrical signal.The energy-conversion process that takes place is referred to as transduction.,传感器（换能器）是一个将被测量转换为光信号、机械信号或者更常见电信号装置。能量转换过程称之为换能。,Unit16 Transducers,第11页,16.1 Introduction,Transducers are classified according to the transduction principle involved and the form of the,measurand(被测对象),.Thus a,resistance transducer(电阻式传感器),for measuring,displacement(位移),is classified as a resistance displacement transducer.Other classification examples are pressure bellows,force diaphragm,and so on,Unit16 Transducers,第12页,16.2 Transducer Elements,Unit16 Transducers,Although there are exception,most transducers consist of a,sensing element,and a,conversion,or,control element,as shown in the,two-block diagram(二方框图),of Fig.16.1.,第13页,辅助电源,敏感元件,转换元件,基本转换电路,被测量,电量,敏感元件,是直接感受被测量，并输出与被测量成确定关系某一物理量元件。,转换元件,：敏感元件输出就是它输入，它把输入转换成电路参量。,基本转换电路,：上述电路参数接入基本转换电路（简称转换电路），便可转换成电量输出。,Unit16 Transducers,第14页,For example,diaphragms(振动膜),bellows(波纹管),strain tubes and rings(应力管和应力环),bourdon tubes(布尔登管),and cantilevers(悬臂),are sensing elements which respond to changes in pressure or force and convert these physical quantities into a displacement.,Unit16 Transducers,第15页,磁铁,手柄外环,手柄,霍尔元件,F,2,F,2,F,1,F1,晶体,晶体,第16页,超声波传感器工作原理,压电晶片,压电晶片,压电晶片,是一个压电式传感元件，它既能够将机械能转换为电能，又能够将电能转换为机械能。,发射器,接收器,第17页,磁铁,手柄外环,手柄,手柄,旋转手柄，调整磁铁和霍尔元件之间距离，电路输出对应电压，从而控制车速。,磁传感器,电动车车速控制,霍尔元件,第18页,2This displacement may then be used to change an electrical parameter such as,voltage(电压),resistance(电阻),capacitance(电容),or,inductance(电感).,Such combination of mechanical and electrical elements form electromechanical transducing devices or transducers.Similar combinations can be made for other energy input such as thermal,photo,magnetic and chemical,giving thermoelectric,photoelectric,electromagnetic,and electrochemical transducers respectively.,这个位移可用于转换成电参数，比如电压、电阻、电容或电感。这种由机械和电气元件组成组合就形成了机电式传感器或传感器。类似组合能够有其它类型能量输入，比如热、光、磁和化学能，分别组成热电、光电、电磁和电化学传感器。,Unit16 Transducers,第19页,16.3 Analog and Digital Transducers,Unit16 Transducers,Considerable experience has been accumulated with analog transducers,signal conditioning,A/D converters etc.and it is natural that majority of current systems tend to use these techniques.3,我们在模拟式传感器、信号调整器以及模-数转换器等方面积累了大量经验，所以，很自然，多数现有系统趋向于采取这些技术。,第20页,16.3 Analog and Digital Transducers,Unit16 Transducers,This type of transducer,if coupled to computer,does not necessarily require the same amount of equipment,since much of the processing done by the,integral circuitry,could be programmed and performed by the computer.,这种类型传感器怎样连接到计算机上，就不再需要相同数量其它设备，因为由积分数字电路完成大量信号处理工作完全能够由计算机编程完成。,第21页,Coded-digital,Digital,Analog,Signal Types,In which the parameter of the system to be measured although,initially(最初)derived(源于),in an analog form by a sensor,is converted to an electrical analog,either voltage or current.Some averaging usually occurs,either by design or,inherent(固有),in the methods adopted.,In which a parallel digital is generated,each bit radix-weighted according to some predetermined code.4 These,are referred to as,direct digital transducers.,In which a function,such as mean rate of a repetitive signal,is a measure of the parameter being measured.These are,subsequently,referred to as frequency-domain transducers.,Unit16 Transducers,第22页,16.3 Analog and Digital Transducers,Unit16 Transducers,The most popular of these are out,synchros(同时器),and similar devices which produce,a modulated output of a carrier frequency(载频调制输出),.,第23页,16.3 Analog and Digital Transducers,Unit16 Transducers,For ordinary analog use,this output has to be,demodulated(解调),to provide a DC signal whose,magnitude(主要性),and sign represents any displacement of the transducers moving element.,对于普通模拟用途，这种输出必须解调，以提供一个其大小和符号能代表传感器运动元件位移直流信号。,第24页,16.3 Analog and Digital Transducers,Unit16 Transducers,The usual disadvantage of these system is that the,inertia(惯性),of the instrument and encoder often limits the speed of response and therefore the operation frequencies.,这些装置普遍缺点是仪器和编码器惯性经常限制了响应速度，从而也限制了工作频率。,6In designing such system,consideration must be given to the computer time required to access and process the transducer output data.,在设计这类系统时，必须考虑到存取和处理传感器输出数据所需要计算机时间。,第25页,16.4 Use of Sensor in Programmable Automation,Unit16 Transducers,In this section we are concerned with the application of sensor-mediated programmable automation to material-handling,inspection,and assemble operations in batch-produced,discrete-part manufacturing.,这部分介绍以传感器为媒介可编程自动化在批量生产和分散零部件制造时材料搬运，检测和装配工序上应用。,第26页,16.4 Use of Sensor in Programmable Automation,Unit16 Transducers,Programmable automation consists of a system of multi-degree-of-freedom manipulators(commonly known as industrial robots)and sensors under computer control,which can be programmed to perform specified jobs in the manufacturing process and can be applied to new(but similar)jobs by reprogramming.,可编程自动化装置是由计算机控制多自由度机械手（通常称为工业机器人）和传感器组成系统，它能够经过编程完成加工过程中特定加工任务，并能重新编程以适应新（类似）加工任务。,第27页,16.4 Use of Sensor in Programmable Automation,Unit16 Transducers,Extending the present capabilities of industrial robots will require a considerable improvement in their capacity to,perceive(感知),and interact with the surrounding environment.,扩大工业机器人现有能力需要大大促进它对周围环境感知和与之匹配能力。,第28页,