基于热电偶的单片机温度控制系统设计

鞍山科技大学本科生毕业设计（论文）第I页温度控制系统摘要本设计是采用热电偶为温度检测元件的单片机温度控制系统，这个系统是由硬件和软件两部分组成的。硬件电路包括三个部分：温度检测及放大电路、键盘/显示电路、温度控制电路。工作过程如下：热电偶检测炉内温度，得到的温度值经过A/D转换后输入到8155进行显示，同时从8155键盘输入系统温度设定值，将设定值与实际测量值进行比较会得到一个偏差值，将此偏差值进行PID处理，处理后的控制量送给双向可控硅。双向可控硅在给定周期T内具有不同的导通时间，这是由双向可控硅控制极上的触发脉冲控制的，这个触发脉冲是8031的P1.3引脚上产生的，经过零同步脉冲同步后经光耦管和驱动电路输出到可控硅的控制极上，从而改变加热的时间，达到温度控制的目的。软件部分包括主程序、T0中断服务程序、T1中断服务程序等。关键词：单片机，温度控制，硬件，PID算法鞍山科技大学本科生毕业设计（论文）第II页TemperatureControlSystemAbstractThedesignisasinglechipmicrocomputertemperaturecontrolsystemadoptingtheelectricthermocoupletomeasuretemperature,thissystemismadeupofhardwareandsoftware.Thecircuitofthehardwareincludesthreeparts:temperaturemeasureandenlargecircuit、keyboardandLEDcircuitandtemperaturecontrolcircuit.Theworkingcourseisasfollowing:theelectricthermocouplemeasuresthetemperatureofthestove,thetemperaturevalueischangedbyA/Dconverter,andthenitisinputto8155andshown.Atthesametimetheestablishingvalueofsystematictemperatureisinputfrom8155keyboards,itcanreceiveonedifferenceaccordingtoactualmeasurementvalueandtheestablishingvalue,thisdifferencevalueisdealwithPID,andthengivethisamounttothetwo-waysiliconcontrolledrectifier.Thetwo-waysiliconcontrolledrectifierhasdifferentleadingtimeinthegivencycleT,thistimeiscontrolledbypolarity’spulseoftouchingofthetwo-waysiliconcontrolledrectifier,thispulseoftouchingisprovidedbytheP1.3of8031,itissynchronouswiththezeropulse,andtheninputtocontrolpolarityofsiliconcontrolledrectifierthroughthePhotoelectriccouplinganddrivecircuit,itcanchangethetimeofheating,atlastthissystemcanachievethecontrolaim.Thepartofthesoftwareismadeupofmainprogram,T0cuttingoffserviceroutine,andT1cuttingoffserviceroutineandsoon.Keywords:singlechipcomputer,temperaturecontrol,thehardware,PIDalgorithm鞍山科技大学本科生毕业设计（论文）第III页目录摘要.........................................................................................................................................IABSTRACT..............................................................................................................................II1绪论....................................................................................................................................11.1选题的背景......................................................................................................................11.2温度控制技术的现状及其发展趋势..............................................................................11.3国内温度控制技术的研究成果......................................................................................21.4课题的研究内容..............................................................................................................22温度检测部分........................................................................................................................42.1热电偶简介......................................................................................................................42.2热电偶在本设计中的应用..............................................................................................53数据采集部分........................................................................................................................73.1ADC0809简介.................................................................................................................73.2ADC0809在本设计中的应用.........................................................................................73.3ADC0809转换程序.........................................................................................................848155的输入与显示部分......................................................................................................104.18155简介........................................................................................................................104.28155在本设计中的应用................................................................................................114.2.18155的显示过程.....................................................................................................124.2.28155的输入过程.....................................................................................................145温度控制部分......................................................................................................................165.1双向可控硅简介............................................................................................................165.2温度控制过程................................................................................................................165.3温度控制的算法............................................................................................................185.3.1PID控制的原理和特点..........................................................................................185.3.2温度控制的具体算法..............................................................................................196MAX232的介绍...................................................................................................................216.1收发器的历史..........................................................................................................