退火炉自动控制系统设计

I摘要退火炉是金属热处理中的重要设备，而温度是退火炉的主要被控变量，是保证其产品质量的一个重要因素。因此，退火炉温度控制的稳定性和控制精度直接影响产品的质量。所以，本次毕业设计设计了基于单片机的退火炉温度自动控制系统，实现了温度的自动控制。本控制系统是采用AT89S52单片机为核心，对退火炉温度和燃料流量进行实时监控。由按键设定温度初值，通过温度和流量传感器进行信号的采集，由AD574对其电压信号转换数字信号。通过AT89S52单片机和LCD1602液晶显示屏处理和实时显示相应的数据。当所有设定值设定结束后，通过DAC8420将数字信号转换成模拟信号驱动电动调节阀进行阀门大小的调节即流量调节，进而改变炉内温度，实现温度的自动控制。软件部分采用一种新型的智能控制方法，大林算法来控制系统的温度、流量。其最突出的优点是具有专门针对大滞后系统设计的算法。此算法具有消除余差、对纯滞后有补偿作用等特点，能够达到良好控制效果。本系统实现了对退火炉的温度、燃料的流量进行实时监控。它不但工程造价较低、运行维护简单、运行费用低，而且是一种简便、可靠、经济、快速的退火方法。关键词：退火炉；数据采集；大林算法；单片机IIAbstractAnnealingisanimportantmetalheattreatmentequipment,andannealingtemperatureisthemaincontrolledvariabletoensurethequalityoftheirproducts.Therefore,thefurnacetemperaturecontrolstabilityandcontrolaccuracydirectlyaffectsthequalityofproducts.So,thisgraduationprojectisdesignedbasedonsingle-chipfurnacetemperaturecontrolsystemtoachieveautomaticcontroloftemperature.TheMCUAT89S52isusedtothecenterofthecontrolsystem,theannealingfurnacetemperatureandfuelflowisreal-timelymonitered.Initialtemperatureissettedbythekey.Itisusedthetemperaturetransducerandflowtransducertoaquirethesignal.ItischangedfromthevoltagesignalstothedigitalsignalbyuseingtheAD574.Processingandreal-timedisplaythecorrespondingdatabyuseingtheMCUAT89S52andLCD1602display.Whenthesettingiscompletedallsettings,thedigitalsignalisconvertedbyDAC8420intoananalogsignaltodrivetheelectriccontrolvalveisthevalveflowcontrolregulationofthesize,therebychangingthefurnacetemperature,automatictemperaturecontrol.SoftwarepartusesanewtypeofintelligentcontrolmethodtocontrolthesystemDahlintemperature,flow.Itsmostprominentadvantageisasystemdesignedspecificallyforlargedelayalgorithms.Thisalgorithmhastoeliminateresidualerror,thereiscompensationforpurelageffectandothercharacteristics,canachievegoodcontroleffect.Theannealingtemperature,fuelflowrateforreal-timemonitoringisrealizedinthesystem.Itisnotonlylowercostproject,simpleoperationandmaintenance,lowoperatingcosts,butalsoitisasimple,reliable,economical,rapidannealingmethod.Keywords：annealer；dateacquisition；computingcontrol；MCUIII目录第1章绪论..........................................................................................................11.1课题研究的背景及意义...........................................................................11.2国内外研究现状和发展...........................................................................21.3本文研究的主要内容...............................................................................2第2章方案设计及论证........................................................................................32.1方案设计...................................................................................................32.2方案论证...................................................................................................6第3章硬件电路设计............................................................................................93.1温度传感器的选择...................................................................................93.2气体流量传感器的选择.........................................................................113.3控制阀门的选择.....................................................................................123.4A/D转换器的选择...................................................................................133.5D/A转换器的选择...................................................................................143.6单片机的选择.........................................................................................163.78255扩展I/O口的设计..........................................................................163.8电源电路的设计.....................................................................................183.9晶振电路的设计.....................................................................................193.10复位电路的设计...................................................................................203.11温度检测电路的设计...........................................................................213.12I/V转换电路的设计..............................................................................223.13多路转换开关的设计...........................................................................243.14A/D转换电路的设计.............................................................................243.15D/A转换电路的设计.............................................................................263.16键盘电路的设计...................................................................................263.17报警电路的设计...................................................................................283.18显示电路的设计...................................................................................28第4章软件设计..................................................................................................304.1主程序系统流程图.................................................................................304.2温度检测系统流程图.............................................................................314.3流量检测系统流程图.............................................................................31IV4.4键盘系统流程图................................................................