第页摘要当今，自动化控制系统已经在各行各业得到了广泛的应用和发展，而直流驱动控制作为电气传动的主流在现代化生产中起着主要作用。长期以来，直流电动机因其转速调节比较灵活，方法简单，易于大范围平滑调速，控制性能好等特点，一直在传动领域占有统治地位。[2]本毕业设计主要是通过PWM调速器实现直流电机的正转、反转、加速、减速、停止等操作，并实现电路的仿真。为实现系统的微机控制，在设计中，采用了AT89C51单片机作为整个控制系统的控制电路的核心部分，配以各种显示、驱动模块，实现对电动机转速参数的显示和测量；由命令输入模块、光电隔离模块及H型驱动模块组成。采用带中断的独立式键盘作为命令的输入，单片机在程序控制下，不断给光电隔离电路发送PWM波形，H型驱动电路完成电机正反转控制.在设计中，采用PWM调速方式，通过改变PWM的占空比从而改变电动机的电枢电压，进而实现对电动机的调速。设计的整个控制系统，在硬件结构上采用了大量的集成电路模块，大大简化了硬件电路，提高了系统的稳定性和可靠性，使整个系统的性能得到提高。关键词：直流电机，AT89C51单片机，PWM调速，仿真AbstractNowadays,automationcontrolsystemhasbeenwidelyusedinallwalksoflifeanddevelopment,andDCdrivecontrolasamainstreamelectricdriveplaysamajorroleinthemodernizationofproduction.Foralongtime,becausetheDCmotorspeedregulationismoreflexible,simple,easy-to-large-scalesmoothspeedcontrolperformanceandgoodfeatures,hasbeenthedominantinthefieldoftransmission.ThegraduationprojectismainlyachievedbyPWMDCmotorspeedcontrollerforward,reverse,speedup,slowdown,stopandotheroperations,andtoachievethesimulationofthecircuit.Toachievemicrocomputercontrolsystemdesign,usingacontrolcircuitAT89C51microcontrollerasthecoreoftheentirecontrolsystempart,withvariousdisplaydrivermodule,theparametersofthemotorspeeddisplayandmeasurement;bythecommandinputmoduleopticalisolationmoduleandH-drivemodule.Usingaseparatekeyboardwithinterruptinputasacommand,themicrocontrollerunderprogramcontrol,continuousopticalisolationcircuittotransmitPWMwaveform,H-drivemotorreversingcontrolcircuitiscompletedinthedesign,usingPWMspeedcontrolmodebychangingthuschangingthedutycycleofthePWMmotorarmaturevoltage,andthusrealizethemotorspeed.Thewholecontrolsystemdesign,thehardwarestructurewithalotofintegratedcircuitmodule,greatlysimplifyingthehardwarecircuittoimprovethestabilityandreliabilityofthesystem,sothatoverallsystemperformanceisimproved.Keywords:Dcmotor，AT89C51microcontroller，PWMspeed,，Simulation目录TOC\o"1-3"\h\z\uHYPERLINK\l_Toc311911绪论PAGEREF_Toc311911HYPERLINK\l_Toc317891.1系统背景PAGEREF_Toc317891HYPERLINK\l_Toc1622