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《汽车电动助力转向系统(EPS)硬件设计本科毕业论文》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、汽车电动助力转向系统(EPS)硬件设计内容摘要电动助力转向(ElectricPowerSteering,简称EPS)作为一种新型转向系统,因其具有节能、环保等优点而受到世界各大汽车公司和企业的青睐,它将逐步取代传统的液压助力转向系统(HydraulicPowerSteering,简称HPS)。本文以传统的转向柱助力式EPS为研究对象,建立EPS系统数学模型,给出了汽车电动助力系统的动力学方程。根据电动助力转向系统的工作原理及控制器可靠设计的关键技术,设计了以P87C591单片机为主控单元的EPS系统
2、,系统采用闭环电流控制方案,利用目标电流技术调节电机端电压达到控制电机电流力矩的目的。EPS控制器采用模块化设计,把信号处理电路和功率驱动电路进行分层设计,以增强系统的抗干扰能力和可靠性。在进行PWM驱动频率的选择时,考虑开关时电流脉峰对开关管及电动机安全的影响。最后通过研究分析了EPS系统的经济性、系统硬件电路板空间与发热功耗及可靠性合理地选择散热片及其参数,提高了驱动效率和稳定运行能力。实验表明,该系统具有良好的电动助力特性,满足电动助力转向要求,证明了这种系统在实际应用中的有效性。关键词·43
3、·电动助力转向;单片机;H桥驱动;PWM斩波;控制系统HardwareDesignoftheElectricPowerAssistedSteeringSystem050607337ZhangqiangInstructor:HelinlinAssociateprofessorAbstractElectricpowersteeringisanewpowersteeringtechnologyforvehicles.Meritsuchasenergyconservation,environmentalpr
4、otectionthatthepersonhasacceptstherespectivelybigautomobilesofworldcompanyandtheenterprisefavour,homeandabroaddevelopingtrendistouseelectricpower-assistancetochangetothehydraulicpressurepower-assistancevergencesubstitutingtraditionstepbystep.Themathema
5、ticmodelthemainbodyofabookisestablishedsystematicallywithdyadicEPSofthetraditionvergencepostpower-assistancefortheobjectofstudy,hasgivenanautomobileoutelectricsystematicpower-assistancedynamicsequation,hascombinedclassicscontroltheoryandtheoptimization
6、algorithm,theparametercarriesoutvalidityinapplyingtorealityhavingstudied,testifyingthissystemonsystematicpower-assistance.Thispaperpresentsanelectricpowersteeringsystemcontrolledby·43·P87C591microprocessor.Themotorgiventorqueiscomputedbyexpertcontrolsy
7、stem.Thepracticaloutputtorqueisclosed-loopcontrolled.TheworkingprincipleandkeytechnologiesforreliabledesignofEPScontrollerwereanalyzed.Thesignalprocessingcircuitandthepowerdrivecircuitwerehierarchicallydesignedtoimprovetheantijammingcapabilityandreliab
8、ility.ThePWMfrequencywasselectedconsideringtheinfluenceofswitchingcurrentpulseonthesafetyofthetransistorsandthemotorshouldbetakenintoaccount.Besidesparalleledfortheeconomy,theheatdissipationandthereliability.Itsrelevantparametersweresel