车辆半主动悬架控制研究论文

摘要I摘要悬架系统是汽车实现操纵稳定性和乘坐舒适性的重要机械结构。车辆悬架系统性能的优劣直接影响车辆的乘坐舒适性和操纵安全性。传统的被动悬架系统设计参数一旦优化确定后就无法动态改变，难以使汽车具有良好的平顺性。由弹性元件和阻尼可调减振器组成的半主动悬架有耗能少，易实现等优点，可以改善汽车行驶的平顺性和操作稳定性。半主动悬架既克服了被动悬架系统的缺陷，又使实现成本降低，成为汽车技术中的研究热点之一。本文以汽车半主动悬架系统为研究对象，在对悬架的性能进行分析的基础上，建立了的二自由度1/4的汽车半主动悬架的数学模型。同时，考虑到路面扰动输入对悬架控制的重要影响，建立积分白噪声形式的路面不平度数学模型。在此基础上，提出了适用于半主动悬架系统的模糊逻辑控制，以控制输出信号动态改变可调阻尼器的阻尼系数从而达到自适应减振控制的目的。最后采用我国常见的C级路面作为激励信号，根据前面所建立的数学模型，利用Matlab/Simulink建立了动态模型，并进行计算机仿真，与被动悬架就簧载质量加速度、轮胎动载荷、悬架动挠度这些性能指标进行了对比分析。通过仿真表明，模糊控制较大的改善了半主动悬架系统的性能，比传统的被动悬架具有更好的减振性能，能够明显地改善舒适性。关键词：半主动悬架，模糊控制，仿真分析，MATLABAbstractIIAbstractSuspensionistheimportantpartofvehicle,itcanimproveridecomfortandhandlingsteadiness.ThedynamicPerformanceofsusPensionsystemdirectlyinfluencesridecomfortandhandlingofdrivingvehicles.Itisverydifficultforthetraditionalpassivesuspensionwhoseparametershavebeenfixedbyoptimizationtoadjustthemtoimproveontheridecomfort.Semi-activesuspension,composedofcontrollablespringanddamperelement,consumeslittleenergyandiseasytodesignandmanufacture.Andthensemi-activesuspensioncanalsoimproveridecomfortandhandlingsteadiness.Notonlythesemi-activesuspensioncanperformthefunctionofactivesuspensionsystem,buttherequirementsofthepowerisveryfew，Soithasbeenahottopicintheresearchfieldofcars.Thearticlestudiestheautomobilesemi-activesuspension.Basedonanalyzingtheperformances,thetextusesthetwofreedoms1/4suspensionmodel..Consideringtheinfluenceoftheinputdisturbance,amathematicaldescriptionofroadsurfaceirregularityisestablished，whichisthemodelofintegralwhitenoise.Onthebasisoftheabovestudy,Afuzzylogiccontrolmethodforsemi-activesuspensionisputforwardtocontroltheoutputsignalandadjustthedampercoeffieientinordertoadaptivelyabsorbtheshockandimprovetheridecomfort.ThenthesoftwareMatlab/Simulinkisusedtosimulatethesemi-activesuspensioncontrolledbytheabove-mentionedfuzzycontrolmethodonBleveltypicalroad.Theperformancesofbodyworkacceleration,thetireloadandsuspensiondisplacemenareanalyzingbetweenthesemi-activesuspensionandthepassivesuspension.Acordingtothesimulationresults，comparedwiththepassivesuspensioncontrol，semi-activesuspentionfuzzycontrolwhichobviouslyimproveridecomfortandhandlingsteadinesscouldreducethebodyworkacceleration,thetireloadandsuspensiondisplacementinalargedegree.Keywords:Semi-activesuspention,Fuzzycontrol,Simulationanalysis,MATLAB目录III目录摘要...........................................................................................................................IABSTRACT.................................................................................................................II目录.........................................................................................................................III第一章引言....................................................................................................-1-1.1车辆悬架系统发展概述.................................................................................-1-1.2半主动悬架的控制方法.................................................................................-3-1.3课题的研究意义.............................................................................................-5-1.4论文的主要研究工作.....................................................................................-5-1.5本章小结........................................................................................................-6-第二章车辆半主动悬架系统的分析与建模....................................................-7-2.11/4车二自由度悬架模型............................................................................-7-2.1.1被动悬架模型........................................................................................-7-2.1.2半主动悬架模型......................................................................................-8-2.2路面输入模型.................................................................................................-9-2.2.1路面不平度的功率谱..............................................................................-9-2.2.2空间频率谱函数与时间频率谱函数的转化........................................-11-2.2.3积分白噪声随机路面轮廓....................................................................-12-2.3本章小结.......................................................................................................-13-第三章半主动悬架系统的模糊控制..............................................................-14-3.1模糊逻辑系统概述.......................................................................................-14-3.2理想天棚阻尼控制策略...............................................................................-14-3.3模糊控制器的设计.......................................................................................-16-3.3.1半主动悬架模糊控制器的基本结构及设计流程................................-16-3.3.2定义系统的输入、输出变量及模糊化................................................-17-3.3.3隶属函数的确定....................................................................................-17-目录IV3.3.4模糊控制规则的选取............................................................................-19-3.3.5模糊逻辑推理........................................................................................-22-3.3.6清晰化................................