汽车悬架系统非线性动力学行为分析及控制.pdf

江苏大学硕士学位论文摘要悬架系统能够缓冲和吸收来自车轮的振动,传递车轮与路面的驱动力和制动力,还能在汽车转向时承受来自车身的侧倾力,在汽车起动和制动时抑制车身的俯仰和点头,它是影响乘坐舒适性的关键部件。悬架系统存在着复杂的非线性特征,虽然采用线性的悬架系统振动模型可以近似反映振动的一些特性,。随着现代汽车的高速化,非线性悬架模型的研究越来越受到重视。悬架弹簧、阻尼非线性因素受到的关注较多,但是对于轮胎非线性因素的研究尚不多见,本文在MATI AB/SIMULINK中仿真研究了轮胎非线性因素对悬架系统振动的影响。仿真的结果表明轮胎非线性项对汽车的平顺性和安全性都有较大的影响,合理的选择轮胎参数可以同时改善平顺性和安全性。以前对于悬架系统非线性动力学行为的研究主要是从理论上求解单自由度悬架模型的组合共振解问题以及揭示分岔、混沌现象。本文在考虑了悬架非线性因素和轮胎非线性因素的基础上建立了一个两自由度的l/4车非线性振动模型, 采用数值积分的方法定性的研究了该系统中的分岔现象,并结合相图、Poincare 截面图等来分析复杂的动力学行为。模糊控制可以用来解决强非线性系统的控制问题,可以实现对动态系统的实时控制。本文采用一种简单实用的模糊控制规则表来实现对悬架系统的控制,仿真的结果说明本文采用的模糊控制可咀较好的降低车身加速度,并同时能够提高汽车的安全性。关键词:悬架,非线性动力学,数值积分方法,分岔,模糊控制江苏大学硕士学位论文 ABSTRACT Suspension system calleliminate and absorb theshocks fromwheels,transmit driveforce andbrakeforcefrommad andwheel,supportthe rollforceofbodywhen theautomobile steers,and depress thepitching ofbody when theautomobile starts is ponent that can influence theauWmofive performance. Suspension system plex some characteristics cm approximately reflect invibration extuafion oflinearsuspension response oflinearsuspension model faraway from thepractice when drivesthrough rough roadsurface inhigll moreandmoreattentionshavebeenobtained to the researchofnonlinaarsuspension model. Researches ofnonlinearfactorsofspring anddamp a他n均惦thanthetyre,in也is paper,the impact of nonlinearfactorsoftyreupon suspension systeⅢn’vibration is study onMATLAB/ resultsofsimulation isthatnonlinearfavorsof tyre effect on both therideandsafety,selected tyreparameters suitably can improve boththe rideandsafety. Combination andbifurcationphenomena of 1DOF qllart日-c∞ model thispaper,a 2DOF nonlinearmodel considering nonlinearity ofbothsuspeusion andrite's$ti艋ess isbuilt,using the method of numerical integration tOresearch the bifurcation behaviors of thissystem which analyze bypha∞diagram, SeCIi00 and soOIL fuzzy·controlCan resolve thecont