车辆磁流变半主动悬架模糊LQG控制策略研究

Study on Fuzzy LQG Control Strategy for Semi-active Vehicle Suspensions with Magnetorheological Dampers

为提升车辆行驶舒适性,提出一种半主动悬架模糊LQG(Linear-quadratic-Gaussian control)控制策略。对磁流变阻尼器(Magnetorheological Damper,MRD)进行力学特性测试,并建立改进双曲正切模型,利用试验数据采用遗传算法对力学模型进行参数辨识,从而得到可以用于准确描述MRD非线性特性的数学模型。建立1/4车辆悬架模型,设计模糊LQG控制策略,在正弦激励及随机路面激励条件下进行数值仿真,根据车身加速度、悬架动挠度及轮胎动载荷3个指标进行性能评价。与被动悬架控制和模糊控制效果相比,结果表明,模糊LQG控制策略使半主动悬架各评价指标的均方根值均明显降低,基于模糊LQG控制的半主动悬架具有更好的减振性能,能有效提升悬架性能。

In order to improve the driving comfort of vehicles,a fuzzy LQG control strategy of semi-active suspensions is proposed.The mechanical characteristics of the magnetorheological damper(MRD)is tested.An improved hyperbolic tangential model is established.Based on the test data,the genetic algorithms is used to identify the parameters of the mechanical model,so as to obtain an accurate description of the nonlinear characteristics of the MRD mathematical model.A quarter of vehicle suspension model is established,and a fuzzy LQG control strategy is designed.Through numerical simulation under sinusoidal excitation and random road excitation,the performance of the vehicle suspension is evaluated from three indicators of vehicle body acceleration,suspension dynamic deflection and tire dynamic load.Compared with the effects of passive suspension control and fuzzy control,it is shown that the root mean square value of the semi-active suspension evaluation index of fuzzy LQG control is significantly reduced,and the semi-active suspension controlled by fuzzy LQG has better damping performance.And the suspension performance is effectively improved.