变工况下半主动悬架系统滑模控制器的优化设计与仿真

Optimal Design and Simulation of Semi-active Suspension Based on Sliding Mode Control

变工况环境下,半主动悬架系统的性能优劣直接影响汽车行驶平顺性和操纵稳定性,为改善名义工况下半主动悬架系统的动力学特性,建立了半主动悬架系统二自由度1/4车体动力学模型,设计了滑模控制切换函数和滑动模态控制律,提出了一种半主动悬架滑模控制器模型,并在多种工况条件下进行了仿真实验.实验结果表明:相比于被动悬架,传统的PID控制对某型号车辆动挠度均方根、车身加速度均方根、车身位移均方根的改善程度分别大于9.5%、1.4%、2.0%,而所设计的滑模控制器对其改善程度分别大于15.8%、21.1%、6.0%,可显著地提高汽车行驶平顺性和操纵稳定性.

The performance of semi-active suspension system under variable working condition directly affects the ride comfort and handling stability of a vehicle.In order to improve the dynamic characteristics of the semi-active suspension system under nominal conditions,a semi-active suspension system with two degrees of freedom 1/4 vehicle dynamics model is established,the sliding mode control of switching function and sliding mode control law are designed,a kind of semi-active suspension controller model is put forward,and simulation experiments are carried out under various conditions.The experimental results show that compared to passive suspension,the degrees of improvement of the dynamic deflection root mean square,body acceleration root mean square,body displacement root mean square of the traditional PID control for a certain type of vehicle are higher than 9.5 %,1.4 %,2 % respectively,and the sliding mode controller can improve them to more than15.8 %,21.1 % and 6 %respectively,which can significantly improve the ride comfort and handling stability of a vehicle.