基于SPEA2+的某轻型客车悬架多目标优化

Multi-objective optimization of suspension of light bus based on SPEA2

为了改善某轻型客车的平顺性和操纵稳定性,使用Matlab和Adams-Car联合建立了该车的整车多体动力学优化模型,采用SPEA2+多目标进化算法对该车的前后悬架进行了匹配优化。为保证模型的准确性,特对该车轮胎的力学性能进行了测试,并通过参数辨识得到了基于魔术公式的轮胎属性文件(Pac2002)。其中优化变量包括前悬架扭杆的扭转刚度、前后减振器的阻尼曲线系数、前后稳定杆的扭转刚度和后悬架板簧的刚度,并根据该车实际情况确定了优化变量的约束范围。优化目标为稳态回转试验的最大侧向加速度、基准车速下蛇行试验的车身横摆角速度和侧倾角及速度80km/h、B级路面的前后悬架上方的车架大梁Z向加速度均方根值。然后根据优化的结果进行了悬架样件试制,并在某汽车试验场进行了对比验证试验。试验结果表明:优化后平顺性提高约20%,操从稳定性基本不变,采用的联合优化方法是有效可行的;该优化方法是汽车CAO技术发展的一种趋势,对汽车底盘的虚拟开发及优化具有一定的指导作用。

In order to improve the vehicle＇s ride comfort and stability,a virtual dynamic model of a light bus was established in Matlab and Adams-Car.Multi-objective method of SPEA2＋ was used for reasonably matching and optimizing the front and rear suspensions＇parameters.The tire mechanical characteristics was firstly tested to secure the accuracy of the model,then the magic formula tire model（Pac2002）was obtained by parameter identification method.An optimal method for light bus＇s suspension system was put forward,in which the torsion stiffness of front torsion bar,the pre and post damping curve coefficients,the torsional stiffness of pre and post stabilizer bars and the stiffness of rear suspension were selected as the optimal variables.The allowed regions of optimization variables were separately determined according to the bus＇s actual situation.The max lateral acceleration of steady static circular simulation,the yaw rate and rollangle of the body of slalom simulation,and the Z-direction acceleration RMS of the frame on Blevel road at speed of 80km/h were chosen as the optimal target.Later,the suspension samples were manufactured,and the comparative trials were respectively done at an automotive proving ground to verify the optimization results.The results show that the ride comfort of the optimized bus increases by about 20%,while the stability remain unchanged and the proposed optimization method can be used for improving the vehicle＇s ride comfort and stability and it has become a development trend of automotive computer-aided optimization technology（CAO）.It has the guiding significance for virtual development and optimization of automotive chassis.2tabs,17 figs,18refs.