由于悬架系统结构复杂,系统特性指标较多,各项指标相互关联,对车辆的影响规律较为复杂,从理论的角度提出悬架系统优化的目标函数是十分困难的,由此根据多体系统动力学原理,建立了某微型客车的虚拟样机模型,综合考虑整车的操纵稳定性和乘坐舒适性,分别以稳态回转试验中的不足转向度、车身侧倾度和汽车平顺性随机输入行驶试验中总的加权加速度均方根作为评价指标,设计正交试验,从理论上说明前后悬架刚度、横向稳定杆扭转刚度、前后减震器阻尼等悬架参数对微型客车操纵稳定性、平顺性的影响程度,找出显著因素,得到基于仿真试验的悬架参数的最优组合,为后期样车悬架参数的优选及调校提供指导和支持。
The suspension is a complex mechanical system,for which it is very difficult to define the optimization function.There are more than one system performance indices for every component of the vehicle,which are interrelated,with complicated impact on the vehicle.From a theoretical viewpoint,the objective function to optimize the suspension system is very difficult to formulate.In this paper,based on the multi-body system dynamics method,the virtual prototyping model of a mini passenger car is built.Considering vehicle handling stability and ride comfort,by using the degree of understeering and the roll rate in the steady circular test and the total RMS acceleration values in the method of random input running test of automotive ride comfort as the evaluation indices,the orthogonal experiment is designed,and the effects of the suspension structure parameters on handling stability and riding such as the suspension rate of the front suspension and the rear suspension,the torsion stiffness of the antiroll bar,the damping ratio of the front and rear suspensions are studied.Then the important factors are found,together with the optimum combination of the simulation-based suspension parameters.The final results provide some guidance and support for the optimization of the suspension parameters.