汽车操纵稳定性与前轮摆振的非线性仿真分析

以某轿车为例,建立3自由度整车系统动力学模型,利用常微分方程稳定性理论和数值仿真计算,详细研究整车的稳态转向特性和系统失稳后的前轮摆振特性。阐明汽车的操纵稳定性与前轮摆振特性同属汽车整车稳定性问题,前者是负刚度系统,后者是负阻尼系统。在一定的参数组合下,具有不同转向特性的汽车都或多或少地存在摆振现象,这与实际情况相符,建议适当增加转向系阻尼和刚度以减小甚至消除摆振的发生。

Nonlinear Simulation on Vehicle Handling Stability and Front Wheel Shimmy

A car dynamic model with three degrees of freedom is constructed.Both stable steering characteristics and front wheel shimmy occurring in unstable conditions are studied based on stability theory of ordinary differential equation and numerical simulation.It is clarified that the vehicle handling stability and front wheel shimmy are both the issues of vehicle stability,and that shimmy will occur more or less in a vehicle with different steering characteristics under certain combination of parameters,which conforms to the vehicle driving practice.A suggestion is also made that the damping and stiffness of steering system should be appropriately increased to reduce or even eliminate the occurring of front wheel shimmy.