汽车转弯高维非线性动力学特性研究

High-dimensional nonlinear vehicular turning dynamics

车辆的转弯动力学特性是衡量车辆机动性能好坏的一个重要标准.通过建立汽车高维非线性动力学仿真模型,分析了悬架参数与轮胎参数对系统非线性动力学特性的影响,深入研究了车辆在特定转向角输入条件下的转弯非线性动力学响应;对四轮在不同扭矩作用下车辆的转弯机动性进行了对比分析;引入LuG re模型,充分考虑了轮胎的非线性特性,悬架单元采用绝对值型非线性弹性力与分段线性阻尼力,详细计算了车辆转弯时滚转角加速度、偏航角加速度、车体质心加速度、轮胎摩擦力的变化规律,应用M atlab6.5得到了具体的仿真结果;对确定车辆的横向动力学控制、转弯动力学性能预测及轮胎的磨损程度预测具有一定的指导意义.

Nonlinear dynamic turning characteristics are regarded as valuable for appraising the capabilities of vehicles. The authors formulated a novel methodolgy for producing their model, and then, through a high-dimensional nonlinear dynamic vehicular simulation, nonlinear dynamic responses were calculated for given turning angles. At the same time, influences on the dynamic model were analyzed by comparing different torsion loads on all four wheels and different parameters of the supension and tires. The LuGre friction model sufficiently depiets nonlinear characteristics of tires. The suspension unit has absolute values of elasticity and subsection linear damping forces, which results in complexity during simulation. A series of results including turning roll under acceleration, angular yaw under acceleration, centroid acceleration, rules for ehanging tire friction , and so on were derived uoing Matlab 6.5, which confirrned the accuracy of the model. It is of instructional significance for transverse dynamic control of vehicles, accurately predicting turning dynamics and abrasion of tires.