滚动阻力对车辆运动稳定性的影响分析

Analyses on the Effects of Rolling Resistance on the Motion Stability of Vehicle

鉴于传统的以经典线性2自由度模型为基础的多自由度非线性车辆系统模型中通常忽略轮胎滚动阻力的影响而难以反映车辆运动的真实状态,本文中在发动机制动工况下,建立计及轮胎滚动阻力的5自由度(纵向速度、侧向速度、横摆角速度和前后轮转动速度)车辆模型,利用非线性系统的全局相平面和状态变量时间序列等分析方法研究了滚动阻力对高速转向行驶车辆动力学特征的影响。仿真结果表明,在发动机制动工况下,车速逐渐降低的过程中,滚动阻力严重影响车辆系统的运动状态。因此,建立包含滚动阻力的车辆模型有利于分析汽车的操纵稳定性特征,为实验验证理论模型的正确性提供理论支持。

In view of that traditional multi-DOF nonlinear vehicle model based on classic 2 DOF linear vehicle model usually neglects the effects of wheel rolling resistance,leading to inadequacy in reflecting real states of vehicle motion,a 5 DOF（ longitudinal velocity,lateral velocity,yaw rate and the rotational velocities of front and rear wheels） nonlinear dynamics vehicle model under engine braking condition with consideration of wheel rolling resistance is established in this paper. The effects of rolling resistance on the dynamics features of vehicle in highspeed cornering are studied by using analysis methods of globe phase plane and state variables time sequence for nonlinear system. Simulation results show that in the course of gradual reduce in vehicle speed under engine braking condition,rolling resistance has significant impact on vehicle motion states. Therefore,vehicle model containing rolling resistance is conducive to the analysis on the handling and stability characteristics of vehicle,providing theoretical supports for the test verification on the correctness of theoretical model.