线控变传动比四轮转向的操纵稳定性研究

Research on vehicle handling stability of variable steering ratio four-wheel-steer-by-wire system

根据车辆横向运动动力学模型,采用全反馈控制策略,并考虑到人的差异,提出了影响控制策略的组合系数,可以通过人为地选择组合系数,来调整转向传动比和转向增益。仿真结果表明,可使质心侧偏角降低到零而侧向加速度增益和横摆角速度增益保持不变,并能减少系统波动幅值和进入稳态所经历的时间,从而保证车辆的反应快速灵活。在保持上述特性不变的情况下,可人性化地选择转向传动比和转向增益,进一步提高了车辆的操纵稳定性、行驶安全性和司机的驾驶舒适性。

According to the vehicle lateral motion dynamics model ,the complete feedback control strategy is adopted. Considering the difference between people, the combination coefficients influencing control strategy are proposed, and the steering ratio and the steering gain are adjusted after the combination coefficients are chosen by people. Simulation results show that the side slip angle can reduce to zero, the lateral acceleration gain and yaw angle velocity gain can keep invariant, and the system fluctuation amplitude and the time entering into the steady state are also reduced. While maintaining the above-mentioned characteristics of the same circumstances, the choice may be user-friendly steering gear ratio and steering gain, in order to further enhance the vehicle＇s handling and stability, driving safety and driving comfort.