基于线控技术的四轮转向全滑模控制

Four-wheel steering with total sliding mode control

针对具有线控技术的四轮转向车辆,设计了一种全滑模控制器用于提高车辆的操纵稳定性.以前、后车轮转角作为控制输入,设计全滑模控制器使实际的质心侧偏角和横摆角速度跟踪理想的质心侧偏角和横摆角速度,通过在滑模面中加入跟踪误差积分项来消除稳态跟踪误差不为零的现象,并运用Lyapunov定理给出了全滑模控制器的稳定条件.最后通过2种车辆模型下不同工况的仿真分析,对比了传统前轮转向、常规滑模控制的四轮转向和全滑模控制的四轮转向的动力学响应,结果表明所设计的全滑模控制器不仅消除了稳态跟踪误差不为零的现象,而且提升了车辆抵抗外界干扰和系统参数摄动的鲁棒性.

A total sliding mode controller is proposed to improve the stability for four-wheel steering vehicle with steer-by-wire technology.By controlling the steering angle of front wheel and rear wheel,the total sliding mode controller can make the real body sideslip angle and yaw rate track the ideal body sideslip angle and yaw rate.The integration of tracking error is considered in the sliding surface to ensure the tracking error to be zero.Then,a stable condition is given based on Lyapunov theory.The conventional front wheel steering,four-wheel steering with common sliding mode control and total sliding mode control are compared by simulations under different vehicle models and different conditions.The results show that the total sliding control not only ensures the tracking error to be zero,but also improves the robustness to resist the external disturbance and the change of system parameters.