四轮转向智能车辆路径跟踪控制策略研究

Research on Path Tracking Control Strategy of Four-wheel Steering Intelligent Vehicle

针对较高车速下智能车辆路径跟踪控制不稳定问题,提出一种分层架构下的四轮转向联合差动制动路径跟踪控制策略。上层基于路径跟踪模型设计了前轮主动转向控制器;下层应用滑模变结构控制理论设计了后轮转向与附加横摆力矩集成控制器,通过差动制动分配策略,将附加横摆力矩转化为车辆单轮制动控制。仿真结果表明:该联合控制策略跟踪精度达到92.16%,相比于前轮转向控制,横向跟踪误差峰值降低37.9%,横摆角误差峰值降低50.6%,侧向加速度峰值降低29.8%,提高了智能车辆在高速工况下的跟踪精度和稳定性。

Aiming at the instability of path tracking control of intelligent vehicle at high speed, a path tracking control strategy of four-wheel steering combined with differential braking is proposed. In the upper layer, the front wheel active steering controller is designed based on the path tracking model. In the lower layer, the integrated controller of active rear steering and additional yaw moment is designed using the sliding mode control method. The additional yaw moment is transformed into the control of single wheel by designing differential braking distribution strategy. Simulation results show that the tracking accuracy of the combined control strategy is 92.16%. Compared with the front wheel steering control strategy, the peak value of lateral tracking error is reduced by 37.9%, the peak value of yaw angle error is reduced by 50.6%, and the peak value of lateral acceleration is reduced by 29.8%, which improves the tracking accuracy and stability of intelligent vehicles at high speed.