Abstract:

To stability lane keeping for intelligent four wheel steering vehicle, a cascade control strategy is proposed which integrate the direct yaw moment control and the lane keeping control. The main controller achieves the front wheel angle control for lane keeping. The deputy controller achieves the yaw stability control. The front wheel angle of the main controller is as input of the deputy controller, and the desired slip angle and desired yaw rate are obtained. The rear wheel angle and yaw moment are as inputs of deputy controller, and compensation of the rear wheel steering angle and yaw moment is calculated based on the LQ algorithm. The actual vehicle slip angle and actual yaw rate can track desired slip angle and yaw rate. After controlling of stability control, the main control can achieve lane keeping accurately, to ensure the intelligent vehicle driving in the inside lane driving safely. The experimental results show that, the cascade control strategy is effective, and it can improve the accuracy of lane tracking for intelligent vehicle, but also can improve stability and maneuverability.

Key words: intelligent transportation, stability lane keeping, cascade control, four wheel steering, model predictive control, linear quadratic programming

摘要：

针对四轮前后轮转向车辆的稳定车道线保持，提出集成直接横摆力矩和车道 线保持的串级控制策略.主控制器实现车道线保持控制；副控制器实现车辆稳定性控制. 主控制器的前轮转角作为副控制器的参考输入，计算期望滑移角和期望横摆率.后轮转角 和横摆力矩作为副控制器控制输入，基于LQ算法计算补偿后轮转角和横摆力矩，实际滑 移角和实际横摆率跟踪期望滑移角和期望横摆率.在副控制器车辆稳定性控制基础上，主 控制器实现准确地车道线保持控制，保证车辆在车道内安全行驶.实验结果表明，实现准 确车道线保持，并保证车辆的稳定性和操纵性.

关键词: 智能交通, 稳定车道线保持, 串级控制, 四轮转向, 模型预测控制, 线性二次型 规划