高速公路上自动超车过程的轨迹规划与跟踪控制

Trajectory planning and tracking control of automatic overtaking process on highway

研究了自动驾驶汽车在高速公路上超车过程中的轨迹规划和跟踪控制。基于纵向位移与时间(s-t)图,对超车过程进行建模和数字仿真分析,并应用多项式来规划车辆横纵向运动。采用集中式模型预测控制器,综合控制车辆横纵向的运动,以实现超车过程的轨迹跟踪。结果表明:相较于分散式控制方法,利用集中式控制方法下的车辆侧向加速度的整体波动减小19.0%,横摆角速度的整体波动减小11.6%。因而,集中式控制方法下的横向运动偏差更小,纵向加速过程更加平滑、稳定,符合高速公路超车过程安全平稳性的要求。

The trajectory planning and tracking control were investigated in the overtaking process for the autonomous driving vehicles on highway.The overtaking process was modeled and analyzed by digital simulation through longitudinal displacement-time graph(s-t graph).The algorithm planned the vehicle’s longitudinal and lateral motion with polynomials.The centralized model predictive controller controlled the vehicle’s longitudinal and lateral motion to realize the trajectory tracking of the overtaking process.The results show that compared to the decentralized control method,the centralized control method decreases the vehicle lateral acceleration fluctuation by 19.0%,and decreases the vehicle yaw rate fluctuation by 11.6%.Therefore,the centralized control method has smaller deviations in the lateral motion with smoother and more stable longitudinal accelerations.Thus,it meets the basic safety and stability requirements at highway overtaking.