关键词: 智能汽车, 换道, 动态轨迹规划, 滚动优化

Abstract: According to the shortcoming that the traditional lane change trajectory planning method is difficult to effectively deal with the changes of the movement state of the preceding vehicle, a dynamic trajectory planning method for vehicle lane change based on rolling optimization is proposed, and a trajectory tracking controller is designed to track desired trajectory. Firstly, the lane change reference trajectory equation is designed based on the fifth degree polynomial, and the lane change trajectory evaluation index is established to determine the lane change time. Secondly, the lane change dynamic trajectory planning function is constructed. Considering the deviation of the two planned trajectories in consecutive period, the optimal objective function is designed. The constraint of the dangerous envelope ellipse following the movement of the preceding vehicle is established to ensure collision avoidance safety. Considering the stability constraints and road boundary constraints, the dynamic trajectory planning problem is transformed into a rolling optimization problem to plan a dynamic lane change trajectory that can adapt to the changing vehicle in the state. Then, to obtain the desired front wheel steering angle, a model predictive controller is designed. Finally, simulations and hardware-in-the-loop tests of the proposed algorithm are carried out. The simulation and test results show that the proposed method can control the vehicle cope with different lane changing environments, and can ensure the safety and maintain the comfort of lane-changing.

Key words: Intelligent vehicle, Lane change, Dynamic trajectory planning, Rolling optimization