基于前车轨迹预测的高速智能车运动规划

针对现有运动规划算法大多只考虑障碍车当前状态,本文中提出一种基于前车运动轨迹预测的高速车辆运动规划算法。首先,融合考虑驾驶意图与基于车辆运动模型的方法对前车轨迹进行预测;然后,采用贝塞尔曲线(Bezier)规划主车运动轨迹,结合避撞过程中与前车碰撞风险概率,高速避撞车辆速度变化特点以及车辆运动稳定性等因素建立目标函数,并考虑车辆动力学与运动学约束,使用序列二次规划(SQP)方法对Bezier曲线的控制点和主车运动目标点位置进行优化求解,得到最优避撞运动轨迹;最后,以前车直行和换道两种工况为例,对主车的避撞运动轨迹进行规划,分析不同工况下主车避撞过程中的运动状态变化以及与前车碰撞风险概率变化。结果表明,所提出的运动规划算法能够保证车辆的避撞安全性与运动稳定性。

Motion Planning of High Speed Intelligent VehicleBased on Front Vehicle Trajectory Prediction

In view of the fact that most of the existing motion planning algorithms only consider the current state of the obstacle vehicle,a high-speed vehicle motion planning algorithm based on trajectory prediction of the front vehicle is proposed.Firstly,the front vehicle trajectory is predicted by combining the driving intention and the vehicle motion model.Then,the Bezier curve is used to plan the main vehicle trajectory.By combining the risk probability of collision with the front vehicle in the process of collision avoidance,the characteristics of vehicle speed variation and vehicle motion stability in high-speed collision avoidance,the objective function is established.Taking into consideration of the vehicle dynamics and kinematics constraints,the sequential quadratic programming(SQP)is used to optimize the position of the control point of Bezier curve and the moving target point of the main vehicle,and the optimal collision avoidance trajectory is obtained.Finally,the main vehicle collision avoidance trajectory is planned under the two working conditions of straight ahead and lane changing of the front vehicle and the movement state change and the collision risk probability change of the main vehicle in the process of collision avoidance are analyzed under different working conditions.The results show that the proposed motion planning algorithm can ensure vehicle collision avoidance safety and motion stability.