汽车紧急换道避障的路径规划与跟踪控制

Path Planning and Tracking Control for Emergency LaneChange and Obstacle Avoidance of Vehicles

针对汽车紧急换道避障路径规划和跟踪控制问题,基于B样条曲线提出一种高效率的汽车紧急换道避障路径规划算法,并基于模型预测控制方法提出一种高精度的汽车紧急换道避障路径跟踪策略。首先,利用B样条曲线微分平坦输出参数化方法,将汽车紧急换道避障路径规划问题转化为B样条曲线控制点的非线性规划问题,并通过内点法求解该非线性规划问题得到最优的汽车紧急换道避障路径。为了执行基于B样条曲线规划的汽车紧急换道避障路径,基于汽车运动学和动力学模型建立线性预测模型,并采用模型预测控制方法推导出可有效处理前轮转向角和转向角速度约束的汽车紧急换道避障路径跟踪控制策略。最后,采用车辆动力学软件对所提出的汽车紧急换道避障路径规划算法和汽车紧急换道避障路径跟踪控制策略的可行性和有效性进行仿真验证,结果表明:所提出的方法可以安全、快速、稳定地引导汽车避开障碍物。

An efficient path planning algorithm based on B-spline curve and a high-precision path tracking control strategy based on model predictive control method for emergency lane change and obstacle avoidance of vehicles were proposed,aiming at the problem of path planning and tracking control for emergency lane change and obstacle avoidance.Firstly,the B-spline curve-based differential flat output parameterization method was used to transform the problem of path planning for emergency lane change and obstacle avoidance of vehicles into the nonlinear programming problem of the control points of B-spline curve,and the interior point method was used to solve the nonlinear programming problem to obtain the optimal path for emergency lane change and obstacle avoidance of vehicles.To execute the optimal path,a linear prediction model was established based on vehicle kinematics and dynamics model,and a path tracking control strategy for emergency lane change and obstacle avoidance of vehicles,which can effectively deal with the constraints of the front wheel steering angle and the front wheel steering angle speed,was derived based on model predictive control method.Finally,the feasibility and effectiveness of the proposed path planning algorithm and path tracking control strategy for emergency lane change and obstacle avoidance of vehicles were verified by the vehicle dynamics software,and the simulation results show that the proposed method can guide the vehicle to avoid the obstacle safely,quickly and stably.