基于滑模控制的自动泊车系统路径跟踪研究

现有的自动泊车系统研究,由于忽略实际车辆转向约束和初始位姿条件而影响实际车辆跟踪参考路径效果,本文提出基于B样条曲线的路径规划算法和基于趋近律的非时间参考终端滑模路径跟踪控制算法。首先,对车辆的运动过程进行研究,建立车辆的运动学模型。其次,基于B样条曲线理论建立非线性约束平行泊车路径优化函数,并分析车辆运动学约束条件。然后,结合非时间参考路径跟踪控制和终端滑模控制方法,提出基于趋近律的非时间参考终端滑模路径跟踪控制方法。最后,通过Simulink和Car Sim联合仿真,验证了规划路径的合理性以及路径跟踪控制器的效果。

Path Tracking of Automatic Parking System Based on Sliding Mode Control

In the research of the existing automatic parking system, the actual vehicle tracking constraints and initial pose conditions were ignored, which affected the actual vehicle tracking reference path effect. A path planning algorithm based on the B-spline theory and a non-time reference terminal sliding mode tracking control method based on approach law were proposed. Firstly, the motion process of vehicle was studied and the vehicle kinematics model was set up. Secondly, based on the B-spline theory, a nonlinear constraint single step parallel parking path optimization function was established, and vehicle kinematics constraints was analyzed. Then, based on non-time reference path tracking control and terminal sliding mode control method, a non-time reference terminal sliding mode tracking control method based on approach law was proposed. The non time reference method was applied to avoid the influence of vehicle speed control and reduce the speed control requirement. Combining with the terminal sliding mode control method based on the reaching law, the controller controlled the vehicle tracking to the reference path, reduced the tracking error, improved the approach quality and reduced the buffing phenomenon. Finally, the path planning simulation was conducted for the initial position of the tilted parking, in order to verify the rationality of the path planning method. The effect of the design controller was verified by tracking the sinusoidal reference path on Simulink. And based on the Simulink and CarSim software, the rationality of the planning path and the control effect of the path tracking controller were verified.