基于线控底盘的无人驾驶轨迹跟踪控制研究

Trajectory Tracking Control of Unmanned Driving Based on Wire Controlled Chassis

为提高结构化工况下无人驾驶汽车轨迹跟踪的精确性,提出一种融合纵向车速跟踪控制器的预瞄轨迹跟踪控制算法。针对四轮转向的特性,基于传统纯跟踪算法设计了四轮转向纯跟踪控制模型;针对纯跟踪算法跟踪效果受车速影响较大的缺陷,设计了纵向车速跟踪控制器并采用n维插值表方式在不同曲率处设置不同车速;将四轮转向纯跟踪算法融合纵向车速跟踪控制器,以达到更好的跟踪效果。仿真与实车试验表明,试验平台可较精确地跟踪规划轨迹并平稳抵达目标终点,实车轨迹跟踪过程中最大横向误差控制在0.497m。

To improve the tracking accuracy of unmanned vehicles under structured working conditions,a preview trajectory tracking control algorithm with longitudinal vehicle speed tracking controller is proposed.Firstly,according to the characteristics of four-wheel steering,a pure pursuit control model of four-wheel steering was designed based on the traditional pure pursuit algorithm.Secondly,aiming at the defect that the tracking effect of pure pursuit algorithm was greatly affected by the vehicle speed,a longitudinal vehicle speed tracking controller was designed,and different vehicle speeds were set at different curvatures by N-dimensional interpolation table.Finally,four-wheel steering pure pursuit algorithm was combined with longitudinal speed tracking controller to achieve better tracking effect.The simulation and real vehicle test show that the test platform can accurately track the planned trajectory and smoothly reach the target destination,and the maximum lateral error in the track tracking process of real vehicle is controlled at 0.497m.