适应道路曲率多变的前馈-预测LQR横向控制

Feed-forward predictive LQR lateral control adapted to variable road curvature

针对传统LQR(linear quadratic regulator)横向控制的不足,提出了一种前馈-预测LQR反馈控制,实现了曲率多变道路的跟踪控制。在传统动力学模型的基础上建立了误差模型,以误差模型为研究对象分别求解了反馈控制量和前馈控制量。为提高LQR对道路多变的适应性,根据航向和横向位置误差建立了模糊规则实时调节Q、R矩阵。同时利用道路曲率信息,设计了预测模块,实时更新预测点和预测时间,解决了传统LQR响应迟滞问题。在给定规划路径的基础上进行了硬件在环实验,测试了单、双移线多车速工况下传统LQR和前馈-预测LQR的路径跟踪效果,结果表明本文中设计的前馈-预测LQR的控制效果优于传统LQR,单移线工况下轨迹跟踪误差最大可减少4.5%,双移线工况下轨迹跟踪误差最大可减少9.5%。

To address the weaknesses of the traditional LQR(linear quadratic regulator)lateral control,a feed-forward-predicted LQR feedback control is proposed to realize the tracking control of roads with variable curvature.On the basis of the traditional dynamic model,the error model is built,and the feedback control quantity and the feed forward control quantity are solved respectively with the error model as the research object.To improve the adaptability of LQR to road changeability,the Q and R matrices are adjusted in real time based on the fuzzy rules which are made according to the heading and lateral position errors.Meanwhile,the road curvature information is employed to build a prediction module and update the prediction point and time in real time to address the problem of traditional LQR response hysteresis.Based on the given planning path,hardware-in-the-loop experiments are conducted,and the path tracking effects of traditional LQR and feed-forward predicted LQR under single-shift and double-shift multi-vehicle speed conditions are tested.Our results show the control effect of the newly developed predictive LQR is superior to that of traditional LQR,and the trajectory tracking error is reduced by 4.5%under single-line shift condition and 9.5%under double-line shift condition.