基于时变局部模型的无人驾驶车辆路径跟踪  

Path tracking of unmanned vehicles based on the time-varying local model

作　　者：白国星 周蕾 孟宇[1] 刘立[1] 顾青[1,2] 王国栋 BAI Guo-xing;ZHOU Lei;MENG Yu;LIU Li;GU Qing;WANG Guo-dong(School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China;Shunde Graduate School,University of Science and Technology Beijing,Shunde 528399,China)

机构地区：[1]北京科技大学机械工程学院,北京100083 [2]北京科技大学顺德研究生院,顺德528399

出　　处：《工程科学学报》2023年第5期787-796,共10页Chinese Journal of Engineering

基　　金：国家重点研发计划资助项目(2019YFC0605300,2018YFE0192900);国家自然科学基金资助项目(52202505);中国博士后科学基金资助项目(2022M710354);中国有色金属集团科技计划资助项目(2018KJJH01);中央高校基本科研业务费专项资金资助项目(FRF-TP-20-052A1)。

摘　　要：目前常用于无人驾驶车辆路径跟踪控制的有模型控制方法有两类,一类是基于全局模型的控制方法,另一类是基于局部模型的控制方法.基于全局模型的路径跟踪控制中无人驾驶车辆的纵向速度与全局坐标系中的横向、纵向位移误差之间存在随航向角变化的耦合关系,这种耦合关系使得控制器无法将纵向速度作为控制输入来提高路径跟踪控制的精确性.基于局部模型的路径跟踪控制器通常采用误差模型作为参考模型,这种模型使得控制器在参考路径曲率变化幅度较大时精确性较低.针对前述问题,基于非线性模型预测控制滚动优化的原理,提出一种基于时变局部模型的无人驾驶车辆路径跟踪控制方法,并在低速高附着路面、低速低附着路面和高速低附着路面等工况下进行仿真验证.在仿真结果中,相比于基于全局模型的路径跟踪控制器、基于局部模型的路径跟踪控制器以及Stanley路径跟踪控制器,基于时变局部模型的路径跟踪控制器精确性更高,其位移误差绝对值不超过0.3342 m,航向误差绝对值不超过0.0913 rad.The development of unmanned vehicles has been extremely rapid in recent years. Unmanned vehicles require path tracking control. Based on mature mathematical modeling methods for unmanned vehicles, path tracking control research using modelbased control methods, such as feedback linearization control, optimal control, and model predictive control, is very common. Currently,two types of model-based control methods are commonly used in the path tracking control of unmanned vehicles: based on global and local models. The path tracking control based on the global model has a coupling relationship between the longitudinal speed of the unmanned vehicle and the lateral displacement error and longitudinal displacement error in the global coordinate system. Furthermore,this coupling relationship varies with the heading angle, making the controller unable to take the longitudinal speed as a control input to improve the accuracy of path tracking control. Path tracking controllers based on local models usually use errors as reference models,making the controller less accurate when the curvature of the reference path greatly varies. To address the above issue, an unmanned vehicle path tracking control method based on a time-varying local model is proposed considering the principle of rolling optimization of nonlinear model predictive control. Specifically, a time-varying local coordinate system is first established based on the time-varying pose of the vehicle. Then, a reference path in front of the vehicle is entered into this local coordinate system. The model-based iterative prediction is completed in this local coordinate system, and finally, the control is achieved using the optimization solution. The proposed control method is verified by co-simulation using MATLAB and CarSim. The simulation conditions include low-speed and highadhesion road conditions, low-speed and low-adhesion road conditions, and high-speed low-adhesion road conditions. The simulation results show that the path tracking controller based on the time-v

关 键 词：无人驾驶 车辆 路径跟踪 局部坐标系 模型 预测控制 

分 类 号：U471.15[机械工程—车辆工程]