汽车工程 ›› 2021, Vol. 43 ›› Issue (4): 580-587.doi: 10.19562/j.chinasae.qcgc.2021.04.016

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基于最小模型误差估计的智能汽车路径跟踪控制

任玥1,冀杰1,赵颖1,梁艺潇2,郑玲2()   

  1. 1.西南大学工程技术学院,重庆 400715
    2.重庆大学汽车工程学院,重庆 400044
  • 收稿日期:2020-11-16 修回日期:2021-01-27 出版日期:2021-04-25 发布日期:2021-04-23
  • 通讯作者: 郑玲 E-mail:zling@cqu.edu.cn
  • 基金资助:
    国家自然科学基金面上项目(51875061);重庆市自然科学基金面上项目(cstc2020jcyj?msxmX0496);中央高校基本业务费(SWU119021)

Path Tracking Control of Intelligent Vehicle Based on Minimal Model Error Estimation

Yue Ren1,Jie Ji1,Ying Zhao1,Yixiao Liang2,Ling Zheng2()   

  1. 1.College of Engineering and Technology,Southwest University,Chongqing 400715
    2.College of Automobile Engineering,Chongqing University,Chongqing 400044
  • Received:2020-11-16 Revised:2021-01-27 Online:2021-04-25 Published:2021-04-23
  • Contact: Ling Zheng E-mail:zling@cqu.edu.cn

摘要:

为提高分布式驱动电动智能汽车在自主循迹过程中关键参数的估计精度并降低模型不确定性对控制系统鲁棒性的影响,本文中提出了一种基于观测器的自适应滑模路径跟踪控制策略。首先,针对难以直接精确测量的车辆纵、侧向速度,建立了5输入3输出3状态的状态估计系统,并采用最小模型误差准则以降低估计过程轮胎的非线性特性带来的观测模型误差。接着,基于运动学模型,计算出了路径跟踪期望横摆角速度响应,并采用自适应滑模算法实现主动转向控制。考虑线控转向系统的潜在失效风险,引入径向基神经网络对系统不确定性进行在线估计。同时,设计了直接横摆稳定控制器并采用最优转矩分配策略,进一步提高车辆的稳定性。最后,对车辆状态估计和路径跟踪进行了Carsim/Matlab联合仿真,结果表明:基于最小模型误差准则的观测器能取得较可靠的估计结果,路径跟踪控制器能保证车辆具有较好的跟踪精度和鲁棒性。

关键词: 路径跟踪, 最小模型误差, 自适应滑模控制, 径向基神经网络

Abstract:

To enhance the estimation accuracy of key parameters and reduce the effects of model uncertainty on the robustness of control system in the autonomous path tracking process of distributed?drive intelligent electric vehicle, an observer?based adaptive sliding mode path tracking control strategy is proposed in this paper. Firstly, in view of the difficulty in directly and accurately measuring the longitudinal and lateral speeds, a state estimation system with 5 inputs, 3 outputs and 3 states is established, and the minimal model error criterion is adopted to reduce the error of observation model caused by the nonlinear feature of tire. Then based on kinematic model, the desired yaw rate response of path tracking is calculated, the sliding mode algorithm is employed to achieve active steering control, and with consideration of the potential failure risk of steer?by?wire system, the RBF neural network is introduced to perform an online estimation on system uncertainty. Meanwhile, the direct yaw controller is designed with optimal torque distribution strategy used to further improve the stability of vehicle. Finally, a Carsim/Matlab co?simulation is conducted on vehicle state estimation and path tracking. The results demonstrate that the observer based on minimal model error criterion can get more reliable estimation results and the path tracking controller can ensure the vehicle have higher tracking accuracy and robustness.

Key words: path tracking, minimal model error, adaptive sliding mode control, RBF neural network