基于NMPC的智能汽车纵横向综合轨迹跟踪控制

本文中针对大曲率转弯工况下,智能汽车纵横向动力学特性的耦合和动力学约束导致轨迹跟踪精度和稳定性下降的问题,提出一种基于非线性模型预测控制(NMPC)的纵横向综合轨迹跟踪控制方法,通过NMPC和障碍函数法(BM)的有效结合,提高了跟踪精度,改善了行驶稳定性.首先建立四轮驱动-前轮转向智能汽车动力学模型和轨迹跟踪模型,采用...

Longitudinal and Lateral Comprehensive Trajectory Tracking Control of Intelligent Vehicles Based on NMPC

Aiming at the lowering of the trajectory tracking accuracy and stability caused by the coupling of longitudinal and lateral dynamic characteristics and the dynamic constraints of intelligent vehicles under large?cur?vature turning conditions,a longitudinal and lateral comprehensive trajectory tracking control method based on non?linear model predictive control(NMPC)is proposed in this paper.Through the effective combination of NMPC and barrier(function)method(BM),the tracking accuracy and driving stability are improved.Firstly,a dynamics mod?el for a four?wheel drive and front wheel steering vehicle and its trajectory tracking model are established and the NMPC is adopted to calculate the desired longitudinal force,lateral force and yaw moment.Then a nonlinear pro?gramming mathematical model with constraints is constructed based on tire dynamics model and the BM is used to solve out the optimal distribution of the tire forces of four?wheels,and finally the longitudinal and lateral comprehen?sive trajectory tracking control for a four?wheel drive intelligent vehicle is achieved.In the end,a Carsim and Simu?link joint simulation is conducted with a result showing that compared with the traditional preview PID control,the method proposed can significantly improve the tracking accuracy and driving stability with consideration of the cou?pling between longitudinal and lateral dynamics characteristics.