Path Tracking Control of Vehicles Based on Variable Prediction Horizon and Velocity.

NMPC was widely applied to the path tracking control of vehicles. However, the impacts of prediction horizon and velocity on the performances of path tracking control were not considered in reported researches. Thus, the relationship among prediction horizon, velocity and the performances of path tracking control was analyzed. Through the cubic polynomial fitting, the control laws of the optimal prediction horizon and reference velocity were obtained, which may guarantee the lateral error of path tracking less than 0.1 m. Then, the NMPC controller for path tracking control was improved, and the performances of the NMPC controller were verified by simulation. The simulation results show that, for the improved NMPC controller, the literal error is within 0.092 8 m and the heading error is within 0,072 4 rad. Compared with the traditional NMPC controller, the improved NMPC controller reduces the maximum lateral error by more than 4.267 1 m and reduces the maximum heading error by more than 0. 392 7 rad, and the performances of path tracing control are improved. [ABSTRACT FROM AUTHOR]