Lane‐keeping control based on an improved artificial potential method and coordination of steering/braking systems

Abstract

Based on the impact of the vehicle velocity on the potential field function, considering the overall lane-keeping performance and vehicle stability, the yaw angular adjusting factor is introduced to regulate the potential field function. The proportions of vehicle velocity and yaw angle factors in potential field function are distributed by extension decision. The sliding mode controller is designed based on the two-degree-of-freedom vehicle dynamics model to obtain the front wheel steering angle. The fuzzy decision is made for the dynamic thresholds of distance deviation and angle deviation of lane-keeping system to avoid the control frequently start-up. Next, the combined control strategy of active steering and differential braking systems is designed based on vehicle driving safety boundary, and the yaw angle rate and mass-centroid sideslip angle are selected as the characteristic variables for dividing the vehicle driving safety regions. The different weights are determined for the steering and braking systems in different regions. Finally, the simulation by Carsim/Simulink and the hardware-in-loop test are carried out to demonstrate that it is effective and superior by adopting the sliding-mode controller based on the improved artificial potential function and the coordination strategy of steering and braking systems.