Lateral Control Strategy Based on MPC for Autonomous Vehicle under Extreme Road Adhesion Conditions

When autonomous vehicle moves under the extreme tire-road adhesion condition, its lateral stability decrease sharply making it difficult to accurately track the target trajectory. In order to improve the lateral control performance under extreme condition, the vehicle's centroid slip angle and yaw rate phase plane are utilized to analyze the steady state in which the vehicle can ensure stable driving. The upper and lower limits are determined by the maximum yaw rate under the friction limit between the tire and the road surface. The left and right boundaries are determined by keeping the tire slip angle in the unsaturated zone for restraint. Therefore, the boundary of the steady state area is supposed to a constraint when establishing the MPC controller. Finally, field test experiments with 2 typical scenarios have been conducted to evaluate the control strategy’s performance.