Dynamic coordinated control strategy of autonomous vehicles during emergency braking under split friction conditions

Abstract

In case of emergency braking in danger, autonomous vehicle usually uses electronic stability control system to maintain the dynamic stability of the vehicle, and by adjusting the steering system, the vehicle can realize autonomous driving. However, when the autonomous vehicle is in emergency braking on the split-mu road, due to the inconsistent adhesion coefficient on both sides of the road, the inconsistency of tire force will not only damage the dynamic stability, but also make the vehicle deviate from the planned trajectory. Because the path tracking algorithm of autonomous vehicle needs to detect the trajectory error first, it will lead to the time delay of trajectory error correction, and its correction ability will weaken with the decrease of speed, so that the vehicle's trajectory will deviate unilaterally. Thus, the tracking accuracy is reduced and the driving safety is endangered. This paper proposes a dynamic coordinated control strategy based on dynamics and kinematics. In response to the rapid changes in lateral disturbances, a flexible control transfer mechanism based on vehicle status is constructed, realize dynamic coordinated control based on path tracking algorithm and active steering algorithm. While improving the lateral stability, the trajectory error is reduced.