Safe Replanning and Motion Control for Automated Emergency Braking Under Braking System Failures

The automated emergency braking system is designed to prevent rear-end collisions. However, unexpected failures within this system during braking could potentially lead to accidents. To address this concern, we propose an integrated safe replanning and motion control framework to mitigate collision risks in the event of braking failures. Unlike previous fault-tolerant control works, the steering system is intervened to eliminate failure risks instead of re-configuring the braking torque; therefore, the longitudinal driving risks can be lessened from the lateral perspective. To achieve this approach, firstly, a risk assessment function with a failure factor is constructed to reconsider the driving target. Then, the driving target position and surrounding obstacle information are incorporated into one novel integral heuristic barrier Lyapunov function to reformulate the motion replanning and tracking problems as one yaw angle tracking problem. After, a novel barrier function-based sliding mode controller is introduced to ensure the yaw angle tracking performance within constraints. In this paper, decision-making, motion planning, and tracking tasks are incorporated into one analytical solution framework uniformly.Additionally, the prescribed time stability of our strategy ensures an upper bound setting time, indicating stability before the ego vehicle stop completly. Finally, numerous simulation results are carried out to confirm the effectiveness and superiority of our strategy in circumventing the troubles of braking system failures.