Supervisory Control Strategy for AVs under Unexpected Emergency Conditions

To avoid subsequent collisions after first post-impact under complicated operating circumstance, a supervisory control framework characterized by hierarchical architecture is proposed for the overactuated ground vehicles. Within such a framework, a supervisor is designed to monitor the motion attitudes after first post-impact, which is used for deciding whether drift control mode or yaw control mode is enabled. After that, two controllers are respectively developed according to the judgement results and vehicular movement, where a direct yaw-moment controller and a longitudinal motion controller based upon sliding mode control technique are presented for yaw control mode. Lastly, a control allocation scheme is constructed to distribute the additional yaw moment and resultant longitudinal force into four wheels as the driving/braking torques using the dynamic distribution scheme method. Finally, two post-impact scenarios i.e., lateral post-impact and offset rear-end post-impact scenarios, are performed on the Carsim-Simulink co-simulation platform to validate the effectiveness of the proposed control scheme and approaches.