Coordinated control of DBS and RWS based on the hybrid of data-driven model-free control and fuzzy allocation

The vehicle stability is the core of the control of the intelligent chassis. Previous studies achieved vehicle stability using multi-actuators. However, they hardly considered the execution allocation of multi-actuators, leading to a balance difficulty between the handling stability and ride comfort. This paper presents a coordinated control strategy for the differential braking system (DBS) and rear wheel steering (RWS) to enhance yaw control through their optimal control and execution. The proposed strategy has a hierarchical structure with three layers. The upper layer calculates the additional yaw moment using a data-driven model-free control. The medium layer coordinates the DBS and RWS, dynamically allocating execution proportion based on fuzzy logic. The lower layer converts the allocated yaw moment into distributed braking torques and RWS angles. Vehicle tests during the slalom, steady-state circular, and double-lane change were conducted. The results demonstrated that the proposed coordinated strategy can simultaneously achieve the optimal control and execution of the DBS and RWS, generating a 32.7% improvement in yaw rate tracking accuracy and a 20.6% reduction in steering wheel angle requirements compared to existing control strategies in industry.