Yaw stability control of commercial vehicle based on variable stability region

Abstract

Yaw stability is a core issue in commercial vehicle(CV) driving safety, especially in the emergencies and extreme conditions. This study aims to address it with the concept of variable stability region (VSR) in dynamic and unpredictable conditions. The critical boundary of yaw stability is analyzed through the Routh-Hurwitz criterion with the impact of pavement adhesion disturbance. Then, the variable boundaries of absolute stability, critical stability, and instability are constructed, considering the relationship between nominal and observed states interfered with adhesion disturbance. Meanwhile, an intervention mechanism coordinating active steering control (AFS) and direct yaw control (DYC) is implemented within the VSR framework. A hybrid model predictive control with VSR (HMPC-VSR) is proposed to handle various control objectives and constraints with the intervention mechanism. Furthermore, rollover stability and tire slip are also incorporated into the HMPC-VSR for improved control performance. Simulation results show that, the effectiveness of the VSR intervention mechanism is demonstrated in maintaining stability with improved accuracy and timeliness in the presence of adhesion disturbances, and the HMPC-VSR reflects potential in enhancing yaw stability limit for CV in spite of complicated situations with low adhesion and variable loads.