Chassis coordinated control based on ideal roll angle to improve vehicle stability

The current active control system for vehicles mainly focuses on following the reference trajectory constituted by the ideal yaw rate and sideslip angle, without considering the influence of the body roll angle on the vehicle stability performance. To improve the vehicle stability, in this study, a method of determining the three-dimensional stability region of ‘lateral speed–yaw rate–roll angle’ was proposed, the variation of the stability region with respect to the front steering angle was studied, and the limit steering angle boundary and vehicle ideal roll angle were obtained. Subsequently, a hierarchical coordinated control framework was proposed for actively controlling the front steering angle, suspension force, and motor torque of a four-wheel independent-drive electric vehicle with active front steering and active suspension systems. Finally, considering the effects of different motor torque distribution algorithms on the control performance, the performance of several control strategies was compared for high and low adhesion roads. The results indicated that the control strategy considering the body roll angle under different working conditions can improve the vehicle stability. On this basis, the torque distribution strategy based on minimum tire utilisation has the best following and stability performances among the strategies examined in this study.