Roll stability control of in-wheel motors drive electric vehicle on potholed roads

The dynamics performance of in-wheel motors drive electric vehicles can be greatly improved by adjusting the torque and speed of the in-wheel motors, but the increased unsprung mass will bring greater dynamic load impacts on the body when the vehicle runs on potholed roads, which may make the vehicle roll when turning. To improve the roll stability, a collaborative control based on four-wheel differential drive and suspensions active adjustment is proposed. At first, a vehicle-road coupled dynamics model on a potholed road is developed. Next, the spatial stability evolution mechanism of the vehicle and the coupling effects of four-wheel differential drive and active suspensions control on the vehicle are analyzed. Then, a roll stability collaborative controller is constructed, which consists of a four-wheel differential sliding mode variable structure controller and an active suspension adaptive robust sliding mode controller. Finally, the control effects are verified by dynamics simulation and real vehicle test. The results show that the proposed collaborative control method can effectively control the vehicle roll and yaw motion, and improve the spatial stability of the vehicle. The research has potential theoretical and engineering value for improving the active safety of in-wheel motors drive electric vehicles on potholed roads.