Longitudinal and lateral coordinated motion control of four-wheel-independent drive electric vehicles

The movement of vehicle on the road can be divided into longitudinal motion and lateral motion. A coordinated longitudinal and lateral motion control system for four-wheel-independent drive electric vehicles (4WID EV) is proposed in order to improve the vehicle handling stability and energy efficiency. Using the information from GPS and INS, the state estimator is established to estimate longitudinal velocity and vehicle sideslip angle. The upper controller is used for tire force distribution based on the optimization of tire workload and energy dissipation. With the use of an inverse tire model, the lower controller is built for tire force control. The simulation and field test results show that the longitudinal and lateral coordinated motion control system can improve the vehicle handling stability and energy efficiency effectively.