Wheel Slip Ratio Adaptive Control for Distributed Drive Electric Vehicles

This article conducts a research on wheel slip ratio control for distributed drive electric vehicles. In consideration of wheel rotation dynamics and its strong nonlinear properties, a proportional-integral controller is designed in this paper aimed at regulating the wheel slip ratio to a constant value regardless of the road adhesion conditions. At the same time, an online road coefficient estimator is proposed to provide optimal slip ratio for the designed wheel slip ratio controller. The global asymptotic stability of the system is proved by the Lyapunov stability theory. In addition, a distributed drive electric vehicle model is established for performance assessment due to its precise and fast-response torque control. Simulation results show that the proposed controller adaptively regulates the wheel slip ratio to the optimal value of current road with fast convergence speed and high accuracy. Generally, the proposed adaptive controller greatly improves the driving performance of the electric vehicle.