A road surface identification method for a four in-wheel-motor drive electric vehicle

A four in-wheel-motors drive electric vehicle need to identify the road surface in order to optimise the slip-ratio control. This paper builds a four in-wheel-motor drive electric vehicle dynamic model and estimates the vehicle speed and driving forces of four wheels by the method of adaptive filtering. According to the calculated tyre adhesion coefficient and slip ratio, the paper employs the method of combining fuzzy inference with Slope determination to evaluate the road type and determine the target slip ratio, and obtains a better slip ratio regulation effect through timely and precise adjustment of output torque of the in-wheel motors. The simulation and experiment results confirm that it is a reliable design.