Current distribution control of dual directly driven wheel motors for electric vehicles

This paper proposes a current distribution control for dual directly driven wheel motors for electric vehicles. The objective is to maintain two driving wheels at a synchronous speed in order to keep the vehicle straight, or at differential speeds when cornering, even when they incur uneven load disturbance or parameter changes. The proposed control scheme employs a load disturbance observer, a model following controller, and a velocity command compensator to determine the proper amount of current supplied to each driving wheel. The vehicle dynamics and control strategy were modeled and the control performance was simulated numerically. Experiments were performed in a hardware-in-the-loop configuration with a dedicated wheel motor on a dynamometer and a virtual one on a field programmable gate array chip where the current distribution control was implemented. The resulting control performance verified the stability and robustness of the system in terms of its insensitivity to parameter variations and its rejection of external disturbances.