Motion control and road condition estimation of electric vehicles with two in-wheel motors

In this paper, novel direct yaw moment control and anti-skid control are proposed for electrical vehicles with two in-wheel motors. The proposed controllers are composed of double disturbance observers. The inner-loop observer controls the vehicle traction, and outer-loop observer stabilizes the yawing motion. The advantages of these approaches are: 1) the stability robustness for road condition is guaranteed and 2) the proposed controllers require no immeasurable parameters. The experiments demonstrate the performance of these controllers under snowy conditions, and the stability is theoretically analyzed as inertia variation and dead-time system. Finally, the cornering stiffness is identified by the proposed yaw-moment observer.