Direct yaw-moment control of electric vehicle based on cornering stiffness estimation

In this paper, novel direct yaw-moment control (DYC) with road condition estimation and anti-slip control is proposed for electric vehicles. An inner-loop observer controls the vehicle traction, and an outer-loop controller stabilizes the yawing motion. An immeasurable parameter known as cornering stiffness is estimated from the detected yaw-rate, steering angle, wheel speed and yaw-moment observer output in real time. Thus, the accurate control input can be generated with the estimated parameters. The proposed adaptive control is compared with a conventional robust control on dry and snowy terrain conditions. The experimental results show that the yaw-rate error is properly attenuated by the proposed control algorithm.