Fundamental study on design method of Yaw-Moment Observer for improvement of drivers´ comfort for electric vehicle

Commercialized electric vehicles (EVs) at the present time are comparatively small and light. Such vehicles are sensitive to lateral wind especially at high speed, which reduces steering stability and comfortability. In this paper, Yaw-Moment Observer (YMO) is applied to improve steering stability and comfortability by reducing the effect of disturbance caused by lateral wind. Moreover, vehicle behavior can be designed freely since YMO can nominalize the vehicle yaw characteristics. Therefore the design method of YMO to improve driver comfort and ease of driving is considered. Effectiveness of the proposed method is verified with simulations and experiments. In addition, a quantitative evaluation method for evaluating steering stability is proposed.