Robust design of gain matrix of body slip angle observer for Electric Vehicles and its experimental demonstration

Electric Vehicles (EVs) are inherently suitable for 2-dimension control. To utilize EV´s advantages, body slip angle β and yaw rate γ play an important role. However as sensors to measure β are very expensive, we need to estimate β from only variables to be measurable. In this paper, an improved estimation method for body slip angle β for EVs is proposed. This method is based on a linear observer from side acceleration a_y and γ sensors. We especially considered the design of gain matrix and we achieved succeeded in exact and robust estimation. We performed experiments by UOT MarchII. This experimental vehicle was made for study of advanced control of EV to be driven by four in-wheel motors. Some experimental results are shown to verify the effectiveness of the proposed method.