State Estimation for 4WD In-Wheel Motor Electric Vehicle

This article proposed a Double Extended Kalman Filters (Double EKFs) observer to estimate states of 4WD in-wheel motor electric vehicle. One EKF observer was used to estimate vehicle longitudinal velocity. The other EKF observer was employed to estimate vehicle sideslip angle. The structure has two benefits: Firstly, two EKFs reduce the order of the wholly state observer, so that calculation load could be lower. Secondly, the two EKFs could be adjusted easier and more independently. The paper investigates the feasibility of this observer in two vehicle test conditions. The test results indicate the effectiveness of the Double EKFs State estimation.