Proposal of Lateral Force Disturbance Estimation Method for In-Wheel-Motored Electric Vehicles

Abstract

The longitudinal tire forces can be estimated with in-wheel-motored electric vehicles (IWM-EVs). By exploiting this advantage, the authors have realized human friendly EV based on force control but only the longitudinal motion was considered. The aim of this paper is to achieve the next step: to propose a lateral external force estimation method. External force vectors can be estimated if each of tire forces can be detected. Longitudinal tire forces can be easily obtained with a disturbance observer (DOB). One easiest way to get lateral tire force is using lateral force sensors (LFS). In addition, steering DOB-based method is also discussed here. The Extended Kalman Filter (EKF) is used to calculate a external force vector from each tire forces. A precise external force vector estimation is achieved in the simulations and the experiments. The results of this paper can be applied not only to disturbance compensation but also to hand operated parking control.