자율주행 조향권 이양을 위한 R-MDPS 제어 설계

Abstract

In this paper, we present a hybrid impedance control for smoothly and easily taking over the steering wheel from the autonomous driving system as well as to for the steering angle tracking control in the rack-mounted MDPS (R-MDPS). The proposed method consists of an impedance control for taking over and a sliding mode control for steering angle tracking. With the driver’s torque, the proposed method is activated as the impedance controller. The desired impedance transfer function from the driver’s torque to the steering angle is designed to reflect the driver’s torque to the steering control. Then, the desired impedance steering angle is derived for the desired impedance. If the unintended driver’s torque is small, the effect of the driver’s torque to the steering angle is also small by the designed impedance. If the intended driver’s torque for steering control is relatively large, the driver’s torque can be reflected to the steering control by the designed impedance. Without the driver’s torque, the proposed method is activated as the steering angle tracking controller for the autonomous driving. The sliding mode control method is designed based on the super twisting algorithm for the steering angle tracking control.