Control of steering-by-wire system of electric vehicle using bilateral control designed by passivity approach

Steer-by-wire (SBW) system, in which the conventional mechanical linkages between the steering wheel and the front wheel are removed, is suited to active steering control, improving vehicle stability, dynamics and maneuverability. With conventional controller for SBW system, it is difficult for driver to feel reaction torque exactly from steering system. In this paper, a new SBW system using bilateral control designed by passivity approach is proposed. At first, conventional bilateral control scheme using disturbance observer is outlined. Secondly, a novel bilateral control with passivity is introduced. We also examine performance of the proposed control scheme and compare with conventional bilateral control scheme. The effectiveness of the proposed method is demonstrated by experiments with an electric vehicle.