The Study on Control Method of Steer-By-Wire with Torque Estimation and Speed Compensation

Steer-by-wire system (SBW), which is a new steering system, is expected to be adapt automated driving vehicles. However, SBW has problems with increasing cost and redundancy and these hinder its popularization. Recently, a lot of research about SBW has proposed a system using disturbance torque observer to obtain steering torque or reaction torque with low costs. A resolution of a position sensor directly affects the disturbance estimation accuracy at this time, so a high resolution position sensor is required for the system. But it is inappropriate for SBW to adopt it because of increasing costs. In this paper, therefore, we aim to improve the estimation accuracy of disturbance torque observer with keeping low cost. For that purpose, we propose new method which can improve the position information accuracy by using instantaneous speed observer, and we compare the result between new method and conventional one.