Analysis of torque sensorless steer by wire system using the bilateral tele-operation concept

Abstract

The mechanical linkage of the steering column can ideally be replaced by a bilateral controller-based steer by wire system. This paper presents an intuitive method of designing a bilaterally controlled steer by wire system based on disturbance observers and reaction torque observers. The presented system can overcome the force sensing demerits of traditional force sensors as well as the demerits of existing steer by wire systems based on bilateral control systems. Feedback torque from the steering rack to the steering wheel conveys important data about the road conditions as well as the vehicle conditions to the driver. Hence, accurate feedback to the driver is vital for smooth vehicle handling. The presented method has the capability of tuning the system as per the desire. The validity of the proposed method has been verified through simulations using real-world vehicle and controller data.