Steering control of a steer-by-wire system vehicle with time delay and actuator saturation via anti-windup controller

Abstract

This paper presents a design of an anti-windup controller that aims to improve vehicle handling and stability of a Steer-by-Wire (SbW) system with consideration of time delays and actuator saturation. Due to the physical constraints of road wheel steering actuators, control saturation is considered in controller design. A controller that is designed without a saturation condition, and is only to operate in a linear region might have significantly deteriorated performance in the presence of actuator saturation. In this study, an anti-windup controller employing a back-calculation method was used to handle the effect of actuator saturation in the system. The designed controller was used on a SbW system with a linearized vehicle model to verify the effectiveness of the proposed strategy. The vehicle-body sideslip angle and the yaw rate at the centre of gravity of the vehicle while turning can be used to indicate vehicle stability. The simulation results demonstrated that the designed controller promotes better handling during steering and preserves vehicle stability regardless of the changes in the time delays in the system.