Fault detection and isolation using sliding mode observer for steer-by-wire

Abstract

Recent advances toward Steer-by-Wire (SbW) technology have promised significant improvements in vehicle, safety, stability, dynamics and maneuverability. The conventional mechanical linkages between the steering wheel and the front wheel are removed in this system. While the complete separation of the steering wheel from the road wheels provides exciting opportunities for vehicle dynamics control, it also presents practical Problems for steering control about fault tolerant function such as the detection of sensor fault and multiplicative fault simultaneously. Thus Fault Detection and Isolation (FDI) plays important rule in this system. This thesis presents the method of fault detection and isolation for a Steer-by-Wire NAV) vehicle with sensor and multiplicative faults simultaneously. In Steer-by-Wire (SbW) vechicle, the Fault Detection and Isolation (FDI) problem for the sensor fault where (locoing and isolating are independent of the influence of multiplicative fault is considered. Secondly a Sliding Mode Observer (SMO) is designed which adds a general full-order observer for the Steer-by-Wire (SbW) model to feed-forward injection map and feed-forward compensation signal, and with sliding mode observer the sensor and multiplicative fault are detected and isolated. Finally, the effectiveness of the proposed method was verified by simulation results.