Generating Diagnostic Residuals for Steer-by-Wire Vehicles

Steer-by-wire remains unavailable on production vehicles today, despite the numerous benefits it will provide, due to the expense of high-reliability designs. Model-based fault detection techniques can eliminate the need for redundant sensors in steer-by-wire vehicles, lowering costs without compromising reliability. This paper presents the modeling and fault detection filter design techniques used to construct a set of diagnostic residuals suitable for detecting and isolating a wide variety of steering system faults, based only on measurements from sensors already present in a steer-by-wire system. These diagnostic residuals are sensitive enough to detect faults at a magnitude well below where they would impact the driver's ability to control the vehicle. Experimental results from a full-scale research steer-by-wire vehicle demonstrate this sensitivity