Fault-tolerant control of steer-by-wire systems under voltage and current sensors faults

Steer-by-wire (SBW) systems benefit from several advantages including lower weight, volume, and cost compared to counterpart electric power steering systems. However, system reliability is impacted since SBW performance is highly dependent on correct operation of several voltage, current, speed, yaw rate, and position sensors. This paper presents a new method in SBW system reliability improvement by introducing a novel fault detection, isolation, and reconstruction (FDIR) control technique. The proposed FDIR method detects if any fault is observed on voltage or current sensors and identifies the faulty sensor location. Additionally the identified faulty sensor's output is replaced with an estimated value to allow system continuous fault-ride through operation. The SBW system equipped with proposed FDIR technique provides fault-tolerance property against up to 3 faulty voltage or current sensors. Therefore, enhanced overall reliability is obtained at no further hardware costs associated with additional sensors redundancy solutions. The proposed technique is studied using system modelling and hardware prototyping, and its effectiveness is demonstrated using simulation and experimental results.