Individual Auxiliary and Fault-tolerant Control of Steer-by-wire System Considering Different Drivers Steering Characteristics

This article proposes an individual auxiliary and fault-tolerant control (IAFTC) for the electric vehicles with the steer-by-wire system considering different drivers steering characteristics. It is composed of an individual auxiliary controller, a fault detection and diagnosis controller (FDDC), and an individual fault-tolerant controller. The individual auxiliary controller is used to specifically assist the drivers’ steering behaviors and maintain their steering style when the steering motors are healthy. The FDDC detects and estimates the state and parameter of actuators in real time as well as feedbacks the condition or the extent of partial damage concerning motors to ECU. After the fault-tolerant command is transmitted from ECU, an individual fault-tolerant controller will be turned on to deal with the influence of faulty motor on different drivers. The IAFTC strategy can specifically assist the drivers to track the reference path, reducing the physical and mental workloads of drivers in the no-fault or fault vehicle steering process. The results of simulation using the Matlab and hardware-in-the-loop tests indicate that the controller can provide appropriate assistance control to different drivers in a human–vehicle cooperative method so as to deal with complex actuator's condition.