Hardware-in-the-Loop Simulation of Synchronous Motion Control for Dual-Motor Driving Steer-by-Wire System Integrated With Optimal Finite Preview Path-Tracking Control

Recently, to produce a large steering torque or ensure fault-tolerant control (FTC), dual motorized actuators for a steering system in automobiles have been emerged. In particular, the commercial vehicle requires an electrical-powered multiple motor based steering system generating large steering torque, which can replace the existing hydraulic steering one. However, the control of such system become more complicate than controlling of a single actuator and must deal with the unavoidable non-synchronous nature of multiple motors. In line with the trends and issues, many automobile manufacturers are currently paying attention to the robust and efficient motion controls of a dual-motor driving steer-by-wire (DSBW). Therefore, we proposed a novel synchronous motion control system of DSBW using passive decomposition and sliding mode control (SMC) techniques guaranteeing the passivity and robustness of the overall synchronized motion. Furthermore, the performance of proposed control system is validated through HILS of an actual DSBW using a developed vehicle model and an optimal finite preview control (OFPC) scheme tracking a specific test scenario, Double Lane Change (DLC). It is found that the motor-to-motor synchronization error and tracking one for the target reference trajectory are less than 1 degree, which sufficiently meets the requirement of automobiles manufacture company and is comparable to other existing approaches. We also investigated the tracking performance of the control system based on the different steering characteristics of OFPCs generated by the several preview times. Moreover, we investigated the tolerance level of proposed technique (without any additional FTC) against a partial fault condition in one of the motors and compared it with other control schemes in terms of tracking performance. This work will be valuable asset for those who wish to design the robust synchronous motion control of DSBW and construct the corresponding HILS of system considering different steering characteristics.