Vehicle Level Fault Injection and Fault-Tolerant Control of Dual-Motor Steer-by-Wire Systems

Abstract

This paper addresses the demand for enhancing the functional safety of the Dual-motor Steer-by-Wire System, and proposes a comprehensive solution that combines coordinated control and fault isolation. Firstly, a dynamic mathematical model is developed for the system. Building upon this foundation, an Improved Adaptive Nonlinear Active Disturbance Rejection Control-Sliding Mode Synchronization Control (IANL-ADRC-SMC-SC) strategy utilizing a cross-coupling structure is formulated, which successfully addressed the issue of elevated energy consumption resulting from discrepancies in the torque output between the two motors. Concurrently, an Improved Non-singular Fixed-Time Sliding Mode Control (INFTSMC) fault isolation mechanism was established, allowing for swift torque disengagement of the malfunctioning motor and smooth torque transition to the functioning motor. Simulation tests under typical conditions such as angular step and double lane change demonstrated that the IANL-ADRC-SMC-SC control strategy reduced the current tracking error by 68% and the peak transient error by 31-32%; the INFTSMC fault isolation mechanism reduced the fault current impact by 50% and shortened the stabilization time by 23.1%. Hardware-in-the-loop experiments further verified the engineering practicability of the control strategy, and the measured data showed that the current fluctuation range under IANL-ADRC-SMC-SC control was stable within ±0.2 A, the INFTSMC mechanism completely eliminated the current sudden change phenomenon, and strictly controlled the reverse electromotive force effect within the safe range. The findings offer a practical technical solution for enhancing the reliability and safety of the steer-by-wire system.