Vehicle Stability and Synchronization Control of Dual-Motor Steer-by-Wire System Considering Time-Varying CAN Network Time Delay

The development of intelligent driving and steer-by-wire (SBW) technologies has increased the computational complexity and the number of CAN bus nodes in SBW vehicles, leading to the presence of significant time-varying CAN network time delay (TV-CAN-TD) in the control inputs of the SBW system. For dual-motor steer-by-wire (DMSBW) vehicles, TV-CAN-TD not only severely affects vehicle stability but also further deteriorates the synchronization performance of two motors, potentially causing accidents. To ensure vehicle safety under TV-CAN-TD conditions, a hierarchical time delay control strategy is proposed. For the upper-level controller, a TD-H₂/H∞ mixed sensitivity stability controller is designed. Based on the operational mechanism of the CAN network, the random time delay uncertainties in the vehicle's lateral dynamics model are modeled in detail using a polytope model. Combined with H₂/H∞ robust control, the controller mitigates the adverse effects of time delay uncertainties on vehicle stability. For the lower-level controller, a synchronization strategy that combines the novel reaching law sliding mode control with a cross-coupling synchronization structure is designed to ensure synchronization performance under TV-CAN-TD conditions. Simulations and hardware-in-the-loop experiments demonstrate that the proposed hierarchical control strategy effectively enhances the stability and synchronization performance of the DMSBW vehicle under TV-CAN-TD.