Fixed‐Time Control Method for High‐Speed Trains Based on Extended Sliding Mode Disturbance Observer

ABSTRACT When operating a high‐speed train (HST) under practical conditions, unknown disturbances (such as unmodeled dynamics, external disturbances, and parameter perturbations) may cause vehicle synchronization loss, this paper presents a fixed‐time non‐singular fast terminal sliding mode control (FTNFTSMC) approach based on a fixed‐time extended sliding mode disturbance observer (FTESMDO) (hereafter referred to as the FTNFTSMC‐FTESMDO approach) to enable accurate, rapid, and stable tracking of the target velocity‐displacement curve across all vehicles. First, an HST multi‐agent model is constructed based on vehicular operational dynamics. Next, a fixed‐time integral sliding mode controller (FTISMC) is designed for the virtual leader vehicle; this is achieved by incorporating a dual‐power reaching law and selecting an integral sliding surface. Then, an FTESMDO‐FTNFTSMC approach is designed for the follower vehicles. This approach uses a non‐singular fast terminal sliding surface with an improved variable‐power reaching law to mitigate chattering induced by the conventional exponential reaching law. The FTESMDO accurately estimates unknown disturbances within a fixed time, while the FTNFTSMC compensates for these disturbances via feedback. The stability and convergence of the presented control approach are rigorously analyzed and proven using the Lyapunov stability theory. Finally, numerical simulations using the CRH3‐type train parameters validate the approach. The results demonstrate significant improvements in tracking accuracy compared to the FTNFTSMC and non‐singular terminal sliding mode control (NTSMC) methods. The presented approach achieves precise tracking of the target curve, equidistant operation between adjacent vehicles, and enhanced robustness.