Saturation-Tolerant Prescribed Instant Sliding Mode Control for High-Speed Trains With Actuator Saturation and Active Constraints

This article addresses the prescribed instant disturbance-rejection tracking control problem for high-speed trains (HSTs) under simultaneous actuator saturation and active constraints. By introducing an auxiliary dynamic system and a reference convergence differential function, a saturation-tolerant prescribed instant controller (SPIC) is proposed to make the states of the system with actuator saturation converge in a preset time. On this basis, considering the uncertainty of the system, an integrated sliding mode surface and a robust gain adaptive law are designed, and a SPI sliding mode controller (SPISMC) is proposed, which can ensure the stability of the train system and avoid chattering caused by disturbance overestimation. Further, an adaptive actuator enablement control (AAEC) algorithm is proposed to improve the overall operation efficiency of the train by actively constraining actuators under the premise of satisfying the traction/braking force demand for tracking control. The prescribed instant convergence and stability of the train states are strictly proved, and the effectiveness of the proposed methods is demonstrated through numerical simulations using data from CR450 HST.