Fault-Tolerant Control of Multi-Clamp Disc Elevator Brakes with Fixed-Time Convergence

This paper proposes a passive fault-tolerant control strategy for a multi-caliper disc elevator brake system subject to unknown external disturbances and multiple actuator faults. Initially, a detailed analysis of the dynamic equations of the actuator in a multi-caliper disc elevator brake system with actuator faults is conducted. Subsequently, a nonsingular terminal sliding mode fault-tolerant control scheme with rapid fixed-time convergence is proposed, where the settling time is independent of the system’s initial state and can be preset through design parameters. The upper bound of the convergence time is derived using Lyapunov theory, ensuring that the faulty elevator brake control system converges within a predetermined fixed time. Ultimately, theoretical analysis and numerical simulation results confirm that the proposed controller can effectively handle the effects of actuator faults, parametric uncertainties, and external disturbances, ensuring satisfactory tracking accuracy.