Discrete-Time Disturbance Observer-Based Fault-Tolerant Trajectory Tracking Control of Fully Actuated Systems: A Dual-Rotor Helicopter Study

This paper proposes a discrete-time disturbance observer-based fault-tolerant control strategy for trajectory tracking of fully actuated systems, specifically for a dual-rotor helicopter system. A novel discrete-time disturbance observer with a nonlinear gain structure is proposed, guaranteeing the asymptotic stability while accurately reconstructing actuator faults. Furthermore, a discrete-time fault-tolerant trajectory tracking controller is designed using a parametric gain synthesis approach for the derived fully actuated system model of the dual-rotor helicopter platform, which leverages full actuation to reject actuator faults. Simulations demonstrate the efficacy of the unified approach in sustaining accurate trajectory tracking despite actuator faults.