Disturbance Observer-based Adaptive Fault-Tolerant Control of an Electro-Hydraulic Actuator with Output Constraint

In this article, the problem of tracking control for a double rod electro-hydraulic actuator (DEHA) in presence of both lumped disturbances and faults is investigated to satisfy the prescribed performance. A fault-tolerant controller (FTC) is developed consisting of three parts, a nonlinear disturbance observer (NDO), the combination of barrier Lyapunov function and adaptive command filter controller, and fault detection. The proposed FTC can tackle not only internal leakage fault but also matched/mismatched disturbances. Based on the Lyapunov stability analysis, the tracking errors of the proposed control scheme converge to a small neighborhood of zero. The effectiveness of the proposed method is demonstrated by numerical simulations and comparison with existing works.