3. Fault Mode Probability Factor-Based Fault-Tolerant Control for Dissimilar Redundant Actuation System

This chapter introduces an approach for fault-tolerant control (FTC) in a dissimilar redundant actuation system (DRAS) comprising hydraulic (HA) and electro-hydrostatic (EHA) actuators. DRAS, prone to multiple gradual faults due to prolonged service and harsh conditions, can degrade system performance, inducing parameter uncertainty and eventual drift into a fault state. To mitigate this, historical gradual fault statistics and a fault mode probability factor (FMPF) are used to amend the uncertain system model. The FTC strategy based on FMPF is implemented for the amended model, with updates to system estimation and linear quadratic regulator (LQR) at the sampling period’s conclusion. Simulations of DRAS under various faults validate the efficacy of this approach.