Robust fault estimation and compensation for LPV systems under actuator and sensor faults

Abstract

We propose a fault tolerant control scheme that compensates for actuator and sensor faults in linear parameter varying (LPV) systems by adjusting controller and observer gains based on estimates of the fault magnitude. The scheme consists of a plant in closed loop with an observer-based feedback tracking controller, which is adapted to the fault situation diagnosed by a fault detection and isolation (FDI) algorithm. Assuming the presence of unknown but bounded process and measurement disturbances, invariant sets are derived for the relevant system variables, and these sets are used to obtain error bounds in the fault estimate. Using these bounds, we provide conditions that ensure correct FDI and robust stability of the compensated closed-loop system even under errors in the fault magnitude estimation.