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.

Iterative learning scheme‐based fault estimation design for nonlinear systems with varying trial lengths and specified constraints

“…However, fault diagnosis is insufficient to provide the precise magnitude and shape of the faults. Fault estimation (FE) is supplementary to give the exact information of faults, thereby helping to reconstruct fault signals . From above all, FE is further needed for the purpose of active fault‐tolerant control to maintain the normal performance of systems.…”

Verification of the control system performance using viability theory

“…They are shown in Figures 4 and 5. Invariance kernel is around the steady state of the system and can be used as a tool for detecting faults in steady state [20]. Also, it can be used as initial set for capture basin construction.…”

“…After Euler discretisation with sampling period τ = 1 s, the whole system is formulated in its quasi-LPV form through parameter non-linear embbeding approach [20] x (t + 1) = A (ρ (t)) x (t) + Bu (t) + Ew (t)…”

Parameter‐dependent Lyapunov function‐based robust iterative learning control for discrete systems with actuator faults

“…Fault tolerant control (FTC) schemes are designed to guarantee overall systems stability and acceptable performance in the presence of faults. This general problem is an active area of control systems research with recent work including [16,17,18,19,20,21].…”