Actuator fault diagnosis of singular delayed LPV systems with inexact measured parameters via PI unknown input observer

A Review of Convex Approaches for Control, Observation and Safety of Linear Parameter Varying and Takagi-Sugeno Systems

“…On the other hand, other works have considered the case in which the scheduling variables are measured inexactly, see for example, Refs. [128,161,162]. Further improvements have been provided by Ref.…”

Design of unknown input fractional order proportional–integral observer for fractional order singular systems with application to actuator fault diagnosis

“…The matrices Υ, S 1 and Σ can be achieved by solving the optimisation problem (36). The observer gain matrices S, T 2 and G can be calculated from (35), (30) and (22), respectively. Finally, the matrices H and L are deduced from (24) and (25).…”

“…On the other hand, the proposed methods in [16][17][18] are not suitable for systems with unknown inputs appearing in the output equation, since the observer gain matrices amplify the measurement output disturbance unavoidably. There are only a few results on simultaneous state and fault estimation in singular systems which are used in fault diagnosis [19][20][21][22][23]. In [19] it is assumed that sth derivative of the fault is bounded and to simultaneously estimate the singular system state and the fault, an unknown input Luenberger observer is augmented with integral actions.…”

Generalized dynamic observers for quasi‐LPV systems with unmeasurable scheduling functions

“…The first solution is to consider the estimation error dynamics and the original system in an uncertain system structure. The uncertainty describes the mismatch between either scheduling variable measurement or estimated scheduling variables with the real values as in other works . Then, the observer design needs to guarantee robust convergence against those uncertainties.…”

“…The uncertainty describes the mismatch between either scheduling variable measurement or estimated scheduling variables with the real values as in other works. 15,28,[30][31][32][33][34] Then, the observer design needs to guarantee robust convergence against those uncertainties. Other solutions are established by Heemels et al, 35 Maalej et al, 36 and Millerioux et al 37 based on the input-to-state stability property, designing LPV observers through bounded estimation error convergence, instead of asymptotic convergence.…”