This paper presents a sliding mode observer (SMO) for robustly reconstructing faults affecting a class of nonlinear non-infinitely observable descriptor systems. Preliminary transformations are utilised to re-express the system such that the design freedom in its structure is easier to exploit. An infinitely observable system is formed by treating some states as unknown inputs. The faults are then reconstructed from measurable inputs and outputs using a SMO. The structure of the SMO bounds the nonlinear components of its estimation errors. The effect of disturbances on the fault reconstruction is minimised using linear matrix inequality techniques. A summarised design procedure for the SMO scheme is presented. Finally, a simulated example is carried out to showcase the efficacy of the scheme.

A sliding mode observer for robust fault reconstruction in a class of nonlinear non-infinitely observable descriptor systems

This paper studies a new approach for synthesizing an observer to estimate both unmeasurable states and faults of the T-S fuzzy system with uncertainties, simultaneously, where the bounded constraints of the uncertainties are unnecessary. Both continuous and discrete time systems are taken into account. To deal with the uncertainties and faults, first, the uncertain T-S fuzzy system is transformed into the unknown-input one; then, it is reconstructed by adding one more state equation to the system. An observer is synthesized to eliminate completely the effects of the uncertainties and estimate the unknown states and faults, simultaneously. The fuzzy Lyapunov function is employed to relax the observer design conditions. On the basis of the Lyapunov theory and the linear matrix inequality technique, the conditions for observer design are derived in the main theorems. Finally, an illustrative example is introduced for both continuous and discrete time systems to prove the effectiveness of the proposed method.

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Fault/State Estimation Observer Synthesis for Uncertain T-S Fuzzy Systems

This article addresses the problem that quadrotor unmanned aerial vehicle (UAV) actuator faults, including small-amplitude bias faults and gain degradation, cannot be detected in time. A hybrid obs...

https://journals.sagepub.com/doi/pdf/10.1177/17298814211002734

Robust fault diagnosis and fault-tolerant control for nonlinear quadrotor unmanned aerial vehicle system with unknown actuator faults:

http://manuscript.elsevier.com/S1874548222000099/pdf/S1874548222000099.pdf

Load-altering attack detection on smart grid using functional observers

Summary This article presents a generalized learning observer (GLO) design for the simultaneous estimation of states and actuator faults for polytopic quasi‐linear parameter varying systems. The pr...

Actuator fault estimation based on generalized learning observer for quasi-linear parameter varying systems

In this paper a new finite-time convergent functional dynamical observer design for descriptor systems is presented. The conditions for its existence and stability are given. This observer is then applied to the sensor and actuator faults detection and estimation. This estimation is used in the observer-based fault tolerant control design. All the obtained results are illustrated by numerical examples.

Finite time functional observers for descriptor systems. Application to fault tolerant control

An observer-based method for actuator fault estimation for descriptor systems is presented. An innovative generalised dynamic observer for descriptor systems is synthesised to perform a convergent ...

Fault estimation for descriptor linear systems based on the generalised dynamic observer

In this paper a finite-time convergence fault estimator based on functional observers is presented. The stability conditions of the observer are given and their performance evaluation is made through numerical simulations.

Carlos M. Astorga-Zaragoza

Papers

Finite time functional observers for descriptor systems. Application to fault tolerant control

Fault estimation for descriptor linear systems based on the generalised dynamic observer

Design of Finite-Time Convergent Functional Observers