Robust Distributed Fault Estimation in Disturbed Uncertain Interconnected Systems With Time-Varying Delays

Abstract

This paper proposes a new distributed fault estimation method based on the $L_1$ performance, along with its circuit implementation. In order to achieve this objective, the paper begins by offering a thorough model of interconnected systems with time-varying delays, which incorporates multiple faults, input/output disturbances, and uncertainties. Next, a set of $L_1$ distributed estimators is designed to simultaneously estimate the states of the system as well as different types of faults including actuator and sensor faults within all subsystems. This observer is robust against disturbances, uncertainties, and time-varying communication delays. To this end, sufficient conditions are formulated as linear matrix inequalities to ensure that the dynamics related to estimation errors remain robustly stable and also attenuate disturbances. The estimation accuracy and robustness of the proposed approach are studied by an illustrative example. Furthermore, its effectiveness and superior performance are confirmed by comparison with the related methods in the literature. Additionally, the circuit implementations of the system and the suggested estimator are presented for practical applications.