A novel design approach to state and fault estimation for interconnected systems using distributed observer

This paper is devoted to the state and fault estimation design for continuous-time inter-connected systems. By utilizing the associated information among subsystems, a novel un-known input method-based distributed observer synthesis scheme is presented to recon-struct system states and faults simultaneously. It is worth pointing out that our method has much broader applications, since the faults studied in each subsystem do not have to satisfy some constraints made in previous results such as having a known bound or the first derivative being equal to zero. By resorting to the Lyapunov theory and matrix trans-formation technique, some brand-new conditions are proposed to guarantee the stability of local error systems, by which observer gains can be solved in terms of linear matrix inequalities (LMIs). Particularly, all the conditions are expressed in the original system ma-trices rather than augmented matrices framework. Thus, computational complexity is re-duced compared to previous related researches. At last, simulation experiments are shown to verify the validity of our distributed state and fault estimation scheme.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This paper focuses on the design of state and fault estimation for continuous-time inter-connected systems. A novel distributed observer synthesis scheme based on the unknown input method is proposed to simultaneously reconstruct system states and faults by utilizing the associated information among subsystems. The method has broader applications and does not require specific constraints on the faults studied in each subsystem. New conditions based on Lyapunov theory and matrix transformation technique are proposed to ensure the stability of local error systems, and observer gains can be solved using linear matrix inequalities (LMIs). The conditions are expressed in the original system matrices, reducing computational complexity compared to previous research. Simulation experiments are conducted to verify the validity of the proposed distributed state and fault estimation scheme.