– Communication protocol conformance testing has become more complex as protocols have grown larger. The study of design for testability (DFT) is a research area to help overcoming the ever increasing complexity of testing distributed systems. In the previous research, we introduced a new metric for testability of communication protocols, demonstrated the usefulness of the metric for identifyin...

Unknown input observer is one of the most important strategies for robust fault diagnosis of linear systems. Inspired by the unknown input Kalman filter, we extend it to nonlinear cases as the EKF does. Using this as a nonlinear observer, we prove its convergence under some mild conditions. As a result, a robust FDI strategy for nonlinear systems is obtained. Simulation studies on a three-tank ...

Robust unknown input observer for state and fault estimation in discrete-time Takagi–Sugeno systems Damiano Rotondo, Marcin Witczak, Vicenç Puig, Fatiha Nejjari & Marcin Pazera To cite this article: Damiano Rotondo, Marcin Witczak, Vicenç Puig, Fatiha Nejjari & Marcin Pazera (2016): Robust unknown input observer for state and fault estimation in discrete-time Takagi–Sugeno systems, Internationa...

This paper is concerned with actuator fault detection in nonlinear systems in the presence of disturbances. A nonlinear unknown input observer is designed and the output estimation error is used as a residual for fault detection. To deal with the problem of high Lipschitz constants, a modified mean-value theorem is used to express the nonlinear error dynamics as a convex combination of known ma...

-The paper considers the problems of state estimation, unknown input and measurement disturbance reconstruction for a class of Lipschitz nonlinear system. By taking the measurement disturbance vector as an extended state vector, the original system is transformed into an augmented descriptor system. For the descriptor system, the necessary and sufficient condition of the existence of the unknow...

An unknown input high gain observer based parametric fault detection and isolation scheme is presented. First, a reduced order unknown input high gain observer is derived. Then, using these observers, a fault detection and isolation technique is devised to detect and isolate the parametric fault of a system whose parameters are uncertain to some extent. The proposed FDI algorithm consists of tw...

In this paper, we consider fault detection, isolation and reconstruction problem for descriptor systems with actuator faults and sensor faults, respectively. When actuator faults exist in the system, the fault detection and isolation (FDI) problem is solved through an unknown input observer regarding remaining faults excluded a specified fault as unknown inputs. Whereas, in existing sensor faul...

SUMMARY This paper proposes a robust state observer for multi-input multi-output LTI systems. Unknown inputs of polynomial form and high-frequency measurement noises are considered in the system model. The unknown inputs and the noises are not in the same form. Multiple integra-tions of both the observer error signal and the measurement output are used for the observer design. The existence con...

In this paper, the problem of synthesis of a multiple observer for a class of uncertain nonlinear system represented by a Takagi-Sugeno multiple model is studied. The measure’s uncertainties are considered as unknown outputs. To conceive the observer a mathematical transformation is considered to conceive an augmented system in which the unknown output appear as an unknown input. Convergence co...