Finite Memory Observer for Switching Systems: Application to Diagnosis
Authors: | Hocine Abdelfettah, Institut national Polytechnique de Lorraine, France Maquin Didier, Institut national Polytechnique de Lorraine, France Ragot José, Institut national Polytechnique de Lorraine, France |
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Topic: | 6.4 Safeprocess |
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Session: | Safety and Structure Analysis for Fault Diagnosis/ Diagnosis of Hybrid and Discrete-Event Systems |
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Keywords: | Diagnosis, switching system, multiple model, finite memory observer, unknown input, state estimation. |
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Abstract
In this paper, we develop a fault detection method for switching dynamic systems with unknown inputs. The proposed method is based on the use of Finite Memory Observers and mode probabilities with the aim to finding the operating mode of the system and estimating the unknown input. The resulting method also uses the knowledge of a priori information on the mode transition probabilities represented by a Markov chain. The proposed algorithm belongs to the class of the supervised algorithms where the fault to be detected are a priori indexed and modelled. First, the method is used for fault detection in the case of a linear system characterized by a normal model of operation and several fault models. Then, it applies for fault detection in the case of a linear system with unknown input where state and unknown input estimation are done simultaneously.