<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Estimating the state of a hybrid system means accounting for the mode of operation or failure and the current state of the continuously valued entities concurrently. Existing hybrid estimation schemes try to overcome the problem of an exponentially growing number of possible mode-sequence/continuous-state combinations by merging hypotheses and/or deducing likelihood measures to identify tractable sets of the most likely hypotheses. However, they still suffer from unnecessarily high computational costs as the number of possible modes increases. Hybrid diagnosis schemes, on the other hand, estimate the current mode of operation/failure only, thus leaving the continuous evolution of the system implicit. This paper proposes a novel scheme that uses a combination of both the approaches in order to define posterior transition probabilities between the specified modes of the hybrid system, hence focusing better on relevant hypotheses. In order to demonstrate the effectiveness of the proposed method, the algorithm is applied to a satellite attitude control system and compared with existing hybrid estimation/diagnosis schemes, such as the Interacting Multiple Model (IMM) algorithm, a purely parity based method (HyDiag), and an existing hybrid Mode Estimation (hME) algorithm.</p></abstract>

Estimating the state of a hybrid system means accounting for the mode of operation or failure and the current state of the continuously valued entities concurrently. Existing hybrid estimation schemes try to overcome the problem of an exponentially growing number of possible mode-sequence/continuous-state combinations by merging hypotheses and/or deducing likelihood measures to identify tractable sets of the most likely hypotheses. However, they still suffer from unnecessarily high computational costs as the number of possible modes increases. Hybrid diagnosis schemes, on the other hand, estimate the current mode of operation/failure only, thus leaving the continuous evolution of the system implicit. This paper proposes a novel scheme that uses a combination of both the approaches in order to define posterior transition probabilities between the specified modes of the hybrid system, hence focusing better on relevant hypotheses. In order to demonstrate the effectiveness of the proposed method, the algorithm is applied to a satellite attitude control system and compared with existing hybrid estimation/diagnosis schemes, such as the Interacting Multiple Model (IMM) algorithm, a purely parity based method (HyDiag), and an existing hybrid Mode Estimation (hME) algorithm.

Mode set focused hybrid estimation

Institute of Electrical and Biomedical Engineering UMIT, Eduard-Wallnöfer-Zentrum 1, 6060 Hall in Tyrol, Austria

Doctoral School of Information and Communications Engineering (ICE) Graz University of Technology, Rechbauerstrasse 12, 8010 Graz, Austria

Institute of Automation and Control Engineering UMIT, Eduard-Wallnöfer-Zentrum 1, 6060 Hall in Tyrol, Austria

LAAS, CNRS University of Toulouse, 7 Avenue du Colonel Roche, F-31400 Toulouse, France

International Journal of Applied Mathematics and Computer Science

{"article-title":"Mode set focused hybrid estimation"}

Estimating the state of a hybrid system means accounting for the mode of operation or failure and the current state of the continuously valued entities...

Mode set focused hybrid estimation

Pubblicato online: 26 mar 2013

Pagine: 131 - 144

DOI: https://doi.org/10.2478/amcs-2013-0011

This content is open access.