Fault-Tolerant System Design in Multiple Operating Modes using a Structural Model
Résumé
This paper deals with the design of fault-tolerant control system thanks to the use of a structural model. The objective of the developed method is to determine the instrumentation scheme (sensors and actuators) of the controlled system which guaranties to tolerate a given number of failures with the lowest cost. A structural model is used for that purpose. It describes the links between the physical quantities and it is employed in order to determine the various potential ways to estimate a given quantity or to control another one. Using these structural characteristics, a set of required instruments may be deduced. The design problem is formalized as an optimisation problem (Conrad and Bayart, 2003) that consists in searching for a subset of instruments that provides the best reliable system withthe lowest cost. The novelty of that paper lies in taking into account different operating modes or discrete states of the process to be controlled, by introducing qualitative variables in the structural description.