Faults isolation for nonlinear Hessenberg systems

This paper deals with nonlinear upper and lower Hessenberg systems and the structure of this kind of systems is used to study the detectability and isolability of simultaneous faults. In particular structural analysis tools are used to evaluate the estimation redundancy degree of the Hessenberg form with two faults. From this characteristic, isolability conditions are deduced and specific parity equations are proposed. The key of the isolation issue is the determination of monitorable subsets of the bipartite graph which can be jointed, despite the faults. An illustrative example of a transport phenomena process shows how this result can be used in practice and the simplicity of the structural analysis to get generic properties for the isolability of faults in a dynamic system.