Diagnosability Analysis of a Class of Hierarchical State Machines

This paper addresses the problem of Fault Detection and Isolation for a particular class of discrete event dynamical systems called Hierarchical Finite State Machines (HFSMs). A new version of the property of diagnosability for discrete event systems tailored to HFSMs is introduced. This notion, called L1-diagnosability, captures the possibility of detecting an unobservable fault event using only high level observations of the behavior of an HFSM. Algorithms for testing L1-diagnosability are presented. In addition, new methodologies are presented for studying the diagnosability properties of HFSMs that are not L1-diagnosable. These methodologies avoid the complete expansion of an HFSM into its corresponding flat automaton by focusing the expansion on problematic indeterminate cycles only in the associated extended diagnoser. Keywords Discrete Event Systems

• Type: Journal
• Year: 2008
• Where: DEDS
• Authors: Andrea Paoli, Stéphane Lafortune
• Keywords: DEDS 2008, Discrete Event, Finite State Machines, Hierarchical Finite State