The invention discloses a
discrete event system mode fault online diagnosis method based on a Petri network diagnostor. The method comprises the following steps: firstly, constructing a
fault recognition automaton for each mode fault string according to a given mode fault set to identify a mode fault; secondly, a marking state
automaton is constructed according to the
discrete event system and allthe
fault recognition automatons to mark the faulted state in the
discrete event system; converting the mark state
automaton into a
Petri net, finally constructing a
Petri net diagnostor according tothe
Petri net obtained by conversion, and carrying out mode fault online diagnosis on the discrete event
system by utilizing the diagnostor. The problem that an existing method is not suitable for online diagnosis of complex mode faults is solved, and the method can be used for online diagnosis of S-type mode faults and T-type mode faults and can also be used for online diagnosis of traditional
single fault events. The complexity is in
linear relation with the state number and the event number of an original
system, the complexity of fault diagnosis can be reduced, and the fault diagnosis efficiency is improved.