Fault-tolerant controller design using Petri nets with minimum initial state specifications

This paper develops an algorithm for the optimal design of fault-tolerant Petri net controllers with minimum initial state specifications. Given a system controller that is modeled as a Petri net, a fault-tolerant Petri net controller can be obtained by incorporating additional places, tokens, and connections with the original controller. The main contribution of this paper is to develop an algorithm that is able to design this fault-tolerant controller systematically in an optimal sense. The optimality is in terms of minimizing the number of resources required for fault detection and identification at initialization (i.e., the fault-tolerant controller has the minimum initial state). An example of deriving a fault-tolerant controller with minimum initial state for a communication network is also provided to illustrate our approach.