Supervisors Avoiding Deadlock in Flexible Manufacturing Systems with Co-operating Machines

This paper deals with deadlock problems in Flexible Manufacturing Systems including co-operating machines, i.e. workcenters that co-operate for the same operation. Referring to Discrete Event System models, we synthesize two supervisors inhibiting events that could lead the system to deadlock conditions. To characterize the control actions, we utilize digraphs describing the interaction between jobs and resources. A case study illustrates the efficiency of the proposed strategies.