This note presents a control synthesis approach for discrete event systems modeled by marked graphs with uncontrollable transitions. The forbidden behavior is specified by General Mutual Exclusion Constraints (GMEC). We prove that, even if the system to be controlled is live, the closed loop control may generate deadlock situations. Using the structural proprieties of marked graph we defined the causes of deadlock situations, and we defined a formal method to avoid them.

Abstract. This note presents a control synthesis approach for discrete event systems modeled by marked graphs with uncontrollable transitions. The forbidden behavior is specified by General Mutual Exclusion Constraints (GMEC). We prove that, even if the system to be controlled is live, the closed loop control may generate deadlock situations. Using the structural proprieties of marked graph we defined the causes of deadlock situations, and we defined a formal method to avoid them.

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