Synthesis of Safe Sublanguages satisfying Global Specification using Coordination Scheme for Discrete-Event Systems

Modular control of discrete-event systems with a global specification and with only local supervisors is a difficult problem. For global specifications, however, the equivalent conditions may not be met. This paper formulates and solves a control synthesis problem for a generator with a global specification and with a combination of a coordinator and local controllers. Conditional controllability is proven to be an equivalent condition for the existence of such a coordinated controller. A procedure to compute a coordinated controller is provided.