Control of event separation times in discrete event systems

The class of timed discrete event systems which can be modelled by automata known as timed event graphs are structurally related to finite state machines. Consequently, supervisory control problems for these timed DES can be addressed using methods similar to those developed for their untimed counterparts. When the desired behavior takes the form of minimum separation times between events, it also can be expressed as a timed event graph. Supervised behavior is then defined by the synchronous operation of the plant and specification automata. Controllability and the existence of optimal behaviors can be evaluated in this framework