Feedback control of manufacturing systems using controlled marked graphs with time constraints

In this paper manufacturing systems are modeled by a cyclic place-timed controlled marked graph (PTCMG), which is a special class of timed controlled Petri nets. The control problem of manufacturing systems which can be formulated as a forbidden state problem of a discrete event system is considered. A maximally permissive state feedback control is synthesized in a PTCMG to guarantee a more enlarged admissible marking set for most of forbidden state problems than a cyclic controlled marked graph. A practical application is illustrated for an automated guided vehicle (AGV) coordination problem in a flexible manufacturing facility