Title :
Feedback Control Logic for Backward Conflict Free Choice Nets
Author :
Basile, Francesco ; Carbone, Ciro ; Chiacchio, Pasquale
Author_Institution :
Universita di Salerno, Fisciano
fDate :
3/1/2007 12:00:00 AM
Abstract :
This paper discusses the forbidden state problem, as specified by generalized mutual exclusion constraints, in the context of supervisory control of discrete event systems modelled by Petri nets. The case of backward-conflict-free and free-choice uncontrollable subnets is considered and it is shown how to transform such subnets in well-formed free-choice nets. Then, the well-formed free-choice nets are decomposed in marked graph components by recurring to minimal T-invariants. The forbidden state problem is so reformulated for the obtained marked graph components into an equivalent one which is shown to be a linear programming problem. Thus, improving existing results in literature, a polynomial complexity solution, suitable for on-line control, is achieved. Free-choice relationship and cycle modelling, that frequently occur in real-life situations, are so allowed in the uncontrollable subnet
Keywords :
Petri nets; computational complexity; discrete event systems; feedback; linear programming; Petri nets; backward conflict free choice nets; discrete event system; feedback control logic; linear programming; marked graph components; mutual exclusion constraints; polynomial complexity; supervisory control; Automatic control; Context modeling; Control systems; Discrete event systems; Discrete transforms; Feedback control; Linear programming; Logic; Petri nets; Supervisory control; Backward conflict free net; Petri nets; free choice net; state feedback; supervisory control;
Journal_Title :
Automatic Control, IEEE Transactions on
DOI :
10.1109/TAC.2007.893969