Petri net controllers for disjunctive Generalized Mutual Exclusion Constraints
In this paper a type of specifications called OR-GMEC for place/transition nets is defined. Such a specification consists of a set of disjunctive Generalized Mutual Exclusion Constraint, i.e. the requirement is that, at any given time, the controlled system should satisfy at least one of them. We sh...
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Published in | 2013 IEEE 18th Conference on Emerging Technologies & Factory Automation (ETFA) pp. 1 - 8 |
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Main Authors | , , |
Format | Conference Proceeding |
Language | English |
Published |
IEEE
01.09.2013
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Subjects | |
Online Access | Get full text |
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Summary: | In this paper a type of specifications called OR-GMEC for place/transition nets is defined. Such a specification consists of a set of disjunctive Generalized Mutual Exclusion Constraint, i.e. the requirement is that, at any given time, the controlled system should satisfy at least one of them. We show that a bounded OR-GMEC can be enforced by a special control structure composed by a set of monitor places (one for each constraint) plus a switcher that determines the current active constraint. We also show that such a simple control structure is not maximally permissive, and characterize this problem identifying a special subset of transitions that may be over-restricted. A modified controller that ensures maximal permissiveness is also presented. Finally, we discuss a particular control problem, that consists in preventing the firing of a given set of transitions and show that it can be reduced to an OR-GMEC problem. |
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ISSN: | 1946-0740 1946-0759 |
DOI: | 10.1109/ETFA.2013.6648003 |