Modular Feedbacks of Discrete Event Systems with Arbitrary Control Patterns.

The modular feedback design is the following method. When a control specification in a discrete event system is given by conjunction and disjunction of a finite number of predicates, a feedback is designed for each predicate, and the whole feedback is constructed by product and sum of the component feedbacks. By this design method, the state feedback can easily be reconstructed when the control specification is modified. This paper considers the model proposed by Golaszewski and Ramadge, and we derive a condition under which the control invariance of the component predicates implies the control invariance of their conjunction and disjunction. Moreover, we derive a condition tinder which the unique existence of maximally and minimally permissive feedback for each component predicate implies that for the conjunction and disjunction. Finally, the derived result is applied to control of a manufacturing system. [ABSTRACT FROM AUTHOR]