In: Proc. IEEE Int. Conf. on Systems, Man, and Cybernetics (SMC'99), 12-15 October 1999, Tokyo, Japan, Vol. 1, pages 854-859. 1999.
Abstract: A hybrid Petri net based hierarchical control and modeling framework for real-time process procedural control is introduced in this paper. The new modeling tool, called a hybrid predicate Petri nets, is an extension of hybrid Petri net and predicate/transition net, in which the firing speeds of its continuous transitions are changeable and controlled by upper level and continuous mathematical model. Predicates are introduced to discrete transitions to represent the various constraints possibly existing in process systems. Definition of net structure and running rules of the hybrid predicate Petri net are given. On the basis of supervisory model, the issues of safety verification, optimization of control parameters and scheduling of operating sequences are discussed. A distillation column is used as an example for modeling and analysis.
Keywords: hybrid Petri nets, operating procedures, predicate/transition nets, process systems, safety verification.