An improved hybrid approach for the PLC-based implementation of reduced RW supervisors

Authors : Murat UZAM, Gökhan GELEN

Pages : 394-419

Doi:10.3906/elk-1110-29

View : 10 | Download : 12

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :A successful application of a hybrid insert ignore into journalissuearticles values(mixed Petri net/automaton); approach for the real-time supervisory control of an experimental manufacturing system was reported recently. The hybrid approach includes a Ramadge--Wonham insert ignore into journalissuearticles values(RW); supervisor in the form of an automaton. The reduced RW supervisor offers fewer states for the programmable logic controller insert ignore into journalissuearticles values(PLC); implementation of the hybrid controller with less memory requirements, but due to a problem called the avalanche effect, the PLC implementation of the hybrid controller with the reduced RW supervisor was not possible. This paper proposes a method to both detect and eliminate the avalanche effect problem for a RW supervisor in the form of an automaton, which enables the PLC implementation of the hybrid controller with the reduced RW supervisor. In addition, this paper improves the recently proposed hybrid approach by including the reduced RW supervisor and the avalanche effect detection and elimination method. The applicability of the improved hybrid approach is demonstrated by the PLC-based real-time control of an experimental manufacturing system.
Keywords : Automata, Petri nets, supervisory control theory, hybrid supervisor, PLC, real time implementation, ladder logic diagram