Authors:
Romain Pichard
;
Alexandre Philippot
and
Bernard Riera
Affiliation:
CReSTIC (EA3804), University of Reims Champagne Ardenne Moulin de la Housse, BP 1039, 51687 Reims CEDEX 2 and France
Keyword(s):
Discrete-Event Systems, Safety, Programmable Logic Controllers, Manufacturing Systems, Constraint Programming.
Related
Ontology
Subjects/Areas/Topics:
Control and Supervision Systems
;
Informatics in Control, Automation and Robotics
;
Real-Time Systems Control
;
Robotics and Automation
;
Signal Processing, Sensors, Systems Modeling and Control
;
Virtual Environment, Virtual and Augmented Reality
Abstract:
In this study, manufacturing systems are considered as Discrete Event Systems (DES) with logical Inputs (sensors) and logical Outputs (actuators). In previous work, an original implementation of safe controllers (using safety logical constraints) for manufacturing systems, based on the use of a CSP (constraint satisfaction problem) solver, was proposed. However, the proposed solution was not IEC 61131-3 compliant. In other words, it was not possible to implement it in a PLC (Programmable Logic Controller). In this paper, a proof of concept IEC 61131-3 compliant has been carried out. To perform this challenge, an original simple CSP - SAT solver in ST (Structured Text) has been developed and programmed. The algorithm has been tested and validated by using a M340 Schneider Electric PLC and a box sorting simulated process using the FACTORY I/O software from the Real Games Company (www.realgames.co). It seems to be the first time that a SAT solver developed for PLC, is used in real time
as a part of a PLC program to get a safe controller.
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