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Title: A graphical environment for the design of discrete event systems
Author: Song, J.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1993
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Programmable logic controllers have been widely used in real time discrete event control systems. Generally speaking, a programmable logic controller based discrete event dynamic system consists of two parts: control software and the controlled system. The design of a programmable logic controller based discrete event dynamic system involves the following phases: modelling, programming, implementation, testing and maintenance. This thesis only focuses on the software design, which corresponds to the first two phases. The current situation in the design of programmable logic controller software can be summarised as follows: a lack of a powerful design environment, in particular a lack of simulation tools; a lack of a powerful, yet simple, graphical modelling language; a lack of formal syntaxes and semantics of the existing graphical modelling languages and a lack of methodology to deal with the multi-language situation in PLC industry. In this thesis a graphical design environment, EXCES (Extended X-based Control Engineering workStation), has been developed for programmable logic controller based discrete event systems. This environment is based on two existing graphical modelling languages, the ladder diagram and Grafcet, and a new modelling language, PLCNet (programmable logic controller net). Based on the three languages three construction tools, three simulation tools, three compilers and the three transformation tools have been designed and implemented. The formal syntax and semantics have also been defined for each of the three graphical languages. These formal syntaxes and semantics allow the correctness of the designed compilers and simulation tools to be verified. Finally, a synthesis tool based on Petri net allows optimal controllers to be synthesised for discrete event dynamic systems.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available