Design and development of a hybrid control system for flexible manufacturing : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Manufacturing and Industrial Technology at Massey University

Irregular Pagination MisnumberedFlexible Manufacturing Systems (FMS) appeared upon the manufacturing scene in the early 1970s, installations presently number in the thousands. However, many current installations in fact lack flexibility, do not operate in real-time and are prohibitively expensive. Therefore there are obvious benefits to be gained from making improvements to existing flexible manufacturing systems. Research conducted for this thesis focused on two major areas. The implementation of the FMS control system on a SCADA package and the development of an auction based scheduling system. This entailed the development of a hybrid control model composed of three distinct layers; factory, cell and intelligent entity. Key portions of both the factory and cell controllers were then implemented so as to create a minimal system. This has been completed to the point where the auction algorithm has been implemented and tested in an appropriate framework. In achieving the goals mentioned above a number of novel design concepts have been utilised. There are two which are most important, these are the use of low cost modules for the construction of a flexible co-operative manufacturing system, and the ability of this system to operate in a physically distributed area via a Local Area Network. Meaning it is inherently adaptable and resistant to failure. These novel design concepts were ingrained throughout the entire three layered control model. It is felt that this research has succeeded in demonstrating the possibility of implementing a FMS control system on a low cost SCADA package using low cost software and computing elements. The ability of the distributed, auction-based approach to operate successfully within this system, has also been demonstrated through simulation

A study into continuous improvement initiative sustainability

The idea of continuous improvement is familiar to most managers and there are many examples of how its use can increase a company’s overall performance. However, while numerous companies have adopted the approach, very few have seen the long term sustainability of such programmes. This paper reports on research that was carried out into the sustainability of continuous improvement initiatives. A case study was carried out in a manufacturing company that had been using the approach for five years. The case study identified several factors that helped to sustain the initiative but it also revealed some elements that had a negative impact

An incremental development of the Mondex system in Event-B

A development of the Mondex system was undertaken using Event-B and its associated proof tools. An incremental approach was used whereby the refinement between the abstract specification of the system and its detailed design was verified through a series of refinements. The consequence of this incremental approach was that we achieved a very high degree of automatic proof. The essential features of our development are outlined. We also present some modelling and proof guidelines that we found helped us gain a deep understanding of the system and achieve the high degree of automatic proo

Practical Theory Extension in Event-B

Abstract. The Rodin tool for Event-B supports formal modelling and proof using a mathematical language that is based on predicate logic and set theory. Although Rodin has in-built support for a rich set of operators and proof rules, for some application areas there may be a need to extend the set of operators and proof rules supported by the tool. This paper outlines a new feature of the Rodin tool, the theory component, that allows users to extend the mathematical language supported by the tool. Using theories, Rodin users may define new data types and polymorphic operators in a systematic and practical way. Theories also allow users to extend the proof capabilities of Rodin by defining new proof rules that get incorporated into the proof mechanisms. Soundness of new definitions and rules is provided through validity proof obligations.

Incremental Construction of Large Specifications: Case Study and Techniques

The RODIN project is an EU-funded project concerned with the provision of methods and tools for rigorous development of complex software-based systems. Ultimately, through the development of open-source tools and techniques, the project aims to make formal methods more appealing and accessible to industry. The project is driven by a number of case studies, each of which is designed to exercise the technology being developed and create methodologies for the future. In this paper we focus on the methodologies being developed in one of the case studies (the CDIS subset). This case study is based on a commercial air traffic information system that was developed using formal methods 14 years ago, and it is still in operation today. The key goals of our approach are to improve the comprehensibility of large specifications and to achieve a complete mechanical proof of consistency