A new approach to the development and maintenance of industrial sequence logic

This thesis is concerned with sequence logic as found in industrial control systems, with the focus being on process and manufacturing control systems. At its core is the assertion that there is a need for a better approach to the development of industrial sequence logic to satisfy the life-cycle requirements, and that many of the ingredients required to deliver such an approach are now available. The needs are discussed by considering the business case for automation and deficiencies with traditional approaches. A set of requirements is then derived for an integrated development environment to address the business needs throughout the control system life-cycle. The strengths and weaknesses of relevant control system technology and standards are reviewed and their bias towards implementation described. Mathematical models, graphical methods and software tools are then assessed with respect to the requirements for an integrated development environment. A solution to the requirements, called Synect is then introduced. Synect combines a methodology using familiar graphical notations with Petri net modelling supported by a set of software tools. Its key features are justified with reference to the requirements. A set of case studies forms the basis of an evaluation against business needs by comparing the Synect methodology with current approaches. The industrial relevance and exploitation are then briefly described. The thesis ends with a review of the key conclusions along with contributions to knowledge and suggestions for further research

Delay Performance and Cybersecurity of Smart Grid Infrastructure

To address major challenges to conventional electric grids (e.g., generation diversification and optimal deployment of expensive assets), full visibility and pervasive control over utilities\u27 assets and services are being realized through the integratio

Requirements Analysis of Using Object-Orientation in Filling Machine Systems

The use of an object-oriented approach in software engineering has proven to be successful for many years, but in the fields of mechanics and automation it has been ignored for long. The Tetra Pak Carton Bottle automation team believes that a switch from a function-oriented architecture to an object-oriented one would be of benefit not only to them but also any department which is involved with development, production, and maintenance of filling machines. Many product projects of today make the mistake of having its participants jumping straight into the implementation part of the project while skipping the work of first defining requirements of what the product shall accomplish. People in general like to start by doing the how of the project without first focusing on the what. But if the needs of other product concerned are overlooked then there is a risk of an important part being left out, perhaps leading to a weaker product. This master thesis focuses on the what part of a development project where an object-oriented architecture shall be deployed for Tetra Pak’s development, production, and maintenance of machine systems. During the master thesis requirements from various stakeholders were defined based on interviews and discussions held with various Tetra Pak departments. The result, the requirements, show that Tetra Pak has several areas which would be benefited by an object-oriented architecture by making Tetra Pak’s machines more modular and the maintenance of them simpler

A component-based virtual engineering approach to PLC code generation for automation systems

In recent years, the automotive industry has been significantly affected by a number of challenges driven by globalisation, economic fluctuations, environmental awareness and rapid technological developments. As a consequence, product lifecycles are shortening and customer demands are becoming more diverse. To survive in such a business environment, manufacturers are striving to find a costeffective solution for fast and efficient development and reconfiguration of manufacturing systems to satisfy the needs of changing markets without losses in production. Production systems within automotive industry are vastly automated and heavily rely on PLC-based control systems. It has been established that one of the major obstacles in realising reconfigurable manufacturing systems is the fragmented engineering approach to implement control systems. Control engineering starts at a very late stage in the overall system engineering process and remains highly isolated from the mechanical design and build of the system. During this stage, control code is typically written manually in vendor-specific tools in a combination of IEC 61131-3 languages. Writing control code is a complex, time consuming and error-prone process. [Continues.