An extended process automation system : an approach based on a multi-agent system

This thesis describes studies on application of multi-agent systems (acronym: MAS) to enhance process automation systems. A specification of an extended process automation system is presented. According to this specification, MAS can be used to extend the functionality of ordinary process automation systems at higher levels of control. Anticipated benefits of the specification include enhanced reconfigurability, responsiveness and flexibility properties of process automation. Previous research concerning applications of MAS in process automation has been more limited than in other fields of automation. There has been more research about this topic for example in the area of discrete manufacturing. As goal-oriented distributed systems with coordination capabilities MAS have been found applicable to a part of automation functions, e.g. modification of control logic in abnormal situations. However, when applying MAS to process automation the particular characteristics of this application domain need to be taken into account. The important role of continuous control in process automation needs to be considered. In this thesis, a specification of an agent platform for process automation is presented as a basis for applying MAS in this application domain. The specification extends a FIPA-compliant agent platform with process automation specific functionality. It utilises a hierarchical agent organisation, a BDI-agent model and qualitative reasoning. It also presents a model for programming MAS applications for process automation with techniques of distributed planning and search. Two applications are specified using the platform. One of these shows how the techniques of distributed planning can be applied in sequential control. The other provides a design model for supervisory continuous control applications using the techniques of distributed search. Experiments performed with a laboratory test environment using prototype implementations of the applications are presented. The experiments are able to demonstrate the feasibility of the approach in limited test scenarios. They also provide information about in which ways MAS techniques are able enhance the properties of process automation. As a result of the work presented in this thesis more knowledge has been gained about application of MAS in process automation. The specification of the agent platform for process automation and its applications provide a basis for further studies of this topic.reviewe

Applying agent technology to constructing flexible monitoring systems in process automation

The dissertation studies the application of agent technology to process automation monitoring and other domain specific functions. Motivation for the research work derives from the development of industrial production and process automation, and thereby the work load of operating personnel in charge of these large-scale processes has become more complex and difficult to handle. At the same time, the information technology infrastructure in process automation domain has developed ready to accept and utilise novel software engineering solutions. Agent technology is a new programming paradigm which has attractive properties like autonomy, flexibility and a possibility to distribute functions. In addition, agent technology offers a systematic methodology for designing goal based operations. This enables parts of the monitoring tasks to be delegated to the system. In this research, new agent system architecture is introduced. The architecture specifies a structure that enables the use of agents in the process monitoring domain. In addition, an introductory internal layered design of an agent aiming to combine Semantic Web and agent technologies is presented. The developed agent architecture is used in conjunction with the systematic agent design methodology to construct and implement four test cases. Each case has industrially motivated interest and illustrates various aspects of monitoring functionalities. These tests provide evidence that by utilising agent technology it is possible to develop new monitoring features for process operators, otherwise infeasible as such within current process automation systems. As a result of the research work, it can be stated that agent technology is a suited methodology to realise monitoring functionalities in process automation. It is also shown, that by applying solutions gained from the agent technology research, it is possible to define an architecture that enables to utilise the properties offered by agents in process automation environment. The proposed agent architecture supports features that are of generic interest in monitoring tasks. The developed architecture and research findings provide ground to import novel software engineering solutions to process automation monitoring