PROCESS CYBERNETICS GROUP

Department of Engineering Cybernetics, NTNU

Head of group: Professor Bjarne A. Foss

ANNUAL REPORT 1995

The Process Cybernetics group is part of the Department of Engineering Cybernetics. The Department has a faculty of 8 professors, and approximately 50 graduate students working towards their Dr. Ing. degrees.

The activity has the following objectives:

• Perform research focusing on modelling methods and the application of these for plant operations. This includes control, surveillance, diagnosis, and optimization.
• Educate highly-qualified persons suitable for research and industrial challenges.
• Perform research with both high academic quality and industrial relevance.

Summary of main results for 1995

Candidates graduated

In 1995, three candidates graduated with a Dr.Ing. degree. These are:

• Tor Arne Johansen. The thesis 'Operating Regime Based Process Modelling and Identification' was defended in January with Dr. Ken Hunt from Daimler-Benz, Germany as the main opponent. Tor Arne now works with SINTEF Automatic Control in Trondheim, Norway.
• Finn Are Michelsen. The thesis 'A Dynamic Mechanistic Model and Model-Based Analysis of a Continuous Kamyr Digester' was defended in June with Prof. Ivars Neretnieks from the Royal Institute of Technology, Sweden as the main opponent. Finn Are now works as a private consultant for Siemens a.s.
• Ole Bjørn Gjøsæter. The thesis 'Structures for Multivariable Robust Process Control' was defended in June with Prof. Sebastian Engell from the University of Dortmund, Germany as the main opponent. Ole Bjørn now works with Steinco a.s. near Bergen.

Publications and awards

The group has 4 publications in international journals and as book chapters and 7 papers published at international conferences in 1995. A complete list of journal and conference publications is enclosed. Bjarne received the Karl Diesel Best Paper Award from the Society for Design and Process Science for the paper 'Integrated Production Systems for The Process Industries'.

Industrial impact

• The group has financed the development of a software package (ORBIT) for model identification based on the work in Tor Arne's thesis. The development is performed by SINTEF Automatic Control and the package is currently used in a joint project with Daimler-Benz, Germany.
• The Kamyr digester model developed by Finn Are in his thesis work forms the basis for his current private consulting work with Siemens a.s.
• Elkem a.s. is using a simplified version of the comprehensive ferro-manganese model developed by Stein at their Porsgrunn plant.

Ongoing Dr. Ing. Projects

Stein O. Wasbø started his research in April 1993. He has been financed by The Research Council of Norway and Elkem a.s. Stein has developed a method for model building by deriving a set of suitable elementary building blocks. The method is evaluated by modelling a ferro-manganese furnace. The model is implemented by the use of an object-oriented programming language. Stein has also derived new insight into mechanisms in the hearth of the furnace. The work is pursued in close interaction with Elkem a.s. both in Norway and in the USA. Stein will finish his research in 1996.

Tormod Drengstig started his research in February 1994. He has been financed by The Research Council of Norway and Hydro Aluminium a.s. Tormod is working on process modularization with the aim to simplify model building and model changes. He will evaluate his findings on an Aluminium electrolysis process. From August to December 1995, Tormod has stayed with Prof. Wolfgang Marquardt's group at RWTH in Aachen. Tormod will complete his work in 1997.

Grethe Tangen started her research in 1990. She had an 18 month leave in 1992-1993 to become a mother and is financed by The Research Council of Norway and Statkraft s.f. Grethe has developed a method for decision support with the aim to enhance human decision makers' ability to perform rational decisions. The method is evaluated on rehabilitation planning in hydro power production systems. Grethe will complete her research in 1996.

Per Norman Oma started his research in the fall of 1991. He has been financed by The Research Council of Norway. The research is focussed on attitude control of flexible space structures. Per Norman spent one semester at ESTEC (The research part of The European Space Agency). He has in 1995 been on leave from his research.

Kjell Støle-Hansen started his research in Sept. 1994 and is financed by The Research Council of Norway through the INPRO program. He will emphasize improved plant operations by the use of dynamic models. Kjell is using a precipitation process at Falconbridge Nikkelverk a.s. as case, and has developed a model for this process. Kjell's plans for 1996 is to complete a controllability analysis and propose an improved control scheme for the precipitation process. He plans to stay at Falconbridge, Canada, for 6 months from March 1. There he will be working in the process control group at one of Falconbridge's plants. Kjell plans to complete his work by 1997.

Jo Simensen started his research in Sept. 1994 and is financed by The Research Council of Norway through the INPRO program. Jo focuses on batch plant operation, in particular how to structure the model of such a plant. In addition, Jo will investigate the role of modelling in the interplay between a plant and the organization running it. He is using a pharmaceutical plant at Nycomed Imaging a.s. as case. Jo will spend a part of 1996 performing research abroad and plans to complete his research in 1997.

Olav Slupphaug started his research in February 1995. He is working with control of hybrid systems, that is, systems which consists of both logic and continuous parts. Olav has visited some Norwegian companies to get a feel for the-state-of-the-art on the use of formal methods for hybrid process control. He has also attended the "Workshop on Analysis and Design of Event-Driven Operations" at Imperial College (April) and visited the Swedish control groups at the University of Lund and at Chalmers University of Technology (October). Olav will complete his research in the spring of 1998.

Jostein Vada is presently working as a teaching assistant. His research will be in the area of analysis and control synthesis of complex process plants. This topic has many similarities with the work being done by Olav. Jostein expects to complete his research in 1999.

Other activities

Conference attendance

The group has participated at several conferences in 1995. These conferences are listed below with the names of the people representing our group given in brackets.

• Workshop on Analysis and Design of Event-Driven Operations, London, April. (Slupphaug)
• 4th IFAC Symposium on Dynamics and Control of Chemical Reactors, Distillation Columns, and Batch Processes, DYCORD+'95, Helsingør, Denmark, June. (Foss, Wasbø )
• 7th International Ferroalloys Congress, INFACON 7, Trondheim, Norway, June (Foss, Wasbø )
• Intelligent Systems in Process Engineering, Snowmass, USA, July (Simensen).
• Nordic Process Control Workshop VI, Åland, August. (Drengstig)
• EUROSIM Simulation Congress, EUROSIM95, Vienna, Austria, September(Øgaard)
• 1995 IEEE International Conference on Systems, Man and Cybernetics, October, Vancouver, Canada (Tangen)
• Working conference in Enterprise Integration, Heron Island, Australia, November (Støle-Hansen)
• AIChE Annual Meeting, Miami Beach, Florida, November (Foss)
• The first world conference on Integrated Design & Process Technology, Austin, Texas, December (Foss)

Collaboration

The group is engaged in several research programs and networks. This year, the Process Cybernetics Group and the Process Control Group at SINTEF Automatic Control were adopted as new members in the Strong Point Center in Process Systems Engineering (PROST) at the Norwegian University of Science and Technology.

The group is tightly involved in INPRO. The INPRO-program focuses on process plant operation, in particular the cross-disciplinary nature of this problem. There is a heavy engagement from three departments: Department of Organization and Work Science, Department of Chemical Engineering, and our department. The INPRO-program is funded by the Federation of Norwegian Process and Manufacturing Industries (PIL), the Norwegian Oil Industry Association (OLF), the Research Council of Norway, and the nine companies that are associated with INPRO. The group has close couplings with other research groups at our Department and SINTEF Automatic Control.

Financing

Our activities are financed by a number of projects and fellowships. Most of the resources are supplied by The Research Council of Norway. Additional funding from collaborating industry is, however, appreciated as it gives us flexibility to pursue high-risk avenues, attend seminars and conferences, visit other research groups, buy equipment, and perform experiments.

Plans for 1996

Work in 1996 will develop along the same lines as in 1995.

• Two Dr. Ing.students (Grethe Tangen and Stein O.Wasbø) plan to defend their thesis in 1996, and 5 papers are currently accepted for journals and conferences in 1996. We will continue the effort to transfer our research results to the industrial domain.
• The collaboration with the other members of PROST will continue and the activities in the Dr. Ing. program on Distributed Process Control will be escalated as Jostein Vada will start his research this year.
• The INPRO-program will be used as a basis for expanding the activities within plant operations and to develop an inter-departmental curriculum on plant operations at the Norwegian University of Science and Technology.
• Prof. Foss will be back from sabbatical leave at The University of Texas in Austin in July 1996. The ties developed during this stay will form a basis for a continued cooperation.

Publications

Theses

• T. A. Johansen «Operating Regime Based Process Modeling and Identification», Dr. Ing.thesis, Report. no NTH 1994:117, ITK 1994:109-W
• O. B. Gjøsæter. «Structures for Multivariable Robust Process Control, Dr. Ing. thesis, Report. no NTH 1995:29, ITK 1995:13-W
• F. A. Michelsen. «A Dynamic Mechanistic Model and Model-Based Analysis of a Continuous Kamyr Digester», Dr.Ing. thesis, Report. no NTH 1995:40, ITK 1995:4-W

International Journals and book chapters

• T. A. Johansen and B.A. Foss «Identification of Non-linear System Structure and Parameters using Regime Decomposition», 31, 2, pp. 321-326.
• B. A. Foss, T. A. Johansen and A. V. Sørensen «Nonlinear Predictive Control using Local Models», Control Engn. Practice, 3, pp.389-396.
• B.A. Foss and T. A. Johansen «Local modelling as a tool for semi-empirical and semi- mechanistic process modelling, Neural Networks for Chemical Engineers, Elsevier, pp.297-333.
• T. A. Johansen and B. A. Foss «Semi-Empirical Modeling of Non-linear Dynamic Systems through Identification of Operating Regimes and Local Models», Neural Network Engineering in Dynamic Control Systems, Springer Verlag, pp.105-126.

International Conference Papers

• S. O. Wasbo and B. A. Foss «An Object-Oriented Method for Process Modelling, Preprints DYCORD+'95, pp. 117-122, Helsingør, Denmark.
• S. O. Wasbø and B. A. Foss «Object-Oriented Model of a Ferromanganese Furnace'', INFACON7, pp. 545-554, Trondheim, Norway.
• T. A. Johansen and B. A. Foss «Empirical Modeling of a Heat Transfer Process using Local Models and Interpolation», Proc. American Control Conference, pp. 3654- 3658, Seattle, Wa.
• B. A. Foss, S. O. Wasbø and O. Øgaard «Object-oriented Modelling Applied to a Reactor», EUROSIM95, pp. 463-468, Vienna, Austria.
• G. Tangen and B. A. Foss «Decision Support for Planning Upgrading of a Hydropower Plant», 1995 IEEE International Conference on Systems, Man and Cybernetics, pp. 1562-1567, Vancouver, Canada.
• A. Mjaavatten, B. A. Foss, K. Fjalestad «Operator Support for Diagnosis in a Fertilizer Plant», Preprints Intelligent Systems in Process Engineering, Snowmass, Colorado.
• B. A. Foss, R. Klev, M. Levin, K. Lien «Integrated Production Systems for The Process Industries», Proc. The first world conference on Integrated Design & Process Technology, Austin, Texas.

Norwegian research journal

• K. Uhlen, B. A. Foss and O. B. Gjøsæter «Robust control and analysis of a wind-diesel hybrid power plant» Modelling Identification and Control, 16, 1, pp. 35-50 (1995).
• T. A. Johansen and B. A. Foss «Semi-empirical modeling of non-linear dynamic systems through identification of operating regimes and local models» Modelling Identification and Control,16, 4, pp. 213-232 (1995).

Presentations at other international meetings

• T. Drengstig and B. A. Foss «Modularization applied to an aluminum electrolysis cell», Nordic Process Control Workshop'95, Åland.
• B. A. Foss and T. A. Johansen «A Transparent Modeling Scheme for Diagnosis, AIChE Annual Meeting, Miami, Florida.

Technical reports

• O. Slupphaug «A brief Introduction to some Logics, Formal Languages, and Petri Net Theory», Report no. ITK 1995-45-W, Department of Engineering Cybernetics, The Norwegian Institute of Technology, Trondheim, Norway.
• O. Slupphaug and I. Halvorsen «Preliminaries: Control and surveillance of complex industrial plants'', Report no. ITK 1995-29-P, Department of Engineering Cybernetics, The Norwegian Institute of Technology, Trondheim, Norway.
• O. Slupphaug «A Note on Hybrid Systems emphasizing Approaches in the Control Community», Report no. ITK 1995-46-W, Department of Engineering Cybernetics, The Norwegian Institute of Technology, Trondheim, Norway.
• T.A.Johansen «ORBIT v1.1 User's Guide and Reference», SINTEF report STF48 A95013, Trondheim, Norway.