Dynamic Control and Management Systems in Manufacturing Processes, for the Optimisation of Throughput and Energy Usage

DYCOMANS

Andrzej W. Ordys* and * Michael J. Grimble*

on behalf of

the Steering Committee of DYCOMANS Concerted Action

Industrial Control Centre, University of Strathclyde, 50 George Street, Glasgow G1 1QE, UK

Abstract: The paper describes the Concerted Action DYCOMANS project supported by the European Commission COPERNICUS Programme. The project is devoted to management, simulation and control in manufacturing systems. Sixteen institutions, majority from East European countries are the regular members of the Network. In addition many more have been attracted to the events organised within the project. DYCOMANS works towards an approach to manufacturing system design which would combine expertise of control engineering practitioners with the expertise of engineering management community. This is often referred to as hybrid systems design and seems to be one of the key areas is modern manufacturing processes.

Key words: Dynamic control, dynamic simulation, discrete-event systems, management systems, manufacturing processes.


1. INTRODUCTION

Rapid developments in capacity and speed of computer systems enables the wider use of modern computational methods in real industrial and engineering problems. The main issues which must be addressed are identification, simulation, control and optimisation of industrial plants to achieve better efficiency and quality, to minimise waste and to reduce environmental pollution. New tools, so called Icon Oriented Simulation Languages, enabling relatively cheap and accurate simulation of dynamic processes, and providing control design and optimisation, have been become increasingly popular. The new versions of MATRIXx, EASY5 and MATLAB (Simulink) have become available during the last years, adding more features and making the design process easier. The variety of tools present on the market enable problems to be tackled ranging from simple to very complex.

Increased efficiency and falling prices of universal simulation packages ensure that very specialised simulation systems developed by particular industries for their needs are loosing popularity. An example can be taken from the steel industry in Britain which has a lot of effort into converting their in-house software for the modelling of rolling mills into a MATRIXx hot mill simulation (the project is currently active at Strathclyde).

It is becoming a standard for most western industries to use such tools to construct models of industrial plants. Also in academia, the availability of efficient simulation packages has stimulated research in the field of modelling and advanced control of manufacturing processes.

A dynamic simulation enables the behaviour of different industrial modules to be considered in terms of variables which are continuous in time and space (temperatures, pressures etc.). A separate issue is so called Discrete Event Process Simulation and Control. In this case, the interest is in generating the behaviour in time and space of events which are parts of manufacturing activity (e.g. production line, transport system in a factory). Most real industrial problems require both the dynamic and the discrete event part. This need has been recognised at the beginning of the project and stimulated the proposed program of research within the network. Further confirmation came from sampling opinion within the Control Engineering community.

The most important event in the field of Automatic Control, the IFAC World Congress took place last year in San Francisco. From the programme of the Congress and observing the popularity of the sessions it is easy to conclude that areas of research involving discrete events and "hybrid" i.e. discrete-event and continuous-event combined together are to play very important roles in Automatic Control in the near future. This trend is especially visible in the leading research institutions in the United States. Research in this area must be stimulated to ensure that European research programmes will not be left behind.

The following tendencies influence the future directions of the research activities :

2. CONCERTED ACTION DYCOMANS

The Concerted Action DYCOMANS has been established timely to address the above mentioned issues. The network is aimed at manufacturing industry and the adoption of modern simulation and design tools, enabling Technology Transfer from participating research institutions to the manufacturing industries. Thus, the main objectives are as follows :

  1. Bringing western software tools for the design and simulation of manufacturing processes to the attention of all participants, especially East European companies and researchers.
  2. Unification of software systems enabling exchange of research expertise.
  3. Developing the software tools related to Dynamic Systems Identification, Control and Simulation and to Discrete Event Systems Control and Simulation, to cope with particular industrial applications.
  4. Investigations of the overall strategy for the optimisation of manufacturing processes both through the use of management information systems and dynamic control algorithms.
  5. Developing different means of exchanging scientific information between the partners in the network

The network members are institutions with a recognised expertise either in the field of Advanced Industrial Control or Management of Manufacturing Systems. Thus the network aims at unification of research in the two fields and working out a unified global approach to tackle real life manufacturing problems. The project enables exchange of technologies between the two areas of engineering. Also, the technology transfer from academia to industry and from West European to East European countries is supported. Each of the network members brings its own expertise which complements the strength of the group.

3. PARTICIPANTS OF THE PROJECT

DMEM, University of Strathclyde

Department of Design, Manufacture and Engineering Management, University of Strathclyde participates actively in all network activities. The group possesses a significant experience in modelling and simulation of manufacturing processes. The issues concerned with the factory simulation, simulation tools for production planning and development of control architecture for manufacturing systems have been addressed in presentations by the group members.

TU Silesia

The Department of Automatic Control and the Department of Electronic Engineering from the Technical University of Silesia are represented in DYCOMANS. Their expertise is in control systems analysis and synthesis and in signal processing. The group participates actively in organisation of the Network events and in exchange of information.

UT Zylina

The Department of Industrial Engineering, University of Technology Zylina brings to the network their experience in modelling of manufacturing processes and in discrete-event simulation tools. The group has presented the results originated from the network co-operation at the opening session of the Second World Congress on Intelligent Manufacturing Systems.

Patras University

The Laboratory for Automation and Robotics, University of Patras specialises in Integrated Manufacturing Systems. The group has enriched the DYCOMANS Network with the expertise in Artificial Intelligence methods. In addition, through Prof. P. Groumpos, the group provides a useful link to the Network of Excellence in Intelligent Control and Integrated Manufacturing Systems (ICIMS) supported by ESPRIT programme of the EC.

Sofia UT

The group from the Department of Automation of Industry, Sofia University of Technology specialises in industrial applications of control. The group has close links with START Engineering. Their involvement in the network concerned development of new methods for monitoring and control of industrial objects, implementation of the new algorithms, contacts and co-operation with local industry (SME's like AMEES or KARENA and many firms working in power engineering have been pulled into joint initiatives). The group has been strongly involved in organisation of all Network events.

KOPROTECH

KOPROTECH is a design office specialising in building-block machine tools, automatic production lines, flexible manufacturing systems, control systems and drives. The company brings to the Network the expertise in industrial automated manufacturing.

Hungarian AS

Computer and Automation Research Institute, Hungarian Academy of Sciences is a major centre of research in the fields of Artificial Intelligence, Computer Integrated Manufacturing and Systems and Control. The group has been active in presenting the results of their research in the field of computer aided intelligent manufacturing and control design.

AS of the Czech Republic

Institute of Information Theory and Automation, Academy of Sciences of the Czech Republic has been participating actively in all the network events, exchange visits and in organisation of the Network meetings. The group has shared with the Network members the expertise in the field of control system design, computer implementations and high efficiency algorithms.

Laboratoire d'Automatique de Grenoble

Laboratoire d'Automatique de Grenoble, Ecole Nationale Superieure d'Igenieurs Electriciens de Grenoble is active in research in numerous areas including : systems modelling and identification, multivariable control, self-adaptive control. Linked to the group is ADAPTECH, a high-tech company specialising in the development of control software and consulting in the analysis and design of industrial control systems.

University of Ljubljana

The research group at University of Ljubljana, Faculty of Electrical Engineering, composed of members of the Laboratory of Modelling, Simulation and Control and the Laboratory of Industrial Process Control, has actively contributed to the Workshops organised in the frame of the project. Members have presented main research activities that could be interesting to other network members. The presented topics include fuzzy-neuro modelling and its application to model based predictive control, adaptive control and supervisory control. Recently some group members started to work on the area of discrete event and mixed discrete event-continuous systems. Two contributions covering discrete and combined discrete-continuous simulation will be presented at the forthcoming DYCOMANS Workshop in Poland.

START Engineering

START Engineering has close links with Sofia University of Technology. The company has contributed to the network by development of new control methods and specialised software, implementation of the new algorithms, contacts and co-operation with local industry. The engineers from START have obtained access to the modern simulation software which will be of a big help for the further development of the company.

ADERSA

ADERSA designs, implements and commissions high performance control systems for wide variety of industrial applications. The company is known from the contribution to the development of industrial predictive control. Industrial problems and industrial application of predictive control have been regularly presented to the network members. Some East European members of DYCOMANS visited the company premises getting acquaitance with the control design methods. Through Prof. J. Richalet a useful link has been established between DYCOMANS and CIDIC Working Group on predictive control.

Warsaw UT

Institute for Organisation of Production Systems, Warsaw University of Technology carries on research activities with a wide span from work analysis and design to computer integrated manufacturing, operational research and strategic planning. The group has contributed to the Network activities by presenting papers at the Network events and co-organising the meetings.

Lithuanian AS

Institute of Mathematics and Computer Science, Lithuanian Academy of Science participates in the DYCOMANS activities by presenting research results in the field of dynamic recognition of processes.

Russian AS

Institute of Control Sciences, Russian Academy of Sciences specialises in advanced and robust control analysis for uncertain systems. The group offers to DYCOMANS a deep knowledge of mathematical control theory and statistical processes.

ICC, University of Strathclyde

Industrial Control Centre, University of Strathclyde is the Network co-ordinator. The Centre works actively in the field of control applications to industrial processes and in robust control. In addition, the Centre has provided links to a number of Western research institutions through the EURACO network (supported by the EC TMR programme). A joint conference of both DYCOMANS and EURACO networks has been organised.

Associated partners

COMPUREG

COPUREG, as a company dealing with industrial systems and applications helps the network members to focus on real problems. The group's implementation experience adds "real-world" dimension to the research topics.

AMEES

AMEES is a SME working in the field of power generation. The engineers from AMEES have presented joint papers with START Engineering and Sofia University of Technology at the Network meetings. They also participated in visits to ADERSA.

Corresponding partners : ACT Club

The Advanced Control Technology Club is a technology transfer organisation linked to Industrial Control Centre, University of Strathclyde. The Club comprises around 30 British companies interested in recent developments in control engineering and manufacturing techniques. Co-operation of DYCOMANS Network with the Club resulted in presentations delivered by DYCOMANS members at the Club meetings. Also some delegates from the Club member companies attended the Network events. The non-commercial information is exchanged between the two organisations.

4. THE NETWORK ACTIVITIES

First year of the project

To realise the network goals and objectives, the following activities were performed during the first year of the project :

Second year of the project

The review meeting, summarising the first year of the Project took place in Brussels in March 96. The review panel has accepted the outcome of the first year of the project activities and agreed the programme to be realised within the second and the third year.

Following this recommendation, the actions undertaken during the second year of the project were:

Third year of the project

CONCLUSIONS

After over two years of activity of the Concerted Action DYCOMANS several conclusions can be drawn as to the outcome of the project. Apparently the techniques analysed and developed within the project have a very wide area of industrial applications. This ranges from all types of manufacturing processes [Gregor et al, 95], [Reid and Banerjee, 95], robotised production lines [Kadar et al, 96], through metal processing [Hadjisky and Petkova, 96], [Hearns et al, 96], power industry [Toffner-Clausen et al, 96], [Moumdjian, 97], [Ordys and Johnson, 97] to aerospace engineering [Wisniewski and Blanke, 96].

The DYCOMANS group has been working on a global approach to problems in industrial automation. The planning procedures, well established in engineering management field [Stefanik et al, 95] can be combined with control system design practices [Kucera, 95], [Landau, 96] leading to a general scenario which would consist of the following components [Carrie, 95]:

All those elements are described in numerous articles included in the DYCOMANS Workshops Proceedings, e.g. [Santarek and Szumanski, 95], [Keviczky and Banyasz, 96], [Shpilewski, 96], [Georgopoulos and Groumpos, 95].

Several different techniques can be used at different stages of the above process. These include:

Some of the techniques are equally popular in dynamic control and in manufacturing management. A good example is artificial intelligence methods [Santarek and Buseif, 95], [Hadjiski and Kalaykov, 97]. Some other techniques are not equally popular in both fields and therefore would need more wide introduction. The research effort of the network members concentrated of this issue. Below are selected examples of a successful transfer of some design techniques from manufacturing management to control engineering or vice-versa.

It is a strong opinion of the DYCOMANS Steering Committee that the Network has been fulfilling its role very well.

Firstly, it is tightening contacts within the European researchers and control practitioners community. Especially important is that the colleagues from Central and East European countries have been pulled into those activities.

Secondly, the network has gathered together the groups working in classical approach to control of industrial systems and the groups interested in management for industrial manufacturing. This novel combination is now gaining recognition all over the world. DYCOMANS group was one of the first to work in this area and certainly the effort is worth a continuation.

Thirdly, the software tools for the modelling and simulation of industrial and manufacturing processes have been encouraged through the Network activities. Many of the groups involved with the network have gained a significant experience on use of software tools for high quality and efficient system design. This includes the industrial partners who were provided access to professional software tools and training and awareness raising meetings. On the other hand, the academic partners have benefited from industrial contacts by acquiring familiarity with real industrial problems.

The Network has been effective in the transfer of technology and research results in several directions:

Looking at the world-wide trends in industrial automation and management of manufacturing processes, the Steering Committee believes that the DYCOMANS network is a very effective forum to stimulate research in this area.

REFERENCES

Boukas E.K., A. Swierniak and K. Simek, Linear and non-linear robust control of piecewise deterministic processes, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Carrie A., Issues in design, management and modelling of manufacturing systems, Proc. of DYCOMANS special session at ACASP Symposium, Budapest, June 95.

Georgopoulos V.C. and P.P. Groumpos, Information representation and processing in an industrial environment, Proc. of DYCOMANS special session at ACASP Symposium, Budapest, June 95.

Gregor M., J. Kosturiak and E. Samkova, Some experience and development trends in the simulation of manufacturing systems, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Hadjiski M. and I. Kalaykov, Neural network based modelling and identification of parameter depending plants, Preprints of DYCOMANS Workshop Information Processing and Control in Power Generation, Varna, May 97

Hadjisky M. and M. Petkova, Cooling system control on the runout table of hot strip mill, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Hearns G., G.M. van der Molen and M.J. Grimble, Hot strip mill mass flow control, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Kadar B., S. Markos and L. Monostori, Knowledge based monitoring and management of manufacturing cells, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Keviczky L. and Cs. Banyasz, On the dialectics of identification and control in iterative learning schemes, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Kucera V., Algebraic methods in control theory and applications, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Landau I.D., Robust digital control of systems with time delay, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Music G. and D. Matko, Laboratory scale supervisory control system, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Moumdjian G., Advanced control systems for thermal power plants, Preprints of DYCOMANS Workshop Information Processing and Control in Power Generation, Varna, May 97

Ordys A. and M.A. Johnson, Software toolboxes in simulation and control of power systems, Preprints of DYCOMANS Workshop Information Processing and Control in Power Generation, Varna, May 97

Petropoulakis L. and L. Giacomini, Interfacing continuous-time and discrete-event simulation systems for manufacturing processes, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Petropoulakis L., L. Giacomini and A. W. Ordys, Total simulation in manufacturing- initial implementation and first tests, Proc. of DYCOMANS special session at ACASP Symposium, Budapest, June 95.

Reid S.P. and S.K. Banerjee, Information infrastructure for production planning and control systems, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Santarek K. and I.M. Buseif, An approach to manufacturing systems design using Sadt and Petri net tools, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Santarek K. and Z. Szumanski, Computer integrated manufacturing systems in small business and medium sized enterprises, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Shpilewski E., Recognition of dynamic systems structure for intelligent control, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Stefanik J., B. Micieta and J. Rebetak, Production control systems for small and medium sized enterprises, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Swierniak A. and K. Simek, Robust control of linear systems with fault-prone structure, Preprints of DYCOMANS Workshop Information Processing and Control in Power Generation, Varna, May 97

Szelke E. and L. Monostori, Intelligent manufacturing with reactive/proactive scheduling and learning for dynamic operation management, Proc. of DYCOMANS Workshop Industrial Control and Management Methods: Theory and Practice, Prague, Oct. 95.

Toffner-Clausen, P. Andersen and T. Knudsen, Robust nonlinear control of a 400kW wind turbine, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.

Wisniewski R. and M. Blanke, Attitude control for magnetic actuated satellite, Proc. of the joint Workshop of EURACO and DYCOMANS networks, Algarve, May 96.


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