CAM

Conference Reports

Computers in Industry Automated Storage Alternatives for Manulacturing Operations

J. Thomas Allen (Automove Systems Division, LITTON UHS,

San Diego, California, USA) Changing Trends and Functions of Warehousing in the 80's John M. Hill (Identronix, Inc., Santa Cruz, California, USA)

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The Proceedings of the 5th ICAW are available from North-Holland Publishing Company under the title "Automation in Warehousing".

Integration of CAD/CAM The IFIP Working Conference on/ntegration of CAD / C A M was held in Gaussig, G.D.R. from November 8-10, 1983. Supported by Working Groups 5.3 (Discrete Manufacturing) and 5.2 (Computer-Aided Design), the conference was organized by the Dresden Technical University and by the VEB Kombinat Robotron (Dresden), Forschungszentrum des Werkzeugmaschinenbaus (KarI-Marx-Stadt) an VEB Polygraph - Druckmasehinenwerk PLANETA (Radebeul). D. Kochan acted as chairman of the international Program Committee. The topical sessions at the conference covered the following range of topics: (1) Basic Problems of the integration of CAD/CAM, (2) integrated Systems in Electronics and Mechanical Engineering, (3) Hardware, Software and Methodological Support, (4) Technological Process Modelling, and (5) Integration in Experimental Work and Flexible Manufacturing. E. Heidenreich (Dresden Technical University), who presented the Opening Address at the Conference, is convinced that the present solid stage of development in applying automated information processing in the 12 countries represented at the conference was a sound basis for a successful working conference on integration problems in the fields of technical planning and implementation of the production. On the basis of many solutions of rationalization ready to be used and already applied, the necessity has ripened to attain and to complete t~e degree of complexity and integration in different fields of activities. The point, he said, is to combine the numerous "insula solutions" to obtain throughout or integrated solutions of systems. This IFIP conference provided a contribution to solve several problems connected with such solutions, such as the structure and the architecture of throughout automated systems, of interface desig-

ning, and of information on the first exemplary solutions and experiences. Featured below is a report on the lectures delivered at this conference.

Session 1: Basic Problems of the Integration of CAD/CAM Chairman: J. Hatvany (Hungary) This session was concerned with the lessons which the leading experts of the G.D.R. and Czechoslovakia have learned from many years of experience in the implementation of automated manufacturing systems. Two Case Studies were presented, out of which the authors have drawn a number of general conclusions.

Fundamental Aspects for Manufacturing According to D. Kochan, H.-J. Jacobs and W. Voelkner (Dresden Technical University, G.D.R.), the consistent information processing in the preparation of production and in the production demands an efficient division of labor between man and machine. The future-oriented engineer has to be especially prepared for this. The resulting new demands on training and education were formulated in the lecture. Then, Kochan, Jacobs and Voelkner characterized the essential features of integrated systems of the automated information processing and explained the fundamental problems of the complex decision finding from the angle of manufacturing engineering. The presentation was concluded by examples of solutions for the fully automated preparation and execution of production.

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Machinery Production Automation Z. Kozar and J. Prokop (Research Institute of Technology and Economy in Mechanical Engineering, VUSTE Prague, Czechoslovakia) described the individual stages of the process of machinery Production Automation. Present development, they pointed out, gradually aims to integrate CAD/CAM systems. Complicated design and practical applications of these systems calls for definition of possible partial steps of integration. Consultation, training and application services provide necessary background for massive impact of CAD/CAM systems to industry. Kozar and Prokop presented the concept of an integrated C A D / C A M system being implemented at VUSTE Prague. This concept is a follow-up to the previous complex analysis of the Plant Information Model, describing a product in any single stage of production process.

Session 2: Integrated Systems in Electronics and Mechanical Engineering Chairman: J.P. Crestin (France) This second session provided an introduction to the world of real industrial integrated CAD/CAM systems. Two industrial fields were involved: electrical engineering and mechanical engineering. As far as CAD is concerned, a recent evaluation showed that mechanical engineering represents 50% of presently installed CAD systems, and electrical engineering between 20 and 30%. Altogether, those fields represent nearly 80% of CAD. The proportion should be approximately the same for the whole C A D / C A M area. That, claimed J.P. Crestin in his introductory remarks to the session, shows the importance of the examples presented in the session. Moreover, each of the two examples presented is highly significant in its field. Everybody knows the already ancient activity of Philips (The Netherlands) in CAD and the efforts of J. Vlietstra to try to integrate the numerous different CAD programs developed or used by the different elements of the firm. COMPAC, developed by the Institute of Machine Tools and Manufacturing Technology (Berlin), is one of the first and best geometric modellers. It has been at the origin of a whole

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CAD/CAM system, still under development, which has been realized by adding progressively many new programs, finite element calculations, process planning, numerical control, etc. and which is now largely used in industry. Crestin feels that the two examples presented in this session show clearly that integration can be an industrial success. It was important to see how these integrations have been realized and to discuss the problems which have arisen. CAD in Electronics

Even since the introduction of computers in development and engineering departments, design activities have been supported by computer methods in a growing number of design functions, in the interest of reducing development time and cost, and increasing the quality of the products. CAD - a generic term for these computerized tools - is recognized as a method for drastically reducing the development time of industrial products. CAD methods are currently being used during each of the various phases in the development activity. The introduction of these CAD tools for the various stages in the development cycle, however, was to a large extent affected in isolation, Le. not as a "sub-set" of an overall concept. Lack of such a concept, with its inherent disciplines and compatability aspects, has given rise to sub-optimal efficiency and effectivity. J. Vlietstra (Philips' Telecommunicatie Industrie B.V., Hilversum, The Netherlands) pointed out in his presentation that a generalized architecture for CAD has been developed to remedy this situation. This architecture drastically reduces the large variety of input methods, combines all product data in one well-structured product file, supports all necessary design functions, assures the proper generation of technical documents, and above all, facilitates maximum efficiency by integrating the processes for various stages in the development cycle. Vlietstra described the essentials of this Architecture for CAD (ARCADE) and discussed how the system is designed. He also examined the ARCADE way and method of working in an organization in which development, engineering, manufacturing, logistic and documentation departments are concerned with technical automation issues.

Computers in Industry

Computer Internal Representation In the fields of design and technological planning, the application of programming systems for CAD systems, following measures of systemization and classification, is the preferred means for increasing the productivity. So began a lecture, entitled "Computer Internal Representation of Products for the Integration and Design and Technological Planning", authored by G. Spur, F.-L. Krause and E. Pistorius (Institute of Machine Tools and Manufacturing Technology, Technical University of Berlin). For this purpose, they said, a multitude of systems is available by means of which mainly partial jobs are processed in an automatic way. The single computer-aided job-processing resuits, to a certain extent, in only a small increase in productivity. In cases of special tasks, however, considerable increases in productivity are also obtained by means of single systems; improvements regarding door-to-door time, reproducibility and the avoidance of routine activities are attainable, according to Spur, Krause and Pistorius. Because of the reduced input effort, a general increase in productivity can be obtained by interlinking individual systems for a continuous computer-aided processplanning. Investigations in the German industry of mechanical engineering have shown that a connected processing of two partial jobs (provision of drawings and production plan) brings about a reduction of the planning time per planning job of approximately 40%. Spur, Krause and Pistorius showed that by extending multiple use of the input information, even better results can be obtained. In the U.S.A., they noted, statements exist, showing, for the entire range of the product development, a cost reduction of 14% at a time reduction of 8%, versus conventional methods, in cases of C A D / C A M application. In the case of an integrated computer-aided processing of all product development, ranges in cost reduction of 32% and time reductions of 27%, vs the conventional processing, can be expected, they said. Here, the greatest timeand cost-reductions are to be expected in the ranges of prototype development and production preparation as a consequence of a comprehensive product analysis and simulation. To attain an optimum from CAD application, generally valid standards for the transfer of corn-

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puter-internal representations from any CAD system have to be defined. Spur, Krause and Pistorius feel that to this end, a volume-oriented three-dimensional object model could form the basis of a standardization. Greatest attention, they said, should be paid to the advanced development of data banks which, according to today's cognitions, hold a central position with the performance of integration measures. In this connection problems of access time play the greatest role apart from the distributed data organization.

Session 3: Hardware, Software and Methodological Support Chairman: J. Vlietstra (The Netherlands)

Standardized Graphic I / 0

Software

Manfred Mikut (VEB Robotron Zentrum fi~r Forschung und Technik, G.D.R.) began his lecture with a description of the layer-like architecture of the software for C A D / C A M Systems. He presented an implementation of the ISO standard draft "Graphic Kernel System (GKS)" that was performed on the basis of version 7.0 on a 16-bit computer. The purpose of the implementation, Mikut explained, is the uniform work of the application programmer with graphic displays and plotters of different types. Mikut discussed the architecture of the GKS implementation and the particularities of the insertion into FORTRAN. The GKS implementation was subdivided into a device-independent and a device-dependent part. The device-dependent part mainly serves for guaranteeing the device instructions and for guaranteeing a minimum intelligence of the workstations in connection with the device-independent part. After describing the contents of both parts, Mikut presented some special problems that are to be solved in the GKS implementation. Components and Interfaces J. Encarnacao and several colleagues (Technische Hochschule Darmstadt, F.R.G.) have developed "A Reference Model for Components and Interfaces of a CAD System". They outlined this reference model and noted that it is influenced by

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the different international standardization activities in the fields of graphics interfaces (GKS, VDI, VDM, NAPLPS) and product data definitions (IGES). The components and interfaces of the model as well as application methods, dialogue, data structure, data base, and graphics functions were described. Encarnacao also explained how these interfaces correspond to the specific standardization areas and their relation to one another.

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using the dialogue mode, the user is able to temporarily and permanently change the operation time in the process model and thus to prescribe the data required for the manufacture. In their presentation, entitled "Description of Methods for Computer Aided Process Determination in Throughout Integrated Systems - Description of the Program System RATIBERT", Kupper and Hartmann described the basic type of such process models.

Rigour and Permissiveness Free Form Shapes Intensive research and development towards the functional specification of C A D / C A M systems has been carried out during the last 6-7 years at the Hungarian Academy of Science (Mechanical Engineering Automation Division of the Computer and Automation Institute). Peter Bernus (Hungarian Academy of Sciences) gave a chronological overview and evaluation to show the stages by which this methodology reached an industrymature level. He also investigated the benefits and shortcomings of the SADT/ISDOS system. His presentation was entitled "Rigour and Permissiveness in the Design of CAD/CAM Systems - The Theory and Practice of a Methodology".

Session 4: Technological Process Modelling

After describing the primary aims and the structure of the implemented CAD/CAM system, G. Hermann (Computer and Automation Institute, Hungarian Academy of Science) presented the interactive design process. Particular attention was paid to those components which are of primry importance due to their direct contact with the user. Hermann also discussed a CNC option for real-time tool-path generation and some details of roughing and finishing. His presentation was entitled "Free Form Shapes - An Integrated CAD/CAM System", and is reproduced in full elsewhere in this issue.

Session 5: Integration in Experimental Work and Flexible Manufacturing

Chairman: Zd. Kozar (Czechoslovakia) Chairman: F. Kimura (Japan)

Program System RA TIBERT Primary Data of Manufacturing Processes Principle methodological fundamentals in the small-scale and in the individual production are established by computer aided methods in new planning and adjusted planning. Based on the resuits of technological research to design manufacturing processes, software tools were developed enabling the user to prepare by simple auxiliaries process models of sequences of manufacturing processes and to store them into the data base. H. Kupper (Technische Hochschule "Otto von Guericke", G.D.R.) and J. Hartmann (Technische Universit~it Dresden, G.D.R.) explained that the processing of these models is carried out in dialogue mode to select the manufacturing processes and to record data for the technological planning. The geometric and other input data required for the processing are provided by the data base. By

Most solutions in the' field of manufacturing engineering do not meet the requirements of the integrated information processing oriented at C A D / C A M or at CIM at a high enough level. A statistical evaluation software which explicitly gives suitable primary data of tool wear to directly process in programs of computer aided process planning must be considerably more effective. It must provide explicit equations of tool life statistically confirmed and applicable to process optimization. The same software must provide fundamentals for the on-line processing of manufacturing oriented to tool control and to maintain AC systems. H.J. Jacobs and K. Steudner (Technische Universit~it Dresden, G.D.R.) introduced the evaluation system PRITO (Primary Data of

Computers in Industry

Manufacturing Processes) applied in the Data Center for cutting conditions of the G.D.R., in the central tool factory Schmalkalden and at the technical colleges. The actual evaluation system, they noted, is represented by the software PRITO 2 multivalently applicable to evaluate measured technological characteristic values. To explain this universal application, they used examples of characteristic values of wear of multicutting tools, as is the case during milling. Product Modelling According to F. Kimura, S. Kawabe, T. Sata (University of Tokyo, Japan) and M. Hosaka (Tokyo Denki University, Japan) modelling capability for products to be designed and manufactured plays an important role in effectively constructing and utilizing C A D / C A M systems. Product models, they said, should represent all the information about products, which are utilized in manufacturing processes. Therefore it is required that they describe functional structures of machine products, and include not only geometric information, but also various non-geometric data, such as physical, technological and management data. At present there do not seem to exist definite methods or theories for constructing product models. In a lecture, entitled "A Study on Product Modelling for Integration of CAD/CAM", Kimura et al. first investigated the whole manufacturing process and proposed a system structure for integration of CAD/CAM, in which product modelling plays a fundamental role. Then, requirements for product modelling were thoroughly studied, and a new representation framework for product models was proposed. It consists of an object concept called frame, relations among frames and attributes, and it can incorporate the

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existing various modelling capacities, such as solid modelling. The authors used this representation framework in combination with their solid modelling package GEOMAP-III, and showed the effectiveness of this approach by performing illustrative design experiments. (The full paper is reproduced elsewhere in this issue) Distributed Intelligence Cell Concept The Computer and Automation Institute (Hungarian Academy of Sciences, Budapest) has launched a research project that has resulted in the collection of user requirements for large-scale integrated manufacturing systems. A. Krizs&n, G. Haidegger and S.S. Nagy (Computer and Automation Institute, Hungary) summed up aims and requirements and presented a new concept: the manufacturing system based on distributed intelligence cells. Details were given on the structure of the cells and the major features of the cell categories were separately discussed. The modes of operation in an industrial cell are carefully planned, the authors explained, by paying special attention to the needs of un-manned operation. A solution was presented for interconnecting the cells in an integrated system with the self-developed local area control network. The lecture concluded with a discussion of present applications in industry. The concept is to be applied to integrated manufacturing systems. The Proceedings of this conference have been edited by D. Kochan (Technical University of Dresden, G.D.R.) and published by North-Holland Publishing Company under the title Integration of C A D / CAM. 1984. 290 pages. ISBN 0-444-87530-1. Price: US $42.25 (USA/Canada), Dfl.110.00 (rest of the

world).