- Email: [email protected]
CAD82 conference and exhibition
• better links between design and manufacture • faster and more accurate tendering • survival where competing with firms already using CAD
30 March--1 April 1982, Brighton Metropole, UK. Organized by ComputerAided Designjournal Sponsored by CADCentre, CAD and Displays Groups of the British Computer Society, CAM-i, CICA, Institution of Civil Engineers, Royal Institute of British A rchltects, UK Department of the Environment. Organized in cooperation with A CM SIGDA. The fifth international conference and exhibition on computers in design engineering attracted 615 delegates from 33 countries, just over half from the UK but notably also from The Netherlands, Sweden, FRG, Finland, USA, Italy, Norway and France. In all 71 papers, including two invited reviews, were presented, in two parallel streams. These included sessions on Introducing CAD into Industry, Databases, Graphics, Education, Drafting Systems, Geometric Design, CADCAM, Micros in the Design Office
and Energy and Thermal Analysis, as well as in the disciplines of Electronics, Building Design, Mechanical Engineering, and Structures. In addition to the formal sessions, there were two days of the ever-popular System Purveyors sessions and, an innovation at CAD82, poster sessions in the exhibition gallery. Appropriately enough in Information Technology year, IT82, the conference was opened by Kenneth Baker MP, Minister of State for Industry and Information Technology. In his opening speech, he announced that he had set into motion a plan to privatize the Department of I ndustry's CADCentre at Cambridge. In this and the next issue we present reports on individual sessions at CAD82 written by the Chairmen of those sessions. Full texts of the papers are available in the CAD82 proceedings which cost £27.50 from Butterworths, Borough Green, Sevenoaks, Kent TN15 8PH, UK.
Chairmen's reports Overview E Arnold gave details of the study the Science Policy Research Unit at Sussex University had made on the introduction of CAD into the UK engineering industry, paying particular attention to interactive graphics systems but also exploring the linking of the information produced by CAD with its use in manufacture. The study noted how intensive government funding in the USA had generated separate types of systems with two different application areas mechanical engineering (for aerospace) and electronics- since about 1960. In 1980 the US CAD industry grew by 80 per cent largely due to reinvestment of profits in new software development. Firms who started in electronics were moving into mechanical engineering and vice versa. The market in the USA was estimated to be £510M. In the UK the much smaller market
volume 14 number 4 july 1982
is estimated to be expanding by about 100 per cent each year, and is largely being met by US turnkey systems, apart from electronic PCB design systems by Racal and Quest and a promising mechanical engineering system by Ferranti Cetec. The firms finding the most suitable mechanical engineering applications of CAD in the UK are in fields where there is a large amount of drafting, and a relatively small amount of R&D work. The exception is the electronics industry which has been able to cope with a great increase in complexity by using CAD without increasing numbers of draftsmen, and to produce VLSI components which could never be designed without CAD. The benefits of CAD to industry are: • increased drawing office productivity • improved design quality
Although union reaction varies from site to site, unions generally seem to realize the value of using CAD for the survival of their industry, and sometimes the union users are more enthusiastic than management. Three steps are common for the successful introduction of CAD. • an initial experimental use of CAD of up to 2 years • some inefficient use in production • a 3 or 4 fold increase in productivity In the UK several large users are emerging from the first and second phases and this may lead to a more rapid introduction of CAD generally. In the discussion following this paper there was some doubt about how the future designers would be trained because these CAD systems provide less opportunity for young draftsmen because of the smaller number required, without reducing the need for users with an engineering background as the designers. Dr Schoffield of Compeda then described Timelink, a program which is used to provide the methods for producing a mechanical component and the time required for each stage of the production. The main virtue claimed was that this was part of a larger integrated production engineering system which not only aids the production engineers, but also supports enquiries from other departments in a factory and also links to business data processing systems.
W H P Leslie
Introducing CAD into industry Dr Lipchin of A D Little, USA, dealt with the managerial, organizational, planning and economic implications for the successful introduction of CADCAM technology to industry, based on a number of studies of successful and unsuccessful attempts in the US. Experience had shown that it had been a mistake to introduce CAD, possibly linked to NC tape production, without first considering the wider implications to the flow of information throughout a firm. A good working system might well result, but it would probably be found that a great upheaval would be necessary if the system had to be extended to cover all the
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manufacturing and/or business applications later. Some users, on the other hand, had started with a modest sized turnkey CAD system which met some of their needs well, but prevented economic extension to some of their special design needs. Business magazines have been proclaiming that CADCAM systems will be beneficial to any firm, typically claiming that they will lead to a 10 per cent increase in pretax earnings annually. US firms have invested over $1.5 billion on CADCAM in the last 10 years: there are 4 000 CADCAM systems with 20 000 work stations in use and this may well quadruple by 1985. Dr Lipchin fears many problems unless senior management gets involved in ensuring that planning includes impact on data processing and business applications. So far most companies have only had 2 - 5 years' experience of CADCAM, and CADCAM has only penetrated to 25 per cent of its potential. Companies have underestimated implementation and maintenance expenses and have difficulty in quantifying the benefits other than increase in throughput and improved production paperwork. J L Murray, at Heriot Watt University, UK, described the joint work programme undertaken by his University and Ferranti Cetec under the Department of Industry/SERC Teaching Company Scheme. He is evaluating the productivity of the Cetec CAM-X software in a number of industrial situations. The abilities of CAM-X to provide an integrated design synthesis and analysis tool were illustrated by a sequence of diagrams indicating how complex components could be built up either from an assembly of simpler solid shapes, or by describing complex solid shapes, using 3D shapes swept through a distance or rotated about an axis. Hidden line removal, sectioning, etc could be applied and the value of hidden line removal was illustrated on a punching die set which was too complicated to visualize without this simplification. On the other hand for simpler shapes it paid to leave the hidden lines in, to speed up recalculation as the design steps proceed. This was perhaps more graphically brought out by the final paper in this session by M C Bonney of Nottingham University. Their GRASP program has been developed to show graphically the movements of a robot, its work load
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and associated conveyor systems and occasionally its operator. -fo show movement it is necessary to start with a series of desired positions of the work load (or tool) and to calculate from this the necessary positions of each moving element of the robot for each load position. Then the configuration of the robot has to be shown at each position. It is usually adequate to represent the robot and accessories by wireframe models, and not to delete hidden lines, so as to
speed up computation. Positions can then be displayed at not too infrequent intervals. However some situations are so complicated that hidden lines must be removed. In such cases it is usually necessary to slowly calculate positions and store the results until a sequence is completed. The sequence of positions can then be quickly displayed and inspected to check for unintended collisions.
Electronics
or 3 layer routing, and single layer ground and power connections. The program operates on cells, which have been previously designed, and global placement is performed to gain an initial starting layout. The cells are placed in 'slots' and interconnected, forming an advancing wavefront across the chip. The global placement, based on imaginary forces between cells, is evaluated after each slot layout. The selection of algorithm control parameters, and its influence on the placement can, if desired, be subject to manual intervention. This can significantly improve the layout, but is not necessary. Being based on cells, the layout of a large chip can be done hierarchically, a cell at one level being designed by Autolayout at the previous level. Times of the order of minutes for -~ 100 cell layouts w e r e quoted, using a PRIME 750, but the number of signals had a considerable effect. Manfred Ward, of Sperry-Univac, described the idea of using mock cells in the automated verification of VLSI circuits. His system uses functional cells which have already been designed and are guaranteed to work, and replaces them with mock cells of identical exterior dimensions for the verification process. The designer uses logic symbol equivalents of the celt design, and produces a logic sketch for input to the system. This is used to run the simulation, generate test lists, and generate an interconnection file. The designer then performs either manual or automatic placement and interconnection routing. After verification, the mock cells are replaced by the real cells for mask generation. Reminding us that not everyone is designing VLSI chips, the final paper of the session was on AIDES, a design system using SSI and MSI circuits. Charles Fritsch of Bell Laboratories presented the paper, and described a series of tools to help the hardware
The first electronics session began with an invited paper 'Simulation of large nonlinear circuits', by Professor Ken Nichols, Head of the Department of Electronics at Southampton University, UK. Current developments in VLSI technology mean that circuft simulation will have to handle circuits which are orders of magnitude greater in complexity than many popular present-day simulators can manage within realistic time constraints. Professor Nichols, thoughtfully leaving the detailed mathematics to readers of his written paper, discussed techniques which will enable simulators to increase their time efficiency. The obvious technique of structured hierarchical design is usually inadequate because high performance, competitive designs often have parasitic elements which require simulation at the full chip level. Network tearing applied to nonlinear circuits was discussed along with the exploitation of latency. Using manually applied network tearing, practical results showed greater than t0 times speed up and greater than 10 times memory savings over a conventional circuit analyser. Because of the presence of parasitics, the improvement by latency exploitation was only about 2 times. Macro modelling is essential for reducing computation time and general purpose, hybrid (analogue and digital) hierarchical simulators have yet to be developed. The use of special hardware, for instance ICL's Distributed Array Processor, will also play a part. The next two papers continued the VLSI theme. Alex Tweedly of Compeda presented a paper on Autolayout, the automatic layout of VLSl chips developed from the MAGIC system. It currently runs on PRIME and VAX computers, and, being a Compeda product, it is integrated with the GAELIC IC design suite. It handles 2
W H P Lesfie
computer-aided design
system designer. System definition is aided by programs which determine the printed circuit technology required, thermal response, testing constraints and cost. This enables alternatives to be rapidly evaluated before settling on the final design. Design entry is done through a graphical schematic entry program and placement is performed. Prototype wiring on a Multiwire computer controlled wiring machine is done directly from the input information so that initial testing can be done. Reliability and thermal analysis is performed, stock lists and spares requirements prepared, and printed circuit masks generated if required. The second session was regrettably shortened because of the absence of two authors, but the remaining two' papers provided a continuation on the VLSi theme. Richard Jennings of DMT Corporation described a low cost but powerful interactive graphics system for VLSI design and layout based on a DEC PDP11/23. He discussed secondary stores and display devices to explain his design of a single-user interactive graphics system (IGS) with a Winchester disc and cartridge tape backup, and a non-interlaced raster-scan colour graphics display with intelligent controller. A separate keyboard and alphanumeric display is used, and a small data tablet is available. The software runs under RSX-11 M, a standard DEC operating system. It includes DRC software, symbolic layout capability, graphics editor, and interfaces to various mask generation systems, as well as accepting input from several commercial graphics systems. DECNET communications software is used for links to other machines, such as a VAX computer, to offload tasks which are unsuitable for the limited capabilities of the IGS computer. The software is written in DEC assembler, but plans are afoot to conve~t it to language C and run it under the increasingly popular UNIX operating system. The final electronics paper concerned a symbolic layout system for IC masks. Serge Pravossoudovitch of the Automation Laboratory, Montpellier, France, discussed SYLAM. This is a system which greatly facilitates the development of new symbolic languages so that IC designers can work with a language which suits them and with which they are familiar. The basic symbolic level of SYLAM is very close to the physical mask level, and provides a set of primitives for the language designer to use in defining his own higher level language. The system is claimed to be readily
volume 14 number 4 july 1982
adaptable for differing technologies. Overall the papers reflect the current trend in electronics CAD towards the design of VLSI circuits. This naturally encompasses advances in many areas of graphics, as well as the traditional facets of electronics CAD such as simulation, layout, and analysis. While successful VLSI chips have been designed with
Building design : modelling Two of the three papers presented in this session addressed the vexed question of how to describe building geometry to the computer in a way which is natural to the user; the third paper proposed an approach in which the program itself generated building geometry. The paper by John, Julia and Peter Frazer ('Use of simplified three dimensional computer input devices to encourage public participation') described a variety of prototype systems intended to allow computer software to understand design intention by directly 'reading' a physical model made up of electronic components. In some of the prototypes the components represent spaces and are plugged into each other; in other prototypes the components represent walls and are plugged into a baseboard. The presentation evidenced a considerable intellectual investment in the concept but one was forced to the conclusion that significantly greater investment would be needed to bring the concept to an implementation which was, at one and the same time, generally applicable and positively helpful. Eliot Feibush's paper ('A geometric input and editing system for architectural design') also dealt with the input
Geometric design Dr Mullineux and Dr Bali, both of Loughborough University, UK, presented two contrasting views on how to deal with cubic and higher order parametric curves. Dr Mullineux first showed that some higher order curves may not be as complicated as they appear. This can be seen by substituting for t in a cubic curve with t as the parameter, ~(s + s2 ) = t. When the resulting parametric curve equation based on s is simplified, it is formidable and of sixth degree, yet both equations represent an identical curve. Thus this particular sixth degree parametric equation could
very primitive CAD facilities, it is only by extensive use of comprehensive CAD that the true potential of microelectronics will be available to the average designer, and production custom chips become a practical reality.
P W Foulk
of building geometry - elegantly but more conventionally. The TOPDRAWE R system enables the architect to create and edit a representation of 3D building geometry which is viewed on a high speed refresh vector graphics display. The user creates the geometry by assembling it from a catalogue of parts held in a series of libraries; it is viewed in a main viewing 'port' and, from complementary angles, in three smaller ports. Each view changes dynamically in response to 'zoom', 'dolly' and 'pan' commands, a facility well illustrated in the video-tape recording which supplemented the presentation of the paper. The paper from Alan McCartney and Bob King ('MICROBE: a microprocessor based building layout planning system') stimulated controversy during the discussion period. The layout generation algorithm, efficiently implemented on a microprocessor, allows the architect to monitor and redirect the process of search for what is essentially a uni-variate optimum spatial arrangement. A more focused and valuable discussion might have resulted if this paper, and that by Gero and Radford on Pareto optimisation, had been scheduled within the same session. T W Mayer
be simplified to a third degree equation. In general there is no exactly identical simplified solution but the paper dealt with changing the parameter (reparametrizing) to produce a sufficiently good approximation to a high order parametric equation, using a lower order equation which could be employed more economically. It illustrated methods of obtaining a first approximation to a simpler equation, and then of iteratively improving the approximation until a satisfactory solution was obtained. The methods used were invariant with respect to translation, rotation and scaling of the curves. Among the illustrations of the
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method Dr Mullineux showed how an eighth order parametric representation of a complete circle could be simplified to a reasonable good fourth order parametric representation. I n contrast to the above use of parameter changes to simplify the form of representation, Dr Ball used reparametrization to produce a more complicated form of representing the parametric cubics used for the boundaries of bicubic patches. To explain why, he considered a simple situation which could arise when lofting shapes. A surface is defined by sections in two parallel planes at its ends. Each section consists of two straight lines with an acute angle between them, linked by a tangential parabola. The loftsman sees these as defining two ruled surfaces linked by a tangential ridge of parabolas. Three bicubic patches are to be defined to represent each ruled surface and the ridge. Although all the boundaries can be represented by parametric cubics it is found that if the first end section is matched exactly then the other end cannot be matched because the vectors aP aP (l, v) have dual 0u (0, v) and ~uu roles: to maintain continuity of slope between adjacent patches and to control internal shape. These roles clash and the reparametrization advocated by Dr Ball is used to resolve this conflict. Two further parametric values (~o (v) and al (v) are introduced as coefficients into the bicubic equations. These can themselves be of any order in v but the quadratic form does not offer enough flexibility. A cubic form enables the tangents to the bicubic curves at the ends of the patch to be independently scaled and the task then is to optimize the variations of eo (v) and ~j (v) to obtain the best fit to a desired surface. The user need not worry about the mathematics involved, and a suitable representation hidden within the program can force intermediate sections to be parallel to each other. In the ensuing discussion the main points raised were when would the four years effort already invested in the work be crowned by an industrially useful package, and a counter proposal along the lines that if designers could be persuaded to initiate shapes as bicubic patches there would be no need for work to make bicubic patches fit the sorts of shapes discussed. The work described by Mr Dokken of the Central Institute for Industrial
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Research in Oslo showed how points and B-spline curves could be used as a basis for a geometric system for describing curves and surfaces based on four low level functions: •
Find zeros of a Bernstein polynomial. • Subdivide a B-spline curve lying in r-dimensional space. • Calculate the dot product of two B-splines. • Express the i th derivative of a B-
Micros in the design office This session was something of an experiment. Although microcomputers had been invented by the time of CAD80 they had hardly made much impact. This time, however, there were enough good papers describing applications of micros to fill a whole morning, and enough interest in them to keep the Winter Garden comfortably full. In fact the session was something of a Micro CAD82 as the papers spanned mechanical, architectural and electronic applications (there were even one or two which were reminiscent of a vendor session), and also covered the range from programs written for some specific analysis (COMPACS; aerial tuning and acoustics), via the general analysis techniques (GENESYS subsystems and finite element analysis)
Mechanical engineering J P Smith talked about Compeda's experiences in implementing an engineering graphics application system on a microcomputer. They had started from experience in marketing similar software for mainframe and large minicomputers and had set out to develop a portable system for microcomputers of the 8-bit 64 kbyte size. Subsequent developments lead them to favour a 256 kbyte computer with two 5 Mbyte disc drives, or possibly 128 kbyte if the end-user's need for expansion to accommodate other applications is small. The author noted trends which control the development. Thus as more functions are built into terminals it is natural to download selected operations from the host to the local intelligent terminal. Due to the wide variety of functions available in different terminals it becomes more difficult to achieve stability, compatibility, portability and maintainability in the soft-
spline of order k in r-dimensional space as a B-spline of order k - i in the same space. The author went on to show how these could be used as a basis for a wider range of geometric manipulations. These are said to be used for sculptured surfaces in the program described by Sorgen in the Mechanical Engineering section of CAD 82. W H P Leslie
and drafting to NC part programming. The absence of process planning was just a statistical anomaly: at least one package is available on a big micro. Indeed, most of the papers were talking about big micros (£10 000-£20 000). Certainly all the systems of any pretensions to generality needed a full 64 kbyte memory, or more and discs (machines as powerful as those all early CAD used). Only the programs solving specific design problems tried to use the £ 5 0 0 £1 000 machines which companies in their thousands could buy. Is that a bad thing? Maybe companies in their thousands will give a thought to using a tiny micro to improve their designs (and thus their competitiveness) while they are saving up for a big one to do everything else. M Sobin
ware despite the structured and modular approach they have adopted. Hardware changes in the microcomputer have been the trend from 8 bit to 16 bit and 32 bit chips and from 64 kbyte of directly addressable store towards 256 kbytes and above without substantial increase in real cost. The cost of a viable standalone graphics system (at about £30000)is seen by the author to be comparable to that of a milling machine, which can be easily bought by small engineering firms after a successful year's business. He estimated that the annual turnover in the UK of firms taking part in small batch production of engineering components was over £2 O00M, offering scope for the use of many computer graphic systems. In the discussion J P Smith was asked if his system provided data files in a form that could be transferred simply to larger systems later. This was provided for by a suitable interface. There was also some discussion on the similarity of cases for buying milling mach-
computer-aided design
ines and computer graphics systems. Were not milling machines bought on a case argued on the manufacture of a limited number of bread and butter components more cheaply than by using existing equipment? Smith considered that these machines, like computers, were bought for more general application. Dr Medland described the development at Brunel University of a CAD system based on mechanical engineering design. His main interest had been the effect of small design changes on the overall design, either during the design of a completely new product, or when an existing design is being modified. Experience in working in cooperation with a large company showed that it is relatively easy to design a new part to perform a given function, checking that it performs adequately and has the necessary strength, stiffness, etc. The most difficult task is to ensure that it fits into the existing machine without interfering with some other part of the assembled machine. The program developed at Brunel automatically sorted out the spatial information about each part into a structured filing system or database. This contains the position of the part in the machine space, the maximum excursion of the part in each direction, and full silhouettes, sections, surfaces and internal details. From this information engineering drawing and NC control tape information can be constructed and stored in the engineering section of the file while the associated technical section will contain text files, equations for calculations and pictorial data. It was claimed that information is automatically filtered down from the chief designer's file to the engineering and technical files, enabling a detailer to extract information about all parts in a given area and find first whether the maximum/minimum boxes around each part interfere. If so, the silhouettes of the interfering parts can then be checked for actual interference. In the case of a mechanism this can be done kinematically for all its positions. Each new piece of information generated automatically finds its way to the appropriate part of the data files. The prototype system so far developed has now to be converted into a practical design office tool. W Schliep described an integrated CAD system incorporating mechanical calculation programs. Two main features were illustrated,
volume 14 number 4 july 1982
firstly 2D and 3D geometric modules, parts of the COMPAC system which has been under continuous development at Berlin Technical University since 1969, and COMFEM which generates finite element meshes automatically. COMPAC allows several different approaches to the description of geometry. Firstly 2D contours can be described as an assembly of straight lines, circles and B-spline curves. Then 3D bodies can be described as an assembly of rectangular blocks, cylinders and cones which can be described and placed relative to each other using an APT-like language. Two further solid shapes can be incorporated in the assembly of parts. These are formed from any 2D contour which can either be rotated about an axis to form a solid of rotation, or the contour can be swept along one coordinate axis. These five types of solid can be combined, either by merging at touching surfaces or by interpenetration. In the latter case the curves of intersection are derived as B-spline curves. Complex doubly curved surfaces can also be defined by using points to define B-spline surfaces, and these surfaces can be combined with analytic surfaces to describe engineering components such as centrifugal pump bodies. A unified data structure has been designed for workpiece represen-
tation in five levels: at the top are details of assemblies based successively on volume elements, surface elements, edges, and points with their logical relationships. There i~ a standard Fortran subroutine based interface to allow the user to read, delete and add elements, data and relationships. From the stored data, engineering drawings, sections and perspective views can be generated automatically with hidden lines removed if desired. Design calculations can be applied to the solids so described, with a suitable degree of abstraction to achieve compromise between cost and accuracy. The COMFEM program can then be used to automatically provide 2D triangular meshes, or 3D meshes based on tetrahedra. The mesh density is input and then the program transforms planar surfaces on the object into one of the coordinate planes, segments the edges and constructs the triangular elements using a smoothing algorithm to try to generate equilateral triangles. The meshed surface is then returned to its normal position and adjoining surfaces treated and so on. Subareas can be used when it is necessary to vary the density of meshes in highly stressed areas, using interactive graphics.
W H P Lesfie
CAD82 exhibition The exhibition has more than doubled in size since CAD80, with 64 suppliers of hardware, software, systems and services filling over 15 000 ft 2 of exhibition space. Nearly 5000 prospective purchasers visited the stands; many new products were launched and successful sales reported. Within minutes of opening Ferranti-Cetec sold an EP340 photoplotter to fellow exhibitors Quartech for their London bureau. Norrie Hill received an order for their MINT 1000 drafting system from Condor Hardware Ltd and another from TI Research and Development for a SORCE system. Applicon announced three orders worth $1.5M. Cambridge Interactive Systems sold two MEDUSA Systems to Simon Engineering. Compeda, the biggest standholder at CAD82, were showing the first production version of I DE MS (integrated design engineering and manufacturing system). I DEMS' communications
Quest CIL's 4010 and 4020 printer/ plotters database is controlled by a project management system and links a series of modules: DRAGON for drafting, DUCT for surface modelling, SAMMIE for human factors evaluation, SWORD for production planning, NULISP for assembly balancing and TIMELINK for work study. British Aerospace's APT 140, for five-axis NC machining, can also be plugged into IDEMS. Future
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Control Data's EWS workstation
modules will include solid modelling, project monitoring and robot simulation. One of the biggest crowd stoppers at CAD82 was Applicon's colour solid modeller, based on MAGI's Synthavision. Down the corridor, the same software was being offered as part of Control Data's Cybercad bureau service. Also launched at CAD82 was Control Data's EWS (ergonomic workstation), ergonomic because the twin display has three degrees of freedom and can be adjusted by remote control. Quest's own SAMMI E-designed QDesign workstation was the centrepiece of their stand, along with the Emma 30 photoplotter. Nearby, Quest Cl L were showing their new 4000 A3 flatbed plotter, the 4010 9 in printer/plotter and the 4020 15 in printer/plotter. Benson chose CAD82 for the world launch of their 1425 flatbed plotter. The pen draws at 500 mm/s, accelerates at 1.5 g and comes with an 80 x 24 character VDU. Drafting systems dominated CAD82, exhibition. Perkin-Elmer were demonstrating Lockheed's CADAM, now available on 32-bit minis; AD2000 was also being demonstrated on Perkin-Elmer kit, over on Imlac's stand. Mountford and Laxon were showing MLD, a UK designed 2D system available for about £15 000. True parametrized drafting details are given dummy variables for lengths, angles, etc - is a feature of this system. Parametrized drawings, such as heat
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exchangers, engine blocks and Crane booms, can also be created using Davy Computing's EUCLID (no relation to Matra-Datavision's EUCLID solid modeller over on the DEC stand). Applied Research of Cambridge were showing GDS3 for the first time at CAD82 an enhanced version of GDS with a non-graphic database and Macro Basic. Graphics workstations were also prominent at the exhibition. ICL's PERQ was on show as was Apollo's Domain, recently installed at Manchester University. Recent enhancements to Domain (which stands for distributed operating multi-access interactive network) include cache memory and hardware floating point. CAD software available so far includes DOGS and DRAGON for drafting, ROMULUS for solid modelling, GINO-F for graphics, SPICE for IC simulation and MAINSAIL for VLSI design. Sigma had the first showing of their 20 in ] 536 x 1024 resolution T5470 terminal; and Westward, who used to make displays only for Counting House, introduced their 1024 x 784 pixel 2015 terminal, the C2014 colour terminal, the 2019W workstation, and an inexpensive (£1985) 15 in 640 x490 display, the 1015.
R & H Systems launched the Genisco G-6000 raster terminal at CAD82; and BCD Systems launched the DEPIC (designer picture) 1024 × 1024 colour workstation. MGS had on show their colour graphics system for textile designers. Some specialist turnkey systems were launched at CAD82 - Calma were showing STICKS for VLSI design, Brinland introduced their Micrographics Artworker for PCB design and RacalRedac announced the Redac Rapier multistation PCB designer. Racal were also showing the Radan/Bath University solid modeller which runs on a DEC PDP11 and was described recently in these pages (J R Woodwark and K M Quinlan, 'Reducing the effect of complexity on volume model evaluation' Computer-Aided Design Volume 14 Number 2 (March 1982) pp 89 95). Finally, the most enviable exhibit was the Alfa Romeo Giulietta 1.6, showing what can be done with a Computervision Designer system. The next exhibition in the series will be CADNorth, to be held in Bellevue, Manchester, 1-3 March 1983. CAD84 will be back at the Brighton Metropole 3-5 April 1984.
A/an Pipes
Kenneth Baker, MP and John Dean on the Lucas Logic stand
computer-aided design
30 March--1 April 1982, Brighton Metropole, UK. Organized by ComputerAided Designjournal Sponsored by CADCentre, CAD and Displays Groups of the British Computer Society, CAM-i, CICA, Institution of Civil Engineers, Royal Institute of British A rchltects, UK Department of the Environment. Organized in cooperation with A CM SIGDA. The fifth international conference and exhibition on computers in design engineering attracted 615 delegates from 33 countries, just over half from the UK but notably also from The Netherlands, Sweden, FRG, Finland, USA, Italy, Norway and France. In all 71 papers, including two invited reviews, were presented, in two parallel streams. These included sessions on Introducing CAD into Industry, Databases, Graphics, Education, Drafting Systems, Geometric Design, CADCAM, Micros in the Design Office
and Energy and Thermal Analysis, as well as in the disciplines of Electronics, Building Design, Mechanical Engineering, and Structures. In addition to the formal sessions, there were two days of the ever-popular System Purveyors sessions and, an innovation at CAD82, poster sessions in the exhibition gallery. Appropriately enough in Information Technology year, IT82, the conference was opened by Kenneth Baker MP, Minister of State for Industry and Information Technology. In his opening speech, he announced that he had set into motion a plan to privatize the Department of I ndustry's CADCentre at Cambridge. In this and the next issue we present reports on individual sessions at CAD82 written by the Chairmen of those sessions. Full texts of the papers are available in the CAD82 proceedings which cost £27.50 from Butterworths, Borough Green, Sevenoaks, Kent TN15 8PH, UK.
Chairmen's reports Overview E Arnold gave details of the study the Science Policy Research Unit at Sussex University had made on the introduction of CAD into the UK engineering industry, paying particular attention to interactive graphics systems but also exploring the linking of the information produced by CAD with its use in manufacture. The study noted how intensive government funding in the USA had generated separate types of systems with two different application areas mechanical engineering (for aerospace) and electronics- since about 1960. In 1980 the US CAD industry grew by 80 per cent largely due to reinvestment of profits in new software development. Firms who started in electronics were moving into mechanical engineering and vice versa. The market in the USA was estimated to be £510M. In the UK the much smaller market
volume 14 number 4 july 1982
is estimated to be expanding by about 100 per cent each year, and is largely being met by US turnkey systems, apart from electronic PCB design systems by Racal and Quest and a promising mechanical engineering system by Ferranti Cetec. The firms finding the most suitable mechanical engineering applications of CAD in the UK are in fields where there is a large amount of drafting, and a relatively small amount of R&D work. The exception is the electronics industry which has been able to cope with a great increase in complexity by using CAD without increasing numbers of draftsmen, and to produce VLSI components which could never be designed without CAD. The benefits of CAD to industry are: • increased drawing office productivity • improved design quality
Although union reaction varies from site to site, unions generally seem to realize the value of using CAD for the survival of their industry, and sometimes the union users are more enthusiastic than management. Three steps are common for the successful introduction of CAD. • an initial experimental use of CAD of up to 2 years • some inefficient use in production • a 3 or 4 fold increase in productivity In the UK several large users are emerging from the first and second phases and this may lead to a more rapid introduction of CAD generally. In the discussion following this paper there was some doubt about how the future designers would be trained because these CAD systems provide less opportunity for young draftsmen because of the smaller number required, without reducing the need for users with an engineering background as the designers. Dr Schoffield of Compeda then described Timelink, a program which is used to provide the methods for producing a mechanical component and the time required for each stage of the production. The main virtue claimed was that this was part of a larger integrated production engineering system which not only aids the production engineers, but also supports enquiries from other departments in a factory and also links to business data processing systems.
W H P Leslie
Introducing CAD into industry Dr Lipchin of A D Little, USA, dealt with the managerial, organizational, planning and economic implications for the successful introduction of CADCAM technology to industry, based on a number of studies of successful and unsuccessful attempts in the US. Experience had shown that it had been a mistake to introduce CAD, possibly linked to NC tape production, without first considering the wider implications to the flow of information throughout a firm. A good working system might well result, but it would probably be found that a great upheaval would be necessary if the system had to be extended to cover all the
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manufacturing and/or business applications later. Some users, on the other hand, had started with a modest sized turnkey CAD system which met some of their needs well, but prevented economic extension to some of their special design needs. Business magazines have been proclaiming that CADCAM systems will be beneficial to any firm, typically claiming that they will lead to a 10 per cent increase in pretax earnings annually. US firms have invested over $1.5 billion on CADCAM in the last 10 years: there are 4 000 CADCAM systems with 20 000 work stations in use and this may well quadruple by 1985. Dr Lipchin fears many problems unless senior management gets involved in ensuring that planning includes impact on data processing and business applications. So far most companies have only had 2 - 5 years' experience of CADCAM, and CADCAM has only penetrated to 25 per cent of its potential. Companies have underestimated implementation and maintenance expenses and have difficulty in quantifying the benefits other than increase in throughput and improved production paperwork. J L Murray, at Heriot Watt University, UK, described the joint work programme undertaken by his University and Ferranti Cetec under the Department of Industry/SERC Teaching Company Scheme. He is evaluating the productivity of the Cetec CAM-X software in a number of industrial situations. The abilities of CAM-X to provide an integrated design synthesis and analysis tool were illustrated by a sequence of diagrams indicating how complex components could be built up either from an assembly of simpler solid shapes, or by describing complex solid shapes, using 3D shapes swept through a distance or rotated about an axis. Hidden line removal, sectioning, etc could be applied and the value of hidden line removal was illustrated on a punching die set which was too complicated to visualize without this simplification. On the other hand for simpler shapes it paid to leave the hidden lines in, to speed up recalculation as the design steps proceed. This was perhaps more graphically brought out by the final paper in this session by M C Bonney of Nottingham University. Their GRASP program has been developed to show graphically the movements of a robot, its work load
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and associated conveyor systems and occasionally its operator. -fo show movement it is necessary to start with a series of desired positions of the work load (or tool) and to calculate from this the necessary positions of each moving element of the robot for each load position. Then the configuration of the robot has to be shown at each position. It is usually adequate to represent the robot and accessories by wireframe models, and not to delete hidden lines, so as to
speed up computation. Positions can then be displayed at not too infrequent intervals. However some situations are so complicated that hidden lines must be removed. In such cases it is usually necessary to slowly calculate positions and store the results until a sequence is completed. The sequence of positions can then be quickly displayed and inspected to check for unintended collisions.
Electronics
or 3 layer routing, and single layer ground and power connections. The program operates on cells, which have been previously designed, and global placement is performed to gain an initial starting layout. The cells are placed in 'slots' and interconnected, forming an advancing wavefront across the chip. The global placement, based on imaginary forces between cells, is evaluated after each slot layout. The selection of algorithm control parameters, and its influence on the placement can, if desired, be subject to manual intervention. This can significantly improve the layout, but is not necessary. Being based on cells, the layout of a large chip can be done hierarchically, a cell at one level being designed by Autolayout at the previous level. Times of the order of minutes for -~ 100 cell layouts w e r e quoted, using a PRIME 750, but the number of signals had a considerable effect. Manfred Ward, of Sperry-Univac, described the idea of using mock cells in the automated verification of VLSI circuits. His system uses functional cells which have already been designed and are guaranteed to work, and replaces them with mock cells of identical exterior dimensions for the verification process. The designer uses logic symbol equivalents of the celt design, and produces a logic sketch for input to the system. This is used to run the simulation, generate test lists, and generate an interconnection file. The designer then performs either manual or automatic placement and interconnection routing. After verification, the mock cells are replaced by the real cells for mask generation. Reminding us that not everyone is designing VLSI chips, the final paper of the session was on AIDES, a design system using SSI and MSI circuits. Charles Fritsch of Bell Laboratories presented the paper, and described a series of tools to help the hardware
The first electronics session began with an invited paper 'Simulation of large nonlinear circuits', by Professor Ken Nichols, Head of the Department of Electronics at Southampton University, UK. Current developments in VLSI technology mean that circuft simulation will have to handle circuits which are orders of magnitude greater in complexity than many popular present-day simulators can manage within realistic time constraints. Professor Nichols, thoughtfully leaving the detailed mathematics to readers of his written paper, discussed techniques which will enable simulators to increase their time efficiency. The obvious technique of structured hierarchical design is usually inadequate because high performance, competitive designs often have parasitic elements which require simulation at the full chip level. Network tearing applied to nonlinear circuits was discussed along with the exploitation of latency. Using manually applied network tearing, practical results showed greater than t0 times speed up and greater than 10 times memory savings over a conventional circuit analyser. Because of the presence of parasitics, the improvement by latency exploitation was only about 2 times. Macro modelling is essential for reducing computation time and general purpose, hybrid (analogue and digital) hierarchical simulators have yet to be developed. The use of special hardware, for instance ICL's Distributed Array Processor, will also play a part. The next two papers continued the VLSI theme. Alex Tweedly of Compeda presented a paper on Autolayout, the automatic layout of VLSl chips developed from the MAGIC system. It currently runs on PRIME and VAX computers, and, being a Compeda product, it is integrated with the GAELIC IC design suite. It handles 2
W H P Lesfie
computer-aided design
system designer. System definition is aided by programs which determine the printed circuit technology required, thermal response, testing constraints and cost. This enables alternatives to be rapidly evaluated before settling on the final design. Design entry is done through a graphical schematic entry program and placement is performed. Prototype wiring on a Multiwire computer controlled wiring machine is done directly from the input information so that initial testing can be done. Reliability and thermal analysis is performed, stock lists and spares requirements prepared, and printed circuit masks generated if required. The second session was regrettably shortened because of the absence of two authors, but the remaining two' papers provided a continuation on the VLSi theme. Richard Jennings of DMT Corporation described a low cost but powerful interactive graphics system for VLSI design and layout based on a DEC PDP11/23. He discussed secondary stores and display devices to explain his design of a single-user interactive graphics system (IGS) with a Winchester disc and cartridge tape backup, and a non-interlaced raster-scan colour graphics display with intelligent controller. A separate keyboard and alphanumeric display is used, and a small data tablet is available. The software runs under RSX-11 M, a standard DEC operating system. It includes DRC software, symbolic layout capability, graphics editor, and interfaces to various mask generation systems, as well as accepting input from several commercial graphics systems. DECNET communications software is used for links to other machines, such as a VAX computer, to offload tasks which are unsuitable for the limited capabilities of the IGS computer. The software is written in DEC assembler, but plans are afoot to conve~t it to language C and run it under the increasingly popular UNIX operating system. The final electronics paper concerned a symbolic layout system for IC masks. Serge Pravossoudovitch of the Automation Laboratory, Montpellier, France, discussed SYLAM. This is a system which greatly facilitates the development of new symbolic languages so that IC designers can work with a language which suits them and with which they are familiar. The basic symbolic level of SYLAM is very close to the physical mask level, and provides a set of primitives for the language designer to use in defining his own higher level language. The system is claimed to be readily
volume 14 number 4 july 1982
adaptable for differing technologies. Overall the papers reflect the current trend in electronics CAD towards the design of VLSI circuits. This naturally encompasses advances in many areas of graphics, as well as the traditional facets of electronics CAD such as simulation, layout, and analysis. While successful VLSI chips have been designed with
Building design : modelling Two of the three papers presented in this session addressed the vexed question of how to describe building geometry to the computer in a way which is natural to the user; the third paper proposed an approach in which the program itself generated building geometry. The paper by John, Julia and Peter Frazer ('Use of simplified three dimensional computer input devices to encourage public participation') described a variety of prototype systems intended to allow computer software to understand design intention by directly 'reading' a physical model made up of electronic components. In some of the prototypes the components represent spaces and are plugged into each other; in other prototypes the components represent walls and are plugged into a baseboard. The presentation evidenced a considerable intellectual investment in the concept but one was forced to the conclusion that significantly greater investment would be needed to bring the concept to an implementation which was, at one and the same time, generally applicable and positively helpful. Eliot Feibush's paper ('A geometric input and editing system for architectural design') also dealt with the input
Geometric design Dr Mullineux and Dr Bali, both of Loughborough University, UK, presented two contrasting views on how to deal with cubic and higher order parametric curves. Dr Mullineux first showed that some higher order curves may not be as complicated as they appear. This can be seen by substituting for t in a cubic curve with t as the parameter, ~(s + s2 ) = t. When the resulting parametric curve equation based on s is simplified, it is formidable and of sixth degree, yet both equations represent an identical curve. Thus this particular sixth degree parametric equation could
very primitive CAD facilities, it is only by extensive use of comprehensive CAD that the true potential of microelectronics will be available to the average designer, and production custom chips become a practical reality.
P W Foulk
of building geometry - elegantly but more conventionally. The TOPDRAWE R system enables the architect to create and edit a representation of 3D building geometry which is viewed on a high speed refresh vector graphics display. The user creates the geometry by assembling it from a catalogue of parts held in a series of libraries; it is viewed in a main viewing 'port' and, from complementary angles, in three smaller ports. Each view changes dynamically in response to 'zoom', 'dolly' and 'pan' commands, a facility well illustrated in the video-tape recording which supplemented the presentation of the paper. The paper from Alan McCartney and Bob King ('MICROBE: a microprocessor based building layout planning system') stimulated controversy during the discussion period. The layout generation algorithm, efficiently implemented on a microprocessor, allows the architect to monitor and redirect the process of search for what is essentially a uni-variate optimum spatial arrangement. A more focused and valuable discussion might have resulted if this paper, and that by Gero and Radford on Pareto optimisation, had been scheduled within the same session. T W Mayer
be simplified to a third degree equation. In general there is no exactly identical simplified solution but the paper dealt with changing the parameter (reparametrizing) to produce a sufficiently good approximation to a high order parametric equation, using a lower order equation which could be employed more economically. It illustrated methods of obtaining a first approximation to a simpler equation, and then of iteratively improving the approximation until a satisfactory solution was obtained. The methods used were invariant with respect to translation, rotation and scaling of the curves. Among the illustrations of the
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method Dr Mullineux showed how an eighth order parametric representation of a complete circle could be simplified to a reasonable good fourth order parametric representation. I n contrast to the above use of parameter changes to simplify the form of representation, Dr Ball used reparametrization to produce a more complicated form of representing the parametric cubics used for the boundaries of bicubic patches. To explain why, he considered a simple situation which could arise when lofting shapes. A surface is defined by sections in two parallel planes at its ends. Each section consists of two straight lines with an acute angle between them, linked by a tangential parabola. The loftsman sees these as defining two ruled surfaces linked by a tangential ridge of parabolas. Three bicubic patches are to be defined to represent each ruled surface and the ridge. Although all the boundaries can be represented by parametric cubics it is found that if the first end section is matched exactly then the other end cannot be matched because the vectors aP aP (l, v) have dual 0u (0, v) and ~uu roles: to maintain continuity of slope between adjacent patches and to control internal shape. These roles clash and the reparametrization advocated by Dr Ball is used to resolve this conflict. Two further parametric values (~o (v) and al (v) are introduced as coefficients into the bicubic equations. These can themselves be of any order in v but the quadratic form does not offer enough flexibility. A cubic form enables the tangents to the bicubic curves at the ends of the patch to be independently scaled and the task then is to optimize the variations of eo (v) and ~j (v) to obtain the best fit to a desired surface. The user need not worry about the mathematics involved, and a suitable representation hidden within the program can force intermediate sections to be parallel to each other. In the ensuing discussion the main points raised were when would the four years effort already invested in the work be crowned by an industrially useful package, and a counter proposal along the lines that if designers could be persuaded to initiate shapes as bicubic patches there would be no need for work to make bicubic patches fit the sorts of shapes discussed. The work described by Mr Dokken of the Central Institute for Industrial
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Research in Oslo showed how points and B-spline curves could be used as a basis for a geometric system for describing curves and surfaces based on four low level functions: •
Find zeros of a Bernstein polynomial. • Subdivide a B-spline curve lying in r-dimensional space. • Calculate the dot product of two B-splines. • Express the i th derivative of a B-
Micros in the design office This session was something of an experiment. Although microcomputers had been invented by the time of CAD80 they had hardly made much impact. This time, however, there were enough good papers describing applications of micros to fill a whole morning, and enough interest in them to keep the Winter Garden comfortably full. In fact the session was something of a Micro CAD82 as the papers spanned mechanical, architectural and electronic applications (there were even one or two which were reminiscent of a vendor session), and also covered the range from programs written for some specific analysis (COMPACS; aerial tuning and acoustics), via the general analysis techniques (GENESYS subsystems and finite element analysis)
Mechanical engineering J P Smith talked about Compeda's experiences in implementing an engineering graphics application system on a microcomputer. They had started from experience in marketing similar software for mainframe and large minicomputers and had set out to develop a portable system for microcomputers of the 8-bit 64 kbyte size. Subsequent developments lead them to favour a 256 kbyte computer with two 5 Mbyte disc drives, or possibly 128 kbyte if the end-user's need for expansion to accommodate other applications is small. The author noted trends which control the development. Thus as more functions are built into terminals it is natural to download selected operations from the host to the local intelligent terminal. Due to the wide variety of functions available in different terminals it becomes more difficult to achieve stability, compatibility, portability and maintainability in the soft-
spline of order k in r-dimensional space as a B-spline of order k - i in the same space. The author went on to show how these could be used as a basis for a wider range of geometric manipulations. These are said to be used for sculptured surfaces in the program described by Sorgen in the Mechanical Engineering section of CAD 82. W H P Leslie
and drafting to NC part programming. The absence of process planning was just a statistical anomaly: at least one package is available on a big micro. Indeed, most of the papers were talking about big micros (£10 000-£20 000). Certainly all the systems of any pretensions to generality needed a full 64 kbyte memory, or more and discs (machines as powerful as those all early CAD used). Only the programs solving specific design problems tried to use the £ 5 0 0 £1 000 machines which companies in their thousands could buy. Is that a bad thing? Maybe companies in their thousands will give a thought to using a tiny micro to improve their designs (and thus their competitiveness) while they are saving up for a big one to do everything else. M Sobin
ware despite the structured and modular approach they have adopted. Hardware changes in the microcomputer have been the trend from 8 bit to 16 bit and 32 bit chips and from 64 kbyte of directly addressable store towards 256 kbytes and above without substantial increase in real cost. The cost of a viable standalone graphics system (at about £30000)is seen by the author to be comparable to that of a milling machine, which can be easily bought by small engineering firms after a successful year's business. He estimated that the annual turnover in the UK of firms taking part in small batch production of engineering components was over £2 O00M, offering scope for the use of many computer graphic systems. In the discussion J P Smith was asked if his system provided data files in a form that could be transferred simply to larger systems later. This was provided for by a suitable interface. There was also some discussion on the similarity of cases for buying milling mach-
computer-aided design
ines and computer graphics systems. Were not milling machines bought on a case argued on the manufacture of a limited number of bread and butter components more cheaply than by using existing equipment? Smith considered that these machines, like computers, were bought for more general application. Dr Medland described the development at Brunel University of a CAD system based on mechanical engineering design. His main interest had been the effect of small design changes on the overall design, either during the design of a completely new product, or when an existing design is being modified. Experience in working in cooperation with a large company showed that it is relatively easy to design a new part to perform a given function, checking that it performs adequately and has the necessary strength, stiffness, etc. The most difficult task is to ensure that it fits into the existing machine without interfering with some other part of the assembled machine. The program developed at Brunel automatically sorted out the spatial information about each part into a structured filing system or database. This contains the position of the part in the machine space, the maximum excursion of the part in each direction, and full silhouettes, sections, surfaces and internal details. From this information engineering drawing and NC control tape information can be constructed and stored in the engineering section of the file while the associated technical section will contain text files, equations for calculations and pictorial data. It was claimed that information is automatically filtered down from the chief designer's file to the engineering and technical files, enabling a detailer to extract information about all parts in a given area and find first whether the maximum/minimum boxes around each part interfere. If so, the silhouettes of the interfering parts can then be checked for actual interference. In the case of a mechanism this can be done kinematically for all its positions. Each new piece of information generated automatically finds its way to the appropriate part of the data files. The prototype system so far developed has now to be converted into a practical design office tool. W Schliep described an integrated CAD system incorporating mechanical calculation programs. Two main features were illustrated,
volume 14 number 4 july 1982
firstly 2D and 3D geometric modules, parts of the COMPAC system which has been under continuous development at Berlin Technical University since 1969, and COMFEM which generates finite element meshes automatically. COMPAC allows several different approaches to the description of geometry. Firstly 2D contours can be described as an assembly of straight lines, circles and B-spline curves. Then 3D bodies can be described as an assembly of rectangular blocks, cylinders and cones which can be described and placed relative to each other using an APT-like language. Two further solid shapes can be incorporated in the assembly of parts. These are formed from any 2D contour which can either be rotated about an axis to form a solid of rotation, or the contour can be swept along one coordinate axis. These five types of solid can be combined, either by merging at touching surfaces or by interpenetration. In the latter case the curves of intersection are derived as B-spline curves. Complex doubly curved surfaces can also be defined by using points to define B-spline surfaces, and these surfaces can be combined with analytic surfaces to describe engineering components such as centrifugal pump bodies. A unified data structure has been designed for workpiece represen-
tation in five levels: at the top are details of assemblies based successively on volume elements, surface elements, edges, and points with their logical relationships. There i~ a standard Fortran subroutine based interface to allow the user to read, delete and add elements, data and relationships. From the stored data, engineering drawings, sections and perspective views can be generated automatically with hidden lines removed if desired. Design calculations can be applied to the solids so described, with a suitable degree of abstraction to achieve compromise between cost and accuracy. The COMFEM program can then be used to automatically provide 2D triangular meshes, or 3D meshes based on tetrahedra. The mesh density is input and then the program transforms planar surfaces on the object into one of the coordinate planes, segments the edges and constructs the triangular elements using a smoothing algorithm to try to generate equilateral triangles. The meshed surface is then returned to its normal position and adjoining surfaces treated and so on. Subareas can be used when it is necessary to vary the density of meshes in highly stressed areas, using interactive graphics.
W H P Lesfie
CAD82 exhibition The exhibition has more than doubled in size since CAD80, with 64 suppliers of hardware, software, systems and services filling over 15 000 ft 2 of exhibition space. Nearly 5000 prospective purchasers visited the stands; many new products were launched and successful sales reported. Within minutes of opening Ferranti-Cetec sold an EP340 photoplotter to fellow exhibitors Quartech for their London bureau. Norrie Hill received an order for their MINT 1000 drafting system from Condor Hardware Ltd and another from TI Research and Development for a SORCE system. Applicon announced three orders worth $1.5M. Cambridge Interactive Systems sold two MEDUSA Systems to Simon Engineering. Compeda, the biggest standholder at CAD82, were showing the first production version of I DE MS (integrated design engineering and manufacturing system). I DEMS' communications
Quest CIL's 4010 and 4020 printer/ plotters database is controlled by a project management system and links a series of modules: DRAGON for drafting, DUCT for surface modelling, SAMMIE for human factors evaluation, SWORD for production planning, NULISP for assembly balancing and TIMELINK for work study. British Aerospace's APT 140, for five-axis NC machining, can also be plugged into IDEMS. Future
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Control Data's EWS workstation
modules will include solid modelling, project monitoring and robot simulation. One of the biggest crowd stoppers at CAD82 was Applicon's colour solid modeller, based on MAGI's Synthavision. Down the corridor, the same software was being offered as part of Control Data's Cybercad bureau service. Also launched at CAD82 was Control Data's EWS (ergonomic workstation), ergonomic because the twin display has three degrees of freedom and can be adjusted by remote control. Quest's own SAMMI E-designed QDesign workstation was the centrepiece of their stand, along with the Emma 30 photoplotter. Nearby, Quest Cl L were showing their new 4000 A3 flatbed plotter, the 4010 9 in printer/plotter and the 4020 15 in printer/plotter. Benson chose CAD82 for the world launch of their 1425 flatbed plotter. The pen draws at 500 mm/s, accelerates at 1.5 g and comes with an 80 x 24 character VDU. Drafting systems dominated CAD82, exhibition. Perkin-Elmer were demonstrating Lockheed's CADAM, now available on 32-bit minis; AD2000 was also being demonstrated on Perkin-Elmer kit, over on Imlac's stand. Mountford and Laxon were showing MLD, a UK designed 2D system available for about £15 000. True parametrized drafting details are given dummy variables for lengths, angles, etc - is a feature of this system. Parametrized drawings, such as heat
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exchangers, engine blocks and Crane booms, can also be created using Davy Computing's EUCLID (no relation to Matra-Datavision's EUCLID solid modeller over on the DEC stand). Applied Research of Cambridge were showing GDS3 for the first time at CAD82 an enhanced version of GDS with a non-graphic database and Macro Basic. Graphics workstations were also prominent at the exhibition. ICL's PERQ was on show as was Apollo's Domain, recently installed at Manchester University. Recent enhancements to Domain (which stands for distributed operating multi-access interactive network) include cache memory and hardware floating point. CAD software available so far includes DOGS and DRAGON for drafting, ROMULUS for solid modelling, GINO-F for graphics, SPICE for IC simulation and MAINSAIL for VLSI design. Sigma had the first showing of their 20 in ] 536 x 1024 resolution T5470 terminal; and Westward, who used to make displays only for Counting House, introduced their 1024 x 784 pixel 2015 terminal, the C2014 colour terminal, the 2019W workstation, and an inexpensive (£1985) 15 in 640 x490 display, the 1015.
R & H Systems launched the Genisco G-6000 raster terminal at CAD82; and BCD Systems launched the DEPIC (designer picture) 1024 × 1024 colour workstation. MGS had on show their colour graphics system for textile designers. Some specialist turnkey systems were launched at CAD82 - Calma were showing STICKS for VLSI design, Brinland introduced their Micrographics Artworker for PCB design and RacalRedac announced the Redac Rapier multistation PCB designer. Racal were also showing the Radan/Bath University solid modeller which runs on a DEC PDP11 and was described recently in these pages (J R Woodwark and K M Quinlan, 'Reducing the effect of complexity on volume model evaluation' Computer-Aided Design Volume 14 Number 2 (March 1982) pp 89 95). Finally, the most enviable exhibit was the Alfa Romeo Giulietta 1.6, showing what can be done with a Computervision Designer system. The next exhibition in the series will be CADNorth, to be held in Bellevue, Manchester, 1-3 March 1983. CAD84 will be back at the Brighton Metropole 3-5 April 1984.
A/an Pipes
Kenneth Baker, MP and John Dean on the Lucas Logic stand
computer-aided design