Artificial intelligence withinAustin Roverby J. WallbankUniversity of Warwick

and N. A. WhittinghamAustin Rover Group Limited

The use of artificial intelligence techniques promises to be of greatbenefit to engineering design and manufacture. This article outlinesthe current perception of artificial intelligence within Austin Roverand gives examples of the present status of work on its applicationwithin the company.

Introduction

Much interest has been aroused inrecent years concerning the coming ofage of artificial intelligence (Al) tech-niques in general, and expert systems inparticular. This interest is not only fromthe technical press, but exists in a liveform on many shopfloors. The appli-cation of Al techniques promises greatbenefits in terms of producingcomputer systems for both control andinformation processing more quicklyand reliably than was previously pos-sible. A further perceived benefit wouldbe the use of non-mathematicallydefined control systems.

Austin Rover Group (ARC), like manyother companies both large and small,has, of necessity, highly competent and \experienced systems developers. Thetrends in technology within industry atpresent are also, of necessity, forcingengineers, managers, technicians andmany non-systems specialists to designand develop or specify often complexsoftware to carry out their local jobfunction. While much of this design anddevelopment work could be carried out

in conjunction with in-house systemsspecialists or, indeed, with externalconsultants, the resulting system maythen not be fully designed for thedepartment's working methods.

The concept of expert system shells,where the 'programmer' of the shell hasonly the task of structuring the infor-mation and entering it in a controlledbut English language type format, is ahighly desirable one. This makes theuse of expert systems apparently as sim-ple as database programs, with theadded advantage of allowing for'reasoning' to occur in the program.Consequently, many groups withinARC perceive a use for the techniquesas publicised. This need is felt in areasas diverse as:

design analysistool designdesign for manufacturetrainingautomated manufacturing systemsproduct engineeringproduction and material control,

and others, including some non-engin-eering functions.

Computer-Aided Engineering Journal June 1987

Some Al techniques may also beemployed in embedded systems whichARC uses, but is not developing, forexample vision systems and voicerecognition. The greatest emphasisfrom these groups is towards twogeneric problem areas:

• dealing with non-quantified andoften inherently scattered data• dealing with very structured buthighly complex data which may haveseveral possible conclusions from oneset of data.

An example from the first area is easilygiven, but of extreme difficulty toaddress, i.e. design for manufacture.Here some rules are easily defined,while others are still unknown. Thereare programs currently available and indevelopment that allow a design to betested for manufacturability, but theseprograms still require expertise of theprocess to run.

An example from the second areawould be the maintenance function oncomplex automated manufacturingcells. Within these cells many complexdevices act in close proximity, oftenwith computer control linking allactions. In the event of a failure in anycomponent, the cell must cease oper-ation, and this is often accompanied bysome diagnostic aid which informsmaintenance of the fault location. The

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Fig. 1 The Austin Rover Advanced Technology Centre at Warwick University

diagnostic system, however, can onlybe configured to sense a certain amountof data, and generally is not designed toreason from a number of indicatedfaults the real underlying cause. Thisreasoning is at present carried out byexperienced maintenance staff with theaid of manuals, previous backgroundknowledge of the' system and basicengineering understanding.

Considerable interest in Al tech-niques exists within ARC Some systemsare being developed at present, and thelevel of understanding of Al is growing.

Current perception of Al withinARC

Although there is a commitment tointroduce Al into the company and alsoclearly perceived needs, there is alsodisillusionment and disappointmententering into the Al debate. This disil-lusionment arises from problems thatexist throughout the computer field:namely, that of the quality and accuracyof much of the published information.Most published articles in the field fallinto one of three categories:

• academic papers exploring the lim-its of reasoning, possibilities, fuzzylogic etc.• general articles giving global viewson what may be achieved• a small number of articles on whatappears to have been achieved usingthese systems.

Much of this type of information is writ-ten by systems proponents, and hencetends to be overtly positive. Similarly,suppliers of expert system shells andenvironments, many written for the

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microcomputer market, appear to indi-cate great potential for their products.What must be borne in mind, however,are the usual computer considerations,a few of which are highlighted below:

• On developing a knowledge baseon one system, can it be transferred toanother? Generally the answer to this is'no', and at least some re-writing is nec-essary. This is necessarily important aseffort is invested in developing a know-ledge base and structure. If this is ini-tially prototyped on one system and nottransferable to another then mucheffort can be wasted.• Is it possible to get links into and outof the system (for example databases,mathematical-based languages and pro-grams) or, perhaps, into control sys-tems? This will allow for expertreasoning where necessary and otherdata processing techniques as appropri-ate on various parts of the problem.Restrictions here may again result in thetransferability problem.• Has the system any size/speed limi-tations which may affect practicalusage? How can system response beassessed in early development? If thesystem is to be used in control type situ-ations, re-writing in a faster languagemay become a priority and extremelyexpensive. Simple demonstrations donot demonstrate the slowness of someof the algorithms operating on reason-able-size knowledge bases.• How friendly are the input and sys-tem testing routines? Is it necessary tobe a computer programmer/operator?Often these are not uniformly detailedfrom manufacturer to manufacturer;consequently, it is difficult to assessthem on a comparative basis.• Will later versions of the systems becompatible with earlier ones? If not, are

we again to be faced by obsolescence?• Can the shell only be run on oneoperating system? If so, and it is to beused for prototyping, major efforts maybe required to transfer the shell to theuser system. Even an introductory sys-tem developed under the Alvey Pro-gramme to give a wide range ofappreciation runs only on IBM PCs andcompatibles.

• Good documentation is required,and system debugging may not yet havebeen completed. Software companiesin this field also may be financiallyunstable in the long term. This may leadto inefficient development and, in thelonger term, no security.

• The understanding of artificial intel-ligence leads not only to the runningand development of programs, but alsoto a re-examination of the types of prob-lem which are most effectivelyaddressed in this manner.

• Can the shell carry out the reason-ing process required? The concepts offorward- and backward-chaining mayinitially be easily understood by simpleanalogies. In real life, however, eitherone (and sometimes both together) maynot prove sufficient. At this point it maybe necessary to edit the inferenceengine — is this facility available?

• Can the knowledge base be pro-tected against unsolicited modificationand yet have the facility to explain itsreasoning? To untrained personnel theconcept that the computer may be onlygiving a best guess is an anathema: thismust be clear from the outset, and con-sequently the knowledge bases need tobe protected from self-appointedexperts.

• How are the system limits to bedetermined, and what actions are to betaken when the system is unsure?Expert systems are capable of errorswhich are not 'bugs'.

• How can an estimate be made ofdevelopment time, cost and benefitsderived? In larger companies provisionof budgets can be as restricting asdeveloping the technologies. Havingfaith in what a system will do will notsatisfy a hard-nosed financier's views oninvestment (nor should it be the view ofa manager on a controlled budget).

Many of the above considerations can-not at present be quantified, althoughmuch research may provide some of thedata necessary and perhaps highlightsome of the problems likely to beencountered. Austin Rover, however,has accepted this state of the market,recognising the potential of the tech-nology. Consequently, projects haveoriginated to act as exploratory pro-grams with a view not only to develop-

Computer-Aided Engineering Journal June 1987

ing usable working systems, but also toincreasing awareness throughout thecompany.

Education and training for Al

Within a large organisation there willalways be a wide variety of understand-ing of any technology, and there willalso be a desire to buy an 'off-the-shelfsystem. Consequently, there is a neces-sity to understand not only some of thefundamentals, but also how and whereto apply the commercially availablepackages. This need is apparent from allends of the engineering/managementspectrum, and has resulted in a range ofeducational/training activities in orderto stimulate the growth of the Altechniques.

To ensure that ideas on the usage ofnew technology gain the correctresponse in terms of acceptable budgetproposals and also fit in with companypolicy, senior management needs to beaware of the possibilities and limitationsof the technology as early as it is practi-cal. ARC has started a series of seminarsto brief management on new tech-nology after a very successful pro-gramme run by Warwick University.These awareness programmes coverthe whole of the company, includingareas which traditionally may beregarded as indirect functions, forexample finance and personnel.

Stemming from this initial widecoverage, individual managers maythen perceive a need to explore further.In this case it is necessary that all con-cerned should learn from each other,and following an initial Al seminar forsenior managers, ARC has set up agroup involved with expert systems. It isthis group that will determine the needforfurthertrainingand theground to becovered by that training. This methodensures that a wide examination of thepotential of the technology occursacross the company and that trainingneeds can easily be identified. A furtherpoint is that often the best source oftraining can be easily identified by thegroup.

Different technology groups withinthe company have taken differentapproaches, based on their own cir-cumstances. One group has seconded ateam member to the Turing Institute todevelop a system for the company. Thiswas initially funded through the AlveyJourneyman scheme. A second group isworking closely with Birmingham Uni-versity, developing a useful system for

. forging design (described in more detaillater). A further group began its owneducation by using the Alvey Expert Sys-tems starter pack before buying bigger

shells for development work.Two other groups are now also start-

ing to use Al — one via a sponsoredPh.D. student at Warwick University,and.the other using the knowledge ofthe systems developed within the com-pany to examine a particular problemarea and, it is hoped, move towards pur-chasing a useful shell in the near future.The company's recently openedAdvanced Technology Centre at War-wick University (Fig. 1) will developin-house knowledge of about eight dif-ferent shells initially to enable detailedadvice to be given.

From this very broad front the ques-tion may now be asked as to the pos-sibility of standardisation on the useof shells within ARG such that a morethorough training process can beimplemented company-wide. Thisstandardisation would obviously giveother useful benefits, but is at present aquestion for the future.

Use of Al in forging tool design

Within ARC, as previously stated, sev-eral projects are under way. Forgingdesign is chosen as an illustrativeexample because it deals with a blend ofconventional programming techniquesand some Al uses. This illustrates wellwhere Al is applicable, and potentiallymore powerful than conventionalcomputing.

Austin Rover has recently installed anumber of precision metal formingmodules within the Birmingham oper-ations area. These modules aredesigned to produce high-toleranceforged components, often possessing'as forged' features which require littleor no machining. These requirementshave resulted in highly automated plantwhich operates in an environment moreakin to a toolroom than a conventionalforge, and which necessitates accurateand well understood methods of deter-mining the component formingsequences and subsequent tool designand manufacture.

A collaborative project between Aus-tin Rover's Manufacturing TechnologyDevelopment Department at Long-bridge and the Department of Mechan-ical Engineering at the University ofBirmingham commenced in April 1986with the objective of automating thisdesign process. The project is sup-ported by the UK Science and Engineer-ing Research Council ACME Directorateand is due for completion in March1989. The use of Al techniques is beingincorporated such that previous know-ledge and experience of forging andtool design can be retained and used toshorten the otherwise lengthy and

Computer-Aided Engineering Journal June 1987

expensive process of full mathematicalanalysis of each component design. Itwill also enable a more friendly 'front-end' to the forging programs to bedeveloped.

This integration of conventionalanalysis techniques and Al will thusallow the segregation of the theoreticaland empirical methods used during tooldesign from those which still remain atype of 'black art'. It will also allow thesubsequent automation of both into asingle computer-based system. Thisshould result in tool designs which,rather than undergoing costly and time-consuming tool trials, have been ana-lytically proven to the best of currentknowledge. Integration is thought to bethe key idea here, because 'intel-ligence', certainly within engineeringand manufacturing, must includereasoning about complex theoreticaland empirical knowledge, and there-fore the interfacing of Al and con-ventional techniques is essential.

System overviewThe system was described in greater

detail in a recent paper written by Prof.C. W. Rowe of the University ofBirmingham and published in a specialissue of Computer-Aided EngineeringJournal on the topic of expert systems(Ref. 1). A diagrammatic overview isgiven in Fig. 2. In the system shown Altechniques are being used principally toassess the confidence in a design pro-duced by the empirical design moduleon the basis of similarity to previousdesigns held in various data and know-ledge bases. This type of philosophysimulates the process that a tooldesigner might go through when creat-ing a new design from previous experi-ence. The intelligent knowledge-basedsystem (IKBS) module also front-endsand controls the operation of the othermodules.

Work is also being carried out at ARCto deduce a set of 'intelligent' designrules which could, at a later date, beincorporated into the system toenhance the operation of the empiricaldesign module. A recently conductedknowledge acquisition exercise resultedin the formation of an encouraging setof initial design rules, some principlesof which were until then totally unre-cognised and certainly not writtendown. The rules as they stand are beingused by designers so that they can beevaluated in future design operationsand developed into a comprehensiveset which could then be used by thesystem. In the mean time the automa-tion of these rules, in their limited form,is also being investigated via a micro-computer-based expert system shell.

To achieve this set of rules, manufac-

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PRODUCT DESIGN

EMPIRICAL FORGING, PRE-FORM AND TOOL DESIGNMODULE. utilising solid modelling

IKBS MODULE, assesses confidence in design module results, front-ends ' * (

and controls other modules

,. high confidencelow confidence

TOOL MANUFACTURE: via automaticNC part program generation

FINITE-ELEMENT ANALYSISMODULE, forging process simulation

COMPONENT PRODUCTION

Fig. 2 Precision metal forming intelligent knowledge-based system

turing engineers and tooling engineers(designers) at many levels wererequired to sit together and exploretheir own knowledge thoroughly. Manyof the rules developed were sub-consciously held by designers and/ormanufacturing engineering. This dem-onstrates the necessity for many dif-ferent branches of a company to worktogether to develop a complete design-manufacture interface. This is acharacteristic of the many areas ofexpert system development. As theresponsibility for these systems mayoften stretch across many functions,management and control needs tocome from a senior level.

One of the conceptual problems thathas arisen during this work has been inattempting to integrate conventionalalgorithmic methods of problem solv-ing, which are so firmly established inengineering, with the more object-ori-ented methods of Al. For this reasondetails of all the Al techniques used arebeing retained by the knowledge engin-eers; this has the added advantage that,in the case of the design rules, tooldesigners who identify a deficiency in

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the rules will need to inform the know-ledge engineers so that a rule can bemodified or a new rule added. In con-trast, in the case of the system's IKBSmodule a 'self-learning' approach isbeing adopted. Another possible exten-sion of the system which is also beingconsidered is the use of Al techniquesto assist the pre- and post-processing offinite-element analysis data (a systemhas been designed elsewhere for this).

The current status of the IKBS projectis that the finite-element analysis andinitial empirical design modules havebeen installed at Longbridge and workis ongoing on both the IKBS andadvanced design modules at the Uni-versity of Birmingham. The IKBS mod-

ule is being written in the Lisp Allanguage, and therefore training in thelanguage is currently under way atLongbridge together with the prepara-tion of a suitable hardware platform.

Conclusions

The present status of Al within ARC hasbeen summarised, and concerns aboutinformation available on expert systemshave been highlighted. Substantialinterest exists within the company andexploitation is beginning on a widefront. Further work will develop in thisarea as more unbiased information isgiven and engineers are trained to bemore aware of the technology.

Reference

1 ROWE, C.R.: 'An intelligent knowledge-based system to provide design and manufactur-ing data for forging', Computer-Aided Engineering journal, 1987, 4, (1), pp. 56-61

Dr. J. Wallbank is with the Department of Engineering, University of Warwick, Coventry,Warks. CV4 7AL, England, and N. A. Whittingham is Senior Engineer with the ManufacturingTechnology Development Department, Austin Rover Croup Limited, PO Box 41, Longbridge,Birmingham B31 2TB, England.

Computer-Aided Engineering Journal June 1987