University of Nigeria Virtual Library

Serial No

Author 1

OSUAGWU, Charles Chukwudi

Author 2

Author 3

Title Software Engineering: An Education For

Automation

Keywords

Description Software Engineering: An Education For

Automation

Category

Engineering

Publisher

Development Countries And The New

Information Age

Publication Date

September, 1989

Signature

.

DEVELOPING COUNTRIES AND THE'NEw IMFOWMATllOM AGE.

Proceedings of the International Conjerencec on urveiopirrg Countries And The New In formation Age:" ...- , . . . -4 - - . 2- I

I DECONIA '89. I !

Organised by

SPONSORS \

L

. '4

Nigerian Telecommunications Ltd.

Nigerian National ~ e t r o l e u m CO-operation , ,

ON ~ E ~ X J T I N G COUNTRIES AND THE NEW 1NE1ORi"ik'l'lGfl AGE' .,. SZJ;QNIAt 89

SOE'T'vJm mGINmRING: AN EDUCXTIGI4.G ZUNDMENTAL FOR AUTOMATIOfi

C. C. OSUAGWJ Department of Elect ronic Engineering, University of Nigeria,

Nsukka, Nigeria.

ABSTRACT

The in t eg ra t ion cf computers i n indust ry f o r computer aided desi- gn (CAD), computer aided manufac- turlng (CAN) and p lan t condition uocicor ing (PCM) i n the highly i n u - a s ~ r i a l i s e d countr ies i s part- l y responsible f o r t h e i r increa- sed i n d u s t r i a l product iv i ty and t h e g rea t e r market share of t h e i r goods and se rv ices i n t he highly competiti've i n t e rna t iona l markets. I f Nigerian indus t r i e s are t o be- come competive i n fu tu re through the appl ica t ion of low cost auto- mation i n design, production and maintenance, f a c u l t i e s of engi- neering must r e s t ruc tu re t h e i r cu r r i cu l a now, t o o f f e r courses i n software engineering; and t o i n t eg ra t e t he use of computers i n individual courses. The paper suggests s t r a t e g i e s f o r introdu- cing CAD and d i g i t a l s ignal pro- cessing education f o r low cost automation if we, as a nation, a r e t o survive t he challenges of the emerging information techno- logy.

1, INTRODUCTION

Computers have revolutio- nised the way work is orgacised and may i n fu tu re lead t o a fuo- damental re-def in i t ion of what a c t i v i t i e s cons t i tu te work. T h i s gradual t r a n s f e r of s k i l l e d work from man t o mechine accele- r a t ed when computers were trans- formed from huge, very expensive cen t ra l i sed f a c i l i t i e s t o emall, a f fordable , personal systems by t h e enabling microelectronic technology. The astonishing e f f e c t s of t h i s technology have

b e e n f e l t i n o f f ices , i n medi- cine, i n education and i n t h e home (1). But t h e g rea tes t trans- formation i n t h e - u s e of computers hss occurred i n indus t r ies where com2ucers have been moved from Lhe b o ~ d rooms t o the shop f l o o r and t h e i r applicz t ion p r o f i l e has changed from a predominantly accounting function t o use i n in tegra ted manufacturing.

Computers a r e rout inely used i n high technology indus t r ies t o aid design (CAD), t o a s s i s t i n mmuf acturing (CAM), t o carry out f a u l t disgnosis (PCM) and t o per- form complex or hazardous opera- t i o n s with t h e a id of computer control led robots. Successes achieved by researchers i n t he f i e l d s of a r t i f i c i a l i n t e l l i genze ( A I ) , speech recognition, expert systems and robot v i s ion a r e being used t 9 achieve computer i n t egsat ed f l exibl e manufacturing. The r e s u l t i s a continued increa- s e i n the nat ional productivi ty of the information r i c h countr ies i n t h e post i ndus t r i a l era and t h c i i - almost complete dominance of the h ighly competitive world market.

The need of these countr ies t o export i n order t o survive l e d them t o invest i n these kay indust r ies . The projected CAD- CAM workplaces i n t he USA w i l l ?each 190,OOC by 1995 and the re w i l l be 21,000 CAD workplaces i n Geraany by 1990; while t he t o t a l world CADLCAM market was estima- t ed a t 3 - 4 b i l l i o n U.S, do l l a r s i n 1986 (2).

Indus t r ies ia America and

185,

L E G E N D

Word processing

Communication ,

Computer aided design and Engineering

ACC ADM PM R a D WP P C COMM C A D 8 C A E

Fig, I. Computer Appllcotionr in Nigarian . Indurtriar ... * .

. . . . - - . .

evolution of a maintenance cul- ture i n Nigeria, For t h e expen- sive, continuou~ly operating large scale systems increasingly used i n the petro-chemical, l iqui- fied natural gas and steel mills, the tradit ional breakdown or pre- ventive maintenance i s inadequate. Such high availability plants re- quire the use of plant condition monitoring (PCM) techniques for incipient fault detect ion and diagnosis.

' PCM techniques are computer bas'kd and offer a number of advan- tages over tradit ional techniques:

structured maintenance decisions. In PCM, the cmputer acts as a very powerful asaistant thct helps a salntenance , - engineer exercise proper maintenance judgement;

(ii) enables a more accurate modelling of the failure mechanism and theref ore bet ter understanding of the poss ible f a i l u r e modes;

(iii) facilitates the interac- t i o n between design and maintenance, For example, the operational knoidl e- dge accumulated by ~ n a i ~ t enance engineers &bout t h e performance of a plant ox machine ca2

P h z e I/ hct lv i t ies

Steps! ----

I I Givzn mechire to b e i m x i t ored

Given Signature i .Develop algorithm

.Search f o r i n v a r i a n t based oc d e t a i l e d understasding of

Beature Extra- f ea twes ~n ~ i ~ e -;irne, t h e signal genera ) ct ion For s t a t i s t i c a l 6 ~ d I tion and transmi- F a u l t Detection ' frequency d o n a i ~ s

ssior process .Establ ish Thresholds .Develop software --- i

i i .*.st; Feature Ext rac t ion For Fault Diag- nosis

Gigen Zacl c Det,,?cticr. Fea tures ,Search f c r dLagnost is feature i n t h e t ime and Prequency d o ~ a i a s

. I t e r a t e %ill r e s u i t L b sat is - f a c t or:

,Select s l n i m feature set

t i o n p roc cond

1

Maintenance Planning

I Ha in t enance Opera t ion

From appendix 1 and equa- possible to implement computa- 1, it i s c l e a r that signal t i ona l l y intensive algorithms i n

essing algorithms for plant r e a l time unless f a s t transform ition monitoring a r e mathe- techniques are used, Many such

matically and computatianally techniques exis t f o r analysis i n intensive. It may not be t h e frequency domain.

.- - 1

Givea a kncwa Inc~-?xent L Faul t .Decide when to caryy out maintenawe

.Organise resourc :s I (tools, t e s t equipmcxs , spare p a r t s , personnel se lec t ion , logistics e t c)

.Restore machine to acceptable opezathg S t 2 C d

!

. L : 9 > ; ~ ~ e n ~ i-.ctf - l r t - t l eF I

1 I

PROCEEDINGS

The computer handles digi- t a l informatim. But the acquired signature is i n analogue form, Theref ore , the acquired signature must .be suitably conditioned (amplified and f i l t e red ) and then sampled,

From the foregoing, it is clear t ha t , i n engineering soft- ware fo r pl'ant condition monito- ring, d i g i t a l signal processing education is required i n t h e following areas:

.Signal acquisition, condi- t ioning and windowing

.Algorithm design i n the time, s t a t i s t i c a l and frequency domains

,Past transform techniques .Digital f i l t e r i n g (foc noise suppression o r removal)

,Sof Ware design methodology (software l i f e cycle)

.Digital design with micro- processors (for implemen- t ing programmqbl e stand alone.faul t diagnostic instruments),

The depth , t o which such a course i s taught depends on the level a t which i t is offered (undergraduate, postgraduate, continuing enginee- r ing education) and t h e experience of the course participants, The resources needed and the s t r a t e gies t o be adopted i n introducing d i g i ~ a l signal processing educa- t ion for. PCM a re similar t o t h a t required for CAD education (see section 5 - 7). 3.

ges and

PliOBLEMS OF INTRODUCISG PCPl AND CAD TECETOLOGIES,

Given the numerous advsnta- of using PCM in maintenace CAD in design, why are. theae

technologies not used i n Niigeria? The reasons are many..

The low cost of computbg is responsible f o r the widespread application of computers i n engi- neering i n the indus t r ia l i sed countries. But i n Nigeria, t h e cost of computing i s re l a t ive ly very expensive because of the very high cost of imported c.ompu- t e r hardware and software. This high cost of computing a c t s as a disincentive t o the widespread use of computers par t icu lar ly i n the medium and small scale indus- t r i e ~ . Industr ia l managers i n such fims may not be able t o justify the high, capi ta l costs involved i n the integration of computers i n indus t r ia l design, production and maintenance.

secondly, many indus t r i a l managers i n Nigeria have no idea of comput era and programming. Such subjects were not generally taught when they were i n school, So they are i n no posit ion to evaluate the usefulness of csmpu- t e r s i n industry and hence a r e unlikely t o plan t o use them i n makntenance o r i n t h e i r product design, Clearly, there i s a need f o r professional soc ie t ies and univers i t ies t o organise eonti- nuing engineering education on t h e engineering application of compu- t e r s , Such courses w i l l help in- dus t r ia l managers appraise arid evaluate the benefi ts and r i s k s of automation.

_--..*I - -

Thirdly, there is an acnte shortage of trained manpower i n the use of plant condition moni- toring techniques a s well as i n CAD technology. The reason for this appears circular. There a r c no high technology industrien in Nigeria where workers can l earn by doing or learn informally through exposure the techniques of condition monitoring and CAD,

PROCEEDINGS - DECOXVIA ' 89

known as software engineering (9) . ~ii . 4 shows the l i f e cycle of a s o i p a r e product .

Customer i requirements ri r'

Y Study document

and users

integration and ~dsign definition acceptance pion8 test plons

Fig. 4 : The life cycle of a software product (Source : P. D . Sizer) .

5, ESSENTIAL COMPONENTS AND CONTENTS OF A SOFT'rJkRE E N G I I ~ I N G COURSE FOR CAD AND PCM.

The p r o l i f e r a t i o n of perso- nal computers has made possible the teaching of CAD-CAM i n mi- v e r s i t i e s i n the industrialised countries. Although the accura- c i e s of such computers may not be adequate for industrial design use, nevertheless they provide the means of imparticg t h e nece- ssary s k i l l s required of engi- neers of the future, Advances i n processor architecture, i n memories, including secondary memories, indicate that faster, more powerful and inexpensive microcomputers w i l l be available

for engineering practf ce. The major object ive of a software e m - neering education i s t o teach the e f f e c t i v e use of computers as too la i n engineering practice,. The achievement of this objective requires work i n three essential areas: Hardware, Software anti System Configuration,

5-1. HARDWARE

Hardware for C!B-CAM has t w o essential components:

(a ) Computer system and environment.

(b) Machine tool system and environment,

Tabia 1: Paci l i - t i es far CAD-CAM education (Source N. Nakajima, 1987).

- Comput e m --

Large Scale Mainframe (LSM) (LSM) + turnkey CAD LSM + Mini CAD

LSM Middle-Scale Mainframe (MsM)

+ PC (45 Sets) M Turnkey CAD Super mini + PC Sup er mini Mini CAD

Mini + PC ( 3 5 Sets)

Mini PC CAD

PC (1 - 11 Sets) PC (20 - sets)

Planning

A (UaSSault systems, France) 1 set

MICRO CADAM (CADAM Services Inc, Japan} 9 Sets

(ii)

(iii)

ELSE

In t roduce a couiyse ix c o m p t e r s i n u l z t i o n ,

Ic t roduce an o p t i o m l in t roductory course i n CAD ~ I A t n e f ioa l year,

Stay i n Phase I

PHASE 111

I f t h e need e x i s t s i n t h e economy, and i n d u s t r i e s and government a r e w i l l i n g t o g i v e massive. a s s i s t a n c e t o procure t h e r equ i red hard- ware and software resources ; and t h e s t a f f s t r e n g t h i s adequate then

DO

(1)

( i i )

f i i i )

( i d

ELSE

Modify curriculum t o o f f e r f u l l undergraduate courses i n CAD,

S ta r t post-graduate courses i n CAD.

E s t a b l i s h j o i n t Univer- s i ty - indus t ry research co l l abora t ion i n CAD.

Encourage indus t ry and prof 'ess ional s o c i e t i e s t o i n s t i t u t e p r i z e s i n sof tware engineering and CAD.

Stay i n Phase 11.

END DO

CoTtware engineering is c e n z ~ d t o t h e successful u s e of T - d,, ;r.d PCM technologies. It i s t h ,,. .>+imdre important t h a t facul- 1- - , J of engineering should res- : rscLcre t h e i r curriculum t o u i f z r t h i s fundamental course snd t o i n t e g r a t e t h e u s e of corn- p t e r s i n most courses, The bene- Zits of t h i s approach w i l l be immense. The na t ion w i l l have enough skilled and competent mark power not only t o acqui re and adapt t h e CAD technology i n fu- t u r e but a l s o t o start l o c a l so f t - ware i n d u s t r i e s t h a t can s u s t a i n such a technology, Government and i n d u s t r i e s must provide t h e huge mater ia l and f i n a n c i a l resources requi red f o r t h e in t roduc t ion of CAD and PCM education, A phased s t r a t e g y f o r introducing CAB edu- ca t ion based on t h e needs of t h e economy and a v a i l a b l e resources has been suggested as one of t h e most p r a c t i c a l ways of acqui r ing and adapting t h e CAD technology, A s i m i l a r technique should be u s e d f o r introducing PCM educa- C 3 . 0 U *

OSUAGWU, C.C. "A Proposal f o r t h e Applicat ion of Microl. computers a s Technological Development Tools i n Nigeria. I' Proceedings of t h e F i r s t UNIBEN Confere- nce on Engineering and Technological Development Sept, 1987, P. 6 - 14.

EURR, N, "CAD-CAM In tegra t ion : Ti ' facts on t h e Employment

. ..- .- .:i, d.-ation. Q u a l i f i c a t i o n s . - anc Requirements f o r Fur- t h e r Training of Engine&', I n t . J. ~ p p l T Engng. Educ, 1987, P. 263-2?1-

VASSILAKOPOULOS , V. "Strat e- gies f o r the In t roduc t ion of CAD- Education". Int. J, appl. Xngi-;-i, E m c , 1987, r. 207-245.

NAKAJIMA, A. "Today1 s CAD-CAM Education, i n Japan". In t . J. appl. Engng Educ, 3-98?, p. r13-2'78-

WACHUKU, M.A. "Microproce- s sor i n Nigerian Industry: A Survey". Department of E l e c t r o n i c Engng, Univer- s i t y of Nigeria, Nsilirka. (Submitted f o r PuSlica- t ion).

OSUAGWU, C,C, "An assessment of the Impact of Nigerian vendors on extent of use of computers i n Nigeria" Dept. of E lec t ron i ' c Engineering, University of Nigeria, Nsukka.

NOLL, A.M. "Cepstrum Pitch Determination" JASA 41, 1%7, P o 293-309.

GUPTA, G,K, "Computing. i n the Developing Countries of Asia", Proceedings of the IFIP 9th World Com- puter Congress, Septa. l%12, 1983, Po 439-4%.

SIZER, ED, "Software Engi- neering and Guidelines f o r t h e Production of Rel iawe Software". T h e Marcfini Review, Vol. XLIV; ND.~. 223, 1981, P. 204-,224.

APPENDIX 1 : NUMERICAL SUBROUTINE FOR COMPUTING THE N Q W i DISTRIBUTION,

The PCF f o r a normally dis- t r i bu t ed variable x with mean and variance 2, denoted by jd i s given by:

The probability d i s t r i b ~ t i o n fun- c t ion PDF is the i n t e g r a l of t he deksi ty func t ion

f12(x) = Blob [: x < X f

Prob -rx s XI - x -) Now i f

The f u n c t i n n 8, (ZI c m he

0

,. The e r ro r function e r f ( z ) whose de f in i t i on i s

PROCEEDINGS

can be computed using the qppro- ximation

where al = 0.0705230784

a2 = 0.0422820123

a3 = Ol00927O5272

a4 = O.OOOl5ZOl43

a5 = 0.0002765672

86 = 0.0000430638

For a data w i t h mean m, standard deviation, s, range (a-b) , . window width c and t o - t a l number of i n t e rva l s K the se- quence ( 2 ) is obtained from t h e relation:

f o r j = 1 t o K

Next obtain t h e erf(Z/ $?) using t h e approximation of equation 6. Obtain g(Z) using t h e equations 4.