Education in Basic Technology - A Renaissance in Developing Countries

Copvright © IFAC Trends in Co ntrol and Measurement Education. Swa nsea. L'K. 1988

EDUCATION IN BASIC TECHNOLOGY - A RENAISSANCE IN DEVELOPING COUNTRIES A. Yamamoto Training Cmter, Yokogawa Electric Corporation, Musashino-shi, Tokyo 180, J apan

Abstract:

Developing countries are trying to rapidly modernize their

industries, but they also need to consider how to provide basic technical education for as many people as possible in order to support and effecti v el y utilize this technology.

vocation training courses in technical

colleges and polytechnics are an ideal way. The author has just spent two years in Singapore under the Colombo Plan international technical cooperation scheme, and has developed a basic instrumentation and control training methodology with an emphasis on imparting the "big picture" as well as the fundamentals.

This paper explains the methodology, and

presents a typical syllabus for an introductory course . ~eywords:

Control theory;

industrial control;

education;

instrumentation;

INTRODUCTION

educational aids; process control;

teaching; sensors.

lihood of farmers, hunters and fishermen living in the vicinity.

Some developina countries, in their haste

Basic training

is just as important, because -- in order

to catch up with the forerunners in tech-

to reduce the possibility of human error,

nology, see the acquisition of the latest

and to be able to quickly and effectively

technology as vital for their social,

respond to system failures -- operators

economic and industrial development --

and managers must have a thorough practi-

but do not see the futility of simply

cal understanding of the system they are

acquiring the technology without settinq

supervising.

up the basic infrastructure that is re-

training has contributed to major dis-

quired to support and utilize it fully.

asters at chemical plants and nuclear

It is not simpl y a matter of providing

power plants even in advanced countries.

A lack of thorough basic

the necessary stable power supplies and reliable communication systems, and teach-

In developing countries, however, the

ing a few operators the basic operatinq

resources available for training and edu-

procedures.

cation are much more limited.

It is necessary to instill

To limit

in a wide spectrum of people -- ranging

the number of people who are eligible for

from operators and technicians to plant

higher education, the education and exam-

managers -- an understanding of basic

ination system tends to become extremely

control theory, the knowledge required to

theoretical and broad but superficial,

support and utilize the new technology,

with the emphasis on memorizing the eso-

and an appreciation of the human, environ-

teric rather than understanding the prac-

mental and financial consequences of in-

tical.

adequate planning or training.

tors can pass the examinations for the

Planning

Only a minority with private tu-

is important, because larqe-scale indus-

better universities.

trial schemes can have a disastrous ef-

ceeds in restricting the numbers at uni-

fect on the environment, and on the live-

versity, but fails to instill the basics

235

Such a system suc-

236

A. Ya ma mo to

in a wide spectrum of people.

While it

METHODOLOGY

is more satisfying to teach a small elite than to teach large numbers of "ordinary"

The most effective ways to transmit knowl-

people, universal education is the real

edge and skill to a wide range of people

secret of social and technological pro-

are basically:

gress.

Just as tall trees have broad

roots, industrial and technological giants need a broad basic training infrastructure.

In the more advanced coun-

(1) Visualization

(2) Big picture approach (3) Learning through practice Vi suali za t ion the appropriate use of

tries, companies provide considerable

illustrations

on-job training, as well as supporting

stand.

correspondence courses and refresher

which can be understood by all mankind.

courses.

In classroom lectures, overhead projector

In developing countries, tech-

helps people to under-

Pictures are a common language

nical colleges and pol y technics pla y a

(OHP) transparencies can be used to dis-

ver y important role in vocational

play figures.

training.

course, especially, it is recommended

For this purpose, then, there is a need

"ice-breaker" between the lecturer and

for syllabus and textbooks to be "well

his audience.

At the beginning of the

that a number of cartoons be used as an People learn best in a

tempered" -- neither too detailed nor too

friendly setting.

su p erficial, but containing necessary and

of some cartoons which are suitable for

Fig. 1 shows examples

sufficient theor y in an easily-digestible

introductory instrumentation and process

form for introductory-level audiences.

control courses.

') ) )

)

} )

«'~ (al

(Wo)man - man contro l

( b)

(Wo lma n -mach ine con tro l

(d)

Au toma ti c cont r ol - r u naw ay

/

(c l

~ an - a n imal

Fig. 1.

cont r o l - con tr o l l o st

Introduction of control concepts by cartoons.

237

Educa tion in Basic Technolog\' The "big picture" approach to the industrial control instrumentation course starts with a block-diagram overview of a feedback control svstems as shown in Fig. 2, then each block in turn -- process, sensor, controller and actuator -is studied in detail. To reinforce skills through practice is a fundamental way of not only teaching manual skills, but also of helping students

Fig. 2.

A control system configuration

retain theoretical knowledge.

Classroom lectures can only describe abstract con-

cepts:

these should be verified, elabo-

SYLLABUS

rateQ, and reinforced by laboratory experiments.

It is important to allow

adequate laboratory time,

A typical basic syllabus for an indus-

inter linked

trial control instrumentation course

with lecture time, for this purpose.

~ypical

TABLB 1

1. 2.

Syllabus for Industrial Control Instrumentation

7.

Intr oduction What is co ntr ol? Sy stem st ruc t ure Concep ts

is shown in Table 1.

Foreword

7.2

4.

Gene r al Basic pr ocess co n trol loops (Flow , pre ssure, level. temperature) Process Ch arac teristi cs

5.

Mathematical Representati.on of Process Models

7.3 7 .4

Leve l

Temperature

8.

Fundamental Terms

Transducer

Tr ansmi teer CRlibratio n Error

Span Inaccuracy 6.2

9.

9.1

flowmeter

Variable area IJltrasonic

Turb ine

9.2

Measurement Fundamental terms and units

liQui d col umn

9.3

Capa cit ance

Buoyancy

6 .6

Radiation Bimeta l

Rad i at ion py r ometer Compos i t i o n

Mechani cal/Servo Variabl e Transducers Potentiometer Vel oci ty

Variable Transformer

Encoder

Magnetic scale

Acce 1 er a t i on /For c e

Rangeabi1ity

10.4 Hydraulic Or ive s Electroma~neti c

Or ives

10.6 Electric Servomotors DC motor

Valve

Valve

10.2 Butterfly Valves Bnd Louvers 10.3 Power Cyl inders 10 . 5

Turbidity

Inner valve

chara cter is tics

Filled t hermal sys tem

Analytical Se ns or s pH Densi ty Vis cosity

Synchro

Da ta

PlO con trol

10.1 Control Valves Pneumatic ope rated diaphragm motor body

Thermo couple

Humidity 6.7

Weight

Temperature Measureme nt

RTO

Binary data

transmission Co mmu n ication protocols Digital C:ontrol Algorithms

10. Final Co ntrol Elements

Level Measurement Hydrosta ti c h ead

r.eneral

(DCC)

algor i thms

Ge neral 6.5

Distributed computer co n t r o l Digital Data Communication

Funda mental mathematics

Pr es s u r e

F.lastic elements

transducers 6.4

Class if ication of Computer Con tr ol Data l ogger Direct digital control (DDC)

Binary representation

Pres~ure

manometer

Cascade con trol Auto Feed fo rwar d control

Supervisory computer cont r ol (SCC)

Flow Measuremen t

Positive disp l aceme nt

6.3

Systematic tuning

Feedback with feed f or ward c ontrol D1gi tal C:omputer Cont rol Systems

Accuracy rating

Di Herential pres s ure Ma~netic

Co ntrol Ha rdw are Controll er Tuning

Ratio Con trol selector control

Measurement

P+I

Selection of

Ult imate sensitivity Reac tion Curve Multi-Element Control Systems

Sensors/Transducers 6.1

P+I+D

Controller Quality

Servo 6.

P+D

co ntrol action

8.

na i n Pressure

Inte~ral

Proportional

Derivative

Instrumentation Diagrams

Response

Control Action On - of f

Simple control examples

1.

Flow

Contro llers 7.1 Functional Configurati on

AC motor

Pulse motor

10.7 Electrical Power Converters 11. Contr ol Center Design 11.1 Man-Machine Interface 11.2 Safety And Envir o nment Consi derati o ns 12. Control System Applications

Pas i t i o ner

238

A. Yamamoto

LECTURE NOTES As lectures are conducted according to the syllabus, each subject in the syllabus should ideally correspond to a section of the teaching materials.

It

was not possible to find a single suitable textbook for a vocational education course in industrial control instrumentation, so a special set of lecture notes was prepared for the purpose. Ideally, the lecture notes should be arranged so that each teaching unit is condensed into one or two pages.

Explan-

ations that are too long may make the material less interesting and less easy to understand.

(a)

Disturbance in control

(b)

Human sens e s

(c)

Primitive Bourdon tube

If a detailed explanation

is thought necessarv, it should be put in an appendix as a supplementary tutorial. Again, using attractive illustrations or cartoons, such as shown in Fig. 3, can help to keep the audience interested in the subject.

In future, when audiovisual

facilities become available in such educational institutes, it will be possible to use videotapes/discs to increase the learning efficiency.

However, it would

take a lot of time to prepare audiovisual program material that is suitable for the course.

OHP illustrations are a simple

and inexpensive way to enhance lectures.

LABORATORY EXPERIMENTS The best way of 'learning through practice' is to use laboratory experiments.

J~" ~~=JSss~~~ ~ ~4?" ~-------""

Kits for industrial control instrumentation training laboratories are available from many suppliers, and provide good material for assigning basic experiments to the students.

But basic experi-

ments using these kits alone are not sufficient.

To give the students confidence

with their acquired knowledge and skills in industrial control instrumentation, they should have to design and set up a small process control system themselves -- with flow, pressure, and temperature control loops, for example.

(d)

Utilizing radiation

It is very

effective to make them think by giving them such a project to do on their own.

Fig. 3.

Effectiv e use of cartoons

in instrumentation lectures.

Education

In

Basic Technology

239

Such projects must include the selection

tial to prepare appropriate figures,

and application of actual sensors/trans-

lustrations or cartoons for such courses.

ducers, siqnal

con~itioners,

controllers

il-

Laboratory experiments are also indispen-

and control valves, etc . rather than sim-

sable for reinforcing teaching.

ply followinq standard procedures with

classroom lectures and related labora-

laboratory kits from suppliers.

A typi-

All

tory experiments must be properly organized for best results.

cal example of a recommended students' project in process control instrumentation is the

air-weig~t

control system project is stu~ents

s~own

e~ucational

The syllabus and "CAE"

flow computinq

in Fiq. 4. and safe.

paper were part of an elective course in process instrumentation and control for about 250 third-year mechanical engineer-

must calculate the main tube

and control valve sizing,

(Cartoon Assisted

F.ducation) methodology described in this

This

decide the

ing diploma course students (5 classes)

ranqes for flow, pressure and tempera-

at a polytechnic.

ture,

course consisted of the author's "CAE"

select transducers and siqnal

The process control

conditioners, decide the control action,

tutorial plus 90 hours of lectures and

and

30 hours of laboratory work (ten differ-

set controller tuning parameters.

A thorough understandinq of industrial

ent experiments) spread over about 30

control instrumentation theory -- pro-

weeks.

cess, sensors,

odology greatly improved motivation and

control-

trans~ucers,

The introduction of "CAE" meth-

enhanced understanding, allowing the

lers and valves -- is required.

amount of class time for the tutorial to be reduced from 24 to about 12 hours. CONCLUSIONS Visual instruction is quite effective and

REFERENCE

powerful in the beqinner-level education and vocational training in

in~ustrial

control instrumentation that is in developing countries.

neede~

It is essen-

AIR TEMPERATURE

Les nonaldson and E. E. Scannel (1986). Human Resource Development.

Addison-

Wesley, U. S. A.

AIR WEIGHT FLOW

PT AIR SUPPLY

E)(HAUST

Fig. 4.

Air-weight computing control system recommended as a students project.