1. Automation

• As machines are used in production, we need to consider how they are applied to the tasks.

1.1 Introduction

1.1.1 The Questions

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• What?: By adding electronics, sensors, actuators, computers and mechanisms human capabilities can be augmented to improve manufacturing.

• Why?: In many cases there are valid reasons for assisting humans

tedious work -- consistency required

dangerous

tasks are beyond normal human abilities (e.g., weight, time, size, etc)

economics

• When?

 

1.1.2 Why Bother with Automated Manufacturing?

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• Without production, a company has nothing of real value to sell.

• A company which is poor at production is guaranteed to go out of business eventually.

• Competition drives production, and every advantage counts.

• Automation can act as valuable weapons against competitors.

• Advantages of Automated Manufacturing,

improved work flow

reduced handling

simplification of production

reduced lead time

increased moral in workers (after a wise implementation)

more responsive to quality, and other problems

etc.

1.2 THE BIG PICTURE

How Computers Can Be Used in an Automated Manufacturing System

 

• Some Acronyms

CAD: Computer Aided/Automated Design: Design geometry, dimensions, etc.

CAE: Analysis of the design done in the CAD system for stresses, flows, etc. (often described as part of CAD)

CAM: Computer Aided/Automated Manufacturing: is the use of computers to select, setup, schedule, and drive manufacturing processes.

CAPP: Computer Aided Process Planning: is used for converting a design to a set of processes for production, machine selection, tool selection, etc.

PPC: Production Planning and Control: also known as scheduling. Up to this stage each process is dealt with separately. Here they are mixed with other products, as required by customer demand, and subject to limited availability of manufacturing resources.

Factory Control: On a minute by minute basis this will split up schedules into their required parts, and deal with mixed processes on a factory wide basis. (This is very factory specific, and is often software written for particular facilities) An example system would track car color and options on an assembly line.

Workcell Control: At this system level computers deal with coordination of a number of machines. The most common example is a PLC that runs material handling systems, as well as interlocks with NC machines.

Machine Control: Low level process control that deals with turning motors on/off, regulating speeds, etc., to perform a single process. This is often done by the manufacturers of industrial machinery.

1.2.1 Acronyms

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• A Blessing and a curse

• Acronyms make it possible to convey exact technical meaning in a quick efficient way. But, they also make it possible to confuse a subject with poorly defined terms

 

• There are many acronyms involved with this book, such as CAPP, CIM, CAM, CAD, CAE, PPC, MRP, MRP-II, UNIX, DOS, CNC, DNC, etc.

1.2.2 What is CAD/CAM?

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• Using computers for design and manufacturing

• We computerize the easier tasks, which are tedious and mistake prone when done manually.

• In CAD we design product geometries, do analysis (also called CAE), and produce final documentation.

• In CAM, parts are planned for manufacturing (eg. generating NC code), and then manufactured with the aid of computers.

• CAD/CAM tends to provide solutions to existing problems. For example, analysis of a part under stress is much easier to do with FEM, than by equations, or by building prototypes.

• CAD/CAM systems are easy to mix with humans.

• This technology is proven, and has been a success for many companies.

• There is no ‘ONE WAY’ of describing CAD/CAM. It is a collection of technologies which can be run independently, or connected. If connected they are commonly referred to as CIM

1.2.3 What is the difference between CAD, CAM AND CIM

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• CAD/CAM involves the use of computers to make Design and Manufacturing more profitable.

• Parts of CIM use CAD/CAM techniques and products to try and make the factory fully connected using computers.

• The essential difference is CAD/CAM provides the tools, CIM is the philosophy which is used when organizing the computers, programs, etc. and all the information that flows between them.

• Another way to think of CIM is that it allows the structure of an organization to be entered into the computers.

• CIM focuses on connecting the various CAD/CAM modules.

1.2.4 Examples of CAD/CAM Usage

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• An FMS is made out of CAD/CAM components (and can be PART of a CIM system).

• The list below shows users of FMS in the U.S.A. The variety of applications illustrates that the technology may be used by any industry. The companies employing the technology show confidence in the technology. [Source -- find]

Table 1:

Company

FMS location

Product

Main supplier

Aerospace: Engines

Avco Lycoming

Stratford, CT

Engine components

Kearney & Trecker

Pratt & Whitney

Columbus, GA

Engine components

 

General Electric

 

 

WIlmington, NC Lynn, MA

Engine components

Lodge & Shipley

Aerospace

Boeing

Auburn, WA

Aircraft components

Shin Nippon Koki

FMC

Corporation

Brea, CA

Aiken SC

Joints and Hoses components for military vehicles and rocket launch systems

Cincinnati Milacron

General

Dynamics

Fort Worth, TX

Components for F-16 aircraft

Westinghouse

Lockheed

Georgia

Marietta, GA

Airframe parts

White-

Consolidated

Vought

Dallas, TX

Aircraft fuselage for B-1 bomber

Cincinnati Milacron

McDonnell

Douglas

Torrence, CA

St.Louis, MO

Aircraft components

Missile bodies

Cincinnati Milacron

Giddings & Lewis

Westinghouse

Electrical

Systems

 

Lima, OH

Aircraft generator components

Westinghouse

Equipment

Caterpillar

East Peoria, IL

Decatur, IL

Tractor components

Cincinnati Milacron

Giddings & Lewis

John Deere

Waterloo, IA

Tractor parts

Kearney & Trecker

Detroit Diesel

Detroit, MI

Piston engines

Lamb Technicon

Ford

New Holland, PA

Sheet metal parts for farm equipment

Trumpf

Ingersoll Rand

Roanoke, VA

Hoist equipment

White-Sunstrand

Mack-Truck

Hagerstown, MD

Transmission

Housing and casting

kearney & Trecker

Machine Tool

Cincinnati

Milacron

Mt. Orab, OH

Parts for plastics

Processing equipment

Cincinnati Milacron

Mazak

Florence, KY

Parts for machine tools

Mazak

White-

Sunstrand

Belvidere, IL

Machine tool parts

White-

Consolidated

Other Industries

Allen-Bradley

Milwaukee, WI

Motor starters

kearney & Trecker

Borg Warner

York, PA

Compressor components

Comau

Federal Mogul

Littiz, PA

Bearings

 

G.E. Medical

Systems

Milwakee, WI

Parts for medical equipments

Trumpf

Mercury Marine

Fond Du Lac, WI

Outboard motor crankcase and block

Kearney & Trecker

 

NY Air Base

Watertown, NY

Brake Systems

 

OMC-Evinrude

Milwakee, WI

Outboard motor parts

 

Swedish Machine Group

Onan

MInneapolis, MN

Electrical switchgear for generators

Trumpf

 

Remington Arms

Ilion, NY

Firearm parts

 

Union Special

Huntley, IL

Sewing machine bodies

kearney & Trecker

Westinghouse Electric Corp.

Pittsburgh, PA

Wire harness for electrical equipment

 

Xerox

Webster, NY

Panels for copiers

 

• The table below indicates the countries which are using the FMS technology. The countries with the higher numbers of FMS systems are also a sample of the major economic leaders. [Ayres et al, 1991, pg. 212, an estimate based on limited information] [ source: find]

Table 2:

Country

FMS installed

percentages

Austria

6

0.7

Belgium

6

0.7

Bulgaria

15

1.7

Canada

4

0.5

CSFR

23

2.6

Finland

12

1.4

France

72

8.2

FRG

85

9.7

GDR

30

3.4

Hungary

7

0.8

India

1

0.1

Ireland

1

0.1

Israel

2

0.2

Italy

40

4.5

Japan

213

24.2

Netherlands

8

0.9

Norway

1

0.1

Poland

5

0.6

Romania

1

0.1

Singapore

1

0.1

South Korea

4

0.5

Spain

2

0.2

Sweden

37

4.2

Switzerland

6

0.7

Taiwan

5

0.6

UK

97

11.0

USA

139

15.8

USSR

56

6.4

Yugoslavia

1

0.1

• Driving forces of CIM/FMS are shown in the figure below[ source: find]

1.2.5 Computer Integrated Manufacturing (CIM),

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• We should aspire to meet the ideals of CIM when designing CAD/CAM technology

• CIM architectures contain,

Computing Hardware

Application Software

Database Software

Network Hardware

Automated Machinery

• CIM benefits,

Optimizes data flow in company

Simplifies sharing and translation of information

Reduces careless errors in data

Allows checking of data against standards

Promotes use of standards

• CIM modules,

Customer Order Entry

Computer Aided Design (CAD) / Computer Aided Engineering (CAE)

Computer Aided Process Planning (CAPP)

Materials (e.g., MRP-II)

Production Planning and Control (Scheduling)

Shop Floor Control (e.g., FMS)

• Reference model for enterprise related CIM [find source]

1.3 PRACTICE PROBLEMS

Problem 1.1 CAD and CAM are,

a) Integrated production technologies.

b) The best approaches to manufacturing.

c) Part of CIM.

d) None of the above.

Answer 1.1 c

Problem 1.2 FMS systems are,

a) faster than robots.

b) a good replacement for manual labor.

c) both a) and b)

d) none of the above.

Answer 1.2 d
1.4 COMPUTER AIDED MANUFACTURING (CAM)

• CAM is the use of computers for any part of manufacturing.

1.4.1 Overview

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• The competitive world of manufacturing is requiring that computers now be used in a production environment to make things faster and more precise.

• Some basic roles of computers in manufacturing are,

Prepare product designs for shop floor production

Schedule jobs into machines in the factory

Track inventory, work in process, etc.

Control workcells

Control of processes

• When these functions happen automatically, and don’t require human intervention, we tend to say they are part of a CIM system.

1.4.2 Devices

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• Basically any device that can be controlled or interfaced to a computer, and be used in automated manufacturing.

• These devices include,

robots

NC machines

PLCs

material handling

 

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