34 Automation in Manufacturing35 Computers and Production36 Computer Systems in Product

Manufacturing

Unit 11Automating Manufacturing Systems

Green Manufacturing LinkGreen Manufacturing LinkGreen Lighting in Manufacturing Facilities

It takes a lot of energy to power the manu-facturing industry. You might think of huge fur-naces melting steel or trucks and ships carrying cargo around the globe. But have you ever thought of how much electricity is used to pro-vide light inside all of the manufacturing facili-ties and office buildings in the world?

The greenest way to provide light inside of these facilities is to let in the natural light of the sun. Facilities are being designed and retrofit-ted to let in more natural light. This decreases energy consumption while increasing the morale of the workforce.

Fluorescent light fixtures have always used less electricity than incandescent bulbs. For that reason, fluorescent lights are much more

common in commercial facilities. But older style fluores-cent fixtures are being replaced with newer, smaller, style fluorescent fixtures. Changing to the newer fixtures decreases energy consumption by 20 percent. Compact fluorescent lights (CFLs) are used to replace traditional incandescent lightbulbs in industrial as well as residential applications.

LEDs (light-emitting diodes) were once used only as indicator lights on electronic devices. As LED technology advanced, they became more common in applications like automobile taillights, traffic signals, and flashlights. LEDs are now being used in light fixtures. They are ideal for use in manufacturing facilities because they use very little energy, create very little heat, and last for a long time.

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Chapter 34Automation in Manufacturing

automation. Replacement of human control for a machine, process, or system, with control by mechanical or electronic devices.

ObjectivesAfter studying this chapter, you will be able to:

✓ Give a brief history of automation. ✓ Name a device that has revolutionized factory automation. ✓ List five reasons for employing automation. ✓ Name at least three components of CIM. ✓ Explain what CAD and CAM are.

Throughout the history of manufacturing, people have sought more effi-cient ways to make products. These efforts can be divided into two tasks:

✲ Designing products for efficient manufacture

✲ Making products more efficiently

Although divided, these tasks are not independent. Often the work of one directly impacts the other. For example, Eli Whitney’s work in producing mus-kets with interchangeable parts required design changes. Musket parts were designed so that all like parts were exactly alike so they could be easily manu-factured. The parts were made so that any like part would fit any musket. This enabled the muskets to be assembled more efficiently. Thus, the first task impacted the second.

This interdependence must be addressed if a company is to compete in the world market. See Figure 34-1. Key to this focus is automatic or automated manufacture, which is often called automation. Automation is the application of control to an apparatus, a process, or a system by means of mechanical or electronic devices. Automation uses computer and automatic controls to replace direct human control.

Development of Automated Manufacturing

It is difficult to trace automated manufacture to any specific event or inven-tion. Ideas for automatic manufacturing machines have many roots.

Early efforts to accomplish automation used strictly mechanical controls.

This sample chapter is for review purposes only. Copyright © The Goodheart-Willcox Co., Inc. All rights reserved.

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One of the earliest attempts in factory automation came around 1800. At that time there was a grow-ing need for blocks (pulleys) to raise and lower sails, move heavy cargo, and position cannons on ships. See Figure 34-2. A typical warship of that age required over 1400 blocks. At that time, each block was individually made by artisans working on lathes, drills, and other machines. In England, Henry Maudslay undertook the task to produce blocks using an automated production line. After six years of hard work, the world saw its first large-scale, mass production, manufacturing line. However, mass production did not extend to other industries for another 50 years. Furthermore, its adoption was not in England, but in America. Such a movement, marked by revolutionary changes in production, is called an industrial revolution. This industrial revolution ushered the Western world into what became known as the industrial age.

Even earlier roots of factory automation trace back to mechanized toys. They were developed to entertain members of high society. One such toy, a wooden model of a pigeon designed by Archytas of Tarentum, dates back to about 350 B.C.

Soon after 350 B.C., Hero of Alexandria began to experiment with pneumatics and hydraulics.

He developed a number of water-driven mechanisms including automatic

Efficient Design Efficient Manufacture World-Class ProductFigure 34-1. Manufacturers must develop efficient designs and manufacturing processes to produce world-class products. (American Petroleum Institute, Reynolds Metals Co., Deere and Co.)

Figure 34-2. This is the Cutty Sark, an early sailing ship that brought tea from India.

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temple doors and singing mechanical birds. His work was applied to many mechanical toys, music boxes, and musical clocks developed in Europe during the eighteenth century. These devices had mechanisms that used disks. The disks had ridges or holes that encoded a program (detailed operating instruc-tions) that guided the apparatus. The program code held on the disk caused the item to chime or move according to a set plan.

The idea of programmed cards or disks was adapted in 1804 by the French loom maker, J. M. Jacquard. His looms used a series of punched cards to pro-gram the machine to automatically produce a set pattern in fabrics and carpets. In 1822, Babbage proposed building a machine called the Difference Engine to automatically calculate mathematical tables. The Difference Engine was only partially completed when Babbage conceived the idea of another, more sophis-ticated machine called an Analytical Engine. Later, Herman Hollerith applied this principle to an automatic data-recording and accounting machine using punched cards. This invention was first used for the 1890 United States census. It reduced the time needed to tabulate the results of the census by 50%. His punched cards became the forerunner of the computer card, which was used to enter data in early computers.

In the twentieth century, the idea of a punched-tape program was tried on manufacturing machines. These machines, called numerical control (NC) machines, became the backbone for the second industrial revolution—the automation age.

The arrival of modern factory automation came with the recent develop-ment of the computer. This useful machine is the dominant feature of the com-puter revolution, which impacts our lives every day. Its advent brought us out of the automation age and moved us into the information age. See Figure 34-3.

Computers

Control Machines Process Data

Figure 34-3. Computers can be used to control machines and processes. They can also process written, graphic, and numerical data.

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Academic LinkAcademic Link

This period in history began in 1945 with the development of the first electronic computer. It was called the ENIAC (Electrical Numerical Integrator and Calculator). See Figure 34-4. From this dramatic start, came the mainframe computer, the minicomputer, and the microcomputer that operate today in almost every facet of the public and private community.

Components of an Automated System

All efforts to automate manufacturing are guided by a few basic goals. These include:

✲ Reducing manufacturing costs

✲ Increasing product quality and consistency

✲ Enhancing manufacturing flexibility

✲ Improving marketability of products

✲ Reducing the reaction time to changes in market demands

These goals have caused most manufacturing companies to adopt labor- and material-saving practices, programs, and systems. A number of these are

Computer science is the study of the design of computers and their processes. It is a young discipline that is evolving rapidly from its begin-nings. In its most general form, com-puter science is concerned with the understanding of information transfer and transformation. Partic ular inter-est is placed on making processes efficient and providing them with some form of intelligence.

Computer science includes theo-retical studies, experimental methods, and engineering design all in one dis-cipline. This differs from other physical sciences that separate the under-standing and advancement of the

science from the applications of the science in fields of engi-neering design and implementation. In computer science there is a natural intermingling of the theoretical con-cepts of computability and mathe-matical efficiency with the modern practical advancements in electronics, which continue to stimulate advances in the discipline. It is this close inter-action of the theoretical and design aspects of the field that binds them together into a single discipline and makes computer science a rewarding area of study.

Figure 34-4. This is an example of an early computer. (John W. Mauchly Papers; Rare Book and Manuscript Library, University of Pennsylvania)

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listed in Figure 34-5. The complexity of the systems increases as they move upward on the chart. The simplest are mechanical, numerical, and computer machine controls. These range from simple tracer lathes to complex, computer-controlled machining centers. The most complex is artificial intelligence in which computers are programmed to process data and make decisions. This is a radi-cal departure from the normal computer tasks of data processing.

All of the various components presented in Figure 34-5 are used to make up a package called computer-integrated manufacture (CIM). CIM is defined by the National Research Council as all activities from the recognition of a need for a product; through the conception, design, and development of the product; and on through production, marketing, and support of the product in use.

All of these activities use written, numeric, or graphic data. This data is integrated into a working system by computers. The result is diverse operations integrated into a single, dynamic system.

CIM is an ultimate goal of many manufacturing enterprises. It is only begin-ning to be implemented into manufacturing companies today. The two main components of CIM are computer-aided design (CAD) and computer-aided manufacturing (CAM). See Figure 34-6.

CAD is a computer-based system used for creating, modifying, and communicating a plan or product design. Activities performed by CAD, as shown in Figure 34-7, include:

✲ Engineering design. This is the preparation and documentation of various product design ideas and solutions.

✲ Design analysis. This is the evaluation of product designs using computer-simulated tests, such as for stress, heat transfer, and deflection.

✲ Design presentation. This is the preparation of engineering drawings that are used to communicate approved designs to manufacturing personnel.

Some references say CAD stands for computer-aided drafting. Some say that CAD is strictly a drafting tool. They refer to a system that also has design and analyzing capa-bilities as computer-aided drafting and design (CADD).

* Artificial Intelligence (AI)* Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM)* Flexible Manufacturing System (FMS)* Process Automation* Just-In Time (JIT)* Manufacturing Resource Planning II (MRP II)* Materials Requirement Planning (MRP)* Basic Machine Controls

Figure 34-5. Computer use in manufacturing extends from relatively simple to highly complex tasks.

computer-integrated manufacture (CIM). An approach in which all steps in producing a product, from recognition of need for it through manufacture and marketing, are integrated into a single, dynamic computer-controlled system.

computer-aided design (CAD). A computer-based system used to create, modify, and communicate a plan or product design.

Engineering DesignDesign Analysis

Design Presentation(Engineering Drawings)

Computer Process ControlComputer Numerical Control

Robotic ControlAdaptive Control

Manufacturing SupportProduction Scheduling

Inventory ControlMaterial Requirement Planning

Numerical Control Tapes

CAD

CAM

Figure 34-6. CAD and CAM are important parts of computer-integrated manufacture.

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More recent practice accepts CAD as standing for all drafting, design, and analyzing functions.

CAM is the use of computer technology in the manage-ment and control of manufacturing operations. CAM operation is concerned with one or both of the following:

✲ Computer process control. This is the process of using mechanical and electronic means (NC machines and robots, for example) to change the shape, size, or composition of materials.

✲ Manufacturing support. This is the processing of data including such things as machine status, part counts, and processing variables.

CAM uses a computer to assist in monitoring and con-trolling either or both components of manufacturing oper-ations. See Figure 34-8. Computers may be used to direct machines through a series of steps to process materials. Also, computers may gather and process data about the effectiveness of an operation.

Much more may be said about CAD and CAM opera-tions. They will be the focus of the next two chapters of this book.

computer-aided manufacture (CAM). A system that uses computer technology in the management and control of manufacturing operations.

Figure 34-7. Computer-aided design is used for engineering design, design analysis, and design presentation activities.

Controlling Manufacturing Processes

Providing Manufacturing Support

Figure 34-8. Computer-aided manufactur-ing involves controlling operation and processing manufacturing data. (Battenfeld Inc., AT&T Co.)

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Key Words

STEM Activities

Summary

Test Your Knowledge

SummaryManufacturing companies are rapidly auto-

mating their operations in an effort to remain competitive in the world market. Computers are being used to make product design and manu-facturing more efficient.

Two major systems are widely used in indus-try today. They are CAD and CAM. Unified into a total system, they are a part of CIM.

Key WordsAll of the following words have been used in this chapter. Do you know their meanings?automationcomputer-aided design (CAD)computer-aided manufacture (CAM)computer-integrated manufacture (CIM)

Test Your KnowledgePlease do not write in this text. Place your answers on a separate sheet. 1. True or False? Automation evolved as a

result of a desire for more efficient ways to manufacture products.

2. Name three roots of automation. 3. What modern device revolutionized factory

automation?

STEM Activities 1. Prepare a bulletin board, poster, or handout

that shows the major tasks of CAD and CAM systems.

2. Visit a local manufacturing company to observe CAD and/or CAM systems in oper-ation. Write a brief report about what you observed.

4. True or False? One reason manufacturers choose to automate is to increase product quality and consistency.

5. List three components of CIM. 6. Which of the following tasks do CAD

systems help designers and engineers complete?

a. Engineering design. b. Design analysis. c. Design presentation. d. All of the above.

7. What are the two major functions of a CAM system?

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Career LinkCareer LinkAssembler and Fabricator

Assemblers and fabricators pro-duce a wide range of finished goods from manufactured parts or subas-semblies. They produce intricate man-ufactured products, such as aircraft, automobile engines, computers, and electrical and electronic components.

Assemblers may work on subas-semblies or the final assembly of an array of finished products or com-ponents. For example, electrical and electronic equipment assemblers put together or modify missile con-trol systems, radio or test equip-ment, computers, machine-tool numerical controls, radar, or sonar, and prototypes of these and other products. Electromechanical equip-ment assemblers prepare and test equipment or devices such as appli-ances, dynamometers, or ejection-seat mechanisms. Coil winders, tapers, and finishers wind wire coil used in resistors, transformers, gen-erators, and electric motors. Engine

and other machine assemblers con-struct, assemble, or rebuild engines and turbines, and office, agricultural, construction, oilfield, rolling mill, tex-tile, woodworking, paper, and food wrapping machinery. Aircraft struc-ture, surfaces, rigging, and systems assemblers put together and install parts of airplanes, space vehicles, or missiles, such as wings or landing gear. Structural metal fabricators and fitters align and fit structural metalparts according to detailed specifi-cations prior to welding or riveting.

Assemblers and fabricators involved in product development read and interpret engineering spec-ifications from text, drawings, and computer-aided drafting systems. They also may use a variety of tools and precision measuring instruments. Some experienced assemblers work with engineers and techni-cians, assembling prototypes or test products.