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835

Industrial

Part F

Part F Industrial Automation

48 Machine Tool Automation

Keiichi Shirase, Kobe, Japan

Susumu Fujii, Tokyo, Japan

49 Digital Manufacturing

andRFID-BasedAutomation

Wing B. Lee, Kowloon, Hong Kong

Benny C.F. Cheung, Kowloon, Hong Kong

Siu K. Kwok, Kowloon, Hong Kong

50 Flexible and Precision Assembly

Brian Carlisle, Auburn, USA

51 Aircraft Manufacturing and Assembly

BrankoSarh,HuntingtonBeach,USA

James Buttrick, Seattle, USA

Clayton Munk, Seattle, USA

Richard Bossi, Renton, USA

52 Semiconductor Manufacturing Automation

Tae-Eog Lee, Daejeon, Korea

53 Nanomanufacturing Automation

Ning Xi, East Lansing, USA

King Wai Chiu Lai, East Lansing, USA

Heping Chen, Windsor, USA

54 Production, Supply, Logistics

and Distribution

Rodrigo J. Cruz Di Palma, San Juan, Puerto Rico

Manuel Scavarda Basaldúa, Buenos Aires,

Argentina

55 Material Handling Automation in Production

and Warehouse Systems

Jaewoo Chung, Daegu, South Korea

Jose M.A. Tanchoco, West Lafayette, USA

56 Industrial Communication Protocols

Carlos E. Pereira, Porto Alegre RS, Brazil

Peter Neumann, Magdeburg, Germany

57 Automation and Robotics in Mining

and Mineral Processing

Sirkka-Liisa Jämsä-Jounela, Espoo, Finland

Greg Baiden, Sudbury, Canada

58 Automation in the Wood and Paper Industry

Birgit Vogel-Heuser, Kassel, Germany

59 Welding Automation

Anatol Pashkevich, Nantes, France

60 Automation in Food Processing

Darwin G. Caldwell, Genova, Italy

Steve Davis, Genova, Italy

René J. Moreno Masey, Shefﬁeld, UK

John O. Gray, Genova, Italy

836

Industrial Automation. Part F Industrial automation is well known and fascinating to all of us who were born

in the 20th century, from visits to plants and factories to watching movies highlighting the automation marvels of

industrial operations and assembly lines. This part begins with explanation of machine tool automation, includ-

ing various types of numerical control (NC), ﬂexible, and precision machinery for production, manufacturing,

and assembly, digital and virtual industrial production, to detailed design, guidelines and application of automa-

tion in the principal industries, from aerospace and automotive to semiconductor, mining, food, paper and wood

industries. Chapters are also devoted to the design, control and operation of functions common to all industrial

automation, including materials handling, supply, logistics, warehousing, distribution, and communication pro-

tocols, and the most advanced digital manufacturing, RFID-based automation, and emerging micro-automation

and nano-manipulation. Industrial automation represents a major growth and advancement opportunity, because

as explained in this part, it can provide signiﬁcant innovative solutions to the grand challenges of our generation,

including the production and distribution capacity of needed goods and equipment, as well as food, medical and

other essential sustenance supplies for the quality of life around the globe.

837

Machine Tool

48. Machine Tool Automation

Keiichi Shirase, Susumu Fujii

Numerical control (NC) is the greatest inno-

vation in the achievement of machine tool

automation in manufacturing. In this chap-

ter, ﬁrst a history of the development up to

the advent of NC machine tools is brieﬂy re-

viewed (Sect. 48.1). Then the machining centers

and the turning centers are described with

their key modules and integration into ﬂexi-

ble manufacturing systems (FMS) and ﬂexible

manufacturing cells (FMC)inSect.48.2. NC part

programming is described from manual pro-

gramming to the computer-aided manufacturing

(CAM) system in Sect. 48.3.InSect.48.4 and

Sect. 48.5, following the technical innova-

tions in the advanced hardware and software

systems of NC machine tools, future control

systems for intelligent CNC machine tools are

presented.

48.1 The Advent of the NC Machine Tool ........ 839

48.1.1 From Hand Tool

to Powered Machine................... 839

48.1.2 Copy Milling Machine.................. 840

48.1.3 NC Machine Tools ....................... 840

48.2 Development of Machining Center

and Turning Center............................... 841

48.2.1 Machining Center ....................... 841

48.2.2 Turning Center ........................... 843

48.2.3 Fully Automated Machining:

FMS and FMC.............................. 843

48.3 NC Part Programming............................ 844

48.3.1 Manual Part Programming........... 845

48.3.2 Computer-Assisted Part

Programming: APT and EXAPT....... 846

48.3.3 CAM-Assisted Part Programming... 846

48.4 Technical Innovation in NC Machine Tools 847

48.4.1 Functional and Structural

Innovation by Multitasking

and Multiaxis ............................ 847

48.4.2 Innovation in Control Systems

Toward Intelligent CNC Machine

Tools......................................... 848

48.4.3 Current Technologies

of Advanced CNC Machine Tools.... 849

48.4.4 Autonomous and Intelligent

Machine Tool ............................. 853

48.5 Key Technologies

for Future Intelligent Machine Tool ........ 856

48.6 Further Reading ................................... 857

References .................................................. 857

Numerical control (NC) is the greatest innovation in the

achievement of machine tool automation in manufac-

turing. Machine tools have expanded their performance

and ability since the era of the Industrial Revolution;

however all machine tools were operated manually

until the birth of the NC machine tool in 1952. Nu-

merical control enabled control of the motion and

sequence of machining operations with high accu-

racy and repeatability. In the 1960s, computers added

even greater ﬂexibility and reliability of machining

operations. These machine tools which had computer

numerical control were called CNC machine tools.

A machining center, which is a highly automated NC

milling machine performing multiple milling opera-

tions, was developed to realize process integration as

well as machining automation in 1958. A turning cen-

ter, which is a highly automated NC lathe performing

multiple turning operations, was also developed. These

machine tools contributed to realize the ﬂexible man-

ufacturing system (FMS), which had been proposed

during the mid-1960s. FMS aims to perform automatic

machining operations unaided by human operators to

machine various parts.

The automatically programmed tool (APT)isthe

most important computer-assisted part programming

language and was ﬁrst used to generate part programs

Part F 48

838 Part F Industrial Automation

Tools

The first innovation

The second innovation

Machine tools

NC machine tools

Analog control/mechanical control

(mechanics)

The third innovation

Digital control with AC

(performance function/constraint conditions)

Digital control with AC

(machining strategy/decision making)

NC machine tools

with adaptive control

Intelligent

NC machine tools

Digital control

(servo, actuator, sensor)

• High speed

• High precision

• High productivity

• Motion control

• Multi tasks/multi functions

• System

• Cutting process control

• Feedback of cutting process

• Artificial intelligence

• Knowledge/knowhow

• Learning/evolution

Automatic operation

pre-instructed by NC programs

Hardware

Software

Information

Autonomous operation

instructed by in-process planning and decision

Fig. 48.1 Evolution of machine tools toward the intelligent machine for the future

in production around 1960. The extended subset of

APT (EXAPT) was developed to add functions such

as setting of cutting conditions, selection of cutting

tool, and operation planning besides the functions of

APT. Another pioneering NC programming language,

COMPACT II, was developed by Manufacturing Data

Systems Inc. (MDSI) in 1967. Technologies developed

beyond APT and EXAPT were succeeded by computer-

aided manufacturing (CAM). CAM provides interactive

part programming with a visual and graphical environ-

ment and saves signiﬁcant programming time and effort

for part programming. For example, COMPACT II

has evolved into open CNC software, which enables

integration of off-the-shelf hardware and software tech-

nologies. NC languages have also been integrated with

computer-aided design (CAD) and CAM systems.

In the past ﬁve decades, NC machine tools have

become more sophisticated to achieve higher accuracy

and faster machining operation with greater ﬂexibil-

ity. Certainly, the conventional NC control system can

perform sophisticated motion control, but not cutting

process control. This means that further intelligence

of NC control system is still required to achieve more

sophisticated process control. In the near future, all ma-

chine tools will have advanced functions for process

planning, tool-path generation, cutting process monitor-

ing, cutting process prediction, self-monitoring, failure

prediction, etc. Information technology (IT) will be

the key issue to realize these advanced functions. The

paradigm is evolving from the concept of autonomy to

yield next-generation NC machine tools for sophisti-

cated manufacturing systems.

Machine tools have expanded their performance

and abilities as shown in Fig. 48.1. The ﬁrst inno-

vation took place during the era of the Industrial

Revolution. Most conventional machine tools, such as

lathes and milling machines, have been developed since

the Industrial Revolution. High-speed machining, high-

precision machining, and high productivity have been

achieved by these modern machine tools to realize mass

production.

The second innovation was numerical control (NC).

A prototype machine was demonstrated at MIT in

1952. The accuracy and repeatability of NC machine

tools became far better than those of manually oper-

ated machine tools. NC is a key concept to realize

programmable automation. The principle of NC is

to control the motion and sequence of machining

operations. Computer numerical control (CNC)was

introduced, and computer technologyreplaced the hard-

ware control circuit boards on NC, greatly increasing

the reliability and functionality of NC. The most im-

portant functionality to be realized was adaptive control

(AC). In order to improve the productivity of the ma-

Part F 48

Machine Tool Automation 48.1 The Advent of the NC Machine Tool 839

chining process and the quality of machined surfaces,

several AC systems for real-time adjustment of cutting

parameters have been proposed and developed [48.1].

As mentioned above, machine tools have evolved

through advances in hardware and control technologies.

However, the machining operations are fully dominated

by the predetermined NC commands, and conventional

machine tools are not generally allowed to change the

machining sequence or the cutting conditions during

machining operations.This means that conventionalNC

machine tools are allowed to perform only automatic

machining operations that are pre-instructedby NC pro-

grams.

In order to realize an intelligent machine tool for

the future, some innovative technical breakthroughs are

required. An intelligent machine tool should be good at

learning, understanding, and thinking in a logical way

about the cutting process and machining operation, and

no NCcommands will be required to instruct machining

operations as an intelligent machine tool thinks about

machining operations, and adapts the cutting processes

itself. This means that an intelligent machine tool can

perform autonomous operations that are instructed by

in-process planning made by the tool itself. Information

technology (IT) will be the key issue to realize this third

innovation.

48.1 The Advent of the NC Machine Tool

48.1.1 From Hand Tool to Powered Machine

It is well known that John Wilkinson’s boring ma-

chine (Fig.48.2) was able to machine a high-accuracy

cylinder to build Watt’s steam engine. The perfor-

Fig. 48.2 Wilkinson’s boring machine (1775)

Fig. 48.3 Maudsley’s screw-cutting lathe with mecha-

nized tool carriage (1800)

mance of steam engines was improved drastically by

the high-accuracy cylinder. With the spread of steam

engines, machine toolschanged fromhand tools to pow-

ered machines, and metal cutting became widespread

to achieve modern industrialization. During the era of

the Industrial Revolution, most conventional machine

tools, such as lathes and milling machines, were devel-

oped.

Maudsley’s screw-cutting lathe with mechanized

tool carriage (Fig.48.3) was a great invention which

was able to machine high-accuracy screw threads. The

screw-cutting lathe was developed to machine screw

threads accurately; however the mechanical tool car-

riage equipped with a screw allowed precise repetition

of machined shapes. Precise repetition of machined

shape is an important requirement to produce many of

the component parts for mass production. Therefore,

Maudsley’s screw-cutting lathe became a prototype of

lathes.

Whitney’s milling machine (Fig.48.4) is believed

to be the ﬁrst successful milling machine used for

cutting plane of metal parts. However, it appears that

Whitney’s milling machine was made after Whitney’s

death. Whitney’s millingmachine wasdesigned to man-

ufacture interchangeable musket parts. Interchangeable

parts require high-precision machine tools to make ex-

act shapes.

Fitch’s turret lathe (Fig.48.5)wastheﬁrstauto-

matic turret lathe. Turret lathes were used to produce

complex-shaped cylindrical parts that required several

operating sequences and tools. Also, turret lathes can

perform automatic machining with a single setup and

can achieve high productivity. High productivity is an

Part F 48.1

840 Part F Industrial Automation

Fig. 48.4 Whitney’s milling machine (1818)

Fig. 48.5 Fitch’s turret lathe (1845)

important requirement to produce many of the compo-

nent parts for mass production.

As mentioned above, the most important modern

machine tools required to realize mass production were

developed during the era of the Industrial Revolution.

Also high-speed machining, high-precision machining,

and high productivity had been achieved by these mod-

ern machine tools.

48.1.2 Copy Milling Machine

A copy milling machine, also called a tracer milling

machine or a proﬁling milling machine, can dupli-

cate freeform geometry represented by a master model

Fig. 48.6 A copy milling machine

for making molds, dies, and other shaped cavities and

forms. A prove tracing the model contour is controlled

to follow a three-dimensional master model, and the

cutting tool follows the path taken by the tracer to ma-

chine the desired shape. Usually, a tracing prove is fed

by a human operator, and the motion of the tracer is

converted to the motion of the tool by hydraulic or elec-

tronic mechanisms. The motion in Fig.48.6 shows an

example of copy milling. In this case, three spindle

heads or three cutting tools follow the path taken by the

tracer simultaneously. In some copy milling machines

the ratio between the motionof thetracer and the cutting

tool can be changed to machine shapes that are similar

to the master model.

Copy milling machines were widely used to ma-

chine molds and dies which were difﬁcult to generate

with simple tool paths, until CAD/CAM systems be-

came widespread to generate NC programs freely for

machining three-dimensional freeform shapes.

48.1.3 NC Machine Tools

The ﬁrst prototypeNC machinetool, shown inFig.48.7,

was demonstrated at the MIT in 1952. The name nu-

merical control was given to the machine tool, as it

was controlled numerically. It is well known that nu-

merical control was required to develop more efﬁcient

manufacturing methods for modern aircraft, as aircraft

components became more complex and required more

machining. The accuracy, repeatability, and productiv-

ity of NC machine tools became far better than those of

machine tools operated manually.

The concept of numerical control is very impor-

tant and innovative for programmable automation, in

which the motions of machine tools are controlled or

Part F 48.1

Machine Tool Automation 48.2 Development of Machining Center and Turning Center 841

Fig. 48.7 The ﬁrst NC machine tool, which was demon-

strated at MIT in 1952

instructed by a program containing coded alphanu-

meric data. According to the concept of numerical

control, machining operation becomes programmable

and machining shape is changeable. The concept of

the ﬂexible manufacturing system (FMS) mentioned

later required the prior development of numerical

control.

A program to control NC machine tools is called

a part program, and the importance of a part program

was recognized from the beginning of NC machine

tools. In particular, the deﬁnition for machining shapes

of more complex parts is difﬁcult by manual opera-

tion. Therefore, a part programming language, APT,

was developed at MIT to realize computer-assisted part

programming.

Recently, CNC has become widespread, and in most

cases the term NC is used synonymously with CNC.

Originally, CNC corresponded to an NC system oper-

ated by an internal computer, which realized storage of

part programs, editing of part programs, manual data

input (MDI), and so on. The latest CNC tools allow

generation of a part program interactively by a machine

operator, and avoid machine crash caused by a miss-

ing part program. High-speed andhigh-accuracycontrol

of machine tools to realize highly automated machin-

ing operation requires the latest central processing unit

(CPU) to perform high-speed data processing for sev-

eral functions.

48.2 Development of Machining Center and Turning Center

48.2.1 Machining Center

A machining center is a highly automated NC milling

machine that performs multiple machining operations

such as end milling, drilling, and tapping. It was devel-

oped to realize process integration as well as machining

automation, in 1958. Figure 48.8 shows an early ma-

chining center equipped with an automatic tool changer

(ATC). Most machining centers are equipped with an

ATC and an automatic pallet changer (APC)toper-

form multiple cutting operations in a single machine

setup and to reduce nonproductive time in the whole

machining cycle.

Machining centers are classiﬁed into horizontal and

vertical types according to the orientation of the spindle

axis. Figures 48.9 and 48.10 show typical horizon-

tal and vertical machining centers, respectively. Most

horizontal machining centers have a rotary table to

index the machined part at some speciﬁc angle rela-

tive to the cutting tool. A horizontal machining center

which has a rotary table can machine the four ver-

tical faces of boxed workpieces in single setup with

minimal human assistance. Therefore, a horizontal ma-

chining center is widely used in an automated shop

ﬂoor with a loading and unloading system for work-

pieces to realize machining automation. On the other

Fig. 48.8 Machining center, equipped with an ATC (cour-

tesy of Makino Milling Machine Co. Ltd.)

Part F 48.2

842 Part F Industrial Automation

Fig. 48.9 Horizontal machining center (courtesy of Yamazaki

Mazak Corp.)

Fig. 48.10 Vertical machining center (courtesy of Yamazaki Mazak

Corp.)

hand, a vertical machining center is widely used in a die

and mold machine shop. In a vertical machining cen-

ter, the cutting tool can machine only the top surface

of boxed workpieces, but it is easy for human opera-

tors to understand tool motion relative to the machined

part.

Automatic Tool Changer (ATC)

ATC stands for automatic tool changer, which permits

loading and unloading of cutting tools from one ma-

chining operation to the next. The ATC is designed to

exchange cutting tools between the spindle and a tool

magazine, which can store more than 20 tools. The

Fig. 48.11 AT C: automatic tool changer (courtesy of Ya-

mazaki Mazak Corp.)

large capacity of the tool magazine allows a variety of

workpieces to be machined. Additionally, higher tool-

change speed and reliability are required to achieve

a fast machining cycle. Figure 48.11 shows an example

of a twin-arm-type AT C driven by a cam mechanism to

ensure reliable high-speed tool change.

Automatic Pallet Changer (APC)

APC stands for automatic pallet changer, which permits

loading and unloading of workpieces for machining au-

tomation. Most horizontal machining centers have two

pallet tables to exchange the parts before and after ma-

Fig. 48.12 APC: automatic pallet changer (courtesy of Ya-

mazaki Mazak Corp.)

Part F 48.2

Machine Tool Automation 48.2 Development of Machining Center and Turning Center 843

Fig. 48.13 Turning center or CNC lathe (courtesy of Ya-

mazaki Mazak Corp.)



chining automatically. Figure 48.12 shows an example

of an APC. The operator can be unloading the ﬁnished

part and loading the next part on one pallet while the

machining center is processing the current part on an-

other pallet.

48.2.2 Turning Center

A turning center is a highly automated NC lathe to per-

form multiple turning operations. Figure 48.13 shows

a typical turning center. Changingof cutting tools is per-

formed by a turret tool changer which can hold about

ten turning and milling tools. Therefore, a turning cen-

ter enables not only turning operations but also milling

operations such as end milling, drilling, and tapping in

a single machine setup. Some turning centers have two

spindles and two or more turret tool changers to com-

plete all machining operations of cylindrical parts in

a single machine setup. In this case, the ﬁrst half of the

machining operations of the workpiece are carried out

on one spindle, then the second half of the machining

operations are carried out on another spindle, without

unloading and loading of the workpiece. This reduces

production time.

Turret Tool Changer

Figure 48.14 shows a tool turret with 12 cutting tools.

A suitable cutting tool for the target machining opera-

tion is indexed automatically under numerical control

for continuous machining operations. The most sophis-

ticated turning centers have tool monitoring systems

which check tool length and diameter for automatic

tool alignment and sense tool wear for automatic tool

changing.

48.2.3 Fully Automated Machining: FMS

and FMC

Flexible Manufacturing System (FMS)

The concept of the ﬂexible manufacturing system

(FMS) was proposed during the mid-1960s. It aims to

perform automatic machining operations unaided by

human operators to machine various parts. Machining

centers are key components of the FMS for ﬂexible ma-

chining operations. Figure 48.15 shows a typical FMS,

which consists of ﬁve machining centers, one conveyor,

one load/unload station, and a central computer that

controls and manages the components of the FMS.

Fig. 48.14 Tool turret in turning center (courtesy of Ya-

mazaki Mazak Corp.)

Fig. 48.15 Flexible manufacturing system (courtesy of Ya-

mazaki Mazak Corp.)

Part F 48.2

844 Part F Industrial Automation

No manufacturing system can be completely ﬂex-

ible. FMSs are typically used for mid-volume and

mid-variety production. An FMS is designed to ma-

chine parts within a range of style, sizes, and processes,

and its degree of ﬂexibility is limited. Additionally,

the machining shape is changeable through the part

programs that control the NC machine tools, and the

part programs required for every shape to be ma-

chined have to be prepared before the machining

operation. Therefore a new shape that needs a part pro-

gram is not acceptable in conventional FMSs, which

is why a third innovation of machine tools is re-

quired to achieve autonomous machining operations

instead of automatic machining operations to achieve

true FMS.

An FMS consists of several NC machine tools such

as machining centers and turning centers, material-

handling or loading/unloading systems such as indus-

trial robots and pallets changer, conveyer systems such

as conveyors and automated guided vehicles (AGV),

and storage systems. Additionally, an FMS has a central

computer to coordinate all of the activities of the FMS,

and all hardware components of the FMS generally

have their own microcomputer for control. The central

computer downloads NC part programs, and controls

the material-handling system, conveyer system, storage

system, and management of materials and cutting tools,

etc.

Human operators play important rolesin FMSs, per-

forming the following tasks:

1. Loading/unloading parts at loading/unloading sta-

tions

2. Changing and setting of cutting tools

3. NC part programming

4. Maintenance of hardware components

5. Operation of the computer system.

These tasks are indispensable to manage the FMS suc-

cessfully.

Flexible Manufacturing Cell (FMC)

Basically, FMSs are large systems to realize manu-

facturing automation for mid-volume and mid-variety

production. In some cases, small systems are applicable

to realize manufacturing automation. The term ﬂexible

manufacturing cell (FMC) is used to represent small

systems or compact cells of FMSs. Usually, the number

of machine tools included in a FMC is three or fewer.

One can consider that an FMS is a large manufacturing

system composed of several FMCs.

48.3 NC Part Programming

The task of programming to operate machine tools au-

tomatically is called NC part programming because the

program is prepared for a part to be machined. NC part

programming requires the programmer to be familiar

with both the cutting processes and programming pro-

cedures. The NC part program includes the detailed

commands to control the positions and motion of the

machine tool. In numerical control, the three linear axes

(x, y, z) of the Cartesian coordinate system are used

a) b)

–z

–x

–z

–y

Fig. 48.16a,b Coordinate systems in numerical control.

(a) Cylindrical part for turning; (b) cuboid part for

milling

to specify cutting tool positions, and three rotational

axes (a, b, c) are used to specify the cutting tool pos-

tures. In turning operations, the position of the cutting

tool is deﬁned in the x–z plane for cylindrical parts, as

showninFig.48.16a. In milling operations, the position

of the cutting tool is deﬁned by the x-, y-, and z-axes for

cuboid parts, as shown in Fig.48.16b.

Numerical control realizes programmable automa-

tion of machining. The mechanical actions or motions

of the cutting tool relative to the workpiece and the con-

trol sequence of the machine tool equipments are coded

by alphanumerical data in a program. NC part program-

ming requires a programmer who is familiar with the

metal cutting process to deﬁne the points, lines, and

surfaces of the workpiece, and to generate the alphanu-

merical data. The most important NC part programming

techniques are summarized as follows:

1. Manual part programming

2. Computer-assisted part programming – APT and

EXAPT

3. CAM-assisted part programming.

Part F 48.3