Part II
Automation and Control Technologies
Chapter 4
Introduction to Automation
Chapter Contents
4.1 Basic Elements of an Automated System
4.1.1 Power to Accomplish the Automated Process
4.1.2 Program of Instructions
4.1.3 Control System
4.2 Advanced Automation Functions
4.2.1 Safety Monitoring
4.2.2 Maintenance and Repair Diagnostics
4.2.3 Error Detection and Recovery
4.3 Levels of Automation
Automation can be defined as the technology by which a process or procedure is ac-
complished without human assistance. It is implemented using a program of instructions
combined with a control system that executes the instructions. To automate a process,
power is required, both to drive the process itself and to operate the program and control
system. Although automation is applied in a wide variety of areas, it is most closely as-
sociated with the manufacturing industries. It was in the context of manufacturing that
the term was originally coined by an engineering manager at Ford Motor Company in
1946 to describe the variety of automatic transfer devices and feed mechanisms that had
been installed in Ford’s production plants (Historical Note 4.1). It is ironic that nearly all
modern applications of automation are controlled by computer technologies that were
not available in 1946.
75
,76 Chap. 4 / Introduction to Automation
Historical Note 4.1 History of Automation
The history of automation can be traced to the development of basic mechanical devices,
such as the wheel (circa 3200 B.C.), lever, winch (circa 600 B.C.), cam (circa 1000), screw
(1405), and gear in ancient and medieval times. These basic devices were refined and used to
construct the mechanisms in waterwheels, windmills (circa 650), and steam engines (1765).
These machines generated the power to operate other machinery of various kinds, such as
flour mills (circa 85 B.C.), weaving machines (flying shuttle, 1733), machine tools (boring
mill, 1775), steamboats (1787), and railroad locomotives (1803). Power, and the capacity to
generate it and transmit it to operate a process, is one of the three basic elements of an
automated system.
After his first steam engine in 1765, James Watt and his partner, Matthew Boulton,
made several improvements in the design. One of the improvements was the flying-ball
governor (around 1785), which provided feedback to control the throttle of the engine.
The governor consisted of a ball on the end of a hinged lever attached to the rotating shaft.
The lever was connected to the throttle valve. As the speed of the rotating shaft increased,
the ball was forced to move outward by centrifugal force; this in turn caused the lever to
reduce the valve opening and slow the motor speed. As rotational speed decreased, the ball
and lever relaxed, thus allowing the valve to open. The flying-ball governor was one of the
first examples of feedback control—an important type of control system, which is the second
basic element of an automated system.
The third basic element of an automated system is the program of instructions that
directs the actions of the system or machine. One of the first examples of machine program-
ming was the Jacquard loom, invented around 1800. This loom was a machine for weav-
ing cloth from yarn. The program of instructions that determined the weaving pattern of
the cloth consisted of a metal plate containing holes. The hole pattern in the plate directed
the shuttle motions of the loom, which in turn determined the weaving pattern. Different
hole patterns yielded different cloth patterns. Thus, the Jacquard loom was a programmable
machine, one of the first of its kind.
By the early 1800s, the three basic elements of automated systems—power source,
controls, and programmable machines—had been developed, although these elements were
primitive by today’s standards. It took many years of refinement and many new inventions
and developments, both in these basic elements and in the enabling infrastructure of the
manufacturing industries, before fully automated systems became a common reality. Important
examples of these inventions and developments include interchangeable parts (circa 1800,
Historical Note 1.1); electrification (starting in 1881); the moving assembly line (1913, Historical
Note 15.1); mechanized transfer lines for mass production, whose programs were fixed by their
hardware configuration (1924, Historical Note 16.1); a mathematical theory of control systems
(1930s and 1940s); and the MARK I electromechanical computer at Harvard University (1944).
These inventions and developments had all been realized by the end of World War II.
Since 1945, many new inventions and developments have contributed significantly to
automation technology. Del Harder coined the word automation around 1946 in reference to
the many automatic devices that the Ford Motor Company had developed for its production
lines. The first electronic digital computer was developed at the University of Pennsylvania
in 1946. The first numerical control machine tool was developed and demonstrated in 1952
at the Massachusetts Institute of Technology based on a concept proposed by John Parsons
and Frank Stulen (Historical Note 7.1). By the late 1960s and early 1970s, digital computers
were being connected to machine tools. In 1954, the first industrial robot was designed and
in 1961 it was patented by George Devol (Historical Note 8.1). The first commercial robot
was installed to unload parts in a die casting operation in 1961. In the late 1960s, the first flex-
ible manufacturing system in the United States was installed at Ingersoll Rand Company to
,Chap. 4 / Introduction to Automation 77
perform machining operations on a variety of parts (Historical Note 19.1). Around 1969, the
first programmable logic controller was introduced (Historical Note 9.1). In 1978, the first
commercial personal computer (PC) was introduced by Apple Computer, although a similar
product had been introduced in kit form as early as 1975.
Developments in computer technology were made possible by advances in electron-
ics, including the transistor (1948), hard disk for computer memory (1956), integrated cir-
cuits (1960), the microprocessor (1971), random access memory (1984), megabyte capacity
memory chips (circa 1990), and the Pentium microprocessors (1993). Software developments
related to automation have been equally important, including the FORTRAN computer
programming language (1955), the APT programming language for numerical control (NC)
machine tools (1961), the UNIX operating system (1969), the VAL language for robot pro-
gramming (1979), Microsoft Windows (1985), and the JAVA programming language (1995).
Advances and enhancements in these technologies continue.
The terms automation and mechanization are often compared and sometimes con-
fused. Mechanization refers to the use of machinery (usually powered) to assist or re-
place human workers in performing physical tasks, but human workers are still required
to accomplish the cognitive and sensory elements of the tasks. By contrast, automation
refers to the use of mechanized equipment that performs the physical tasks without the
need for oversight by a human worker.
Part II examines the technologies that have been developed to automate manufactur-
ing operations. The position of automation and control technologies in the larger production
system is shown in Figure 4.1. The present chapter provides an overview of automation:
What are the basic elements of an automated system? What are some of the advanced fea-
tures beyond the basic elements? And what are the levels in an enterprise where automation
can be applied? The following two chapters discuss industrial control systems and the hard-
ware components of these systems. These chapters serve as a foundation for the remaining
chapters on automation and control technologies: computer numerical control (Chapter 7),
industrial robotics (Chapter 8), and programmable controllers (Chapter 9).
Manufacturing
support systems
Enterprise level
Quality control
systems
Automation and Material handling
control technologies and identification
Factory level
Manufacturing systems
Manufacturing operations
Figure 4.1 Automation and control technologies
in the production system.
, 78 Chap. 4 / Introduction to Automation
4.1 Basic Elements of an Automated System
An automated system consists of three basic elements: (1) power to accomplish the
process and operate the system, (2) a program of instructions to direct the process, and
(3) a control system to actuate the instructions. The relationship among these elements is
illustrated in Figure 4.2. All systems that qualify as being automated include these three
basic elements in one form or another. They are present in the three basic types of auto-
mated manufacturing systems: fixed automation, programmable automation, and flexible
automation (Section 1.2.1).
4.1.1 Power to Accomplish the Automated Process
An automated system is used to operate some process, and power is required to drive the
process as well as the controls. The principal source of power in automated systems is elec-
tricity. Electric power has many advantages in automated as well as nonautomated processes:
• Electric power is widely available at moderate cost. It is an important part of the
industrial infrastructure.
• Electric power can be readily converted to alternative energy forms: mechanical,
thermal, light, acoustic, hydraulic, and pneumatic.
• Electric power at low levels can be used to accomplish functions such as signal
transmission, information processing, and data storage and communication.
• Electric energy can be stored in long-life batteries for use in locations where an
external source of electrical power is not conveniently available.
Alternative power sources include fossil fuels, atomic, solar, water, and wind.
However, their exclusive use is rare in automated systems. In many cases when alternative
power sources are used to drive the process itself, electrical power is used for the controls
that automate the operation. For example, in casting or heat treatment, the furnace may
be heated by fossil fuels, but the control system to regulate temperature and time cycle is
electrical. In other cases, the energy from these alternative sources is converted to electric
power to operate both the process and its automation. When solar energy is used as a
power source for an automated system, it is generally converted in this way.
Power for the Process. In production, the term process refers to the manu-
facturing operation that is performed on a work unit. In Table 4.1, a list of common
(1)
Power
(2) (3)
Program of Control Process
instructions system
Figure 4.2 Elements of an automated system: (1) power,
(2) program of instructions, and (3) control systems.
Automation and Control Technologies
Chapter 4
Introduction to Automation
Chapter Contents
4.1 Basic Elements of an Automated System
4.1.1 Power to Accomplish the Automated Process
4.1.2 Program of Instructions
4.1.3 Control System
4.2 Advanced Automation Functions
4.2.1 Safety Monitoring
4.2.2 Maintenance and Repair Diagnostics
4.2.3 Error Detection and Recovery
4.3 Levels of Automation
Automation can be defined as the technology by which a process or procedure is ac-
complished without human assistance. It is implemented using a program of instructions
combined with a control system that executes the instructions. To automate a process,
power is required, both to drive the process itself and to operate the program and control
system. Although automation is applied in a wide variety of areas, it is most closely as-
sociated with the manufacturing industries. It was in the context of manufacturing that
the term was originally coined by an engineering manager at Ford Motor Company in
1946 to describe the variety of automatic transfer devices and feed mechanisms that had
been installed in Ford’s production plants (Historical Note 4.1). It is ironic that nearly all
modern applications of automation are controlled by computer technologies that were
not available in 1946.
75
,76 Chap. 4 / Introduction to Automation
Historical Note 4.1 History of Automation
The history of automation can be traced to the development of basic mechanical devices,
such as the wheel (circa 3200 B.C.), lever, winch (circa 600 B.C.), cam (circa 1000), screw
(1405), and gear in ancient and medieval times. These basic devices were refined and used to
construct the mechanisms in waterwheels, windmills (circa 650), and steam engines (1765).
These machines generated the power to operate other machinery of various kinds, such as
flour mills (circa 85 B.C.), weaving machines (flying shuttle, 1733), machine tools (boring
mill, 1775), steamboats (1787), and railroad locomotives (1803). Power, and the capacity to
generate it and transmit it to operate a process, is one of the three basic elements of an
automated system.
After his first steam engine in 1765, James Watt and his partner, Matthew Boulton,
made several improvements in the design. One of the improvements was the flying-ball
governor (around 1785), which provided feedback to control the throttle of the engine.
The governor consisted of a ball on the end of a hinged lever attached to the rotating shaft.
The lever was connected to the throttle valve. As the speed of the rotating shaft increased,
the ball was forced to move outward by centrifugal force; this in turn caused the lever to
reduce the valve opening and slow the motor speed. As rotational speed decreased, the ball
and lever relaxed, thus allowing the valve to open. The flying-ball governor was one of the
first examples of feedback control—an important type of control system, which is the second
basic element of an automated system.
The third basic element of an automated system is the program of instructions that
directs the actions of the system or machine. One of the first examples of machine program-
ming was the Jacquard loom, invented around 1800. This loom was a machine for weav-
ing cloth from yarn. The program of instructions that determined the weaving pattern of
the cloth consisted of a metal plate containing holes. The hole pattern in the plate directed
the shuttle motions of the loom, which in turn determined the weaving pattern. Different
hole patterns yielded different cloth patterns. Thus, the Jacquard loom was a programmable
machine, one of the first of its kind.
By the early 1800s, the three basic elements of automated systems—power source,
controls, and programmable machines—had been developed, although these elements were
primitive by today’s standards. It took many years of refinement and many new inventions
and developments, both in these basic elements and in the enabling infrastructure of the
manufacturing industries, before fully automated systems became a common reality. Important
examples of these inventions and developments include interchangeable parts (circa 1800,
Historical Note 1.1); electrification (starting in 1881); the moving assembly line (1913, Historical
Note 15.1); mechanized transfer lines for mass production, whose programs were fixed by their
hardware configuration (1924, Historical Note 16.1); a mathematical theory of control systems
(1930s and 1940s); and the MARK I electromechanical computer at Harvard University (1944).
These inventions and developments had all been realized by the end of World War II.
Since 1945, many new inventions and developments have contributed significantly to
automation technology. Del Harder coined the word automation around 1946 in reference to
the many automatic devices that the Ford Motor Company had developed for its production
lines. The first electronic digital computer was developed at the University of Pennsylvania
in 1946. The first numerical control machine tool was developed and demonstrated in 1952
at the Massachusetts Institute of Technology based on a concept proposed by John Parsons
and Frank Stulen (Historical Note 7.1). By the late 1960s and early 1970s, digital computers
were being connected to machine tools. In 1954, the first industrial robot was designed and
in 1961 it was patented by George Devol (Historical Note 8.1). The first commercial robot
was installed to unload parts in a die casting operation in 1961. In the late 1960s, the first flex-
ible manufacturing system in the United States was installed at Ingersoll Rand Company to
,Chap. 4 / Introduction to Automation 77
perform machining operations on a variety of parts (Historical Note 19.1). Around 1969, the
first programmable logic controller was introduced (Historical Note 9.1). In 1978, the first
commercial personal computer (PC) was introduced by Apple Computer, although a similar
product had been introduced in kit form as early as 1975.
Developments in computer technology were made possible by advances in electron-
ics, including the transistor (1948), hard disk for computer memory (1956), integrated cir-
cuits (1960), the microprocessor (1971), random access memory (1984), megabyte capacity
memory chips (circa 1990), and the Pentium microprocessors (1993). Software developments
related to automation have been equally important, including the FORTRAN computer
programming language (1955), the APT programming language for numerical control (NC)
machine tools (1961), the UNIX operating system (1969), the VAL language for robot pro-
gramming (1979), Microsoft Windows (1985), and the JAVA programming language (1995).
Advances and enhancements in these technologies continue.
The terms automation and mechanization are often compared and sometimes con-
fused. Mechanization refers to the use of machinery (usually powered) to assist or re-
place human workers in performing physical tasks, but human workers are still required
to accomplish the cognitive and sensory elements of the tasks. By contrast, automation
refers to the use of mechanized equipment that performs the physical tasks without the
need for oversight by a human worker.
Part II examines the technologies that have been developed to automate manufactur-
ing operations. The position of automation and control technologies in the larger production
system is shown in Figure 4.1. The present chapter provides an overview of automation:
What are the basic elements of an automated system? What are some of the advanced fea-
tures beyond the basic elements? And what are the levels in an enterprise where automation
can be applied? The following two chapters discuss industrial control systems and the hard-
ware components of these systems. These chapters serve as a foundation for the remaining
chapters on automation and control technologies: computer numerical control (Chapter 7),
industrial robotics (Chapter 8), and programmable controllers (Chapter 9).
Manufacturing
support systems
Enterprise level
Quality control
systems
Automation and Material handling
control technologies and identification
Factory level
Manufacturing systems
Manufacturing operations
Figure 4.1 Automation and control technologies
in the production system.
, 78 Chap. 4 / Introduction to Automation
4.1 Basic Elements of an Automated System
An automated system consists of three basic elements: (1) power to accomplish the
process and operate the system, (2) a program of instructions to direct the process, and
(3) a control system to actuate the instructions. The relationship among these elements is
illustrated in Figure 4.2. All systems that qualify as being automated include these three
basic elements in one form or another. They are present in the three basic types of auto-
mated manufacturing systems: fixed automation, programmable automation, and flexible
automation (Section 1.2.1).
4.1.1 Power to Accomplish the Automated Process
An automated system is used to operate some process, and power is required to drive the
process as well as the controls. The principal source of power in automated systems is elec-
tricity. Electric power has many advantages in automated as well as nonautomated processes:
• Electric power is widely available at moderate cost. It is an important part of the
industrial infrastructure.
• Electric power can be readily converted to alternative energy forms: mechanical,
thermal, light, acoustic, hydraulic, and pneumatic.
• Electric power at low levels can be used to accomplish functions such as signal
transmission, information processing, and data storage and communication.
• Electric energy can be stored in long-life batteries for use in locations where an
external source of electrical power is not conveniently available.
Alternative power sources include fossil fuels, atomic, solar, water, and wind.
However, their exclusive use is rare in automated systems. In many cases when alternative
power sources are used to drive the process itself, electrical power is used for the controls
that automate the operation. For example, in casting or heat treatment, the furnace may
be heated by fossil fuels, but the control system to regulate temperature and time cycle is
electrical. In other cases, the energy from these alternative sources is converted to electric
power to operate both the process and its automation. When solar energy is used as a
power source for an automated system, it is generally converted in this way.
Power for the Process. In production, the term process refers to the manu-
facturing operation that is performed on a work unit. In Table 4.1, a list of common
(1)
Power
(2) (3)
Program of Control Process
instructions system
Figure 4.2 Elements of an automated system: (1) power,
(2) program of instructions, and (3) control systems.
