The term automation was coined in the automobile industry about 1946 to describe the increased use of automatic devices and controls in mechanized production lines. The origin of the word is attributed to D.S. Harder, an engineering manager at the Ford Motor Company at the time. The term is used widely in a manufacturing context, but it is also applied outside manufacturing in connection with a variety of systems in which there is a significant substitution of mechanical, electrical, or computerized action for human effort and intelligence.
In general usage, automation can be defined as a technology concerned with performing a process by means of programmed commands combined with automatic feedback control to ensure proper execution of the instructions. The resulting system is capable of operating without human intervention. The development of this technology has become increasingly dependent on the use of computers and computer-related technologies. Consequently, automated systems have become increasingly sophisticated and complex. Advanced systems represent a level of capability and performance that surpass in many ways the abilities of humans to accomplish the same activities.
Automation technology has matured to a point where a number of other technologies have developed from it and have achieved a recognition and status of their own. Robotics is one of these technologies; it is a specialized branch of automation in which the automated machine possesses certain anthropomorphic, or humanlike, characteristics. The most typical humanlike characteristic of a modern industrial robot is its powered mechanical arm. The robot’s arm can be programmed to move through a sequence of motions to perform useful tasks, such as loading and unloading parts at a production machine or making a sequence of spot-welds on the sheet-metal parts of an automobile body during assembly. As these examples suggest, industrial robots are typically used to replace human workers in factory operations.
This article covers the fundamentals of automation, including its historical development, principles and theory of operation, applications in manufacturing and in some of the services and industries important in daily life, and impact on the individual as well as society in general. The article also reviews the development and technology of robotics as a significant topic within automation. For related topics, see computer science and information processing.
Historical development of automation
The technology of automation has evolved from the related field of mechanization, which had its beginnings in the Industrial Revolution. Mechanization refers to the replacement of human (or animal) power with mechanical power of some form. The driving force behind mechanization has been humankind’s propensity to create tools and mechanical devices. Some of the important historical developments in mechanization and automation leading to modern automated systems are described here.
Early developments
The first tools made of stone represented prehistoric man’s attempts to direct his own physical strength under the control of human intelligence. Thousands of years were undoubtedly required for the development of simple mechanical devices and machines such as the wheel, the lever, and the pulley, by which the power of human muscle could be magnified. The next extension was the development of powered machines that did not require human strength to operate. Examples of these machines include waterwheels, windmills, and simple steam-driven devices. More than 2,000 years ago the Chinese developed trip-hammers powered by flowing water and waterwheels. The early Greeks experimented with simple reaction motors powered by steam. The mechanical clock, representing a rather complex assembly with its own built-in power source (a weight), was developed about 1335 in Europe. Windmills, with mechanisms for automatically turning the sails, were developed during the Middle Ages in Europe and the Middle East. The steam engine represented a major advance in the development of powered machines and marked the beginning of the Industrial Revolution. During the two centuries since the introduction of the Watt steam engine, powered engines and machines have been devised that obtain their energy from steam, electricity, and chemical, mechanical, and nuclear sources.
Each new development in the history of powered machines has brought with it an increased requirement for control devices to harness the power of the machine. The earliest steam engines required a person to open and close the valves, first to admit steam into the piston chamber and then to exhaust it. Later a slide valve mechanism was devised to automatically accomplish these functions. The only need of the human operator was then to regulate the amount of steam that controlled the engine’s speed and power. This requirement for human attention in the operation of the steam engine was eliminated by the flying-ball governor. Invented by James Watt in England, this device consisted of a weighted ball on a hinged arm, mechanically coupled to the output shaft of the engine. As the rotational speed of the shaft increased, centrifugal force caused the weighted ball to be moved outward. This motion controlled a valve that reduced the steam being fed to the engine, thus slowing the engine. The flying-ball governor remains an elegant early example of a negative feedback control system, in which the increasing output of the system is used to decrease the activity of the system.
Negative feedback is widely used as a means of automatic control to achieve a constant operating level for a system. A common example of a feedback control system is the thermostat used in modern buildings to control room temperature. In this device, a decrease in room temperature causes an electrical switch to close, thus turning on the heating unit. As room temperature rises, the switch opens and the heat supply is turned off. The thermostat can be set to turn on the heating unit at any particular set point.
![Jacquard loom, engraving, 1874
[Credit: The Bettmann Archive]](http://cache-media.britannica.com/eb-media/81/1781-003-D7EF50C0.gif "Jacquard loom, engraving, 1874
[Credit: The Bettmann Archive]")
Another important development in the history of automation was the Jacquard loom (see photograph), which demonstrated the concept of a programmable machine. About 1801 the French inventor Joseph-Marie Jacquard devised an automatic loom capable of producing complex patterns in textiles by controlling the motions of many shuttles of different coloured threads. The selection of the different patterns was determined by a program contained in steel cards in which holes were punched. These cards were the ancestors of the paper cards and tapes that control modern automatic machines. The concept of programming a machine was further developed later in the 19th century when Charles Babbage, an English mathematician, proposed a complex, mechanical “analytical engine” that could perform arithmetic and data processing. Although Babbage was never able to complete it, this device was the precursor of the modern digital computer. See computers, history of.
Each new development in the history of powered machines has brought with it an increased requirement for control devices to harness the power of the machine. The earliest steam engines required a person to open and close the valves, first to admit steam into the piston chamber and then to exhaust it. Later a slide valve mechanism was devised to automatically accomplish these functions. The only need of the human operator was then to regulate the amount of steam that controlled the engine’s speed and power. This requirement for human attention in the operation of the steam engine was eliminated by the flying-ball governor. Invented by James Watt in England, this device consisted of a weighted ball on a hinged arm, mechanically coupled to the output shaft of the engine. As the rotational speed of the shaft increased, centrifugal force caused the weighted ball to be moved outward. This motion controlled a valve that reduced the steam being fed to the engine, thus slowing the engine. The flying-ball governor remains an elegant early example of a negative feedback control system, in which the increasing output of the system is used to decrease the activity of the system.
Negative feedback is widely used as a means of automatic control to achieve a constant operating level for a system. A common example of a feedback control system is the thermostat used in modern buildings to control room temperature. In this device, a decrease in room temperature causes an electrical switch to close, thus turning on the heating unit. As room temperature rises, the switch opens and the heat supply is turned off. The thermostat can be set to turn on the heating unit at any particular set point.
Another important development in the history of automation was the Jacquard loom (see photograph), which demonstrated the concept of a programmable machine. About 1801 the French inventor Joseph-Marie Jacquard devised an automatic loom capable of producing complex patterns in textiles by controlling the motions of many shuttles of different coloured threads. The selection of the different patterns was determined by a program contained in steel cards in which holes were punched. These cards were the ancestors of the paper cards and tapes that control modern automatic machines. The concept of programming a machine was further developed later in the 19th century when Charles Babbage, an English mathematician, proposed a complex, mechanical “analytical engine” that could perform arithmetic and data processing. Although Babbage was never able to complete it, this device was the precursor of the modern digital computer. See computers, history of.Modern developments
A number of significant developments in various fields have occurred during the 20th century: the digital computer, improvements in data-storage technology and software to write computer programs, advances in sensor technology, and the derivation of a mathematical control theory. All these developments have contributed to progress in automation technology.
Development of the electronic digital computer (the ENIAC [Electronic Numerical Integrator and Computer] in 1946 and UNIVAC I [Universal Automatic Computer] in 1951) has permitted the control function in automation to become much more sophisticated and the associated calculations to be executed much faster than previously possible. The development of integrated circuits in the 1960s propelled a trend toward miniaturization in computer technology that has led to machines that are much smaller and less expensive than their predecessors yet are capable of performing calculations at much greater speeds. This trend is represented today by the microprocessor, a miniature multicircuited device capable of performing all the logic and arithmetic functions of a large digital computer.
Along with the advances in computer technology, there have been parallel improvements in program storage technology for containing the programming commands. Modern storage media include magnetic tapes and disks, magnetic bubble memories, optical data storage read by lasers, videodisks, and electron beam-addressable memory systems. In addition, improvements have been made in the methods of programming computers (and other programmable machines). Modern programming languages are easier to use and are more powerful in their data-processing and logic capabilities.
Advances in sensor technology have provided a vast array of measuring devices that can be used as components in automatic feedback control systems. These devices include highly sensitive electromechanical probes, scanning laser beams, electrical field techniques, and machine vision. Some of these sensor systems require computer technology for their implementation. Machine vision, for example, requires the processing of enormous amounts of data that can be accomplished only by high-speed digital computers. This technology is proving to be a versatile sensory capability for various industrial tasks, such as part identification, quality inspection, and robot guidance.
Finally, there has evolved since World War II a highly advanced mathematical theory of control systems. The theory includes traditional negative feedback control, optimal control, adaptive control, and artificial intelligence. Traditional feedback control theory makes use of linear ordinary differential equations to analyze problems, as in Watt’s flying-ball governor. Although most processes are more complex than the flying-ball governor, they still obey the same laws of physics that are described by differential equations. Optimal control theory and adaptive control theory are concerned with the problem of defining an appropriate index of performance for the process of interest and then operating it in such a manner as to optimize its performance. The difference between optimal and adaptive control is that the latter must be implemented under conditions of a continuously changing and unpredictable environment; it therefore requires sensor measurements of the environment to implement the control strategy.
Artificial intelligence is an advanced field of computer science in which the computer is programmed to exhibit characteristics commonly associated with human intelligence. These characteristics include the capacity for learning, understanding language, reasoning, solving problems, rendering expert diagnoses, and similar mental capabilities. Developments in artificial intelligence are expected to provide robots and other “intelligent” machines with the ability to communicate with humans and to accept very high-level instructions rather than the detailed step-by-step programming statements typically required of today’s programmable machines. For example, a robot of the future endowed with artificial intelligence might be capable of accepting and executing the command “assemble the product.” Present-day industrial robots must be provided with a detailed set of instructions specifying the locations of the product’s components, the order in which they are to be assembled, and so forth.
Development of the electronic digital computer (the ENIAC [Electronic Numerical Integrator and Computer] in 1946 and UNIVAC I [Universal Automatic Computer] in 1951) has permitted the control function in automation to become much more sophisticated and the associated calculations to be executed much faster than previously possible. The development of integrated circuits in the 1960s propelled a trend toward miniaturization in computer technology that has led to machines that are much smaller and less expensive than their predecessors yet are capable of performing calculations at much greater speeds. This trend is represented today by the microprocessor, a miniature multicircuited device capable of performing all the logic and arithmetic functions of a large digital computer.
Along with the advances in computer technology, there have been parallel improvements in program storage technology for containing the programming commands. Modern storage media include magnetic tapes and disks, magnetic bubble memories, optical data storage read by lasers, videodisks, and electron beam-addressable memory systems. In addition, improvements have been made in the methods of programming computers (and other programmable machines). Modern programming languages are easier to use and are more powerful in their data-processing and logic capabilities.
Advances in sensor technology have provided a vast array of measuring devices that can be used as components in automatic feedback control systems. These devices include highly sensitive electromechanical probes, scanning laser beams, electrical field techniques, and machine vision. Some of these sensor systems require computer technology for their implementation. Machine vision, for example, requires the processing of enormous amounts of data that can be accomplished only by high-speed digital computers. This technology is proving to be a versatile sensory capability for various industrial tasks, such as part identification, quality inspection, and robot guidance.
Finally, there has evolved since World War II a highly advanced mathematical theory of control systems. The theory includes traditional negative feedback control, optimal control, adaptive control, and artificial intelligence. Traditional feedback control theory makes use of linear ordinary differential equations to analyze problems, as in Watt’s flying-ball governor. Although most processes are more complex than the flying-ball governor, they still obey the same laws of physics that are described by differential equations. Optimal control theory and adaptive control theory are concerned with the problem of defining an appropriate index of performance for the process of interest and then operating it in such a manner as to optimize its performance. The difference between optimal and adaptive control is that the latter must be implemented under conditions of a continuously changing and unpredictable environment; it therefore requires sensor measurements of the environment to implement the control strategy.
Artificial intelligence is an advanced field of computer science in which the computer is programmed to exhibit characteristics commonly associated with human intelligence. These characteristics include the capacity for learning, understanding language, reasoning, solving problems, rendering expert diagnoses, and similar mental capabilities. Developments in artificial intelligence are expected to provide robots and other “intelligent” machines with the ability to communicate with humans and to accept very high-level instructions rather than the detailed step-by-step programming statements typically required of today’s programmable machines. For example, a robot of the future endowed with artificial intelligence might be capable of accepting and executing the command “assemble the product.” Present-day industrial robots must be provided with a detailed set of instructions specifying the locations of the product’s components, the order in which they are to be assembled, and so forth.
Principles and theory of automation
The developments described above have provided the three basic building blocks of automation: (1) a source of power to perform some action, (2) feedback controls, and (3) machine programming. Almost without exception, an automated system will exhibit all these elements.
Power source
An automated system is designed to accomplish some useful action, and that action requires power. There are many sources of power available, but the most commonly used power in today’s automated systems is electricity. Electrical power is the most versatile, because it can be readily generated from other sources (e.g., fossil fuel, hydroelectric, solar, and nuclear) and it can be readily converted into other types of power (e.g., mechanical, hydraulic, and pneumatic) to perform useful work. In addition, electrical energy can be stored in high-performance, long-life batteries.
The actions performed by automated systems are generally of two types: (1) processing and (2) transfer and positioning. In the first case, energy is applied to accomplish some processing operation on some entity. The process may involve the shaping of metal, the molding of plastic, the switching of electrical signals in a communication system, or the processing of data in a computerized information system. All these actions entail the use of energy to transform the entity (e.g., the metal, plastic, electrical signals, or data) from one state or condition into another more valuable state or condition. The second type of action—transfer and positioning—is most readily seen in automated manufacturing systems designed to perform work on a product. In these cases, the product must generally be moved (transferred) from one location to another during the series of processing steps. At each processing location, accurate positioning of the product is generally required. In automated communications and information systems, the terms transfer and positioning refer to the movement of data (or electrical signals) among various processing units and the delivery of information to output terminals (printers, video display units, etc.) for interpretation and use by humans.
The actions performed by automated systems are generally of two types: (1) processing and (2) transfer and positioning. In the first case, energy is applied to accomplish some processing operation on some entity. The process may involve the shaping of metal, the molding of plastic, the switching of electrical signals in a communication system, or the processing of data in a computerized information system. All these actions entail the use of energy to transform the entity (e.g., the metal, plastic, electrical signals, or data) from one state or condition into another more valuable state or condition. The second type of action—transfer and positioning—is most readily seen in automated manufacturing systems designed to perform work on a product. In these cases, the product must generally be moved (transferred) from one location to another during the series of processing steps. At each processing location, accurate positioning of the product is generally required. In automated communications and information systems, the terms transfer and positioning refer to the movement of data (or electrical signals) among various processing units and the delivery of information to output terminals (printers, video display units, etc.) for interpretation and use by humans.
Feedback controls
![Figure 1: The components of a feedback control system and their relationships.
[Credit: Encyclopædia Britannica, Inc.]](http://cache-media.britannica.com/eb-media/85/6085-003-D9B76DF5.gif "Figure 1: The components of a feedback control system and their relationships.
[Credit: Encyclopædia Britannica, Inc.]")
Feedback controls are widely used in modern automated systems. A feedback control system consists of five basic components: (1) input, (2) process being controlled, (3) output, (4) sensing elements, and (5) controller and actuating devices. These five components are illustrated in Figure 1. The term closed-loop feedback control is often used to describe this kind of system.The input to the system is the reference value, or set point, for the system output. This represents the desired operating value of the output. Using the previous example of the heating system as an illustration, the input is the desired temperature setting for a room. The process being controlled is the heater (e.g., furnace). In other feedback systems, the process might be a manufacturing operation, the rocket engines on a space shuttle, the automobile engine in cruise control, or any of a variety of other processes to which power is applied. The output is the variable of the process that is being measured and compared to the input; in the above example, it is room temperature.
The sensing elements are the measuring devices used in the feedback loop to monitor the value of the output variable. In the heating system example, this function is normally accomplished using a bimetallic strip. This device consists of two metal strips joined along their lengths. The two metals possess different thermal expansion coefficients; thus, when the temperature of the strip is raised, it flexes in direct proportion to the temperature change. As such, the bimetallic strip is capable of measuring temperature. There are many different kinds of sensors used in feedback control systems for automation.
The purpose of the controller and actuating devices in the feedback system is to compare the measured output value with the reference input value and to reduce the difference between them. In general, the controller and actuator of the system are the mechanisms by which changes in the process are accomplished to influence the output variable. These mechanisms are usually designed specifically for the system and consist of devices such as motors, valves, solenoid switches, piston cylinders, gears, power screws, pulley systems, chain drives, and other mechanical and electrical components. The switch connected to the bimetallic strip of the thermostat is the controller and actuating device for the heating system. When the output (room temperature) is below the set point, the switch turns on the heater. When the temperature exceeds the set point, the heat is turned off.
Machine programming
The programmed instructions determine the set of actions that is to be accomplished automatically by the system. The program specifies what the automated system should do and how its various components must function in order to accomplish the desired result. The content of the program varies considerably from one system to the next. In relatively simple systems, the program consists of a limited number of well-defined actions that are performed continuously and repeatedly in the proper sequence with no deviation from one cycle to the next. In more complex systems, the number of commands could be quite large, and the level of detail in each command could be significantly greater. In relatively sophisticated systems, the program provides for the sequence of actions to be altered in response to variations in raw materials or other operating conditions.
![Figure 2: Relationship of program control and feedback control in an automated system.
[Credit: Encyclopædia Britannica, Inc.]](http://cache-media.britannica.com/eb-media/86/6086-003-5F4B82A3.gif "Figure 2: Relationship of program control and feedback control in an automated system.
[Credit: Encyclopædia Britannica, Inc.]")
Programming commands are related to feedback control in an automated system in that the program establishes the sequence of values for the inputs (set points) of the various feedback control loops that make up the automated system. A given programming command may specify the set point for the feedback loop, which in turn controls some action that the system is to accomplish. In effect, the purpose of the feedback loop is to verify that the programmed step has been carried out. For example, in a robot controller, the program might specify that the arm is to move to a designated position, and the feedback control system is used to verify that the move has been correctly made. The relationship of program control and feedback control in an automated system is illustrated in Figure 2.
Some of the programmed commands may be executed in a simple open-loop fashion—i.e., without the need for a feedback loop to verify that the command has been properly carried out. For example, a command to flip an electrical switch may not require feedback. The need for feedback control in an automated system might arise when there are variations in the raw materials being fed into a production process, and the system must take these variations into consideration by making adjustments in its controlled actions. Without feedback, the system would be unable to exert sufficient control over the quality of the process output.
The programmed commands may be contained on mechanical devices (e.g., mechanical cams and linkages), punched paper tape, magnetic tape, magnetic disks, computer memory, or any of a variety of other media that have been developed over the years for particular applications. It is common today for automated equipment to use computer storage technology as the means for storing the programmed commands and converting them into controlled actions. One of the advantages of computer storage is that the program can be readily changed or improved. Altering a program that is contained on mechanical cams involves considerable work.
Programmable machines are often capable of making decisions during their operation. The decision-making capacity is contained in the control program in the form of logical instructions that govern the operation of such a system under varying circumstances. Under one set of circumstances, the system responds one way; under different circumstances, it responds in another way. There are several reasons for providing an automated system with decision-making capability, including (1) error detection and recovery, (2) safety monitoring, (3) interaction with humans, and (4) process optimization.
Error detection and recovery is concerned with decisions that must be made by the system in response to undesirable operating conditions. In the operation of any automated system, malfunctions and errors sometimes occur during the normal cycle of operations, for which some form of corrective action must be taken to restore the system. The usual response to a system malfunction has been to call for human assistance. There is a growing trend in automation and robotics to enable the system itself to sense these malfunctions and to correct for them in some manner without human intervention. This sensing and correction is referred to as error detection and recovery, and it requires that a decision-making capability be programmed into the system.
Safety monitoring is a special case of error detection and recovery in which the malfunction involves a safety hazard. Decisions are required when the automated system sensors detect that a safety condition has developed that would be hazardous to the equipment or humans in the vicinity of the equipment. The purpose of the safety-monitoring system is to detect the hazard and to take the most appropriate action to remove or reduce it. This may involve stopping the operation and alerting maintenance personnel to the condition, or it may involve a more complex set of actions to eliminate the safety problem.
Automated systems are usually required to interact with humans in some way. An automatic bank teller machine, for example, must receive instructions from customers and act accordingly. In some automated systems, a variety of different instructions from humans is possible, and the decision-making capability of the system must be quite sophisticated in order to deal with the array of possibilities.
A fourth reason for decision making in an automated system is to optimize the process. The need for optimization occurs most commonly in processes in which there is an economic performance criterion whose optimization is desirable. For example, minimizing cost is usually an important objective in manufacturing. The automated system might use adaptive control to receive appropriate sensor signals and other inputs and make decisions to drive the process toward the optimal state.
Programming commands are related to feedback control in an automated system in that the program establishes the sequence of values for the inputs (set points) of the various feedback control loops that make up the automated system. A given programming command may specify the set point for the feedback loop, which in turn controls some action that the system is to accomplish. In effect, the purpose of the feedback loop is to verify that the programmed step has been carried out. For example, in a robot controller, the program might specify that the arm is to move to a designated position, and the feedback control system is used to verify that the move has been correctly made. The relationship of program control and feedback control in an automated system is illustrated in Figure 2.Some of the programmed commands may be executed in a simple open-loop fashion—i.e., without the need for a feedback loop to verify that the command has been properly carried out. For example, a command to flip an electrical switch may not require feedback. The need for feedback control in an automated system might arise when there are variations in the raw materials being fed into a production process, and the system must take these variations into consideration by making adjustments in its controlled actions. Without feedback, the system would be unable to exert sufficient control over the quality of the process output.
The programmed commands may be contained on mechanical devices (e.g., mechanical cams and linkages), punched paper tape, magnetic tape, magnetic disks, computer memory, or any of a variety of other media that have been developed over the years for particular applications. It is common today for automated equipment to use computer storage technology as the means for storing the programmed commands and converting them into controlled actions. One of the advantages of computer storage is that the program can be readily changed or improved. Altering a program that is contained on mechanical cams involves considerable work.
Programmable machines are often capable of making decisions during their operation. The decision-making capacity is contained in the control program in the form of logical instructions that govern the operation of such a system under varying circumstances. Under one set of circumstances, the system responds one way; under different circumstances, it responds in another way. There are several reasons for providing an automated system with decision-making capability, including (1) error detection and recovery, (2) safety monitoring, (3) interaction with humans, and (4) process optimization.
Error detection and recovery is concerned with decisions that must be made by the system in response to undesirable operating conditions. In the operation of any automated system, malfunctions and errors sometimes occur during the normal cycle of operations, for which some form of corrective action must be taken to restore the system. The usual response to a system malfunction has been to call for human assistance. There is a growing trend in automation and robotics to enable the system itself to sense these malfunctions and to correct for them in some manner without human intervention. This sensing and correction is referred to as error detection and recovery, and it requires that a decision-making capability be programmed into the system.
Safety monitoring is a special case of error detection and recovery in which the malfunction involves a safety hazard. Decisions are required when the automated system sensors detect that a safety condition has developed that would be hazardous to the equipment or humans in the vicinity of the equipment. The purpose of the safety-monitoring system is to detect the hazard and to take the most appropriate action to remove or reduce it. This may involve stopping the operation and alerting maintenance personnel to the condition, or it may involve a more complex set of actions to eliminate the safety problem.
Automated systems are usually required to interact with humans in some way. An automatic bank teller machine, for example, must receive instructions from customers and act accordingly. In some automated systems, a variety of different instructions from humans is possible, and the decision-making capability of the system must be quite sophisticated in order to deal with the array of possibilities.
A fourth reason for decision making in an automated system is to optimize the process. The need for optimization occurs most commonly in processes in which there is an economic performance criterion whose optimization is desirable. For example, minimizing cost is usually an important objective in manufacturing. The automated system might use adaptive control to receive appropriate sensor signals and other inputs and make decisions to drive the process toward the optimal state.
Industrial robotics
Industrial robotics is an automation technology that has received considerable attention since about 1960. This section will discuss the development of industrial robotics, the design of the robot manipulator, and the methods of programming robots. The applications of robots are examined below in the section Manufacturing applications of automation and robotics.
Development of robotics
Robotics is based on two related technologies: numerical control and teleoperators. Numerical control (NC) is a method of controlling machine tool axes by means of numbers that have been coded on punched paper tape or other media. It was developed during the late 1940s and early 1950s. The first numerical control machine tool was demonstrated in 1952 in the United States at the Massachusetts Institute of Technology (MIT). Subsequent research at MIT led to the development of the APT (Automatically Programmed Tools) language for programming machine tools.
A teleoperator is a mechanical manipulator that is controlled by a human from a remote location. Initial work on the design of teleoperators can be traced to the handling of radioactive materials in the early 1940s. In a typical implementation, a human moves a mechanical arm and hand at one location, and these motions are duplicated by the manipulator at another location.
Industrial robotics can be considered a combination of numerical-control and teleoperator technologies. Numerical control provides the concept of a programmable industrial machine, and teleoperator technology contributes the notion of a mechanical arm to perform useful work. The first industrial robot was installed in 1961 to unload parts from a die-casting operation. Its development was due largely to the efforts of the Americans George C. Devol, an inventor, and Joseph F. Engelberger, a businessman. Devol originated the design for a programmable manipulator, the U.S. patent for which was issued in 1961. Engelberger teamed with Devol to promote the use of robots in industry and to establish the first corporation in robotics—Unimation, Inc.
A teleoperator is a mechanical manipulator that is controlled by a human from a remote location. Initial work on the design of teleoperators can be traced to the handling of radioactive materials in the early 1940s. In a typical implementation, a human moves a mechanical arm and hand at one location, and these motions are duplicated by the manipulator at another location.
Industrial robotics can be considered a combination of numerical-control and teleoperator technologies. Numerical control provides the concept of a programmable industrial machine, and teleoperator technology contributes the notion of a mechanical arm to perform useful work. The first industrial robot was installed in 1961 to unload parts from a die-casting operation. Its development was due largely to the efforts of the Americans George C. Devol, an inventor, and Joseph F. Engelberger, a businessman. Devol originated the design for a programmable manipulator, the U.S. patent for which was issued in 1961. Engelberger teamed with Devol to promote the use of robots in industry and to establish the first corporation in robotics—Unimation, Inc.
The robot manipulator
The most widely accepted definition of an industrial robot is one developed by the Robotic Industries Association:
![Figure 3: Five types of mechanical joints used in robot manipulators. Collinear and …
[Credit: Encyclopædia Britannica, Inc.]](http://cache-media.britannica.com/eb-media/87/6087-003-991BE278.gif "Figure 3: Five types of mechanical joints used in robot manipulators. Collinear and …
[Credit: Encyclopædia Britannica, Inc.]")
The mechanical manipulator of an industrial robot is made up of a sequence of link and joint combinations. The links are the rigid members connecting the joints. The joints (also called axes) are the movable components of the robot that cause relative motion between adjacent links. As shown in Figure 3, there are five principal types of mechanical joints used to construct the manipulator. Two of the joints are linear, in which the relative motion between adjacent links is translational, and three are rotary types, in which the relative motion involves rotation between links.
The manipulator can be divided into two sections: (1) an arm-and-body, which usually consists of three joints connected by large links, and (2) a wrist, consisting of two or three compact joints. Attached to the wrist is a gripper to grasp a work part or a tool (e.g., a spot-welding gun) to perform a process. The two manipulator sections have different functions: the arm-and-body is used to move and position parts or tools in the robot’s work space, while the wrist is used to orient the parts or tools at the work location. The arm-and-body section of most commercial robots is based on one of four configurations. Each of the anatomies, as they are sometimes called, provides a different work envelope (i.e., the space that can be reached by the robot’s arm) and is suited to different types of applications.
An industrial robot is a reprogrammable, multifunctional manipulator designed to move materials, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks.
The technology of robotics is concerned with the design of the mechanical manipulator and the computer systems used to control it. It is also concerned with the industrial applications of robots, which are described below.The mechanical manipulator of an industrial robot is made up of a sequence of link and joint combinations. The links are the rigid members connecting the joints. The joints (also called axes) are the movable components of the robot that cause relative motion between adjacent links. As shown in Figure 3, there are five principal types of mechanical joints used to construct the manipulator. Two of the joints are linear, in which the relative motion between adjacent links is translational, and three are rotary types, in which the relative motion involves rotation between links.The manipulator can be divided into two sections: (1) an arm-and-body, which usually consists of three joints connected by large links, and (2) a wrist, consisting of two or three compact joints. Attached to the wrist is a gripper to grasp a work part or a tool (e.g., a spot-welding gun) to perform a process. The two manipulator sections have different functions: the arm-and-body is used to move and position parts or tools in the robot’s work space, while the wrist is used to orient the parts or tools at the work location. The arm-and-body section of most commercial robots is based on one of four configurations. Each of the anatomies, as they are sometimes called, provides a different work envelope (i.e., the space that can be reached by the robot’s arm) and is suited to different types of applications.
Robot programming
The computer system that controls the manipulator must be programmed to teach the robot the particular motion sequence and other actions that must be performed in order to accomplish its task. There are several ways that industrial robots are programmed. One method is called lead-through programming. This requires that the manipulator be driven through the various motions needed to perform a given task, recording the motions into the robot’s computer memory. This can be done either by physically moving the manipulator through the motion sequence or by using a control box to drive the manipulator through the sequence.
A second method of programming involves the use of a programming language very much like a computer programming language. However, in addition to many of the capabilities of a computer programming language (i.e., data processing, computations, communicating with other computer devices, and decision making), the robot language also includes statements specifically designed for robot control. These capabilities include (1) motion control and (2) input/output. Motion-control commands are used to direct the robot to move its manipulator to some defined position in space. For example, the statement “move P1” might be used to direct the robot to a point in space called P1. Input/output commands are employed to control the receipt of signals from sensors and other devices in the work cell and to initiate control signals to other pieces of equipment in the cell. For instance, the statement “signal 3, on” might be used to turn on a motor in the cell, where the motor is connected to output line 3 in the robot’s controller.
A second method of programming involves the use of a programming language very much like a computer programming language. However, in addition to many of the capabilities of a computer programming language (i.e., data processing, computations, communicating with other computer devices, and decision making), the robot language also includes statements specifically designed for robot control. These capabilities include (1) motion control and (2) input/output. Motion-control commands are used to direct the robot to move its manipulator to some defined position in space. For example, the statement “move P1” might be used to direct the robot to a point in space called P1. Input/output commands are employed to control the receipt of signals from sensors and other devices in the work cell and to initiate control signals to other pieces of equipment in the cell. For instance, the statement “signal 3, on” might be used to turn on a motor in the cell, where the motor is connected to output line 3 in the robot’s controller.
Manufacturing applications of automation and robotics
One of the most important application areas for automation technology is manufacturing. To many people, automation means manufacturing automation. In this section, the types of automation are defined, and examples of automated systems used in manufacturing are described.
Three types of automation in production can be distinguished: (1) fixed automation, (2) programmable automation, and (3) flexible automation.
Fixed automation, also known as “hard automation,” refers to an automated production facility in which the sequence of processing operations is fixed by the equipment configuration. In effect, the programmed commands are contained in the machines in the form of cams, gears, wiring, and other hardware that is not easily changed over from one product style to another. This form of automation is characterized by high initial investment and high production rates. It is therefore suitable for products that are made in large volumes. Examples of fixed automation include machining transfer lines found in the automotive industry, automatic assembly machines, and certain chemical processes.
Programmable automation is a form of automation for producing products in batches. The products are made in batch quantities ranging from several dozen to several thousand units at a time. For each new batch, the production equipment must be reprogrammed and changed over to accommodate the new product style. This reprogramming and changeover take time to accomplish, and there is a period of nonproductive time followed by a production run for each new batch. Production rates in programmable automation are generally lower than in fixed automation, because the equipment is designed to facilitate product changeover rather than for product specialization. A numerical-control machine tool is a good example of programmable automation. The program is coded in computer memory for each different product style, and the machine tool is controlled by the computer program. Industrial robots are another example.
Flexible automation is an extension of programmable automation. The disadvantage with programmable automation is the time required to reprogram and change over the production equipment for each batch of new product. This is lost production time, which is expensive. In flexible automation, the variety of products is sufficiently limited so that the changeover of the equipment can be done very quickly and automatically. The reprogramming of the equipment in flexible automation is done off-line; that is, the programming is accomplished at a computer terminal without using the production equipment itself. Accordingly, there is no need to group identical products into batches; instead, a mixture of different products can be produced one right after another.
Three types of automation in production can be distinguished: (1) fixed automation, (2) programmable automation, and (3) flexible automation.
Fixed automation, also known as “hard automation,” refers to an automated production facility in which the sequence of processing operations is fixed by the equipment configuration. In effect, the programmed commands are contained in the machines in the form of cams, gears, wiring, and other hardware that is not easily changed over from one product style to another. This form of automation is characterized by high initial investment and high production rates. It is therefore suitable for products that are made in large volumes. Examples of fixed automation include machining transfer lines found in the automotive industry, automatic assembly machines, and certain chemical processes.
Programmable automation is a form of automation for producing products in batches. The products are made in batch quantities ranging from several dozen to several thousand units at a time. For each new batch, the production equipment must be reprogrammed and changed over to accommodate the new product style. This reprogramming and changeover take time to accomplish, and there is a period of nonproductive time followed by a production run for each new batch. Production rates in programmable automation are generally lower than in fixed automation, because the equipment is designed to facilitate product changeover rather than for product specialization. A numerical-control machine tool is a good example of programmable automation. The program is coded in computer memory for each different product style, and the machine tool is controlled by the computer program. Industrial robots are another example.
Flexible automation is an extension of programmable automation. The disadvantage with programmable automation is the time required to reprogram and change over the production equipment for each batch of new product. This is lost production time, which is expensive. In flexible automation, the variety of products is sufficiently limited so that the changeover of the equipment can be done very quickly and automatically. The reprogramming of the equipment in flexible automation is done off-line; that is, the programming is accomplished at a computer terminal without using the production equipment itself. Accordingly, there is no need to group identical products into batches; instead, a mixture of different products can be produced one right after another.
Automated production lines
An automated production line consists of a series of workstations connected by a transfer system to move parts between the stations. This is an example of fixed automation, since these lines are typically set up for long production runs, perhaps making millions of product units and running for several years between changeovers. Each station is designed to perform a specific processing operation, so that the part or product is constructed stepwise as it progresses along the line. A raw work part enters at one end of the line, proceeds through each workstation, and emerges at the other end as a completed product. In the normal operation of the line, there is a work part being processed at each station, so that many parts are being processed simultaneously and a finished part is produced with each cycle of the line. The various operations, part transfers, and other activities taking place on an automated transfer line must all be sequenced and coordinated properly for the line to operate efficiently. Modern automated lines are controlled by programmable logic controllers, which are special computers that facilitate connections with industrial equipment (such as automated production lines) and can perform the kinds of timing and sequencing functions required to operate such equipment.
Automated production lines are utilized in many industries, most notably automotive, where they are used for processes such as machining and pressworking. Machining is a manufacturing process in which metal is removed by a cutting or shaping tool, so that the remaining work part is the desired shape. Machinery and motor components are usually made by this process. In many cases, multiple operations are required to completely shape the part. If the part is mass-produced, an automated transfer line is often the most economical method of production. The many separate operations are divided among the workstations. Transfer lines date back to about 1924.
Pressworking operations involve the cutting and forming of parts from sheet metal. Examples of such parts include automobile body panels, outer shells of major appliances (e.g., laundry machines and ranges), and metal furniture (e.g., desks and file cabinets). More than one processing step is often required to complete a complicated part. Several presses are connected together in sequence by handling mechanisms that transfer the partially completed parts from one press to the next, thus creating an automated pressworking line.
Automated production lines are utilized in many industries, most notably automotive, where they are used for processes such as machining and pressworking. Machining is a manufacturing process in which metal is removed by a cutting or shaping tool, so that the remaining work part is the desired shape. Machinery and motor components are usually made by this process. In many cases, multiple operations are required to completely shape the part. If the part is mass-produced, an automated transfer line is often the most economical method of production. The many separate operations are divided among the workstations. Transfer lines date back to about 1924.
Pressworking operations involve the cutting and forming of parts from sheet metal. Examples of such parts include automobile body panels, outer shells of major appliances (e.g., laundry machines and ranges), and metal furniture (e.g., desks and file cabinets). More than one processing step is often required to complete a complicated part. Several presses are connected together in sequence by handling mechanisms that transfer the partially completed parts from one press to the next, thus creating an automated pressworking line.
Numerical control
As discussed above, numerical control is a form of programmable automation in which a machine is controlled by numbers (and other symbols) that have been coded on punched paper tape or an alternative storage medium. The initial application of numerical control was in the machine tool industry, to control the position of a cutting tool relative to the work part being machined. The NC part program represents the set of machining instructions for the particular part. The coded numbers in the program specify x-y-z coordinates in a Cartesian axis system, defining the various positions of the cutting tool in relation to the work part. By sequencing these positions in the program, the machine tool is directed to accomplish the machining of the part. A position feedback control system is used in most NC machines to verify that the coded instructions have been correctly performed.
Today a small computer is used as the controller in an NC machine tool, and the program is actuated from computer memory rather than punched paper tape. However, initial entry of the program into computer memory is often still accomplished using punched tape. Since this form of numerical control is implemented by computer, it is called computer numerical control, or CNC. Another variation in the implementation of numerical control involves sending part programs over telecommunications lines from a central computer to individual machine tools in the factory, thus eliminating the use of the punched tape altogether. This form of numerical control is called direct numerical control, or DNC.
Many applications of numerical control have been developed since its initial use to control machine tools. Other machines using numerical control include component-insertion machines used in electronics assembly, drafting machines that prepare engineering drawings, coordinate measuring machines that perform accurate inspections of parts, and flame cutting machines and similar devices. In these applications, the term numerical control is not always used explicitly, but the operating principle is the same: coded numerical data are employed to control the position of a tool or workhead relative to some object.
To illustrate these alternative applications of numerical control, the component-insertion machine will be considered here. Such a machine is used to position electronic components (e.g., semiconductor chip modules) onto a printed circuit board (PCB). It is basically an x-y positioning table that moves the printed circuit board relative to the part-insertion head, which then places the individual component into position on the board. A typical printed circuit board has dozens of individual components that must be placed on its surface; in many cases, the lead wires of the components must be inserted into small holes in the board, requiring great precision by the insertion machine. The program that controls the machine indicates which components are to be placed on the board and their locations. This information is contained in the product-design database and is typically communicated directly from the computer to the insertion machine.
Today a small computer is used as the controller in an NC machine tool, and the program is actuated from computer memory rather than punched paper tape. However, initial entry of the program into computer memory is often still accomplished using punched tape. Since this form of numerical control is implemented by computer, it is called computer numerical control, or CNC. Another variation in the implementation of numerical control involves sending part programs over telecommunications lines from a central computer to individual machine tools in the factory, thus eliminating the use of the punched tape altogether. This form of numerical control is called direct numerical control, or DNC.
Many applications of numerical control have been developed since its initial use to control machine tools. Other machines using numerical control include component-insertion machines used in electronics assembly, drafting machines that prepare engineering drawings, coordinate measuring machines that perform accurate inspections of parts, and flame cutting machines and similar devices. In these applications, the term numerical control is not always used explicitly, but the operating principle is the same: coded numerical data are employed to control the position of a tool or workhead relative to some object.
To illustrate these alternative applications of numerical control, the component-insertion machine will be considered here. Such a machine is used to position electronic components (e.g., semiconductor chip modules) onto a printed circuit board (PCB). It is basically an x-y positioning table that moves the printed circuit board relative to the part-insertion head, which then places the individual component into position on the board. A typical printed circuit board has dozens of individual components that must be placed on its surface; in many cases, the lead wires of the components must be inserted into small holes in the board, requiring great precision by the insertion machine. The program that controls the machine indicates which components are to be placed on the board and their locations. This information is contained in the product-design database and is typically communicated directly from the computer to the insertion machine.
Automated assembly
Assembly operations have traditionally been performed manually, either at single assembly workstations or on assembly lines with multiple stations. Owing to the high labour content and high cost of manual labour, greater attention has been given in recent years to the use of automation for assembly work. Assembly operations can be automated using production line principles if the quantities are large, the product is small, and the design is simple (e.g., mechanical pencils, pens, and cigarette lighters). For products that do not satisfy these conditions, manual assembly is generally required.
Automated assembly machines have been developed that operate in a manner similar to machining transfer lines, with the difference being that assembly operations, instead of machining, are performed at the workstations. A typical assembly machine consists of several stations, each equipped with a supply of components and a mechanism for delivering the components into position for assembly. A workhead at each station performs the actual attachment of the component. Typical workheads include automatic screwdrivers, staking or riveting machines, welding heads, and other joining devices. A new component is added to the partially completed product at each workstation, thus building up the product gradually as it proceeds through the line. Assembly machines of this type are considered to be examples of fixed automation, because they are generally configured for a particular product made in high volume. Programmable assembly machines are represented by the component-insertion machines employed in the electronics industry, as described above.
Automated assembly machines have been developed that operate in a manner similar to machining transfer lines, with the difference being that assembly operations, instead of machining, are performed at the workstations. A typical assembly machine consists of several stations, each equipped with a supply of components and a mechanism for delivering the components into position for assembly. A workhead at each station performs the actual attachment of the component. Typical workheads include automatic screwdrivers, staking or riveting machines, welding heads, and other joining devices. A new component is added to the partially completed product at each workstation, thus building up the product gradually as it proceeds through the line. Assembly machines of this type are considered to be examples of fixed automation, because they are generally configured for a particular product made in high volume. Programmable assembly machines are represented by the component-insertion machines employed in the electronics industry, as described above.
Robots in manufacturing
Today most robots are used in manufacturing operations; the applications can be divided into three categories: (1) material handling, (2) processing operations, and (3) assembly and inspection.
Material-handling applications include material transfer and machine loading and unloading. Material-transfer applications require the robot to move materials or work parts from one location to another. Many of these tasks are relatively simple, requiring robots to pick up parts from one conveyor and place them on another. Other transfer operations are more complex, such as placing parts onto pallets in an arrangement that must be calculated by the robot. Machine loading and unloading operations utilize a robot to load and unload parts at a production machine. This requires the robot to be equipped with a gripper that can grasp parts. Usually the gripper must be designed specifically for the particular part geometry.
In robotic processing operations, the robot manipulates a tool to perform a process on the work part. Examples of such applications include spot welding, continuous arc welding, and spray painting. Spot welding of automobile bodies is one of the most common applications of industrial robots in the United States. The robot positions a spot welder against the automobile panels and frames to complete the assembly of the basic car body. Arc welding is a continuous process in which the robot moves the welding rod along the seam to be welded. Spray painting involves the manipulation of a spray-painting gun over the surface of the object to be coated. Other operations in this category include grinding, polishing, and routing, in which a rotating spindle serves as the robot’s tool.
The third application area of industrial robots is assembly and inspection. The use of robots in assembly is expected to increase because of the high cost of manual labour common in these operations. Since robots are programmable, one strategy in assembly work is to produce multiple product styles in batches, reprogramming the robots between batches. An alternative strategy is to produce a mixture of different product styles in the same assembly cell, requiring each robot in the cell to identify the product style as it arrives and then execute the appropriate task for that unit.
The design of the product is an important aspect of robotic assembly. Assembly methods that are satisfactory for humans are not necessarily suitable for robots. Using a screw and nut as a fastening method, for example, is easily performed in manual assembly, but the same operation is extremely difficult for a one-armed robot. Designs in which the components are to be added from the same direction using snap fits and other one-step fastening procedures enable the work to be accomplished much more easily by automated and robotic assembly methods.
Inspection is another area of factory operations in which the utilization of robots is growing. In a typical inspection job, the robot positions a sensor with respect to the work part and determines whether the part is consistent with the quality specifications.
In nearly all industrial robotic applications, the robot provides a substitute for human labour. There are certain characteristics of industrial jobs performed by humans that identify the work as a potential application for robots: (1) the operation is repetitive, involving the same basic work motions every cycle; (2) the operation is hazardous or uncomfortable for the human worker (e.g., spray painting, spot welding, arc welding, and certain machine loading and unloading tasks); (3) the task requires a work part or tool that is heavy and awkward to handle; and (4) the operation allows the robot to be used on two or three shifts.
Material-handling applications include material transfer and machine loading and unloading. Material-transfer applications require the robot to move materials or work parts from one location to another. Many of these tasks are relatively simple, requiring robots to pick up parts from one conveyor and place them on another. Other transfer operations are more complex, such as placing parts onto pallets in an arrangement that must be calculated by the robot. Machine loading and unloading operations utilize a robot to load and unload parts at a production machine. This requires the robot to be equipped with a gripper that can grasp parts. Usually the gripper must be designed specifically for the particular part geometry.
In robotic processing operations, the robot manipulates a tool to perform a process on the work part. Examples of such applications include spot welding, continuous arc welding, and spray painting. Spot welding of automobile bodies is one of the most common applications of industrial robots in the United States. The robot positions a spot welder against the automobile panels and frames to complete the assembly of the basic car body. Arc welding is a continuous process in which the robot moves the welding rod along the seam to be welded. Spray painting involves the manipulation of a spray-painting gun over the surface of the object to be coated. Other operations in this category include grinding, polishing, and routing, in which a rotating spindle serves as the robot’s tool.
The third application area of industrial robots is assembly and inspection. The use of robots in assembly is expected to increase because of the high cost of manual labour common in these operations. Since robots are programmable, one strategy in assembly work is to produce multiple product styles in batches, reprogramming the robots between batches. An alternative strategy is to produce a mixture of different product styles in the same assembly cell, requiring each robot in the cell to identify the product style as it arrives and then execute the appropriate task for that unit.
The design of the product is an important aspect of robotic assembly. Assembly methods that are satisfactory for humans are not necessarily suitable for robots. Using a screw and nut as a fastening method, for example, is easily performed in manual assembly, but the same operation is extremely difficult for a one-armed robot. Designs in which the components are to be added from the same direction using snap fits and other one-step fastening procedures enable the work to be accomplished much more easily by automated and robotic assembly methods.
Inspection is another area of factory operations in which the utilization of robots is growing. In a typical inspection job, the robot positions a sensor with respect to the work part and determines whether the part is consistent with the quality specifications.
In nearly all industrial robotic applications, the robot provides a substitute for human labour. There are certain characteristics of industrial jobs performed by humans that identify the work as a potential application for robots: (1) the operation is repetitive, involving the same basic work motions every cycle; (2) the operation is hazardous or uncomfortable for the human worker (e.g., spray painting, spot welding, arc welding, and certain machine loading and unloading tasks); (3) the task requires a work part or tool that is heavy and awkward to handle; and (4) the operation allows the robot to be used on two or three shifts.
Flexible manufacturing systems
A flexible manufacturing system (FMS) is a form of flexible automation in which several machine tools are linked together by a material-handling system, and all aspects of the system are controlled by a central computer. An FMS is distinguished from an automated production line by its ability to process more than one product style simultaneously. At any moment, each machine in the system may be processing a different part type. An FMS can also cope with changes in product mix and production schedule as demand patterns for the different products made on the system change over time. New product styles can be introduced into production with an FMS, so long as they fall within the range of products that the system is designed to process. This kind of system is therefore ideal when demand for the products is low to medium and there are likely to be changes in demand.
The components of an FMS are (1) processing machines, which are usually CNC machine tools that perform machining operations, although other types of automated workstations such as inspection stations are also possible, (2) a material-handling system, such as a conveyor system, which is capable of delivering work parts to any machine in the FMS, and (3) a central computer system that is responsible for communicating NC part programs to each machine and for coordinating the activities of the machines and the material-handling system. In addition, a fourth component of an FMS is human labour. Although the flexible manufacturing system represents a high level of production automation, people are still needed to manage the system, load and unload parts, change tools, and maintain and repair the equipment.
The components of an FMS are (1) processing machines, which are usually CNC machine tools that perform machining operations, although other types of automated workstations such as inspection stations are also possible, (2) a material-handling system, such as a conveyor system, which is capable of delivering work parts to any machine in the FMS, and (3) a central computer system that is responsible for communicating NC part programs to each machine and for coordinating the activities of the machines and the material-handling system. In addition, a fourth component of an FMS is human labour. Although the flexible manufacturing system represents a high level of production automation, people are still needed to manage the system, load and unload parts, change tools, and maintain and repair the equipment.
Computer process control
In computer process control, a digital computer is used to direct the operations of a manufacturing process. Although other automated systems are typically controlled by computer, the term computer process control is generally associated with continuous or semicontinuous production operations involving materials such as chemicals, petroleum, foods, and certain basic metals. In these operations the products are typically processed in gas, liquid, or powder form to facilitate flow of the material through the various steps of the production cycle. In addition, these products are usually mass-produced. Because of the ease of handling the product and the large volumes involved, a high level of automation has been accomplished in these industries.
The modern computer process control system generally includes the following: (1) measurement of important process variables such as temperature, flow rate, and pressure, (2) execution of some optimizing strategy, (3) actuation of such devices as valves, switches, and furnaces that enable the process to implement the optimal strategy, and (4) generation of reports to management indicating equipment status, production performance, and product quality. Today computer process control is applied to many industrial operations, two of which are described below.
The typical modern process plant is computer-controlled. In one petrochemical plant that produces more than 20 products, the facility is divided into three areas, each with several chemical-processing units. Each area has its own process-control computer to perform scanning, control, and alarm functions. The computers are connected to a central computer in a hierarchical configuration. The central computer calculates how to obtain maximum yield from each process and generates management reports on process performance.
Each process computer monitors up to 2,000 parameters that are required to control the process, such as temperature, flow rate, pressure, liquid level, and chemical concentration. These measurements are taken on a sampling basis; the time between samples varies between 2 and 120 seconds, depending on the relative need for the data. Each computer controls approximately 400 feedback control loops. Under normal operation, each control computer maintains operation of its process at or near optimum performance levels. If process parameters exceed the specified normal or safe ranges, the control computer actuates a signal light and alarm horn and prints a message indicating the nature of the problem for the technician. The central computer receives data from the process computers and performs calculations to optimize the performance of each chemical-processing unit. The results of these calculations are then passed to the individual process computers in the form of changes in the set points for the various control loops.
Substantial economic advantages are obtained from this type of computer control in the process industries. The computer hierarchy is capable of integrating all the data from the many individual control loops far better than humans are able to do, thus permitting a higher level of performance. Advanced control algorithms can be applied by the computer to optimize the process. In addition, the computer is capable of sensing process conditions that indicate unsafe or abnormal operation much more quickly than humans can. All these improvements increase productivity, efficiency, and safety during process operation.
Like the chemical-processing industries, the basic metals industries (iron and steel, aluminum, etc.) have automated many of their processes by computer control. Like the chemical industries, the metals industries deal in large volumes of products, and so there is a substantial economic incentive to invest in automation. However, metals are typically produced in batches rather than continuously, and it is generally more difficult to handle metals in bulk form than chemicals that flow.
An example of computer process control in the metals industry is the rolling of hot metal ingots into final shapes such as coils and strips. This was first done in the steel industry, but similar processing is also accomplished with aluminum and other metals. In a modern steel plant, hot-rolling is performed under computer control. The rolling process involves the forming of a large, hot metal billet by passing it through a rolling mill consisting of one or more sets of large cylindrical rolls that squeeze the metal and reduce its cross section. Several passes are required to reduce the ingot gradually to the desired thickness. Sensors and automatic instruments measure the dimensions and temperature of the ingot after each pass through the rolls, and the control computer calculates and regulates the roll settings for the next pass.
In a large plant, several orders for rolled products with different specifications may be in the mill at any given time. Control programs have been developed to schedule the sequence and rate at which the hot metal ingots are fed through the rolling mills. The production control task of scheduling and keeping track of the different orders requires rapid, massive data gathering and analysis. In modern plants this task has been effectively integrated with the computer control of the rolling mill operations to achieve a highly automated production system.
The modern computer process control system generally includes the following: (1) measurement of important process variables such as temperature, flow rate, and pressure, (2) execution of some optimizing strategy, (3) actuation of such devices as valves, switches, and furnaces that enable the process to implement the optimal strategy, and (4) generation of reports to management indicating equipment status, production performance, and product quality. Today computer process control is applied to many industrial operations, two of which are described below.
The typical modern process plant is computer-controlled. In one petrochemical plant that produces more than 20 products, the facility is divided into three areas, each with several chemical-processing units. Each area has its own process-control computer to perform scanning, control, and alarm functions. The computers are connected to a central computer in a hierarchical configuration. The central computer calculates how to obtain maximum yield from each process and generates management reports on process performance.
Each process computer monitors up to 2,000 parameters that are required to control the process, such as temperature, flow rate, pressure, liquid level, and chemical concentration. These measurements are taken on a sampling basis; the time between samples varies between 2 and 120 seconds, depending on the relative need for the data. Each computer controls approximately 400 feedback control loops. Under normal operation, each control computer maintains operation of its process at or near optimum performance levels. If process parameters exceed the specified normal or safe ranges, the control computer actuates a signal light and alarm horn and prints a message indicating the nature of the problem for the technician. The central computer receives data from the process computers and performs calculations to optimize the performance of each chemical-processing unit. The results of these calculations are then passed to the individual process computers in the form of changes in the set points for the various control loops.
Substantial economic advantages are obtained from this type of computer control in the process industries. The computer hierarchy is capable of integrating all the data from the many individual control loops far better than humans are able to do, thus permitting a higher level of performance. Advanced control algorithms can be applied by the computer to optimize the process. In addition, the computer is capable of sensing process conditions that indicate unsafe or abnormal operation much more quickly than humans can. All these improvements increase productivity, efficiency, and safety during process operation.
Like the chemical-processing industries, the basic metals industries (iron and steel, aluminum, etc.) have automated many of their processes by computer control. Like the chemical industries, the metals industries deal in large volumes of products, and so there is a substantial economic incentive to invest in automation. However, metals are typically produced in batches rather than continuously, and it is generally more difficult to handle metals in bulk form than chemicals that flow.
An example of computer process control in the metals industry is the rolling of hot metal ingots into final shapes such as coils and strips. This was first done in the steel industry, but similar processing is also accomplished with aluminum and other metals. In a modern steel plant, hot-rolling is performed under computer control. The rolling process involves the forming of a large, hot metal billet by passing it through a rolling mill consisting of one or more sets of large cylindrical rolls that squeeze the metal and reduce its cross section. Several passes are required to reduce the ingot gradually to the desired thickness. Sensors and automatic instruments measure the dimensions and temperature of the ingot after each pass through the rolls, and the control computer calculates and regulates the roll settings for the next pass.
In a large plant, several orders for rolled products with different specifications may be in the mill at any given time. Control programs have been developed to schedule the sequence and rate at which the hot metal ingots are fed through the rolling mills. The production control task of scheduling and keeping track of the different orders requires rapid, massive data gathering and analysis. In modern plants this task has been effectively integrated with the computer control of the rolling mill operations to achieve a highly automated production system.
Computer-integrated manufacturing
Since about 1970 there has been a growing trend in manufacturing firms toward the use of computers to perform many of the functions related to design and production. The technology associated with this trend is called CAD/CAM, for computer-aided design and computer-aided manufacturing. Today it is widely recognized that the scope of computer applications must extend beyond design and production to include the business functions of the firm. The name given to this more comprehensive use of computers is computer-integrated manufacturing (CIM).
CAD/CAM is based on the capability of a computer system to process, store, and display large amounts of data representing part and product specifications. For mechanical products, the data represent graphic models of the components; for electrical products, they represent circuit information; and so forth. CAD/CAM technology has been applied in many industries, including machined components, electronics products, and equipment design and fabrication for chemical processing. CAD/CAM involves not only the automation of the manufacturing operations but also the automation of elements in the entire design-and-manufacturing procedure.
Computer-aided design (CAD) makes use of computer systems to assist in the creation, modification, analysis, and optimization of a design. The designer, working with the CAD system rather than the traditional drafting board, creates the lines and surfaces that form the object (product, part, structure, etc.) and stores this model in the computer database. By invoking the appropriate CAD software, the designer can perform various analyses on the object, such as heat transfer calculations. The final object design is developed as adjustments are made on the basis of these analyses. Once the design procedure has been completed, the computer-aided design system can generate the detailed drawings required to make the object.
Computer-aided manufacturing (CAM) involves the use of computer systems to assist in the planning, control, and management of production operations. This is accomplished by either direct or indirect connections between the computer and production operations. In the case of the direct connection, the computer is used to monitor or control the processes in the factory. Computer process monitoring involves the collection of data from the factory, the analysis of the data, and the communication of process-performance results to plant management. These measures increase the efficiency of plant operations. Computer process control entails the use of the computer system to execute control actions to operate the plant automatically, as described above. Indirect connections between the computer system and the process involve applications in which the computer supports the production operations without actually monitoring or controlling them. These applications include planning and management functions that can be performed by the computer (or by humans working with the computer) more efficiently than by humans alone. Examples of these functions are planning the step-by-step processes for the product, part programming in numerical control, and scheduling the production operations in the factory.
Computer-integrated manufacturing includes all the engineering functions of CAD/CAM and the business functions of the firm as well. These business functions include order entry, cost accounting, employee time records and payroll, and customer billing. In an ideal CIM system, computer technology is applied to all the operational and information-processing functions of the company, from customer orders through design and production (CAD/CAM) to product shipment and customer service. The scope of the computer system includes all activities that are concerned with manufacturing. In many ways, CIM represents the highest level of automation in manufacturing.
CAD/CAM is based on the capability of a computer system to process, store, and display large amounts of data representing part and product specifications. For mechanical products, the data represent graphic models of the components; for electrical products, they represent circuit information; and so forth. CAD/CAM technology has been applied in many industries, including machined components, electronics products, and equipment design and fabrication for chemical processing. CAD/CAM involves not only the automation of the manufacturing operations but also the automation of elements in the entire design-and-manufacturing procedure.
Computer-aided design (CAD) makes use of computer systems to assist in the creation, modification, analysis, and optimization of a design. The designer, working with the CAD system rather than the traditional drafting board, creates the lines and surfaces that form the object (product, part, structure, etc.) and stores this model in the computer database. By invoking the appropriate CAD software, the designer can perform various analyses on the object, such as heat transfer calculations. The final object design is developed as adjustments are made on the basis of these analyses. Once the design procedure has been completed, the computer-aided design system can generate the detailed drawings required to make the object.
Computer-aided manufacturing (CAM) involves the use of computer systems to assist in the planning, control, and management of production operations. This is accomplished by either direct or indirect connections between the computer and production operations. In the case of the direct connection, the computer is used to monitor or control the processes in the factory. Computer process monitoring involves the collection of data from the factory, the analysis of the data, and the communication of process-performance results to plant management. These measures increase the efficiency of plant operations. Computer process control entails the use of the computer system to execute control actions to operate the plant automatically, as described above. Indirect connections between the computer system and the process involve applications in which the computer supports the production operations without actually monitoring or controlling them. These applications include planning and management functions that can be performed by the computer (or by humans working with the computer) more efficiently than by humans alone. Examples of these functions are planning the step-by-step processes for the product, part programming in numerical control, and scheduling the production operations in the factory.
Computer-integrated manufacturing includes all the engineering functions of CAD/CAM and the business functions of the firm as well. These business functions include order entry, cost accounting, employee time records and payroll, and customer billing. In an ideal CIM system, computer technology is applied to all the operational and information-processing functions of the company, from customer orders through design and production (CAD/CAM) to product shipment and customer service. The scope of the computer system includes all activities that are concerned with manufacturing. In many ways, CIM represents the highest level of automation in manufacturing.
Automation in daily life
In addition to the manufacturing applications of automation technology, there have been significant achievements in such areas as communications, transportation, service industries, and consumer products. Some of the more significant applications are described in this section.
Communications
One of the earliest practical applications of automation was in telephone switching. The first switching machines, invented near the end of the 19th century, were simple mechanical switches that were remotely controlled by the telephone user pushing buttons or turning a dial on the phone. Modern electronic telephone switching systems are based on highly sophisticated digital computers that perform functions such as monitoring thousands of telephone lines, determining which lines require service, storing the digits of each telephone number as it is being dialed, setting up the required connections, sending electrical signals to ring the receiver’s phone, monitoring the call during its progress, and disconnecting the phone when the call is completed. These systems also are used to time and bill toll calls and to transmit billing information and other data relative to the business operations of the phone company. In addition to the various functions mentioned, the newest electronic systems automatically transfer calls to alternate numbers, call back the user when busy lines become free, and perform other customer services in response to dialed codes. These systems also perform function tests on their own operations, diagnose problems when they arise, and print out detailed instructions for repairs.
Other applications of automation in communications systems include local area networks, communications satellites, and automated mail-sorting machines. A local area network (LAN) operates like an automated telephone company within a single building or group of buildings. Local area networks are generally capable of transmitting not only voice but also digital data between terminals in the system. Communications satellites have become essential for communicating telephone or video signals across great distances. Such communications would not be possible without the automated guidance systems that place and retain the satellites in predetermined orbits. Automatic mail-sorting machines have been developed for use in many post offices throughout the world to read codes on envelopes and sort the envelopes according to destination.
Other applications of automation in communications systems include local area networks, communications satellites, and automated mail-sorting machines. A local area network (LAN) operates like an automated telephone company within a single building or group of buildings. Local area networks are generally capable of transmitting not only voice but also digital data between terminals in the system. Communications satellites have become essential for communicating telephone or video signals across great distances. Such communications would not be possible without the automated guidance systems that place and retain the satellites in predetermined orbits. Automatic mail-sorting machines have been developed for use in many post offices throughout the world to read codes on envelopes and sort the envelopes according to destination.
Transportation
Automation has been applied in various ways in the transportation industries. Applications include airline reservation systems, automatic pilots in aircraft and locomotives, and urban mass-transit systems. The airlines use computerized reservation systems to continuously monitor the status of all flights. With these systems, ticket agents at widely dispersed locations can obtain information about the availability of seats on any flight in a matter of seconds. The reservation systems compare requests for space with the status of each flight, grant space when available, and automatically update the reservation status files. Passengers can even receive their seat assignments well in advance of flight departures.
Nearly all commercial aircraft are equipped with instruments called automatic pilots. Under normal flying conditions, these systems guide an airplane over a predetermined route by detecting changes in the aircraft’s orientation and heading from gyroscopes and similar instruments and by providing appropriate control signals to the plane’s steering mechanism. Automatic navigation systems and instrument landing systems operate by using radio signals from ground beacons that provide the aircraft with course directions for guidance. When an airplane is within the traffic pattern for ground control, its human pilot normally assumes control.
Examples of automated rail transportation include American urban mass-transit systems such as BART (Bay Area Rapid Transit) in San Francisco; MARTA (Metropolitan Atlanta Rapid Transit Authority) in Atlanta, Ga.; and the Metrorail in Washington, D.C. The BART system serves as a useful example; it consists of more than 75 miles (120 kilometres) of track, with about 100 trains operating at peak hours between roughly 30 stations. The trains sometimes attain speeds of 80 miles per hour with intervals between trains of as little as 90 seconds. In each train there is one operator whose role is that of an observer and communicator and who can override the automatic system in case of emergency. The automatic system protects the trains by assuring a safe distance between them and by controlling their speed. Another function of the system is to control train routings and make adjustments in the operation of each train to keep the entire system operating on schedule.
As a train enters the station, it automatically transmits its identification, destination, and length, thus lighting up a display board for passenger information and transmitting information to the control centres. Signals are automatically returned to the train to regulate its time in the station and its running time to the next station. At the beginning of the day, an ideal schedule is determined; as the day progresses, the performance of each train is compared with the schedule, and adjustments are made to each train’s operation as required. The entire system is controlled by two identical computers, so that if one malfunctions, the other assumes complete control. In the event of a complete failure of the computer control system, the system reverts to manual control.
Nearly all commercial aircraft are equipped with instruments called automatic pilots. Under normal flying conditions, these systems guide an airplane over a predetermined route by detecting changes in the aircraft’s orientation and heading from gyroscopes and similar instruments and by providing appropriate control signals to the plane’s steering mechanism. Automatic navigation systems and instrument landing systems operate by using radio signals from ground beacons that provide the aircraft with course directions for guidance. When an airplane is within the traffic pattern for ground control, its human pilot normally assumes control.
Examples of automated rail transportation include American urban mass-transit systems such as BART (Bay Area Rapid Transit) in San Francisco; MARTA (Metropolitan Atlanta Rapid Transit Authority) in Atlanta, Ga.; and the Metrorail in Washington, D.C. The BART system serves as a useful example; it consists of more than 75 miles (120 kilometres) of track, with about 100 trains operating at peak hours between roughly 30 stations. The trains sometimes attain speeds of 80 miles per hour with intervals between trains of as little as 90 seconds. In each train there is one operator whose role is that of an observer and communicator and who can override the automatic system in case of emergency. The automatic system protects the trains by assuring a safe distance between them and by controlling their speed. Another function of the system is to control train routings and make adjustments in the operation of each train to keep the entire system operating on schedule.
As a train enters the station, it automatically transmits its identification, destination, and length, thus lighting up a display board for passenger information and transmitting information to the control centres. Signals are automatically returned to the train to regulate its time in the station and its running time to the next station. At the beginning of the day, an ideal schedule is determined; as the day progresses, the performance of each train is compared with the schedule, and adjustments are made to each train’s operation as required. The entire system is controlled by two identical computers, so that if one malfunctions, the other assumes complete control. In the event of a complete failure of the computer control system, the system reverts to manual control.
Service industries
Automation of service industries includes an assortment of applications as diverse as the services themselves, which include health care, banking and other financial services, government, and retail trade.
In health care the use of automation in the form of computer systems has increased dramatically to improve services and relieve the burden on medical staffs. In hospitals computer terminals on each nursing care floor record data on patient status, medications administered, and other relevant information. Some of these systems are used to perform additional functions such as ordering drugs from the hospital pharmacy and calling for orderlies. The system provides an official record of the nursing care given to patients and is used by the nursing staff to give a report at shift-change time. The computer system is connected to the hospital’s business office so that proper charges can be made to each patient’s account for services rendered and medicines provided.
Robotics is likely to play a role in future health care delivery systems. The work that is done in hospitals by nurses, orderlies, and similar staff personnel includes some tasks that are routine and repetitive. Duties that might be automated using robots include making beds, delivering linens, and moving supplies between locations in the hospital. Robots might even become involved in certain aspects of patient care such as transporting patients to services in the hospital, passing food trays, and similar functions in which it is not critical that a hospital staff member be present. Research is currently under way to develop robots that would be capable of providing assistance to paraplegics and other physically handicapped persons. These robots would respond to voice commands and would be able to interpret statements in natural language (e.g., everyday English) from patients requesting service.
Banking and financial institutions have embraced automation in their operations principally through computer technology to facilitate the processing of large volumes of documents and financial transactions. The sorting of checks is done by optical character-recognition systems utilizing the special alphanumeric characters at the bottom of checks. Bank balances are computed and recorded using computer systems installed by virtually all financial institutions. Major banks have established electronic banking systems, including automatic teller machines. Located in places convenient for their customers, these automatic tellers permit users to complete basic transactions without requiring the assistance of bank personnel.
The stock exchanges rely on computer-automated systems to report transactions by ticker tape or closed circuit television. Brokerage houses use a computerized record-keeping system to track their customers’ accounts. Monthly statements indicating the status of each account are automatically prepared and mailed to customers. Account executives employ video monitors in their offices, backed by a massive database, to retrieve current information on each stock almost instantaneously while they discuss possible purchases with their clients. Stock certificates are typically issued with machine-readable identifications to facilitate record keeping in sales and exchanges.
Credit card transactions have also become highly automated. Restaurants, retailers, and other organizations are using systems that automatically check the validity of a credit card and the credit standing of the cardholder in a matter of seconds as the customer waits for the transaction to be finalized. Some credit card transactions trigger immediate transfer of funds equal to the amount of the sale from the cardholder’s account into the merchant’s account.
Many government services are automated by means of computers and computerized databases. The Internal Revenue Service (IRS) of the U.S. government must review and approve the tax returns of millions of taxpayers each year. The detailed checking of returns is a task that has traditionally been done by large staffs of professional auditors on a sampled basis. In 1985 the IRS began using a computerized system to automate the auditing procedure for the 1984 returns. This system is programmed to perform the complex tax calculations on each return being audited. As tax laws change, the system is reprogrammed to do the calculations for the year. The computerized auditing system has permitted a substantial increase in the work load of the IRS auditing department without a corresponding increase in staffing.
Retail trade has seen a number of changes in its operations as a result of automation. Selling merchandise has typically been a very labour-intensive activity, with sales associates needed to assist customers with their selections and then finalize transactions at the cash register. Each transaction depletes the store’s inventory, so the item purchased must be identified for reorder. Much clerical effort is expended by the store when inventory is managed by strictly manual procedures. Computerized systems have been installed in most modern retail stores to speed sales transactions and automatically update inventory records as the stock of each item is reduced. The systems are based on the Universal Product Code (UPC), originally adopted by the grocery industry in 1973, which uses optical bar-code technology. A bar code is an identification symbol consisting of a series of wide and narrow bars attached to each product that can be scanned and recognized by a bar-code reader. At the cash registers, these readers quickly identify the items being purchased. As the sales associate scans across the symbol using a laser beam reader, the product is properly identified and its price is entered into the sales transaction. Simultaneously, a record of the sale is made in the inventory files so that the item can be reordered.
In health care the use of automation in the form of computer systems has increased dramatically to improve services and relieve the burden on medical staffs. In hospitals computer terminals on each nursing care floor record data on patient status, medications administered, and other relevant information. Some of these systems are used to perform additional functions such as ordering drugs from the hospital pharmacy and calling for orderlies. The system provides an official record of the nursing care given to patients and is used by the nursing staff to give a report at shift-change time. The computer system is connected to the hospital’s business office so that proper charges can be made to each patient’s account for services rendered and medicines provided.
Robotics is likely to play a role in future health care delivery systems. The work that is done in hospitals by nurses, orderlies, and similar staff personnel includes some tasks that are routine and repetitive. Duties that might be automated using robots include making beds, delivering linens, and moving supplies between locations in the hospital. Robots might even become involved in certain aspects of patient care such as transporting patients to services in the hospital, passing food trays, and similar functions in which it is not critical that a hospital staff member be present. Research is currently under way to develop robots that would be capable of providing assistance to paraplegics and other physically handicapped persons. These robots would respond to voice commands and would be able to interpret statements in natural language (e.g., everyday English) from patients requesting service.
Banking and financial institutions have embraced automation in their operations principally through computer technology to facilitate the processing of large volumes of documents and financial transactions. The sorting of checks is done by optical character-recognition systems utilizing the special alphanumeric characters at the bottom of checks. Bank balances are computed and recorded using computer systems installed by virtually all financial institutions. Major banks have established electronic banking systems, including automatic teller machines. Located in places convenient for their customers, these automatic tellers permit users to complete basic transactions without requiring the assistance of bank personnel.
The stock exchanges rely on computer-automated systems to report transactions by ticker tape or closed circuit television. Brokerage houses use a computerized record-keeping system to track their customers’ accounts. Monthly statements indicating the status of each account are automatically prepared and mailed to customers. Account executives employ video monitors in their offices, backed by a massive database, to retrieve current information on each stock almost instantaneously while they discuss possible purchases with their clients. Stock certificates are typically issued with machine-readable identifications to facilitate record keeping in sales and exchanges.
Credit card transactions have also become highly automated. Restaurants, retailers, and other organizations are using systems that automatically check the validity of a credit card and the credit standing of the cardholder in a matter of seconds as the customer waits for the transaction to be finalized. Some credit card transactions trigger immediate transfer of funds equal to the amount of the sale from the cardholder’s account into the merchant’s account.
Many government services are automated by means of computers and computerized databases. The Internal Revenue Service (IRS) of the U.S. government must review and approve the tax returns of millions of taxpayers each year. The detailed checking of returns is a task that has traditionally been done by large staffs of professional auditors on a sampled basis. In 1985 the IRS began using a computerized system to automate the auditing procedure for the 1984 returns. This system is programmed to perform the complex tax calculations on each return being audited. As tax laws change, the system is reprogrammed to do the calculations for the year. The computerized auditing system has permitted a substantial increase in the work load of the IRS auditing department without a corresponding increase in staffing.
Retail trade has seen a number of changes in its operations as a result of automation. Selling merchandise has typically been a very labour-intensive activity, with sales associates needed to assist customers with their selections and then finalize transactions at the cash register. Each transaction depletes the store’s inventory, so the item purchased must be identified for reorder. Much clerical effort is expended by the store when inventory is managed by strictly manual procedures. Computerized systems have been installed in most modern retail stores to speed sales transactions and automatically update inventory records as the stock of each item is reduced. The systems are based on the Universal Product Code (UPC), originally adopted by the grocery industry in 1973, which uses optical bar-code technology. A bar code is an identification symbol consisting of a series of wide and narrow bars attached to each product that can be scanned and recognized by a bar-code reader. At the cash registers, these readers quickly identify the items being purchased. As the sales associate scans across the symbol using a laser beam reader, the product is properly identified and its price is entered into the sales transaction. Simultaneously, a record of the sale is made in the inventory files so that the item can be reordered.
Consumer products
Consumer products ranging from automobiles to small appliances have been automated for the benefit of the user. Microwave ovens, washing machines, dryers, refrigerators, video recorders, and other modern household appliances typically contain a microprocessor that works as the computer controller for the device. The consumer operates the appliance by programming the controller to perform the required functions, including timing (ovens, dryers), power levels (microwave ovens), input channels (video recorders), and other cycle options (washing machines). The programming of the device is done simply by pressing a series of buttons in the proper sequence, so the user does not think of the procedure as programming a computer.
The automobile is an example of a highly automated consumer product. The modern automobile is typically equipped with several microprocessors that operate a variety of functions, including engine control (fuel-air ratio, for example), the clock, the radio, and cruise control.
The automobile is an example of a highly automated consumer product. The modern automobile is typically equipped with several microprocessors that operate a variety of functions, including engine control (fuel-air ratio, for example), the clock, the radio, and cruise control.
Automation and society
Over the years, the social merits of automation have been argued by labour leaders, business executives, government officials, and college professors. The biggest controversy has focused on how automation affects employment. There are other important aspects of automation, including its effect on productivity, economic competition, education, and quality of life. These issues are explored here.
Impact on the individual
Nearly all industrial installations of automation, and in particular robotics, involve a replacement of human labour by an automated system. Therefore, one of the direct effects of automation in factory operations is the dislocation of human labour from the workplace. The long-term effects of automation on employment and unemployment rates are debatable. Most studies in this area have been controversial and inconclusive. Workers have indeed lost jobs through automation, but population increases and consumer demand for the products of automation have compensated for these losses. Labour unions have argued, and many companies have adopted the policy, that workers displaced by automation should be retrained for other positions, perhaps increasing their skill levels in the process. This argument succeeds so long as the company and the economy in general are growing at a rate fast enough to create new positions as the jobs replaced by automation are lost.
Of particular concern for many labour specialists is the impact of industrial robots on the work force, since robot installations involve a direct substitution of machines for humans, sometimes at a ratio of two to three humans per robot. The opposing argument within the United States is that robots can increase productivity in American factories, thereby making these firms more competitive and ensuring that jobs are not lost to overseas companies. The effect of robotics on labour has been relatively minor, because the number of robots in the United States is small compared with the number of human workers. As of the early 1990s, there were fewer than 100,000 robots installed in American factories, compared with a total work force of more than 100 million persons, about 20 million of whom work in factories.
Automation affects not only the number of workers in factories but also the type of work that is done. The automated factory is oriented toward the use of computer systems and sophisticated programmable machines rather than manual labour. Greater emphasis is placed on knowledge-based work and technical skill rather than physical work. The types of jobs found in modern factories include more machine maintenance, improved scheduling and process optimization, systems analysis, and computer programming and operation. Consequently, workers in automated facilities must be technologically proficient to perform these jobs. Professional and semiprofessional positions, as well as traditional labour jobs, are affected by this shift in emphasis toward factory automation.
Of particular concern for many labour specialists is the impact of industrial robots on the work force, since robot installations involve a direct substitution of machines for humans, sometimes at a ratio of two to three humans per robot. The opposing argument within the United States is that robots can increase productivity in American factories, thereby making these firms more competitive and ensuring that jobs are not lost to overseas companies. The effect of robotics on labour has been relatively minor, because the number of robots in the United States is small compared with the number of human workers. As of the early 1990s, there were fewer than 100,000 robots installed in American factories, compared with a total work force of more than 100 million persons, about 20 million of whom work in factories.
Automation affects not only the number of workers in factories but also the type of work that is done. The automated factory is oriented toward the use of computer systems and sophisticated programmable machines rather than manual labour. Greater emphasis is placed on knowledge-based work and technical skill rather than physical work. The types of jobs found in modern factories include more machine maintenance, improved scheduling and process optimization, systems analysis, and computer programming and operation. Consequently, workers in automated facilities must be technologically proficient to perform these jobs. Professional and semiprofessional positions, as well as traditional labour jobs, are affected by this shift in emphasis toward factory automation.
Impact on society
Besides affecting individual workers, automation has an impact on society in general. Productivity is a fundamental economic issue that is influenced by automation. The productivity of a process is traditionally defined as the ratio of output units to the units of labour input. A properly justified automation project will increase productivity owing to increases in production rate and reductions in labour content. Over the years, productivity gains have led to reduced prices for products and increased prosperity for society.
A number of issues related to education and training have been raised by the increased use of automation, robotics, computer systems, and related technologies. As automation has increased, there has developed a shortage of technically trained personnel to implement these technologies competently. This shortage has had a direct influence on the rate at which automated systems can be introduced. The shortage of skilled staffing in automation technologies raises the need for vocational and technical training to develop the required work-force skills. Unfortunately the educational system is also in need of technically qualified instructors to teach these subjects, and the laboratory equipment available in schools does not always represent the state-of-the-art technology typically used in industry.
A number of issues related to education and training have been raised by the increased use of automation, robotics, computer systems, and related technologies. As automation has increased, there has developed a shortage of technically trained personnel to implement these technologies competently. This shortage has had a direct influence on the rate at which automated systems can be introduced. The shortage of skilled staffing in automation technologies raises the need for vocational and technical training to develop the required work-force skills. Unfortunately the educational system is also in need of technically qualified instructors to teach these subjects, and the laboratory equipment available in schools does not always represent the state-of-the-art technology typically used in industry.
Advantages and disadvantages of automation
Advantages commonly attributed to automation include higher production rates and increased productivity, more efficient use of materials, better product quality, improved safety, shorter workweeks for labour, and reduced factory lead times. Higher output and increased productivity have been two of the biggest reasons in justifying the use of automation. Despite the claims of high quality from good workmanship by humans, automated systems typically perform the manufacturing process with less variability than human workers, resulting in greater control and consistency of product quality. Also, increased process control makes more efficient use of materials, resulting in less scrap.
Worker safety is an important reason for automating an industrial operation. Automated systems often remove workers from the workplace, thus safeguarding them against the hazards of the factory environment. In the United States the Occupational Safety and Health Act of 1970 (OSHA) was enacted with the national objective of making work safer and protecting the physical well-being of the worker. OSHA has had the effect of promoting the use of automation and robotics in the factory.
Another benefit of automation is the reduction in the number of hours worked on average per week by factory workers. About 1900 the average workweek was approximately 70 hours. This has gradually been reduced to a standard workweek in the United States of about 40 hours. Mechanization and automation have played a significant role in this reduction. Finally, the time required to process a typical production order through the factory is generally reduced with automation.
A main disadvantage often associated with automation, worker displacement, has been discussed above. Despite the social benefits that might result from retraining displaced workers for other jobs, in almost all cases the worker whose job has been taken over by a machine undergoes a period of emotional stress. In addition to displacement from work, the worker may be displaced geographically. In order to find other work, an individual may have to relocate, which is another source of stress.
Other disadvantages of automated equipment include the high capital expenditure required to invest in automation (an automated system can cost millions of dollars to design, fabricate, and install), a higher level of maintenance needed than with a manually operated machine, and a generally lower degree of flexibility in terms of the possible products as compared with a manual system (even flexible automation is less flexible than humans, the most versatile machines of all).
Also there are potential risks that automation technology will ultimately subjugate rather than serve humankind. The risks include the possibility that workers will become slaves to automated machines, that the privacy of humans will be invaded by vast computer data networks, that human error in the management of technology will somehow endanger civilization, and that society will become dependent on automation for its economic well-being.
These dangers aside, automation technology, if used wisely and effectively, can yield substantial opportunities for the future. There is an opportunity to relieve humans from repetitive, hazardous, and unpleasant labour in all forms. And there is an opportunity for future automation technologies to provide a growing social and economic environment in which humans can enjoy a higher standard of living and a better way of life.
Worker safety is an important reason for automating an industrial operation. Automated systems often remove workers from the workplace, thus safeguarding them against the hazards of the factory environment. In the United States the Occupational Safety and Health Act of 1970 (OSHA) was enacted with the national objective of making work safer and protecting the physical well-being of the worker. OSHA has had the effect of promoting the use of automation and robotics in the factory.
Another benefit of automation is the reduction in the number of hours worked on average per week by factory workers. About 1900 the average workweek was approximately 70 hours. This has gradually been reduced to a standard workweek in the United States of about 40 hours. Mechanization and automation have played a significant role in this reduction. Finally, the time required to process a typical production order through the factory is generally reduced with automation.
A main disadvantage often associated with automation, worker displacement, has been discussed above. Despite the social benefits that might result from retraining displaced workers for other jobs, in almost all cases the worker whose job has been taken over by a machine undergoes a period of emotional stress. In addition to displacement from work, the worker may be displaced geographically. In order to find other work, an individual may have to relocate, which is another source of stress.
Other disadvantages of automated equipment include the high capital expenditure required to invest in automation (an automated system can cost millions of dollars to design, fabricate, and install), a higher level of maintenance needed than with a manually operated machine, and a generally lower degree of flexibility in terms of the possible products as compared with a manual system (even flexible automation is less flexible than humans, the most versatile machines of all).
Also there are potential risks that automation technology will ultimately subjugate rather than serve humankind. The risks include the possibility that workers will become slaves to automated machines, that the privacy of humans will be invaded by vast computer data networks, that human error in the management of technology will somehow endanger civilization, and that society will become dependent on automation for its economic well-being.
These dangers aside, automation technology, if used wisely and effectively, can yield substantial opportunities for the future. There is an opportunity to relieve humans from repetitive, hazardous, and unpleasant labour in all forms. And there is an opportunity for future automation technologies to provide a growing social and economic environment in which humans can enjoy a higher standard of living and a better way of life.
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