AUTOMATION

the application of machines to tasks once performed by human beings or, increasingly, to tasks that would otherwise be impossible. Although the term mechanization is often used to refer to the simple replacement of human labour by machines, automation generally implies the integration of machines into a self-governing system. Automation has revolutionized those areas in which it has been introduced, and there is scarcely an aspect of modern life that has been unaffected by it. 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. the application of machines to tasks once performed by human beings or, increasingly, to tasks that would otherwise be impossible. Although the term mechanization is often used to refer to the simple replacement of human labour by machines, automation generally implies the integration of machines into a self-governing system. Automation has revolutionized those areas in which it has been introduced, and there is scarcely an aspect of modern life that has been unaffected by it. Although the difference between automation and mechanization may be difficult to draw in practice, the difference between an automated and a mechanized society is more clearly apprehended; the introduction of automation has brought about a new and distinct stage in the development of industrial civilization. Human beings have striven to transfer some of the burden of labour to mechanical devices for as long as they have worked. Remnants of pulleys, winches, and lifting devices have been found dating from the 3rd millennium BC. However, widespread mechanization and the rudimentary incorporation of machines into a system did not take place until the Industrial Revolution in the 18th century. The development of factories that produced interchangeable parts for products such as rifles paved the way, as did the complementary development of division of labour, the restriction of the activity of each labourer to one specific task to be repeated over and over. It was then a simple step to develop machines to perform these tasks, powered by the newly perfected steam engine and later by electricity. Assembly lines represented another step toward automation. First used on a large scale by Chicago meat-packers in the 1870s, the assembly line utilized a conveyor belt or similar device to move a job in stages from one worker or group of workers to another. Automatic transfer systems were developed during World War II that combined assembly lines with mechanization. These systems consisted of groups of machines linked by a conveyor belt; a workpiece was operated on and was then passed to subsequent production stages independent of human intervention. True automation, as distinct from mechanization, did not come about until the development of feedback systems; it is the presence of these systems, more than anything else, that serves to distinguish the two. Feedback refers to the ability of a machine to regulate itself. Through a feedback system or loop, a machine monitors its own output, compares it with a set of standards stored, along with instructions, as a control program, and adjusts its performance accordingly. Every automated machine or system requires four basic components: (1) power source, (2) sensing mechanisms, (3) decision element, and (4) control element. The power source (e.g., batteries or electric generator) provides an automated system with the energy needed to achieve its desired task. The sensing mechanism enables the system to measure some property of the output. Photoelectric cells, thermocouples, X-ray machines, and electrical meters are typical sensing mechanisms, and the properties they may measure include dimensions, weight, temperature, pressure, colour, or electrical resistance. The decision element compares the data supplied by the sensing element with standards stored in the program; this step is often carried out by a computer. If discrepancies exist, the decision element generates the appropriate commands to activate the control element. The control element then acts to bring the performance of the system into line with the programmed values. The control element may consist of switches, valves, or other mechanisms. When the power source and the sensing, decision, and control elements are all operating properly, an automated system is able to regulate its behaviour in a wide variety of circumstances that need not have been foreseen in detail. An airplane autopilot is a classic example of a self-regulating device; it uses information obtained from flight instruments to make continuous adjustments to the controls, keeping the craft on its preset course. A modern automated factory may have hundreds or even thousands of interconnected feedback loops. Automation has been introduced into areas as diverse as chemical processing, communications, and home appliances (e.g., programmable washing machines, microwave ovens, and videocassette recorders). One of the most significant developments in automation has been computer-aided design/computer-aided manufacturing (CAD/CAM). This technology makes use of computer systems to assist in the creation and optimization of a design as well as to control and monitor the processes that are involved in manufacturing a product from that design. CAD/CAM technology has been adopted by a number of industries, particularly by those engaged in the manufacture of electronic equipment and machine components. In certain areas progress in automation has been much slower than in others. Activities such as shape identification, alignment of two unequal bodies, and word recognition, easy for a human being, have proved to be unexpectedly complex and hence difficult to break down into a series of simple steps that can be performed by a machine. Nevertheless, significant advances have been made even in these areas, as attested to by recent developments in artificial intelligence and robotics (see artificial intelligence; robot). The increased use of automation in factories has led to greater productivity in many sectors of industry. Equally important, it has contributed to worker safety. Complex tasks in situations hazardous for human beings, such as handling radioactive materials or toxic chemicals, can be accomplished by automated machinery at no risk of harm. The effects of automation extend beyond the increase in industrial productivity to society itself. Early predictions of an automation-induced increase in unemployment have been unfulfilled. Automation has, however, introduced large changes in the nature and kinds of jobs offered by society by replacing many unskilled jobs with skilled or semiskilled jobs in the field of creating and maintaining computerized and automated devices. The great demand for computer programmers is one example. Automation has also played a role in fostering a new generation of management methods to control the enormously complex projects it has made possible. Additional reading General works on the technology of automation and its applications in manufacturing include C. Ray Asfahl, Robots and Manufacturing Automation, 2nd ed. (1992); Mikell P. Groover, Automation, Production Systems, and Computer Integrated Manufacturing (1987); and David W. Pessen, Industrial Automation (1980). These are all college-level engineering textbooks. Emphasis is placed on manufacturing systems and/or CAD/CAM in the following books: David D. Bedworth, Mark R. Henderson, and Philip M. Wolfe, Computer-Integrated Design and Manufacturing (1991); J.T. Black, The Design of the Factory With a Future (1991); Tien-Chien Chang, Richard A. Wysk, and Hsu-Pin Wang, Computer-Aided Manufacturing (1991); and Mikell P. Groover and Emory W. Zimmers, Jr., CAD/CAM: Computer-Aided Design and Manufacturing (1984). One of the most comprehensive works on computer-integrated manufacturing is R.U. Ayres et al. (eds.), Computer Integrated Manufacturing , 4 vol. (199192). Robotics technology and applications are treated in Mikell P. Groover et al., Industrial Robotics: Technology, Programming, and Applications (1986). Other books focus more on engineering analysis of robotics, such as John J. Craig, Introduction to Robotics: Mechanics & Control, 2nd ed. (1989); and Antti J. Koivo, Fundamentals for Control of Robotic Manipulators (1989).Certain references consider the social issues of automation and computerization; vol. 4 of the work ed. by Ayres cited above explores these issues. Reports dealing with automation and its social impacts are periodically issued by the United States Congress, Office of Technology Assessment; a recent example is Making Things Better: Competing in Manufacturing (1990).Periodicals that frequently contain articles on technology and management issues of manufacturing and automation include Manufacturing Engineering (monthly); and Managing Automation (monthly). Mikell P. Groover