Automation
From Encyclopædia
The term automation refers to a wide variety of systems and processes that operate with little or no human
intervention. In the most modern automation systems,
Control is exercised by the system itself, through
Control devices that sense changes in such conditions as temperature, rate of flow, and volume, and then command the system to make adjustments to compensate for these changes. The applications of automation are widespread. Indeed, most modern industrial operations are too complex to be handled manually, or even with simple machines under manual
Control.HISTORYAutomation developed as a result of advances in the design of machines (see MACHINE). Although early machines were often complicated, most of them were designed to operate under a specific set of external conditions; when these conditions changed, a manual adjustment was necessary to assure proper operation. This was not a major shortcoming, however, since the machines operated at relatively low speeds, and so it was largely unnecessary to automate the operation. During the Industrial
revolution of the late 1700s and the 1800s, however, more sophisticated machines were developed and applied to situations requiring a faster response than was possible with manual adjustment. This need led to the concept of automation.Automation was quickly recognized as a valuable way to assure efficiency and accuracy in manufacturing processes. The chemical industries developed the
technology of automation to regulate variables such as
pressure and temperature that are involved in the production of chemicals. The food industries found that
packaging, bottling, and sealing operations, as well as the production of food products, could be accomplished more efficiently by the use of automated systems. The methods of automation were refined with the development of aircraft guidance systems and automatic
pilots. The development of digital computers, which can monitor external conditions and make appropriate adjustments to a system, added further impetus to the applications of automation. Today, through automation, an entire oil refinery can be operated by just four persons. Industrial
robots perform numerous functions on
assembly lines, and automated spacecraft on deep-space probes are programmed to automatically make adjustments in operations.PRINCIPLESAn automated system adjusts its operations in response to changing external conditions in three steps: measurement, evaluation, and
Control.MeasurementIn order for an automated system to respond to the external environment, it must be able to measure the physical variables in that environment. Thus, if flow rate is to be controlled, a measurement must be made to determine what the flow rate is. If a complex
assembly procedure is to occur, a measurement or series of measurements must be made to define the present state of the
assembly. These measurements supply the system with information known as FEEDBACK, because the information is fed back to the input of the system and used to
exercise some
Control over it. For example, if the process is self-guidance, the feedback will include the system's location, speed, and acceleration.EvaluationThe measured information is evaluated in order to determine if corrective action must be initiated. Thus, if a spacecraft evaluates its position and finds itself to be off course, a course correction must be made. The evaluation function also determines exactly what kind of corrective action is necessary--for how long and in what direction a rocket should be fired to correct the course of the spacecraft. computer finds greatest application.ControlThe last step of automation is the action resulting from the measurement and evaluation operations. Thus, the rocket gets an appropriate signal to fire and thereby changes the path of the spacecraft.In many automation systems, these operations may be difficult to identify. A system may involve the interaction of more than one
Control loop, that is, a loop in the path of the signal from the output back to the input. All systems, however, include the steps of measurement, evaluation, and
Control.APPLICATIONSAutomation is used in numerous industries throughout the
world. Some industries have become more automated than others, and some devices could not work at all without automated features. In many
cases, specific applications of the principles of automation have led to new fields.Process ControlThe application of the principles of automation to the
Control of continuous manufacturing operations is called PROCESS
Control. It is used extensively in the chemical and petrochemical industries, where gas and liquid temperatures, flow,
pressure, reaction rates, and many other characteristics must be controlled. Some
plants have become so automated that human involvement is needed only to monitor the operation for nonroutine conditions.ServomechanismsMany industrial operations require devices, called servomechanisms (see SERVOMECHANISM), to
Control such simple operations as the rotational rate of motor shafts, the amount of current, hydraulic or phenumatic
pressure within a system, or the position of a valve. Servomechanisms function through a FEEDBACK process. They are usually actuated by changes in a mechanical situation, although some complex servomechanisms are set in motion by electric or electronic frequencies.Industrial RobotsThe use of automated machines that can be programmed to perform different jobs under various operating conditions has recently become widespread. These machines can properly be called industrial
robots (see
robot).
robots are employed to drill, machine, and partially assemble automobile
engines. By reprogramming the
Controls or computer that oversees the operation, the same machine might be used to align and assemble washing machines. The spacecraft sent to the
Moon and on deep-space missions are also types of
robots. Although radio contact is maintained with these craft, the distances involved are so great that the craft must incorporate devices that can adjust operations based on the conditions encountered--without human comma?ds.FUTURE OF AUTOMATIONAs
technology continues to be developed and improved, more and more of the routine activities of business and industry will be taken over by automated systems. Microcomputers, based upon the INTEGRATED CIRCUIT, are already causing a vast change in the applications of automation; even a device as simple as a washing machine can be put under computer
Control and thus be programmed to respond to a variety of environmental conditions. The continued deployment of automated systems will replace some traditional employment opportunities for people, but new opportunities will be established. Indeed, as automation is extended, it will become necessary to evaluate its effect on society.Recent advances in durable miniature systems for computing, mobility, and energy storage have made the
robot of
science fiction a near reality. It is likely that future societies will see the first practical
robot capable of interacting with human beings. The key characteristic of such a completely automated machine will be self-adaptability, the capacity to evaluate a new overall condition and decide upon a course of action. Realizing this potential will require new developments in computer algorithms, pattern recognition, and
Control functions. The use of computers to design and manufacture complex systems is becoming increasingly common (see
COMPUTER-AIDED DESIGN and COMPUTER-AIDED MANUFACTURING). CAD/CAM systems are now capable of designing and controlling entire manufacturing processes. The development of interactive
robots will undoubtedly require the use of even more highly sophisticated CAD/CAM systems.Curtis D. JohnsonBibliography: Arden, B. W., ed., What Can Be Automated? (1980); Barcomb, D., Office Automation (1981); Billingsley, J., et al.,
robots and Automated Manufacture (1985); Bolz, R., Manufacturing Automation Management (1985); Bouldin, Barbara M.,
agents of Change: Managing the Introduction of Automated Tools (1989); Cecil, P. B., Office Automation, 3d ed. (1984); Considine, D. M. and G. D., Standard Handbook of Industrial Automation (1986); Franklin, Gene F., et al., Digital
Control of Dynamic Systems, 2d ed. (1990); Gould, L., Factory Automation: A Key to Survival (1985); Gregory, J., and Marshall, D., eds., Office Automation: Jekyll or Hyde? (1983); Kraut, Robert E., ed.,
technology and the Transformation of White Collar Work (1987); Mody, A., and Wheeler, D., Automation and
world Competition (1991); Noble, David F., Forces of Production: A Social History of Industrial Automation (1986); Prasad, B., Robotics and Factories of the Future, vol. 1 (1989); Scientific American Magazine, The Mechanization of Work (1982); Shaiken, Harley, Work Transformed (1985); Vance, M., Automation in Buildings (1985).
