Automation is the use of computers and robots to automatically control and operate machines or systems to perform work normally done by humans. Although ideas for automating tasks have been in existence since the time of the ancient Greeks, the development of automation came during the Industrial Revolution of the early eighteenth century. Many of the steam-powered devices built by James Watt, Richard Trevithick, Thomas Savery, Thomas Newcomen, and their contemporaries were simple examples of machines capable of taking over the work of humans. Modern automated machines can be subdivided into two large categories: open-loop machines and closed-loop machines.
Open-loop machines are devices that are started, go through a cycle, and then stop. A common example is the automatic dishwashing machine. Once dishes are loaded into the machine and a button pushed, the machine goes through a predetermined cycle of operations: pre-rinse, wash, rinse, and dry. Many of the most familiar appliances in homes today (microwave ovens, coffeemakers, CD players) operate on this basis.
Larger, more complex industrial operations also use open-cycle operations. For example, in the production of a car, a single machine may be programmed to place a side panel in place on the car and then weld it in a dozen or more locations. Each of the steps involved in this process—from placing the door properly to each of the different welds—takes place according to instructions programmed into the machine.
Closed-loop machines are devices that are capable of responding to new instructions at some point in their operation. The instructions may come from a human operator or from some part of the operation itself. The ability of a machine to self-correct by using some part of its output (for example, measurements) as input (new instructions determined by those measurements) is known as feedback.
One example of a closed-loop operation is the machine used in the manufacture of paper. Paper is formed when a mixture of pulpy fibers and water is emptied onto a conveyer belt. The water drains off, leaving the pulp on the belt. As the pulp dries, paper is formed. The rate at which the pulpy matter is added to the conveyer belt can be automatically controlled by a machine.
A sensing device at the end of the conveyor belt is capable of measuring the thickness of the paper and reporting back to the pouring machine on the condition of the product. If the paper becomes too thick, the sensor can tell the pouring machine to slow the rate at which the pulpy mixture is added to the belt. If the paper becomes too thin, the sensor can tell the machine to increase the rate at which the material is added.
Closed-loop machine: Machine that can respond to new instructions during its operation and make consequent changes in that operation.
Feedback mechanism: Ability of a machine to self-correct its operation by using some part of its output as input.
Feedforward mechanism: Ability of a machine to examine the raw materials that come to it and then decide what operations to perform.
Open-loop machine: Machine that performs some type of operation according to a predetermined program and that cannot adjust its own operation.
Other types of closed-loop machines contain sensors, but are unable to make necessary adjustments on their own. Instead, sensor readings are sent to human operators who monitor the machine's operation and input any changes needed. Still other closed-loop machines have feedforward mechanisms. Machines of this type examine the raw materials that come to them and then decide what operations to perform. Letter-sorting machines in post offices are of this type. The machine sorts a letter by reading the zip code on the address and then sending the letter to the appropriate subsystem.
Since the 1960s, the nature of automation has undergone dramatic changes as a result of the development of computers. For many years, automated machines were limited by the amount of feedback data they could collect and interpret. Thus, their operation was limited to a relatively small number of alternatives. A modern computer, however, can analyze a vast number of sensory inputs from a system and decide which of many responses it should make.
Artificial intelligence. Present-day computers have made possible the most advanced forms of automation: operations that are designed to replicate human thought processes. The enormous capability of a computer makes it possible for an automated machine to analyze many more options, compare options with each other, consider possible outcomes for
various options, and perform basic reasoning and problem-solving steps not contained within the machine's programmed memory. At this point, the automated machine can be said to be approaching the types of mental functions normally associated with human beings, that is, to have artificial intelligence.
The impact of automation on individuals and societies has been profound. On one level, many otherwise dangerous, unpleasant, or time-consuming tasks are now being performed by machines. The transformation of the communications industry is one example of the way in which automation has made life better for the average person. Today, millions of telephone calls that would once have had to go through human operators are now handled by automatic switching machines.
Automated systems also make it much easier for people to work in nontraditional settings. They may be able to stay home, for example, and do their jobs by communicating with other individuals and machines by means of highly automated communications systems.
However, automation has also had some negative effects on employment. When one machine can do the work of ten workers, most or all of those people will be out of a job. In many cases, those workers will have to be retrained—often learning newer and higher skills—before they can be reemployed.
[ See also Artificial intelligence ; Robotics ]