Basically, at least, computer control is simple and can be compared to the feedback principle that describes many physical systems including the workings of our own bodies. In practice, the computer can be put in charge of producing something, and by sampling the output of its work can constantly make corrections or improvements that are desired. This is of course an extreme simplification, and the control engineer speaks of “on-line” operation, of adaptive systems that adjust to a changing environment, of predictive control, and so on. One vital requirement of the computer involved in a control process, obviously, is that it cannot take its time about its computations. The control computer is definitely operating “on the line”; that is, in real time, or perhaps even looking ahead by a certain amount so that it can not only keep up with production but also predict forthcoming changes and make corrections in time to be of use.
The human process controller is stuck with methods like those of the cook who mixes up his recipe with a spoonful of this, and three pinches of that, sniffs or tastes the batter subjectively, and may end up with a masterpiece or a flop. Computer control processes the same batter through the pipes at a thousand gallons a minute and catches infinitesimal variations in time to correct them before the hotcakes are baked. In effect it makes hindsight into foresight by compressing time far more than man could hope to do.
Early applications of the computer in industrial processes were simply those of data “loggers,” or monitors. It was still up to the human operator to interpret what the computer observed and recorded, and to throw the switch, close the valve, or push the panic button as the case demanded. Actual computer control, the “closing of the loop” as the engineers call it, is the logical next step. This replaces the human operator, or at least relegates him to the role of monitor.
The Great Lakes hot-rolling steel mill has been mentioned as an example of complete computer control. In Hayange, France, the first European completely automated steel-beam mill is slated to go into operation late in 1962. The Jones & Laughlin Steel Corporation in this country uses a digital computer system to control continuous annealing in its Aliquippa, Pennsylvania, plant, and is evaluating an RCA computer-controlled tin-plating line operating at 3,000 feet a minute. Newer computer-control applications in the offing include sintering and other metal production operations.
Minneapolis-Honeywell
Boston ice cream makers, H. P. Hood & Sons, use computer to make pushbutton ice cream. Analog computer thinks out recipes, punches them on cards to operate valves.
To those of us who consume it, ice cream may not seem a likely candidate for computer control. However, the firm of H. P. Hood & Sons uses computer control in its blending operation, finding it 20,000 times as fast, and more accurate than when handled by human operators, since computer controls hold mixes within one-tenth of 1 per cent accuracy. Automation is a significant breakthrough in this industry, whose history goes back 110 years, and in baking, which is a little older. The Sara Lee bakeries use the computer too in assembling the ingredients for their goodies. To bake such cakes, Mother will have to get herself a computer.
Minneapolis-Honeywell furnished the computer for the ice-cream control; this same company delivered a system for the Celanese Corporation of America’s multimillion dollar acetyl manufacturing plant at Bay City, Texas. The new plant produces a petrochemical used in plastics, paint, synthetic rubber, dye, fibers, and other products. Going “on-stream” in 1962, the Celanese plant will produce half a billion pounds of chemicals annually.
Russia has been mentioned as active in industrial computer control. A case in point is the soda plant at Slavyansk in the Donets Basin, which was recently test-operated for a continuous period of 48 hours by computer. An unusual feature of this test was that the computer was in Kiev, almost 400 miles away. A wire link between the two cities permitted monitoring and control of the plant from Kiev in what the Russians claim as the first remote automatic operation of such a plant.
Other Soviet achievements include two large-scale automatically controlled installations. In oil-field operation at Tataria, gas and oil outputs from many wells are monitored and controlled from a central station, dropping the work force required from 600 to 100. The other installation controls irrigation servicing 9,000 acres. A desktop control handles the pumping of water from the Syr Darya River through underground pipes, and distribution to Uzbekistan cotton fields. The Russians have also designed an automatic distillation unit for the Hungarians. With an annual capacity of a million tons, the unit was installed in the large Szoeny refinery and scheduled for operation by 1962.