Computer Simulation | Research & Encyclopedia Articles

Computer Simulation

Computer simulation involves designing a model of a real system for the purpose of training, teaching, predicting or entertaining. A forerunner of computer simulators was the famous Link trainer used to teach people how to fly in the 1930s. Edwin A. Link, originally a designer of pipe organs and air-driven player pianos, used a device resembling a bellows to twist and turn a cockpit mounted on a movable platform. The "pilot" maneuvered the device by manipulating a mock set of cockpit controls. More complex flight simulators began using computer graphics starting in 1968. Two men, David Evans and Ivan Sutherland, spearheaded a computer graphics program for ARPA, the Advanced Research Projects Agency. ARPA was designed to short-circuit the traditional research funding process, directly funding the creative projects that might help the United States maintain its technological vigor. A key member of ARPA was J.C.R. Licklider, a researcher and professor at Massachusetts Institute of Technology, who wanted to try using computers to interact with people rather than just to crunch numbers. He found Ivan Sutherland at Lincoln Laboratory; it was Sutherland who single-handedly created the field of interactive computer graphics. He and David Evans helped create the graphics used by flight simulators ever since. Computer simulation was also used in the field of psychology. Joseph Weizenbaum, who had worked for General Electric and Bank of America in data processing, began a friendship with Kenneth Colby, a psychiatrist who had grown disenchanted with traditional one-to-one psychotherapy. They believed computers could offer a way of gaining new insights into neurotic behavior and perhaps even develop new therapeutic methods. Several question-answer machines had been developed already; this led Weizenbaum to try to create a more sophisticated one. The result was ELIZA (named after the character in My Fair Lady who learned to speak properly), a program that was intended to simulate the conversation between a psychoanalyst and a patient, with the machine in the role of the analyst. The program might start out with the following: "What brought you here to see me today?" If the patient typed in the response "I'm feeling tired," the machine responded with the question "Why do you think you're feeling tired?" ELIZA took its clues from whatever the patient said in an attempt to create useful questions. The program was such a success that many people spent a great deal of time telling their troubles to the computer even though they knew it was just a computer program. The key to ELIZA was its natural responses to the statements it received. If it was puzzled by a statement it didn't understand, it would fall back on "I see" or "That's very interesting," much like humans do when confused in similar situations. Probably the most exciting current frontier in the area of computer simulation is virtual reality.

This is the most interactive form of simulation. Unlike passive viewing of computer graphics, virtual reality is created by a display and control technology that can surround its user with an artificial environment that attempts to mimic reality. Important contributors to virtual reality technology include Jaron Lanier, a computer programmer who developed successful video games for Atari in the early 1980s, then founded VPL Research, a company that has begun producing a virtual reality headset. Equipped with goggles that contain tiny liquid crystal screens, the headset projects a computer-generated landscape before the user's eyes. Since the image projection program is sensitive to the user's movements, it alters the perspective of the viewed scene as the user's head moves, producing stunningly realistic images. Lanier also created a glove called DataGlove with optical fibers and sensors that can measure the position of the wearer's hand and the movement of the fingers. The glove allows the wearer to move or grab things in the artificial world presented on the headset. A simplified version of the glove, known as the PowerGlove, is sold by Mattel for use with the popular Nintendo video games. Another pathfinder is John Walker, president of Autodesk. Starting as a programmer, Walker founded Autodesk in the belief that architects and designers who had been using personal computers in their businesses would find useful a type of computer-aided design (CAD) software. His company's AutoCAD became one of the best-selling personal computer software packages. Autodesk is working now on virtual reality CAD. Thomas Furness, a designer of visual displays for the military since 1966, developed a headset in 1982 for use by pilots in the Air Force similar to the one produced by VPL. He then worked on voice-operated commands that allowed a pilot to look toward a symbol (as the computer tracked the pilot's eye motion), determine what it was, and, if he wanted to shoot at it, utter a word or two to open fire on it. Finally, Myron Krueger created an artificial reality laboratory at the University of Connecticut in the 1970s, where he has developed virtual reality programs such as CRITTER, a virtual reality cartoon featuring a four-legged yellow creature that interacts with the user. The tremendous practical potential of computer simulation is just beginning to unfold. Matsushita Corporation of Japan is using virtual reality to help customers shop for custom-built kitchens. The customers can "tour" three-dimensional images of their proposed kitchens, using headsets and gloves, suggesting changes before actual installation takes place. Architects and aerospace engineers will be using more simulations in their work as well. Boeing has already developed a new airliner designed and engineered entirely within a computer. Researchers in drug companies are generating models of molecules to tailor specific drugs for specific conditions. Computer simulation may even become the newest medium for entertainment. VPL Research has formed a joint venture with MCA to build a series of test theaters employing virtual reality on a large scale.