The Technology within an Industrial Robot
An industrial robot may be defined as a device with five or more axes with servo-control, capable of being programmed for independent operation. Typically, two or three of these axes may be for a hand, gripper or wrist type of mechanism, and the others for what can be considered a shoulder and arm, giving variable extension, rotation, and elevation. However, there are no hard and fast rules as to what form an industrial robot must take, and their mechanical configurations differ considerably depending on makers.
Even now robots are unique products for all mechanical engineers across the world. Therefore the term "robot" itself requires clarification. Some engineers insisted even until recently that every robot must by all means be like us, people, and be capable of doing any job. Others were inclined to regard any manipulating device as a robot. The standard adopted in many countries defines an industrial robot as automated machine combining a manipulator and programmable control device designed to perform movement and control functions substituting for similar functions of man.
The technology within a robot is really well established from other branches of engineering. It is the detailed application of such technology to a robot that is different. Many features of NC machine tools, for example, can be compared directly with similar features of an industrial robot. The servo-systems for controlling the axes, the minicomputer controller, and memory of tape programming are all established features of existing machine-tool technology, and often the machine tool itself has adopted the technology from other previous developments. There is, therefore, plenty of application experience for robot control designers to draw upon.
The servo-drives for the axes may be pneumatic, hydraulic, or electric, or any combination of these methods. Pneumatic systems are not generally capable of very high accuracy of movement due to the compressibility of air, but they are of low cost and easy to maintain. Hydraulic drives have the capability of providing high forces and good control of speed and positioning. Electrically, stepping motors or dc drives can be used.
The detailed mechanical design of an industrial robot is somewhat different from a machine tool. Industrial robots usually have a hand or wrist incorporating some form of gripper unit. Gripper units have been used in the nuclear machining for many years for the remote machining of radioactive or toxic materials. Such units were designed to perform a range of tasks, not just one simple handling operation. Simpler gripper units have been developed for handling tooling as part of automatic tool changers. There exist many types of gripper units and transfer mechanisms.
From these examples, it can be seen, that there is little new in the technology of industrial robots, and the high levels of reliability obtained in the practical application of robots perhaps reflects this fact. The innovation lies rather in the application of the technology of robots, and it is here that invention and novelty must be considered.
What makes a robot different from an ordinary machine is its electronic brain — a microcomputer that can be programmed to do an assigned task repeatedly, at the same pace and with the same accuracy. It is expected that in the nearest future industrial robots will be able to change their own parts.
In the «War of Worlds» written before the turn of the last century H. Wells told a fantastic story of how Martians almost invaded our Earth. Their weapon was a mysterious «sword of heat». Today Wells' sword of heat has come to reality in the laser. The name stands for light amplification by stimulated emission of radiation.
Laser, one of the most sophisticated inventions of man, produces an intensive beam of light of a very pure single colour. It represents the fulfilment of one of the mankind's oldest dreams of technology to provide1 a light beam intensive enough to vaporize the hardest and most heat-resistant materials. It can indeed make lead run like water, or, when focused, it can vaporize any substance on the earth. There is no material unamenable2 to laser treatment and laser will become one of the main technological tools quite soon.
The applications of laser in industry and science are so many and so varied as to suggest magic3. Scientists in many countries are working at a very interesting problem: combining the two big technological discoveries of the second half of the 20th century — laser and thermonuclear reaction — to produce a practically limitless source of energy. Physicists of this country have developed large laser installations to conduct physical experiments in heating thermonuclear fuel with laser beams. There also exists an idea to use laser for solving the problem of controlled thermonuclear reaction. The laser beam must heat the fuel to the required temperature so quickly that the plasma does not have time-to disintegrate. According to current estimates, the duration of the pulse has to be approximately a billionth of a second. The light capacity of this pulse would be dozens of times greater than the capacity of all the world's power plants. To meet such demands in practice, scientists and engineers must work hard as it is clear that a lot of difficulties are to be encountered on route4.
The laser's most important potential may be its use in communications. The intensity of a laser can be rapidly changed to encode very complex signals.In principle, one laser beam, vibrating a billion times faster than ordinary radio waves, could carry the radio, TV and telephone messages of the world simultaneously. In just a fraction of a second, for example, one laser beam could transmit the entire text of the Encyclopaedia Britannica.
Besides, there are projects to use lasers for long distance communication and for transmission of energy to space stations, to the surface of the Moon or to planets in the Solar system. Projects have also been suggested to place lasers aboard Earth satellites nearer to the Sun in order to transform the solar radiation into laser beams, with this transformed energy subsequently transmitted to the Earth or to other space bodies. These projects have not yet been put into effect5, because of the great technological difficulties to be overcome and, therefore, the great cost involved. But there is no doubt that in time6 these projects will be realized and the laser beam will begin operating in outer space as well.
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