e coliIndustrial robots
There are variety of definitions of the term robot. Depending on the definition ud, the number of robot installations worldwide varies widely。 Numerous single—purpo machines are ud in manufacturing plants that might appear to be robots。 The machines are hardwried to perform a single function and cannot be reprogrammed to preform a different function. Such single-purpo machines do not fit the definition for industrial robots that is becoming widely accepted.this definition was developed by the Robot Institute of America.
A robot is a reprogrammable multifunctional mainipulator designed to move material， parts, tools， or specialized devices through variable programmed motions for the performance of a variety of tasks.
Note that this definition contains the words reprogrammable and multifunctional。 It is the two characteristics that parate the ture industrial robot from the various single-purpo machines ud in modern manufacturing firms. The term “reprogrammableanda>go home” implie
s two things： The robot operates according to a written program， and this program can be rewritten to accommodate a variety of manufactureing tasks。
再造淑女 The term “multifunctional” means that the robot can, through reprogramming and the u of different end—effectors, perform a number of different manufacturing tasks. Definitions written around the two critical characteristics are becoming the accpted definitions among manufacturing professionals。
The first articulated arm came about in 1951 and was ud by the U。 S. Atomic Energy Commission。 In 1954, the first programmable robot was designed by George Devol. It was bad on two important technologies:
(1)Numerical control （NC） technology。
(2)Romote manipulator technology。
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Numerical contorl technology provided a form of machine control ideally suited to robots. It allowed for the control of motion by stored programs. The programs contain date poi
nts to which the quentially moves, timing signals initiate action and to stop movement, and logic staements to allow for decision making.早上好英语
Remote manipulator technology allowed a machine to be more than just another NC machine。 It allowed such machines to become robots that can perform a variety of manufacturing tasks in both inaccessible and unsafe environments. By merging the two technologies, Devol developed the first industrial robot, an unsophisticated programmable materials handling machine.
The first commerically produced robot was developed in 1959. In 1962， General Motors Corporation. This robot was produced by Unimation. A major step forword in robot control occurred in 1973 with the development of the T-3 industrial robot by Cincinnati Milacron。 The T—3 robot was the first commercially produced industrial robot controlled by a minicomputer。
Numerical control and remote manipulator technology prompted the wide-scale development and u of industrial robots。 But major technological developments do not
take place simply becau of such new capabilities。 Something must provide the impetus for taking advantage of the capabilities。 In the ca of industrial robots, the impetus was economics。
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The rapid inflation of wages experienced in the 1970s tremendously incread the personnel costs of manufacturing firms。 At the same time， foreign competition became a rious problem for U. S. manufacturers. Foreign manufacturers who had undertaken automation on a wide-scale basis， such as tho in Japan， began to gain an increasingly large share of the U。 S。 and world market for manufactured goods, particularly automobiles.
Through a variety of automation techniques including robots, Japane manufacturers， beginning in the 1970s， were able to produce better automobiles more cheaply than nonautomated U。 S。 manufacturers。 Conquently, in order to survive， U。 S。 manufacturers were forced to consider any technological developments that could help improve productivity。
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It became imperative to produce better products at lower costs in order to be competitive with foreign manufacturers。 Other factors such as the need to find better ways of performing dangerous manufacturing tasks contributed to the development of industial robots。 However, the principal rationale has always been， and is still， improved productivity。
One of the principal advantages of robots is that they can be ud in ttings that are dangerous to humans. Welding and parting are examples of applications where robots can be ud more safely than humans. Even though robots are cloly associated with safety in the workplace, they can, in themlves, be dangerous.
Robots and robot cells must be carefully designed and configured so that they do not endanger human workers and other machines。 Robot work envelops should be accurately calculated and a danger zone surrounding the envelope clearly marked off。 Rei e you什么意思d flooring strips and barries can be ud to keep human workers out of a robot's work envelope.
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Even with such precautions it is a good idea to have an automatic shutdown system in situations where robots are ud. Such a system should have the capacity to n the need for an automatic shutdown of operations. Fault—tolerant computers and redundant systems can be installed to ensure proper shutdown of robotics systems to ensure a safe enviroment。
