Additional Text. Definition of Robots
Grammar: Revision of Grammar.
I. Pre-reading Exercises
1. Repeat the words in chorus:
Axes, typically, variable, however, considerably, to require, substituting, features, compressibility, perhaps, assigned, repeatedly.
2. While reading the text you will come across a number of international words. Try to guess what Ukrainian words they remind of you:
Operation, mechanism, configuration, unique, product, term, to manipulate, standard, automated, machine, control, function, technology, minicomputer, programming, pneumatic, hydraulic, electric, system, radioactive, toxic, material, operation, fact, innovation, electronic, microcomputer.
3. Pay attention to some grammatical points:
1) An industrial robot may be defined as a device with five or more axes with servo-control, capable of being programmed for independent operation. 2) Some engineers insisted that every robot must be like us, people, and be capable of doingany job. 3) Pneumatic systems are notgenerallycapable of very high accuracy of movement due to the compressibility of air, but they are of low cost and easy to maintain. 4) Gripper units have been used in the nuclear machining for many years for the remote machining of radioactive or toxic materials. 5) The innovation lies rather in the application of the technology of robots, and it is here that invention and novelty must be considered.
Read the text and be ready to find in the text the answers to the following questions:
· How is the term "robot" defined?
· What are the methods of servo-drives for the axes ?
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 drive 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. Simple 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.
Axis ['xksIs] — вісь
shoulder ['SqVldq] — плече
maintain [meIn'ten] — утримувати, обслуговувати, ремонтувати
detailed — детальний
servo-control ['sWvqV kqn'trqVl] — сервоуправління
pneumatic[njH'mxtIk] — пневматичний
extension [Ik'stenS(q)n] — розширення
elevation ["elI'veIS(qn] — піднесення
programmable control device — керувальний пристрій, якому можна задавати програму
NC machine tool — верстат з числовим програмним управлінням, (ЧПУ)
servo-drive — сервопривід
to draw upon — черпати, брати
dc (direct current) drive — привід постійного струму
stepping motor [stpIN 'mqVtq] — крокуючий двигун
gripper-unit— затискуючий привід
nuclear machining ['njHklIq] — механічна обробка радіоактивних матеріалів
remote machining [rI'mqVt] — механічна обробка за допомогою дистанційного управління
automatic tool changer — пристрій для автоматичної зміни інструменту