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HOME TASK 18

A. Look through the texts below (Texts 1 – 5). Choose 1 text you like and write an abstract and a summary.

B. Look through the texts below (Texts 1 – 5). Choose 2 texts you like and write an abstract and a summary for each of them.

СиText 1. History of Robotics

C. Write an abstract and a summary for each of the texts (1 – 5) given below.

The concept of robots dates back to ancient times, when some myths told of mechanical beings brought to life. Such automata also appeared in the clockworkбfigures of medieval churches, and in the 18th century some clockmakers gained fame for the clever mechanical figures that they constructed. Today the term automaton is usually applied to these

handcrafted, mechanical (rather than electromechanical) devices that imi- А

tate the motions of living creatures. Some of the “robots” used in advertising and entertainment are actually automata, even with the addition of remote radio control.

The term robot itself is derived from the Czech word “robota”, meaning “compulsory labour”. It was first used by the Czech novelist and playwright Karel Chapek, to describeДa mechanical device that looks like a human but, lacking human sensibility, can perform only automatic, mechanical operations. Robots as they are known today do not only imitate human or other living forms. True robots did not become possible, however, until the invention of the computer in the 1940s and the miniaturization of computer parts. One of the first trueИrobots was an experimental model designed by researchers at the Stanford Research Institute in the late 1960s. It was capable of arranging blocks into stacks through the use of a television camera as a visual sensor, processing this information in a small computer.

Computers today are equipped with microprocessors that can handle the data being fed to them by various sensors of the surrounding environment. Making use of the principle of feedback, robots can change their operations to some degree in response to changes in that environment. The commercial use of robots is spreading, with the increasing automation of factories, and they have become essential to many labora-

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tory procedures. Japan is the most advanced nation exploring robot technology. Nowadays robots continue to expand their applications. The home-made robots available today may be one sign of the future.

Text 2. Industrial robots in FMS

СAn industrial robot is a reprogrammable, multi-functional manipulator designed to move materials, parts or tools through variable programmed movement to accept a variety of tasks.

It is important to note that robot application and programming methodsиhave progressed far beyond merely handling components since their controllers and sensors have developed the capability to communicate with other intelligent devices. Sensors particularly have been the focus of much development in recent years.

Robotsбare able to provide information not only about their arm position but also about the part being handled and about the gripper or more complex robot tool. They are capable of seeing, hearing, smelting, detecting and analyzing force, torque, heat, pressure, colour and other environmental changes orАconditions.

Sensors can provide information about the presence of a part in a buffer store, in a robot tool or in the chuck of a lathe, and they can, for example, interact with the robot controller and modify the programmed sequence in real time. More sophisticated sensors such as force and torque sensors send stress measurementДvalues. Vision systems use special purpose image processors and image data base which are interfaced with the control program of the arm.

Distributed sensory feedback processing makes robots more intelligent, more reliable and more flexible, and these important trends are

not to be ignored when designing the FMS. И It is necessary to stress that industrial robots have a very wide

range of potential applications in FMS because they are reprogrammable flexible devices themselves. The increasing power of their sensory feedback processing system allows them to work at a high level of intelligence. However, robots are not yet capable of solving most materials handling assembly or inspection tasks in FMS. A relatively low proportion of robots are capable of communicating at a high level with other robots and computers and their sensory systems are usually expensive compared with their performance.

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The major application area of industrial robots include pick and place type of operations.

An example can be given of a robot which ensures smooth product flow in an FMS.

The cell, which includes two drilling machines, was developed to Сproduce 300,000 magnet housings a year on a three-shift operation. It was, therefore, essential to maintain a smooth flow of components into, through and out of the cell. To achieve this product flow the robot was fitted with a pneumatically operated triple gripper to handle raw material,

part machined and fully finished components in turn. иHaving a repeatability accuracy of 0.25 mm at maximum speed, the robot is able to maintain a handling transfer and location program whereby one magnet housing is picked by the triple gripper and moved to the first бtwin chuck machine. The empty grippers grasp a component from each chuck of the machine, remove the part and advance one step to load the chucks again.

A finished part is thus removed from the machine, a part-machined component is progressed to the second chuck, and a new component is loaded into chuck one.АThe robot returns to the unload pallet and deposits the finished part. It then repeats the handling sequence for the second machine, and so on, according to the computer program.

It is of interest to note that supercomputers are fast-functioning computers that were initially developedДfor a few specialized complex applications. They exceed mainframe computers by a factor of two to ten in measures of speed, accuracy, memory size, and memory speed. For example, a calculation that would take about 200 years on a handheld calculator, and about 8 minutes on a mainframe, takes about 1 second on a 1 billion-floating-point-operations-per-secondИsupercomputer.

With supercomputers scientists are able to simulate theories one of the most complex problems – how the universe began. But scientists and engineers have found other uses for these superfast machines: semicompound manufacturers are using them to design chips. Supercomputers are being used to run artificial intelligence programs.

It should be noted, however, that the market for minisupercomputers, a computer slightly less powerful than a supercomputer is growing even faster. They are less expensive. Minisupercomputers are expected to run about 90 per cent of the applications that a supercomputer will run but at a much lower cost.

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Another interesting fact is that a computer is never really fast enough nor has enough memory to satisfy users. That is why scientists and engineers continue to work on developing even faster computers and their components.

Сdling; 2) processing operations; 3) assembly and inspection. иMaterial-handling is the transfer of material and loading and unloading of machines. Material-transfer applications require the robot to move materials or work parts from one to another. Many of these tasks are relatively simple: robots pick up parts from one conveyor and place them on another. Otherбtransfer operations are more complex, such as placing parts in an arrangement that can be calculated by the robot. Machine loading and unloading operations utilize a robot to load and unload parts.

Text 3. ROBOTS IN MANUFACTURING

Today most robots are used in manufacturing operations. The applications of robots can be divided into three categories: 1) material han-

This requires the robot to be equipped with a gripper that can grasp parts. А

Usually the gripper must be designed specifically for the particular part geometry.

In robotic processing operations, the robot manipulates a tool to per-

form a process on the work part. Examples of such applications include spot welding, continuous arc welding and spray painting. Spot welding of automobile bodies is one of theДmost common applications of industrial robots. The robot positions a spot welder against the automobile panels and frames to join them. Arc welding is a continuous process in which robot moves the welding rod along the welding seam. Spray painting is the manipulation of a spray-painting gun over the surface of the object to be coated. Other operations in this categoryИinclude grinding and polishing in which a rotating spindle serves as the robot's tool.

The third application area of industrial robots is assembly and inspection. The use of robots in assembly is expected to increase because of the high cost of manual labour. But the design of the product is an important aspect of robotic assembly. Assembly methods that are satisfactory for humans are not always suitable for robots. Screws and nuts are widely used for fastening in manual assembly, but the same operations are extremely difficult for a one-armed robot.

Inspection is another area of factory operations in which the utilization of robots is growing. In a typical inspection job, the robot positions a

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sensor with respect to the work part and determines whether the part answers the quality specifications. In nearly all industrial robotic applications, the robot provides a substitute for human labour. There are certain characteristics of industrial jobs performed by humans that can be done by robots:

С1) the operation is repetitive, involving the same basic work motions every cycle,

2) the operation is hazardous or uncomfortable for the human worker (for example: spray painting, spot welding, arc welding, and certain machine loading and unloading tasks),

и3) the workpiece or tool are too heavy and difficult to handle,

4) the operation allows the robot to be used on two or three shifts.

As is known, the use of computer-aided design and manufacturing (CAD/CAM) is growing now. Early CAD/CAM systems were based on large computers (mainframes) and focussed on design and drafting functions. During last years,Аhowever, powerful microprocessors have increased the flexibility and power of graphics terminals.

Textб4. CAD/CAM SYSTEM AND FMS

CADD (Computer-Aided Design and Drafting) technology allows

the designer to draw a picture of an object on a video display terminal (VDT) screen. The computer then converts this picture into a mathematical model and stores it in the data baseДfor later use.

Mathematical modelling is considered to be most important feature of a CADD system. This feature can produce a model of a structure for stress analysis, or it can provide input for automated drafting to produce engineering drawings. CADD systems can be ten times faster than man-

ual drafting. И If CAD/CAM systems are linked, the mathematical model can also

be used to create numerical control (NC) tapes for fabricating the part. The oldest CAM technology is numerical control, the technique of

controlling a machine tool with pre-recorded, coded information to fabricate a part. Today, engineers are trying to integrate the technologies of CAD, NC and IR (industrial robots).

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