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.docText 16 ELECTRONIC SENSES
Most of today's robots have difficulty manipulating things because they cannot 'see'. Those that do 'see' have television cameras for 'eyes'. A video screen is divided into tens of thousands of square or rectangular elements, each one of which is either black or white. The more elements, the finer the resolution, so the robot 'sees' a more detailed picture. Newer optical devices with elements in shades of gray will provide greater detail, but for now, most robots decipher only the form of an object and cannot detect color.
As with all other aspects, the vision system must be programmed beforehand to enable the robot to recognize certain objects. Therefore, if six different objects are involved in a manufacturing procedure, the teacher will have to show the robot vision system each object in different positions and orientations. The robot's computerized 'brain' must calculate 30 to 50 measurements of each object, then store the information in its memory. Consequently, vision training requires that the objects be rotated, picked up, and put down many different times.
The robot's electronic eyes find the edges of the object, calculate the measurements, and match them against what it has previously learned in order to identify the object. It takes about
three-quarters of a second for the robot to gather this information (much longer than the human eye) and pick up the object.
Though a robot cannot 'see' as well as a human, it will not blink, and one of its best uses is for quality control and inspection of a product. Moreover, some of these 'steel collar workers' are being equipped to 'look' with laser (highly focused) light, an advantage, because the laser enables the robot to do some important geometry, calculating angles and finding precisely how far away or how tall an object is.
Robots equipped with lasers or sonar, sound echoing devices, may become adept at range finding, measuring distance and locating faraway targets. They could, therefore, be 'employed' by the military.
Using a microphone as an ear, a robot's computer could convert sound waves into computer language (a series of 'on' and 'off' electrical messages) and compare these messages with information stored in its memory. This would help the robot 'understand' sounds and respond to voice commands. Robots operated by voice command could help physically handicapped people to dress, feed, or otherwise care for themselves. So far, voice recognition and control of computers is difficult and not widely utilized in factories.
Robots will become qualified for many new tasks as we develop new senses for them. Some robots will have sensors that detect ultraviolet light. Others will 'feel' infrared heat. Still others will have a sense of touch.
Massachusetts Institute of Technology researchers are now designing 'artificial skin'. This is actually sheets of rubber laced with wire. The top sheet has an electric current running through it. As increasing pressure is applied, the top sheet passes the current down to other sheets. A computer measures the voltage in different levels of 'skin' and forms an image of the object being touched. Touch is important in manipulating objects because it tells a robot where a part is and how tightly to grip it without crushing it.
Electronic 'eyes', 'ears', and 'skin', integrated with electronic 'brains' could provide enough information for a robot to respond quickly to changes in the environment and start making alterations.
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RELAY COMPUTERS
Even in the 40s the primary speed limit on these rudimentary computers was mechanical, so developers looked to other technologies to build their computers. Bell Telephone Laboratories began work on relay-based computers in 1938. A relay is an electrically controlled switch-one source of electricity activates an electromagnet which operates a switch which, in turn, alters the electrical flow in another circuit. Relays are a hybrid technology, electro-mechanical. Their mechanical side performs physical work while their electrical nature makes them very flexible. One relay can control others almost unlimited in number and distance. The gears and fevers of
purely mechanical calculators are limited in reach in both regards.
The choice of relay technology was a natural one for the telephone company. After all, the telephone switching systems of the time made extensive use of relays-rooms and rooms fitted with them.
Electronic Computers
Early in the development of the computer, designers recognized the speed advantages of an all electronic machine. After all, electronic signals could switch thousands or millions of times faster than mechanical cams or electrical relays.
The first successful electronic machine was secretly developed as part of the British cryptoanalysis program at Bletchley Park during World War II. There, T. H. Flowers created an electronic machine known as Colossus for comparing cipher texts. Colossus, first tested in December 1943, pioneered the concept of electronic clocked logic (with a clock speed of 0.005 MHz) and used 1,500 vacuum tubes.
Although Colossus was a programmable machine, neither it nor the succeeding generations of cryptographic machines developed at Bletchley Park were designed to handle decimal multiplication. Moreover, the development of Colossus and its kin was kept secret until long after the war, so it did not in itself contribute to the development of the computer. In fact, many details of the Bletchley Park operation are still secret forty years later.
The seminal machine in the history of the electronic computer is generally regarded as ENIAC, the Electronic Numerical Integrator and Computer, developed at the Moore School of the University of Pennsylvania in Philadelphia by a team led by John Mauchly and J. Presper Eckert. Proposed in 1943, it was officially inaugurated in February 1946. The most complex vacuum tube machine ever built, ENIAC occupied a 30 by 50 foot room (at 1,500 square feet, that's the size of a small house), weighed 30 tons, and required about 200 kilowatts of electricity. It used 18,000 vacuum tubes and was based on a clocked logic design. When operating at its design clock speed of 0.1 MHz, ENIAC required a mere 200 microseconds for addition, and 2.6 milliseconds for multiplication. At about 5,000 arithmetic operations per second, it was approximately 1,000 times faster than the Harvard Mark I.
The design goal of ENIAC was to calculate ballistic trajectories, and the machine succeeded well. It was able to compute the path of a 16-inch artillery shell in less than real time-that is, it could predict about where a shell would fall after it was fired but before it hit.
The next step in the development of the computer and PC was EDVAC, the Electronic Discrete Variable Automatic Computer. Unlike the decimal-based ENIAC, EDVAC was designed as a binary computer. Information to EDVAC was encoded in its most essential form- the presence or absence of a code symbol-which could be represented by a voltage. This binary basis is the essence of today's digital logic, upon which nearly aH current computers are based.
With UNIVAC, the basic operating principles of the computer were in place. Further
developments have come in the refinement of the technology used to make computer circuits. Switching from tubes to transistors increased reliability and allowed designs to become both more complex (mainframes) and smaller (minicomputers). Memory shifted from mercury delay lines (which briefly stored data as ultrasonic pulses propagating through tubes of liquid mercury) and cathode ray tubes to magnetic core and finally solid-state transistors. Integrated Circuits continued this trend and made possible microprocessors and RAM chips, which, in turn, led to the circuits that formed the basis of the first personal computers.