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| Sunday, 30 October 2005 |
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Junior Observer |  |
| News Business Features Editorial
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Robots : Human-like machines
The term robot comes from the Czech word robota, which is translated as "forced labour". This describes the majority of robots fairly well. Most robots in the world are designed for heavy, continuous manufacturing work. They handle tasks that are difficult, dangerous or boring to human beings. Just like humans, a robot is made up of five components (parts). A typical robot has a movable physical structure, a motor of some sort, a sensor system, a power supply and a computer "brain" that controls all of these parts. Robots are basically man-made versions of animal life - they are machines that behave like humans and animals. Robots are different from other movable machines, such as cars, because of their computer element. Robots are different from ordinary computers in their physical nature - normal computers don't have a physical body attached to them. The vast majority of robots have several qualities in common. First of all, almost all robots have a movable body. Some only have motorised wheels, and others have dozens of movable segments, typically made of metal or plastic. Like the bones in your body, the individual parts are connected together with joints. Robots spin wheels and sections joined on pivots (a central point) with some sort of actuator (activator). Some robots use electric motors and solenoids (coil of wire magnetised by electric current) as actuators; some use a hydraulic (liquid-based) system; and some use a pneumatic system (a system driven by compressed gases). Robots may use all these actuator types. A robot needs a power source to drive these actuators. Most robots either have a battery or should be plugged into the wall. Hydraulic robots also need a pump to pressurise the hydraulic fluid, and pneumatic robots need an air compressor or compressed air tanks. Electrical circuits The actuators are all wired to an electrical circuit. The circuit powers electrical motors and solenoids directly, and activates the hydraulic system by manipulating electrical valves. The valves determine the pressurised fluid's path through the machine. To move a hydraulic leg, for example, the robot's controller would open the valve leading from the fluid pump to a piston cylinder attached to that leg. The pressurised fluid would extend the piston, moving the leg forward. Typically, in order to move their segments in two directions, robots use pistons that can push both ways.The robot's computer controls everything attached to the circuit. To move the robot, the computer switches on all the necessary motors and valves. Most robots are reprogrammable - to change the robot's behaviour, you simply write a new program to its computer. Not all robots have sensory systems, and few have the ability to see, hear, smell or taste. The most common robotic sense is the sense of movement - the robot's ability to monitor its own motion. A standard design uses slotted wheels attached to the robot's joints. An LED (Light Emission Dioders which are tiny bulbs that fit easily into electrical circuits), on one side of the wheel shines a beam of light through the slots to a light sensor on the other side of the wheel. When the robot moves a particular joint, the slotted wheel turns. The slots break the light beam as the wheel spins. The light sensor reads the pattern of the flashing light and transmits the data to the computer. The computer can tell exactly how far the joint has swivelled (turned) based on this pattern. This is the same basic system used in computer mice. These are the basic nuts and bolts of robotics. Roboticists can combine these elements in an unlimited number of ways to create many types of complex robots. The most common manufacturing robot is the robotic arm. A typical robotic arm is made up of seven metal segments, joined by six joints. The computer controls the robot by rotating individual step motors connected to each joint (some larger arms use hydraulics or pneumatics). Unlike ordinary motors, step motors allow the computer to move the arm very accurately, repeating exactly the same movement over and over again. The robot uses motion sensors to make sure it moves just the right amount. Industrial robots An industrial robot with six joints closely resembles a human arm - it is similar to the shoulder, it has an elbow and a wrist. Typically, the shoulder is mounted to a static base structure rather than to a movable body. This type of robot has six degrees of freedom, meaning it can pivot in six different ways. A human arm, on the other hand, has seven degrees of freedom. Your arm's job is to move your hand from place to place. Similarly, the robotic arm's job is to move an end effector (such as a simple version of a hand) from place to place. You can equip robotic arms with all sorts of end effectors, which are suited to a particular application, such as blowtorches, drills and spray painters. Robotic hands often have built-in pressure sensors that tell the computer how hard the robot is gripping a particular object. This keeps the robot from dropping or breaking whatever it's carrying. Industrial robots are designed to do exactly the same thing, in a controlled environment, over and over again. For example, a robot might twist the caps onto jam jars coming down an assembly line. To teach a robot how to do its job, the programmer guides the arm through the motions using a handheld controller. The robot stores the exact sequence of movements in its memory, and does it again and again every time a new unit comes down the assembly line. Most industrial robots work in auto assembly lines, putting cars together. Robots can do a lot of this work more efficiently than human beings because they are so accurate. They always drill in exactly the same place, and always tighten bolts with the same amount of force, no matter how many hours they've been working. Manufacturing robots are also very important in the computer industry. It takes an incredibly precise (accurate) hand to put together a tiny microchip. Robotic arms are relatively easy to build and program because they only operate within a limited area. Things get a bit trickier when you send a robot out into the world. Source: Internet |
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| Politics | Produced by Lake House |
When you are tired and don't feel like doing your maths homework, don't
you wish you had a robot to do it for you? How many times have you wanted
a robot friend, so you could easily do everything that you are unable to
do as a kid? Robots are considered as one of the greatest inventions of
man. Today we will have a closer look at robots: how they are made, how
they function and many more details. 
