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HISTORY OF TECHNOLOGY, TECHNOLOGY, OBJECTS AROUND US
Robot. History of invention and production
Directory / The history of technology, technology, objects around us A robot is an automatic device created on the principle of a living organism. Acting according to a predetermined program and receiving information about the outside world from sensors (analogues of the sense organs of living organisms), the robot independently performs production and other operations that are usually performed by humans (or animals). In this case, the robot can either have a connection with the operator (receive commands from him), or act autonomously.
A robot is an automatic device that has a manipulator - a mechanical analogue of the human hand - and a control system for this manipulator. Both of these components can have a different structure - from very simple to extremely complex. The manipulator usually consists of articulated links, as a human hand consists of bones connected by joints, and ends with a grasp, which is something like the hand of a human hand.
The links of the manipulator are movable relative to each other and can perform rotational and translational movements. Sometimes, instead of a gripper, the last link of the manipulator is some kind of working tool, for example, a drill, a wrench, a paint sprayer or a welding torch. The movement of the links of the manipulator is provided by the so-called drives - analogues of the muscles in the human hand. Typically, electric motors are used as such. Then the drive also includes a gearbox (a system of gears that reduce the number of revolutions of the engine and increase torque) and an electrical control circuit that regulates the speed of rotation of the electric motor.
In addition to electric, a hydraulic drive is often used. Its action is very simple. In the cylinder 1, in which the piston 2 is located, connected by means of a rod to the manipulator 3, a fluid enters under pressure, which moves the piston in one direction or another, and with it the "hand" of the robot. The direction of this movement is determined by which part of the cylinder (in the space above the piston or below it) the liquid enters at the moment. The hydraulic drive can inform the manipulator and rotational movement. Pneumatic drive works in the same way, only air is used here instead of liquid. This is in general terms the device of the manipulator. As for the complexity of the tasks that a particular robot can solve, they largely depend on the complexity and perfection of the control device. In general, it is customary to talk about three generations of robots: industrial, adaptive and robots with artificial intelligence. The very first samples of simple industrial robots were created in 1962 in the USA. These were Versatran from AMF Versatran and Unimate from Union Incorporated. These robots, as well as those that followed them, acted according to a rigid program that did not change during operation and were designed to automate simple operations in an unchanged state of the environment.
For example, a "programmable drum" could serve as a control device for such robots. He acted as follows: on a cylinder rotated by an electric motor, the contacts of the manipulator drives were placed, and around the drum there were conductive metal plates that closed these contacts when they touched them. The location of the contacts was such that when the drum rotates, the manipulator drives turn on at the right time, and the robot begins to perform the programmed operations in the desired sequence. In the same way, control could be carried out using a punch card or magnetic tape. Obviously, even the slightest change in the environment, the slightest failure in the technological process, leads to a violation of the actions of such a robot. However, they also have considerable advantages - they are cheap, simple, easily reprogrammed and may well replace a person when performing heavy monotonous operations. It was in this type of work that robots were first used. They coped well with simple technological repetitive operations: they performed spot and arc welding, loaded and unloaded, serviced presses and dies. The Unimate robot, for example, was designed to automate resistance spot welding of passenger car bodies, while the SMART robot installed wheels on passenger cars. However, the fundamental impossibility of autonomous (without human intervention) functioning of the first generation of robots made it very difficult for them to be widely introduced into production. Scientists and engineers persistently tried to eliminate this shortcoming. The result of their labors was the creation of much more complex second-generation adaptive robots. A distinctive feature of these robots is that they can change their actions depending on the environment. So, when changing the parameters of the manipulated object (its angular orientation or location), as well as the environment (say, when some obstacles appear in the path of the manipulator), these robots can design their actions accordingly. It is clear that, working in a changing environment, the robot must constantly receive information about it, otherwise it will not be able to navigate in the surrounding space. In this regard, adaptive robots have a much more complex control system than first-generation robots. This system is divided into two subsystems: 1) sensory (or sensing) - it includes those devices that collect information about the external environment and the location in space of various parts of the robot; 2) A computer that analyzes this information and, in accordance with it and a given program, controls the movement of the robot and its manipulator. Sensory devices include tactile touch sensors, photometric sensors, ultrasonic sensors, location sensors, and various vision systems. The latter are of particular importance. The main task of technical vision (actually, the “eyes” of the robot) is to convert images of environmental objects into an electrical signal understandable for a computer. The general principle of technical vision systems is that information about the working space is transmitted to the computer with the help of a television camera. The computer compares it with the "models" in memory and selects a program appropriate to the circumstances. Along the way, one of the central challenges in building adaptive robots was to teach the machine to recognize patterns. Of the many objects, the robot must select those that it needs to perform some action. That is, he must be able to distinguish between features of objects and classify objects according to these features. This is due to the fact that the robot has in memory the prototypes of the images of the desired objects and compares with them those that fall into its field of vision. Usually, the task of "recognizing" the desired object is divided into several simpler tasks: the robot searches for the desired object in the environment by changing the orientation of its gaze, measures the distance to the objects of observation, automatically adjusts the sensitive video sensor in accordance with the illumination of the object, compares each object with a "model", which is stored in its memory, according to several criteria, that is, it highlights the contours, texture, color and other features. As a result of all this, "recognition" of the object occurs. The next step in the work of an adaptive robot is usually some kind of action with this object. The robot must approach it, grab it and move it to another place, and not just randomly, but in a certain way. To perform all these complex manipulations, knowledge of the environment alone is not enough - the robot must precisely control its every movement and, as it were, "feel" itself in space. To this end, in addition to a sensor system that reflects the external environment, the adaptive robot is equipped with a complex system of internal information: internal sensors constantly transmit messages to the computer about the location of each link of the manipulator. They kind of give the car an "inner feeling". As such internal sensors, for example, high-precision potentiometers can be used.
The high-precision potentiometer is a device similar to the well-known rheostat, but with higher accuracy. In it, the rotating contact does not jump from turn to turn, as when the handle of a conventional rheostat is displaced, but follows along the turns of the wire themselves. The potentiometer is mounted inside the manipulator, so that when one link is rotated relative to the other, the movable contact also shifts and, therefore, the resistance of the device changes. Analyzing the magnitude of its change, the computer judges the location of each of the links of the manipulator. The speed of movement of the manipulator is related to the speed of rotation of the electric motor in the drive. Having all this information, the computer can measure the speed of the manipulator and control its movement. How does the robot "plan" its behavior? There is nothing supernatural in this ability - the "wit" of the machine depends entirely on the complexity of the program compiled for it. The computer memory of an adaptive robot usually contains as many different programs as different situations can arise. As long as the situation does not change, the robot operates according to the basic program. When external sensors inform the computer about a change in the situation, it analyzes it and selects the program that is more appropriate for this situation. Having a general program of "behavior", a reserve of programs for each individual situation, external information about the environment and internal information about the state of the manipulator, the computer controls all the actions of the robot. The first models of adaptive robots appeared almost simultaneously with industrial robots. The prototype for them was an automatically operating manipulator, developed in 1961 by the American engineer Ernst and later called "Ernst's hand." This manipulator had a gripping device equipped with various sensors - photoelectric, tactile and others. With the help of these sensors, as well as the control computer, he found and took randomly placed objects given to him. In 1969 at Stanford University (USA) a more complex robot "Sheiki" was created. This machine also had technical vision, could recognize surrounding objects and operate them according to a given program.
The robot was driven by two stepper motors driven independently by wheels on each side of the cart. In the upper part of the robot, which could rotate around a vertical axis, a television camera and an optical rangefinder were installed. In the center there was a control unit that distributed the commands coming from the computer to the mechanisms and devices that implement the corresponding actions. Sensors were installed along the perimeter to obtain information about the collision of the robot with obstacles. "Sheiki" could move along the shortest path to a given location in the room, while calculating the trajectory in such a way as to avoid a collision (he perceived walls, doors, doorways). The computer, due to its large dimensions, was separate from the robot. Communication between them was carried out by radio. The robot could select the desired items and move them by "pushing" (it did not have a manipulator) to the right place. Later, other models appeared. For example, in 1977, Quasar Industries created a robot that could sweep floors, dust furniture, operate a vacuum cleaner, and remove water that had spilled onto the floor. In 1982, Mitsubishi announced the creation of a robot that was so dexterous that it could light a cigarette and pick up a telephone receiver. But the most remarkable was the American robot created in the same year, which, using its mechanical fingers, an eye camera, and a brain computer, solved the Rubik's cube in less than four minutes. Serial production of second generation robots began in the late 70s. It is especially important that they can be successfully used in assembly operations (for example, when assembling vacuum cleaners, alarm clocks and other simple household appliances) - this type of work has so far been difficult to automate. Adaptive robots have become an important part of many flexible (quickly adapting to new product releases) automated industries. The third generation of robots - robots with artificial intelligence - is still being designed. Their main purpose is purposeful behavior in a complex, poorly organized environment, moreover, in such conditions when it is impossible to foresee all the options for changing it. Having received some general task, such a robot will itself have to develop a program for its implementation for each specific situation (recall that an adaptive robot can only choose one of the proposed programs). In case the operation fails, the AI robot will be able to analyze the failure, compile a new program and try again. Author: Ryzhov K.V.
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