Кваліфікаційні роботи здобувачів вищої освіти кафедри аерокосмічних систем управління

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Browsing Кваліфікаційні роботи здобувачів вищої освіти кафедри аерокосмічних систем управління by Author "Chaika, Dmytro Mykolayovych"

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    Adaptive system of automatic control of an unmanned aerial vehic
    (National Aviation University, 2024-06-14) Chaika, Dmytro Mykolayovych; Чайка, Дмитро Миколайович
    Multicopter- unmanned aerial vehicle which have two or more rotors that generate lift force. One of the most common types of multicopter is quadrocopter, its a multicopter with four propellers usually placed in a square formation. Control of quadcopter is interesting and at the same time difficult problem because this rotors have 6 degrees of freedom but only four inputs. But mostly used models QuadX and Quad+ they are quite easy at usage and construction. Model X allows to gain more speed than + model because of placement of its rotors, In + model only one of them is responsible for movement in the horizontal direction while X have two of them. At this work speed doesn’t matter so we will be using model + to complete this task easier, in this model only one pair of rotors used in changing position of the copter in relation of its axes. Each engine with a supporting screw is located on the vertices of an imaginary square, so each pair of diagonally placed screws has opposite rotation direction to other pair. At this placement the torque created by screws is compensated, if we make all screws turn in one side than our quadcopter will start turning to opposite direction. Position of quadcopter relative to connected to it coordinate system is determine by angles, to be more precise there are three angles: roll, pitch and yaw. ● roll - angle of rotation of the longitudinal axis; ● pitch - angle between the longitudinal axis of the aircraft and the horizontal plane; ● yaw - angle relative to the vertical axis. Quadcopter can fly in four modes such as: roll, pitch, yaw and to this also add hover. To gain altitude all engines should increase power by the same amount. Control of the roll and pitch angle can be carried out by the increase of the power of one engines while decreasing it in the opposite one. While xis roll and pitch depend on the initial choice of direction of movement. Yaw angle control is carried out by adding power to the engines, that rotates in the opposite direction to other two engines the power of which will be decreased. At the same time, altitude gain is not performed, since total power of the engines does not change Hover mode is used when thrust of engine will balance the force of gravity acting on the quadcopter, while roll and pitch angles must be close to zero. For determination of angles of quadcopter it has installed on-board control system, which is equipped with position sensors. It’s main task is tracking orientation of the device in space and stabilizing its flight by changing speed of rotation of corresponding screws. The first four rotor aircraft shown themselves early starting from 1907. August this year first aircraft with such design lifted off the ground by two feet. It was created by Louis Charles Breguet, it was lacking at stability and control and its motion was limited by four tethers. In 1921 more successful program was funded in USA. In addition to four main rotors they used two propellers for control of direction, and two more placed above engine to help lift it higher and cool engine. By conducting over 100 test flights Dr. George de Bothezat’s model proved to be more stable while flying with three men which provided an asymmetric weight distribution and could rise to maximum height of 1.8 meters and be in the air for 1 minute and 42 seconds.He was provided with additional funding but when test didn’t provide needed result program was canceled i Later, on April 1924 Etienne Oehmichen broke existing record for helicopter flight by lifting by 360m and flying for 525m. He went to fly over thousand test flights using his model of quadrotor with additional propellers for control. In the last years technology evolved to such extent that it is possible to build much better quadcopters and different types, smaller ones which can serve both professional and recreational purpose and big ones mainly used in army for transporting troops.