Удосконалення системи стабілізації швидкості руху автономного ненаселеного підводного апарата

Abstract

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.13.03 – системи та процеси керування. – Національний технічний університет «Харківський політехнічний інститут», Харків, 2023. В дисертаційній роботі вирішено актуальне наукове завдання стабілізації швидкості руху автономного ненаселеного підводного апарату при плоскому криволінійному русі. Розроблено систему автоматичного керування швидкістю руху підводного апарату, що складається з двох регуляторів: оптимального регулятора швидкості руху АНПА та регулятора стабілізації упору рушійно-кермового пристрою при роботі у косому потоці води. Оптимальний регулятор працює за критерієм мінімізації тривалості перехідного процесу при зміні швидкості руху підводного апарату. Регулятор стабілізації упору корегує значення сигналу керування в залежності від умов функціонування рушійного пристрою. Розроблена САК дозволяє максимально швидко змінювати швидкість руху АНПА і підтримувати її на заданому рівні.Dissertation for scientific degree of Candidate of Technical Sciences in specialty 05.13.03 – сontrol systems and processes. – National Technical University «Kharkiv Polytechnic Institute», Kharkiv, 2023. In the presented dissertation, the relevant scientific task of stabilizing an autonomous underwater vehicle (AUV) velocity in a plane curvilinear motion is solved. To solve the scientific task in the dissertation, the mathematical model for the spatial motion of an autonomous underwater vehicle, developed by the scientific school, «Underwater Technology» of the National University of Shipbuilding, was used. From the control theory view point, an autonomous underwater vehicle is considered as an absolutely rigid body, which makes it possible not to take into account the force interaction between its mass-bearing elements. It is assumed that the AUV has a streamlined shape. The vehicle control is carried out by applying the required voltage to the DC motor with independent excitation. The AUV has both forward and reverse motion modes. The value of the applied voltage regulates the screw propeller rotation speed and the vehicle motion direction. In the work, an automatic control system (ACS) of the underwater vehicle speed, consisting of several controllers: the optimal controller for the AUV speed and the controller for stabilizing the total thrust during the propulsion and steering device (PSD) operation in oblique water flow, is developed. The optimal controller works according to the criterion of minimizing the transient process duration during underwater vehicle speed change. Given the significant nonlinearity of the control object, the classical methods for determining the control law do not meet the requirements for the controlled motion accuracy. Therefore, the control law was determined by the AUV motion dynamics mathematical modeling in a given velocity range. Thus, a set of vectors, that determine the dependence of the final vehicle speed from the initial and the signal switching time, was formed. If this dependence is approximated in reverse, the necessary control function (dependence of the signal switching time on the initial and final speeds of the AUV) is obtained. For this purpose, an artificial neural network was used in the dissertation. AUV motion speed stabilization is an important task for controlled trajectory motion, therefore the developed optimal speed controller was improved by adding a propulsion thrust stabilization controller when operating in an oblique flow. In the dissertation, a research of the thrust dependence of propellers of different types on the PSD operating conditions was made. To this purpose, the mathematical model of the AUV dynamics was supplemented with the models of propulsion and steering devices: «propeller – rudder», «screw propeller – rotary nozzle» and «screw rotary column», implemented in the Simulink system. The operability of the developed models of propulsion and steering devices was confirmed by an experimental study using computational fluid dynamics models of the given types of propulsion devices. By mathematical modeling of the AUV dynamics with different types of PSD, the dependence of the propeller device thrust from the angle and speed of the incident water flow during the vehicle plane curvilinear motion was obtained in vector form. Based on the obtained thrust error, the correction of the control signal value was determined depending on the AUV motion velocity and flow angle, which is necessary for the selected propulsion device total thrust stabilization. The error vector obtained experimentally is approximated using an artificial neural network as part of the controller. The developed ACS allows changing the AUV motion velocity as quickly as possible and maintaining it in the vehicle flat curvilinear motion or in an oblique water flow.