Hovering type AUV의 자율운항 시스템에 관한 연구

Abstract

Unmanned Underwater Vehicles(UUVs) are applying to a variety of purposes such as underwater exploration, extraction of minerals and military purpose. Also recently, as offshore industry has been expanding, UUVs will be expected to very useful instead of workers in underwater environments.

UUVs, sometimes known as underwater drones, are special vehicles that are able to operate underwater without a human occupant. These vehicles may be divided into two categorise, remotely operated underwater vehicles(ROVs), and autonomous underwater vehicles(AUVs).

We have been interested in development of AUV and how to control the AUV at the sea. It is reason why we start our research. The goal of this study is technology accumulation of design and manufacturing, employ of AUV.

So, This paper addresses the development process of the Hovering type AUV as a test-bed. which has open-frame structure. This structure was designed to take a test conveniently. It has 4 thrusters and they can control 4-DOF motions such as surge, heave, pitch, and yaw. Various navigation sensors were installed for this vehicle. DVL & GPS are used in order to measure the position of the AUV. In addition, pressure sensor & magnetic compass are used for measuring the depth and heading angle of the AUV.

This thesis describes mathematical modeling of the AUV to confirm the dynamic motion and controller performance before the field test. In this step, we set the coordinate systems and derived the 6-DOF equation of motion. Mathematical modeling of the AUV was consist of 6-DOF equation of motion and hydrodynamic coefficients. To control the AUV, PID controller and Fuzzy PID controller were designed. In addition, We suggest the thruster allocation method for allocating thruster force at each thruster. To analyze the vehicle motion and designed controller to track the desired value, we developed the dynamic simulator using Matlab & Simulink software. Experimental test was performed such as depth control, heading control by PID controller. And autonomous navigation control like way-point control by PID controller and LOS(Line Of Sight) method at yacht harbor in Korea Maritime and Ocean University.