Abstract:
Bathymetry is an activity for which demand is growing as knowledge of the earth is increasing. Even if most of the earths oceans have already been surveyed using different methods, some areas containing highly valuable information have been left unsurveyed. These zones have been left untouched mainly due to the difficulty in accessing them and the prevailing environmental conditions in the zones. This study focuses on the development of a bathymetric system that could face difficult environmental conditions such as waves, currents, and shallow depths. The system is composed of a swarm of autonomous unmanned remote-controlled surface vehicles and a centralized system to guide them. Since the system is designed to be as autonomous as possible, navigation is done in each of the Unmanned Surface Vehicles (USVs) and not in the centralized system. This study is focuses on three aspects. First, the specifications for the bathymetric system are developed with the aim of designing a prototype that fits the needs of the project. Then, the mechanics, the printed circuit board design, and their interfaces are described, excluding sonar and wireless transmission systems. Finally, the study focuses on the USV navigation and control equations, their testing, and their implementation. In order to achieve the most precise navigation, a hybridization is realized with inertial navigation and differential Global Navigation Satellite System (GNSS) navigation. Concerning the guidance of the USVs, the different vehicles are guided in the surveyed zone using waypoints which the system follows as accurately as possible. The thesis deals with the navigation and control law of one USV. However, the study of swarm algorithms is being carried out by another student group and is hence outside the scope of this research. Swarm algorithms will be optimized in the future when the control of one entity of the swarm is complete.