Methods of underwater autonomous navigation

The use of robots in the maritime industry is becoming more widespread in its different branches. Underwater autonomous vehicles (UUVs) have become an essential tool for various underwater activities. Compared to other autonomous systems, navigation and localization for UUVs are particularly difficult due to the unavailability of the Global Positioning System (GPS), where signals are attenuated under water and the complexity and instability of the environment are big. Alternative methods such as acoustic positioning systems, inertial navigation systems (INS) and geophysical navigation approach are used for navigation. In this paper is presented three methods for underwater navigation and the algorithm used to follow a trajectory. The flowmeter is used in this application to identify the underwater route and the results are compared with the inertial sensors (IMU) test especially the magnetometer results. The two prediction are used using PID and Kalman filter to identify the trajectory.