Abstract:
Due to the properties of the underwater environment, the most reliable form of long-distance communication utilized by autonomous underwater vehicles is acoustic communications. This thesis explores the integration of acoustic communications with the autonomy software of an autonomous underwater vehicle. The integration of these two subjects transforms the autonomous underwater vehicle into a mobile platform in an underwater acoustic communications network. A software defined acoustic modem was installed as a payload to an autonomous underwater vehicle, which runs MOOS-IvP as the autonomy software. A group of MOOS applications was created to integrate the acoustic modem with the user computer. First, the Unetstack API, used on the modem as an interface, was used to inform the modem of its location based upon sensor information obtained from the vehicle main computer. Second, additional applications were created to send and receive acoustic commands to control the movement of the vehicle, such as aborting the current mission or switching between different mission tracks. Similarly, the Unetstack API was used send and receive commands that controlled the signal power level of an acoustic transmission remotely. Finally, the first steps were made in acoustic networking by creating a MOOS application that forwards information between different vehicles. The applications were used in multiple field experiments at Lake Tuscaloosa. One experiment involved two autonomous underwater vehicles to form a three-node underwater acoustic network.
