UTEC, a geo-services brand in Acteon’s Data and Robotics division, conducted a day of ‘Gavia’ Autonomous Underwater Vehicle (AUV) trials off Fremantle in Western Australia.
The AUV has recently undergone significant upgrades and the addition of new modules including the subsea ultra-short baseline (USBL) aiding the vehicle inertial navigation system (INS) positioning.
The trial tested the AUV in its reconfiguration and provided further training for the local crew with the support of UTEC’s AUV specialists from the UK.
Following on from the training and trials completed since the AUV arrived in Perth at the end of 2022, UTEC has finalised a significant programme of upgrades and improvements of the system.
It has included INS/Doppler velocity log (DVL) modules (PHINS C3 and Pathfinder DVL); battery modules increasing mission endurance from six hours to 12; cNode USBL modules and nose cone enabling USBL tracking, aiding acoustic communications to the AUV and incorporating a new eight-megapixel camera in the nosecone.
The control modules also received upgrades including calibration of depth and sound velocity (SV) sensors and a firmware upgrade.
The most significant upgrade, however, is the addition of the module that enables subsea USBL aiding of the vehicle INS positioning. This means the vehicle does not need to surface periodically to update the internal position and account for INS/DVL drift, creating efficiencies by allowing the vehicle to remain subsea and on task for the full 12-hour mission endurance as well as allowing use of the full 1000 m depth rating.
Previously, the requirement for the vehicle to return to the surface to update real-world position using Global Positioning System (GPS), meant that the deepest that the AUV had worked was 100 m; anything deeper was too inefficient with the time spent diving and surfacing to update the position in deeper waters.
“The day resulted in several milestones for UTEC in terms of AUV operations with these officially being the deepest dives that we have completed with the Gavia. It was also the first time the AUV has been positioned with USBL aiding. We are looking forward to assisting further clients with their deepwater survey and positioning requirements,” said Paul Barry, Country Manager – Australia, UTEC.
