Page 16: of Marine Technology Magazine (June 2011)

Kongsberg Maritime has completed the world’s longest multi-sensor AUV pipeline survey using one of its

HUGIN 1000 Autonomous Underwater Vehicles (AUV).

The pipeline inspection took place February 9-11, 2011, in the Hjelte fjord near Bergen, Norway and the HUGIN 1000 was operated from the Royal Norwegian Navy ves- sel HNoMS Malty. The subject of the inspection was two subsea pipelines going to the Mongstad oil refinery. The

HUGIN 1000 AUV was equipped with an advanced suite of Kongsberg imaging equipment including the HISAS 1030 synthetic aperture sonar, EM3002 multibeam echo sounder and an optical camera with LED lighting. The instruments were used to inspect around 30 km of subsea pipeline in an 8-hour, two-pass mission.

In the first pass, side-scan data from the HISAS 1030 sonar was used to detect and track the pipelines in real- time, using PipeTracker software for pipeline detection and tracking extracted pipe-like features in the sonar images, with a high degree of robustness towards false detections.

The PipeTracker software, which was developed in a col- laborative effort with the Norwegian Defence Research

Establishment (FFI) in a project funded by the Norwegian

Research Council, runs as a plug-in module in the stan- dard HUGIN payload system. The HUGIN 1000 control system in turn uses the identified pipeline tracks to posi- tion the vehicle at an optimal range for HISAS imaging.

The whole process is fully automated inside the AUV and requires no operator intervention.

In the second pass, HUGIN followed the pipeline tracks identified in the first pass at low altitude and inspected the

Hydrographic Survey

AUV Pipeline Inspection

Kongsberg Maritime HUGIN 1000 Completes World’s Longest Multi-Sensor

AUV Pipeline Inspection

Figure 1: The first 8-hour mission (green line).

Figure 2: A single 3 Megapixel camera image. Altitude 4.6 m. Resolution 2x2 mm. 16 MTR June 2011