Unmanned Systems Technology 007 | UMEX 2016 report | Navya ARMA | Launch & recovery systems | AIE 225CS | AUVs | Electric motors | Lethal autonomous weapons

66 package enables operators to rapidly change one mission package for another, giving the system a wide range of mission capabilities, including bathymetric survey, environmental survey, pipeline inspection and subsea facilities inspection. The plug-and-play architecture also supports remotely operated vehicle propulsion and AUV modes. Its 44 kWh lithium-polymer battery provides mission times of up to 24 hours and an operational range of more than 100 km. The new design will accept sensor packages such as a multi-beam, side scan, 3D laser scanner, sub-bottom profiler and synthetic aperture sonars, as well as high-resolution video, still photo and laser profilers. A key element of the system is supporting 3D laser imaging underwater and fusing this data with the sonar results, and this has been a vital part of the development of the whole platform. This laser system provides angular resolution, range and scan rate to deliver dense 3D point cloud images of subsea structures with millimetre resolution at tens of metres of stand-off distance, according to Lockheed Martin. A simulation where an AUV was moving at 2 knots at about a 5 m stand- off from the target showed an accuracy within 13 mm when measuring a 17 m section of an undersea oil well, even after the insertion of simulated noise for timing, sensor calibration, sensor errors and navigation errors. This sensor fusion was then tested on a Mk2 Marlin moving at 1 knot and a distance of 5 m, scanning a 25 m barge. All the data points from the laser scan were tagged with the location, which was shown to be consistent with the simulation. Tests performed using a Mk2 system showed it was possible to scan structures in a few seconds from a distance of 5- 10 m with the same level of accuracy as the simulations. Multiple passes by the Mk 2 at slower survey speeds and at closer stand-off ranges provided denser point clouds and higher measurement accuracy to produce geo-registered 3D models, again with millimetre resolution. This level of accuracy can then be used to modify the mission plan. Using a reference model of the pipeline and seabed obtained from a previous baseline survey, a new survey would be able to autonomously detect and measure any movement of the pipeline, changes in pipeline contour such as potential buckling or over-bending, changes to pipeline surface conditions such as pits, cracks, dents or new anomalies or debris that could impact pipeline safety. The AUV would be able to ‘hover’ over areas of concern to take more accurate measurements. The Marlin Mk3 will be capable of carrying conventional survey and inspection sensors such as multi-beam sonar, side scan sonar and HD video, as well as the high-resolution 3D sonar and 3D laser sensors for autonomous pipeline inspection. For operation in shallower waters, researchers in Italy have been testing an April/May 2016 | Unmanned Systems Technology Insight | Autonomous underwater vehicles The Marlin Mk 3 is designed for surveying and pipeline inspection at depths of 4000 m (Courtesy of SeaRobotics) The Girona 500 can follow underwater pipelines and turn valves on and off using its end effector