Unmannedsystemstechnology.com: SWARMS’ project: New advanced features for ECA Group's AUV
Published on Unmannedsystemtechnology.com, July 2017.
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ECA Group successfully demonstrated new advanced robotic features on an experimental version of its A9-E AUV (Autonomous Underwater Vehicle), specially modified for the SWARMS project, an EU-funded directive to develop new technologies for underwater robotics. The new features includeds an extra acoustic modem with network protocols from Evologics fitted in a modified front payload section, and an additional advanced autonomy interface with on-board computing capabilities. The demonstration was held in the access channel to the Black Sea port of Mangalia, Romania.
The new modem allows the inclusion of the AUV within a multiple access-capable underwater communication network.
The use of a multiple access acoustic network deconflicts the use of multiple vehicles operating in the same area. Using an unmanned surface vehicle (USV) as a WiFi and RF gateway, a status vector including AUV position, speed, etc was successfully displayed on the topside SWARMS multi-vehicle mission management tool.
The advanced autonomy interface was developed to allow adaptable mission parameters on the fly. Befroehand, only a pre-programmed mission plan was usually executed. To test this new capability, ECA Group demonstrated real-time quality analysis and control of a bathymetric survey conducted using a COTS Klein 3500 interferometric side-looking sonar. A quality factor was extracted in real-time, on-board the experimental A9-E, from the raw sonar data. This quality factor measures the interferometric baseline decorrelation, which can result from many factors including reduced signal to noise, or multipath interference in shallow water, and degrades the accuracy of the depth soundings. It was then used to adapt the altitude of the survey between 4m and 6m (water depth varied from 5m to 8m over the test area) to minimize the baseline decorrelation and therefore increase the accuracy of the soundings.