Memorial University Fishing Gear Demonstration
2G Robotics worked with the Fisheries and Marine Institute of Memorial University to demonstrate laser scanning as an accurate method for assessing the operation of fishing gear in underwater conditions.
Background
2G Robotics performed demonstration scans at the Fisheries and Marine Institute of Memorial University in St. John’s, NL in order to validate the ease of operation of the ULS-500 underwater laser scanning system for commercial fishing and research applications. The Marine Institute’s Centre for Sustainable Aquatic Resources (CSAR) is home to the world’s largest flume tank. The tank is used predominantly for studying fishing gear, usually in a scaled down form. Relationships are drawn from the scaled-down gear, allowing gear technologists to predict performance of full-scale fishing gear without actually going to sea. For the demonstration, 2G Robotics worked with George Legge, the Facility Supervisor, to scan trawl nets, a crab pot, and a flange using the ULS-500.
Precise Measurements in 3-Space
Incumbent methods for analyzing experimental and newly designed gear rely on two cameras to indirectly generate three-dimensional data using linear measurements on independent XY and YZ planes. In evaluating fishing gear, there are a number of common geometrical parameters of interest such as the horizontal spread at the wingtips of a trawl and the height of the trawl from the seafloor. At sea, these parameters are typically measured with hydro-acoustic sensors. However, using a 2G Robotics ULS-500, CSAR was able to fully model the equipment and measure all relevant metrics from a 3D point cloud.
Results
Scans were performed on shrimp trawl nets, red fish trawl nets, crab pots and a flange using both active and inactive flow rates. As the scans progressed, the formation of the point clouds was available for previewing in real-time using the 2G Robotics Scanner Application software.
Legge commented that “researchers were able to gather information about a trawl that would normally be more difficult to obtain. Parameters such as mouth opening and mesh opening were more easily extracted using the 3D models generated by the laser scanners.”
With the Marine Institute’s current metrology method, there is minimal capability for additional information extraction from the acquired data. This potential lack of information means that queries regarding the fishing gear sometimes remain unanswered, or require further testing. With a 2G Laser scanner, much more in-depth studies can be performed.
“The model twines used in trawls provide an almost transparent target, yet the ULS-500 did an excellent job capturing data which would otherwise take a great deal of time.”
