DNV GL has moved closer to offering fully autonomous drone inspections following the completion of a new set of tests on board a Floating Production, Storage and Offloading vessel, with a drone streaming live video from a 19.4m oil tank, which was analysed in real-time by a computer algorithm to detect cracks in the structure.
Altera Infrastructure hosted the test on Petrojarl Varg, which was carried out in conjunction with Scout Drone Inspection.
The drone uses LiDAR to navigate inside the tank, as GPS is not available in the enclosed space. LiDAR creates a 3D map of the tank and geo-tags all images and video with position data. The video was livestreamed via Scout Drone Inspection’s Cloud-based system back to Altera Infrastructure’s headquarters in Trondheim, where the footage was monitored by engineers.
During the test, the drone was controlled by a pilot using the drone’s flight assistance functions, but as the technology matures DNV GL says that it should be able to navigate autonomously. The class society has already been working on the artificial intelligence needed to interpret the video to spot any cracks, and expects that the camera and algorithm will eventually be able to detect anomalies below the surface such as corrosion and structural deformations.
For the customer, costs can run into hundreds of thousands of dollars if the tank has to be taken out of service for days to ventilate and construct scaffolding. For the surveyor, the tanks are also difficult working environments, often requiring climbing or rafting to reach corners.
DNV GL says that using a drone in combination with an algorithm to gather and analyse video footage can benefit all parties, significantly reduce survey times and staging costs while at the same time improving surveyor safety.
“We’ve been working with drone surveys since 2015,” said Geir Fuglerud, Director of Offshore Classification at DNV GL – Maritime.
“This latest test showcases the next step in automation, using AI to analyse live video. As class we are always working to take advantage of advances in technology to make our surveys more efficient and safer for surveyors, delivering the same quality while minimising our operational downtime for our customers.”