In the context of MORPH FP7 research project, at the Underwater Robotics Research Center (CIRS) of the University of Girona we are working on autonomous inspection of 3D underwater environments using optical imaging and sonar. Our automated inspection scheme goes beyond conventional AUV surveys which image the ocean floor from an overhead viewpoint. In contrast, we propose a 3D coverage path planning algorithm that enable the AUV to image the target structure from fair view points at different depths. This enables the AUV sensors to capture the full 3D information of the target structure.
Beyond mere off-line planning, our algorithm adapts the inspection path in real time using sonar range information, dealing with the uncertainty present both in the low-resolution maps used to plan the path and in the AUV's localization system.
In this video, we demonstrate our method at sea in two different inspection tasks using our AUV GIRONA500. First, GIRONA500 follows an automatically pre-planned path to inspect a concrete block on a breakwater structure at 5 m depth. Next, the AUV inspects a natural seamount ranging from 28 m down to 40 m depth. In both tasks the vehicle acquires bathymetry sonar and stereo camera data used to create 3D models and photomosaics of the inspected structures.
