Research on ASV-ROV Cooperative System for Environmental Measurement

The authors developed the ASV (Autonomous Surface Vehicle) / ROV (Remotely Operated Vehicle) cooperative system. The ASV has four thrusters located in a rhombus arrangement which enables omnidirectional movement. The developed ASV is equipped with GNSS (Global Navigation Satellite System), with such functions as dynamic positioning and automatic navigation by setting up route coordinate in advance. Moreover, it has a cable control device for linkage with ROV. A cable wound by drum is connected with a PC on the ASV through a slipring. In addition, a cage for ROV storage is set up between floating units of the ASV. The cage height is adjustable for the ROV to limit the hydrodynamic resistance during ASV cruising. It can take 3D underwater pictures and transmit images to land in real time. The ASV determines its movement from the relative position and azimuth of the ROV, as well as the cable length. The relative position of the ROV to the ASV is determined by an acoustic positioning system. Also, the ROV has AI system to catch images and grasp an image by DPS (Dynamic Positioning System) against current disturbance. The developed ASV/ROV cooperative mobility vehicle was successfully tested in the ocean for monitoring seagrasses and useful for CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> measurement in the sea. Underwater robotics have made visualizing the ocean possible, raising hopes for their role in monitoring seagrass beds, which are crucial for environmental conservation and absorbing carbon dioxide. Authors has developed underwater robotics and acquire 3D orthophotos and identifying underwater environmental parameters with a focus on eel grass beds. This initiative is expected not only to contribute to ocean conservation by helping visualize these areas but also to the calculation of blue carbon credits.