Towards Autonomous Underwater Assembly of Interlocking Structures
Channel: Dartmouth Reality and Robotics
Date: 2020-07-23

This paper investigates and proposes a first autonomous underwater vehicle (AUV) system for block assembly, to enable the visionary goal of constructing large-scale underwater structures, including retaining walls and artificial reefs. The core of the system is an inexpensive heavily modified BlueROV2 autonomous vehicle with a one-degree of freedom hand that can open and close a gripper. The AUV will pick up blocks from a pod and will place them following a prescribed sequence to a target location. We experimentally explore the fundamental limitations on underwater camera-based localization and vectored thruster control in controlled conditions. This analysis will allow us to identify the lower bound accuracy of control and sensing and will guide the design of 3D printed blocks and gripper that feature error correcting components. A proof of concept is presented, and the experiments will culminate in the assembly of structures of at least ten blocks in a pool environment using such a holistic system design.