Evaluation of Under water Positioning by Hanged ROV from USV

Abstract

In this paper, the position measurement method of an underwater inspection system by a remotely operated vehicle (ROV) hanging from an unmanned surface vehicle (USV) is evaluated. Since the ROV goes directly under the USV, its underwater position can be estimated from its depth and the position of the USV. On the other hand, the horizontal position difference between both vehicles affects estimation accuracy. Thus, the position difference when the system is in a water current and when it is moving was evaluated by a simulation. As a result, in low flow rate, the difference falls within the range considered to be practical. In addition, it is confirmed by simulation and experiment that the positional difference during movement can be reduced by the moving method using both vehicles thrusters. Then, an inspection demonstration was carried out. Even in the real environment, the effect that the hanged ROV is located directly below the USV is confirmed and vertically inspection was easily performed.

Image‐Based Underwater Inspection System for Abrasion of Stilling Basin Slabs of Dam

“…is system dropped a remotely operated vehicle (ROV) into water by a hoist system from a boat and implemented an "Water Loupe" visual module to improve the visibility in murky water. Shimono developed an underwater inspection system which consists of an unmanned surface vehicle (USV) and ROV that hangs from USV [8,9]. e system can obtain position of the inspected point without using any higher cost devices.…”