Development of underwater inspection system for dam inspection: Results of field tests

Social infrastructures in Japan are becoming aged and robotic infrastructure inspection tools are required in order to inspect the conditions for maintenance. Authors have been developing the new underwater inspection system for underwater infrastructures. It consists of an unmanned surface vehicle and a remotely operated vehicle (ROV) suspended from the surface vehicle. The system can obtain position of the inspected point without using any higher cost device. This paper explains functions of the developed experimental model and results of experiment at the pool and actual dam. In the pool experiment, the auto inspection function was verified that it can obtain the wide images of target wall with slight manual operation, and in the actual dam, the experimental model obtained the images of target wall and conduit gate. The system has high stability due to such pendant type ROV, thus the inspection was carried out with easy operations. On the other hand, the maneuverability of the experimental model was influenced by the wind, and the position accuracy from the MEMS GNSS/INS sensor became worse near the dam wall.