Autonomous underwater vehicle for inspection of submarine cables

KDD has developed an Autonomous Underwater Vehicle (AUV) AQUA EXPLORER 2 (AE2), the primary mission of which is to inspect buried underwater cables and to survey the seafloor, As AE2 has no tether cables between the vehicle and mother vessel, no large onboard equipment such as cable handling drums are needed. AE2 can therefore be operated from a small vessel, which drastically lowers the operation cost. AE2 communicates with the mother vessel through acoustic links. The onboard operator can monitor the status of the vehicle and the image of the seafloor through the acoustic link, and also can control the vehicle. Two sea tests were successfully performed. In these sea tests, AE2 succeeded in tracking an actual underwater cable laid in the Pacific Ocean. AE2 was also used to survey the seafloor for the construction of a new optical telecommunication cable system surrounding Japan. AE2 is also expected to be used in various underwater inspections other than cable inspection. This paper summarizes AE2 equipment and operation and also describes results of sea tests.