An investigation of low noise reduction gear for the AUV "Urashima "

and sea trial of its acoustic communication

A0182 Satoshi Tsukioka JAMSTEC

A0183 Taro Aoki JAMSTEC

A0184 Takashi Murashima JAMSTEC

A0185 Hidehiko Nakajoh JAMSTEC

A0186 Tadahiro Hyakudome JAMSTEC

A0187 Tadahiko Ida JAMSTEC


Deep sea cruising AUV "Urashima " has capability to cruise along

programmed route in the long distance, and was built as a testing

vehicle which collected the oceanographic data measurement and

seawater in March, 2000. To observe AUV in cooperation with the

support ship in the surface of the sea, it has the acoustic

communication system to send control command from the ship and to

receive vehicle's states. In the acoustic communication experiment in

a real sea area, it has been understood that the communication range

shortens because the sound noise ration at the AUV decreases when a

vertical thruster operates. Noise was caused by reduction gear, it

was changed to helical gear. As the result, noise was reduced and the

communication range was increased to 2.5 times even if the thruster

operated. The command was transmitted successfully by the acoustic in

a vertical thruster was driven at low speed by 3200m depth. Here, it

reports on the noise reduction of a vertical thruster and the result

of acoustic communication test at the maximum operating depth of the