Underwater docking system for autonomous underwater vehicle

1. An underwater docking system for an autonomous underwater vehicle,

the underwater docking system comprising:

an underwater station including

a base mount fixed to a seabed and

a circular frame member supported by the base mount and parallel to a horizontal plane; and

an autonomous underwater vehicle configured to dock with the underwater station while sailing through an upper side of the frame member, wherein:

the autonomous underwater vehicle includes

an underwater vehicle main body,

at least one capturing arm provided at a lower portion of the underwater vehicle main body, the at least one capturing arm including one end coupled to the underwater vehicle main body so as to be rotatable in a forward/rearward direction and the other end at which an engaging hook configured to be engaged with the frame member is provided, and

a locking mechanism provided at the lower portion of the underwater vehicle main body and configured to be locked to a front portion of the frame member in a sailing direction of the autonomous underwater vehicle when the engaging hook is engaged with a rear portion of the frame member in the sailing direction, and the underwater vehicle main body has approached the frame member while the capturing arm rotates rearward.

2. The underwater docking system according to claim 1 , wherein the locking mechanism is unlocked from the frame member by an electric signal.

3. The underwater docking system according to claim 1 , wherein:

the underwater station includes a light emitting portion provided on a central axis of the frame member and configured to emit light; and

the autonomous underwater vehicle includes a light detector configured to detect the light emitted from the light emitting portion.

4. The underwater docking system according to claim 3 , wherein:

the light detector has a function of taking an image of the light emitted from the light emitting portion; and

the autonomous underwater vehicle includes a propulsion device and a control device configured to control the propulsion device based on data of the image taken by the light detector.

5. The underwater docking system according to claim 4 , wherein:

a transponder configured to transmit an acoustic signal is provided at the underwater station;

an acoustic positioning device configured to measure a position of the autonomous underwater vehicle relative to the transponder based on the acoustic signal from the transponder is provided at the autonomous underwater vehicle;

when a distance from the underwater station to the autonomous underwater vehicle is longer than a predetermined distance, the control device controls the propulsion device based on data of the position acquired by the acoustic positioning device; and

when the distance from the underwater station to the autonomous underwater vehicle is not more than the predetermined distance, the control device controls the propulsion device based on data of the image acquired by the light detector.

6. The underwater docking system according to claim 1 , wherein:

a noncontact electricity supplying portion is provided at a middle of the frame member; and

a noncontact electricity receiving portion configured to receive electricity from the noncontact electricity supplying portion is provided at a lower portion of the underwater vehicle main body.

7. The underwater docking system according to claim 1 , wherein the at least one capturing arm comprises two capturing arms provided so as to be spaced apart from each other in a leftward/rightward direction.