Underwater vehicle and method of positioning same

A method of determining a position of an underwater vehicle movable on a vertical wall of a vessel, the vessel being filled with a water, comprising the steps of:

• A) determining a reference point in the vessel;
• B) providing a first depth sounding meter on the reference point and providing a second depth sounding meter, a beam projector and a reflection light sensor on the vehicle respectively:
• C) determining a depth of the reference point using the first depth sounding meter and that of the vehicle using the second depth sounding meter;
• D) calculating a difference between the depth of the reference point and that of the vehicle;
• E) determining a vertical position of the vehicle relative to the vessel based on the depth difference obtained in step D);
• F) projecting a beam of light from the beam projector to a structure built in the vessel;
• G) detecting an amount of beam of light reflected by the structure using the reflection light sensor;
• H) determining a position and a shape of the structure;
• I) determining a horizontal position of the vehicle using the amount of the reflected light detected in step G) and the position and shape of the structure obtained in step H);
• and
• J) determining the position of the vehicle from the vertical and horizontal positions obtained in steps E) and I).

A method of determining a position of an underwater vehicle movable on a vertical wall of a vessel, the vessel being filled with a water and having various kinds of structures on its outer surface, comprising the steps of:

• A) determining sizes, shapes and locations of the structures on the outer surface of the vessel;
• B) providing an ultrasonic wave device on the vehicle for radiating an ultrasonic wave to the wall and receiving a returning wave;
• C) causing the ultrasonic wave device to radiate the ultrasonic wave to the wall and to receive the returning wave while moving the vehicle on the wall;
• D) analyzing the returning wave continuously to determine variations of the returning wave;
• E) determining the kinds of the structures based on the variations of the returning wave;
• F) determining the position of the vehicle relative to the structures based on the determined kinds of the structure acquired in step E) and the determined and sizes, shapes and locations of the structures acquired in step A);
• and
• G) determining the position of the vehicle relative to the vessel from the position of the vehicle relative to the structures obtained in step F) and the determined and sizes, shapes and locations of the structures obtained in step A).