Autonomous unmanned underwater vehicle with buoyancy engine

A method of operating an autonomous unmanned underwater vehicle (“AUV”) in a body of water, comprising:

• operating the AUV in a glider mode, comprising operating a buoyancy engine of the AUV to cause the AUV to move forward in the body of water while alternately descending and ascending in the body of water;
• operating the AUV in rotary propulsion mode, comprising operating a rotary propulsion system of the AUV to cause the AUV to move forward in the body of water;
• detecting a predetermined condition, wherein the predetermined condition comprises at least one condition selected from the group consisting of
• forward speed of the AUV being below a predetermined value,
• depth of the body of water being below a predetermined value, and
• risk of a collision between the AUV and an object exceeding a threshold;
• and
• switching from the glider mode to the rotary propulsion mode in response to the detecting of the predetermined condition, wherein the switching comprises changing from the glider mode to the rotary propulsion mode.

An autonomous unmanned underwater vehicle (“AUV”) for traveling in a body of water, the AUV comprising:

• a body comprising a hull;
• a buoyancy engine carried by the body, wherein the AUV has mass, and the buoyancy engine is for alternately ingesting and expelling the water to change the mass of the AUV and thereby cause the AUV to alternately descend and ascend in the water;
• at least one pitch control surface carried by the body for causing the AUV to move forward while alternately descending and ascending in the water, wherein the at least one pitch control surface comprises a fin that
• projects laterally, outwardly from the hull,
• is pivotable relative to the body of the AUV for adjusting pitch of the AUV, and
• has opposite top and bottom surfaces;
• an actuator operatively connected to the fin for pivoting the fin and thereby adjusting pitch of the AUV;
• a rotary propulsion system carried by the body and including a motor for rotating a rotary agitator in the water to provide thrust, and thereby cause the AUV to move in the water, wherein the rotary agitator includes at least one of a propeller and an impeller;
• and
• a controller operative for responsively, automatically switching between at least
• a glider mode in which the buoyancy engine and the at least one pitch control surface are cooperative for causing the AUV to move forward while alternately descending and ascending, and
• a rotary propulsion mode in which the rotary propulsion system is operative for causing the AUV to move forward,
• wherein the controller is operative for controlling the actuator to pivot the fin between a plurality of positions including
• an inclined configuration in which the top surface of the fin is more forward-facing than the bottom surface of the fin, and
• a declined configuration in which the bottom surface of the fin is more forward-facing than the top surface of the fin.

An autonomous unmanned underwater vehicle (“AUV”) for traveling in a body of water, the AUV comprising:

• a body comprising a hull, wherein the AUV has a center of buoyancy when submerged in water, and the hull defines a centroid that is the center of buoyancy of the AUV when the AUV is submerged in the water;
• a buoyancy engine carried by the body, wherein
• the AUV has mass, and the buoyancy engine is for alternately ingesting and expelling the water to change the mass of the AUV and thereby cause the AUV to alternately descend and ascend in the water, and
• the AUV has a center of mass and the buoyancy engine is operative to move the center of mass of the AUV relative to the center of buoyancy of the AUV;
• at least one pitch control surface carried by the body for causing the AUV to move forward while alternately descending and ascending in the water;
• a rotary propulsion system carried by the body and including a motor for rotating a rotary agitator in the water to provide thrust, and thereby cause the AUV to move in the water, wherein the rotary agitator includes at least one of a propeller and an impeller;
• and
• a controller operative for responsively, automatically switching between at least
• a glider mode in which the buoyancy engine and the at least one pitch control surface are cooperative for causing the AUV to move forward while alternately descending and ascending, and
• a rotary propulsion mode in which the rotary propulsion system is operative for causing the AUV to move forward.

A method of operating an autonomous unmanned underwater vehicle (“AUV”) in a body of water, comprising:

• operating the AUV in a glider mode, comprising operating a buoyancy engine of the AUV to cause the AUV to move forward in the body of water while alternately descending and ascending in the body of water;
• operating the AUV in rotary propulsion mode, comprising operating a rotary propulsion system of the AUV to cause the AUV to move forward in the body of water;
• detecting a predetermined condition, wherein the predetermined condition comprises at least one condition selected from the group consisting of
• any current that flows against the forward movement of the AUV being below a predetermined value,
• a time until arrival at a destination being below a predetermined value, and
• power available for operating the rotary propulsion system being below a predetermined value;
• and
• switching from the rotary propulsion mode to the glider mode in response to the detecting of the predetermined condition, wherein the switching comprises changing from the rotary propulsion mode to the glider mode.