Self-righting unmanned vehicle

1. A self-righting unmanned vehicle, comprising:

a cavity, which is an open space located at a first side of a hull of the unmanned vehicle; wherein when the self-righting unmanned vehicle is in an overturned state, the cavity is below a water surface and then water flows into the cavity;

a sealed cavity, located at a second side of the hull of the unmanned vehicle and provided in a head region of the hull; wherein a density of the sealed cavity is lower than a density of water, which provides the self-righting unmanned vehicle with buoyancy at the second side, and makes the self-righting unmanned vehicle in an inclined state of sinking at the first side while rising at the second side when the self-righting unmanned vehicle is in the overturned state; and

a first propeller, provided in a tail intersection region of a normal waterline with an inversion waterline of the unmanned vehicle, and rotating in a reverse direction when the unmanned vehicle is in the overturned state.

2. The self-righting unmanned vehicle according to claim 1 , wherein the first propeller is located at the first side of the hull.

3. The self-righting unmanned vehicle according to claim 2 , further comprising:

a second propeller, located at the second side of the hull; and

a buoyancy accessory, provided at the second side of the hull.

4. The self-righting unmanned vehicle according to claim 3 , wherein the first propeller comprises a first screw propeller and a first channel in cooperation with the first screw propeller.

5. The self-righting unmanned vehicle according to claim 4 , wherein the first propeller further comprises a screw propeller shield, a tail end of the first channel being connected with the screw propeller shield.

6. The self-righting unmanned vehicle according to claim 4 , wherein the first channel and a rotation plane of the first screw propeller form a preset angle.

7. The self-righting unmanned vehicle according to claim 6 , wherein the preset angle ranges from 30 to 60 degrees.

8. The self-righting unmanned vehicle according to claim 4 , further comprising:

a sensing device, detecting whether the unmanned vehicle is in the overturned state; and

a control device, controlling the first screw propeller to perform a reverse rotation when the unmanned vehicle is in the overturned state.

9. The self-righting unmanned vehicle according to claim 8 , wherein the sensing device is further configured to detect whether the second propeller is above the water surface.

10. The self-righting unmanned vehicle according to claim 9 , wherein the control device controls the second propeller to stop rotating when the second propeller is above the water surface.

11. The self-righting unmanned vehicle according to claim 3 , wherein the second propeller stops rotating when the unmanned vehicle is in the overturned state.

12. The self-righting unmanned vehicle according to claim 8 , wherein the control device transmits to an unmanned vehicle controller information about the overturning of the unmanned vehicle detected by the sensing device.

13. The self-righting unmanned vehicle according to claim 12 , wherein the control device receives propeller control instructions transmitted by the unmanned vehicle controller and controls, based on the control instructions, operation of the first and second propellers.

14. A method for controlling an unmanned vehicle, the unmanned vehicle comprising a hull and a first propeller provided in a tail intersection region of a normal waterline with an inversion waterline of the hull of the unmanned vehicle, the hull comprising a cavity which is an open space located at a first side of the hull and a sealed cavity located at a second side of the hull; wherein when the self-righting unmanned vehicle is in an overturned state, the cavity is below a water surface and is filled by water; wherein a density of the sealed cavity is lower than a density of water; and the method comprising: detecting whether the unmanned vehicle is in an overturned state; providing the self-righting unmanned vehicle with buoyancy at the second side, making the self-righting unmanned vehicle in an inclined state of sinking at the first side while rising at the second side and controlling the first propeller to rotate in a forward direction and then rotate in a reverse direction when the unmanned vehicle is in an overturned state, until the unmanned vehicle is turned over.