Air, sea and underwater tilt tri-rotor UAV capable of performing vertical take-off and landing

An air, sea and underwater tilt tri-rotor unmanned air vehicle (UAV) capable of performing vertical take-off and landing, the air, sea and underwater tilt tri-rotor UAV comprising:

• a fuselage;
• a main wing;
• a front airbag;
• a right rear airbag;
• a left rear airbag;
• an air cylinder;
• an airbag controller;
• two ailerons;
• two vertical tails;
• two front tilt axes;
• two front tilt seats;
• two front motor rotors;
• a rear tilt axis;
• a rear tilt seat;
• a rear motor rotor;
• a propeller;
• and
• two tail vanes,
• wherein the right rear airbag, the left rear airbag, the front airbag, the air cylinder, and the airbag controller are all fixed to the fuselage and a lower surface of the main wing,
• wherein the right rear airbag, the left rear airbag and the front airbag are arranged in an isosceles triangle, and a center of gravity of the air, sea and underwater tilt tri-rotor UAV is located on a line of symmetry of the isosceles triangle;
• and the right rear airbag, the left rear airbag and the front airbag are respectively connected to the air cylinder, and are controlled by the airbag controller,
• wherein the main wing is symmetrical with respect to a longitudinal axis of the UAV and is integrated with the fuselage;
• the two ailerons are of rectangular structure and are connected along a trailing edge of the main wing at each side of the longitudinal axis;
• the two vertical tails are symmetrically and perpendicularly fixed to an upper surface of the main wing on each side of the longitudinal axis and located between the two ailerons,
• wherein the front motor rotors are fixed to the front tilt seats, the front tilt seats are connected to a front part of the fuselage by the front tilt axes, and are symmetrical with respect to the longitudinal axis,
• wherein the rear motor rotor is fixed to the rear tilt seat, the rear tilt seat is connected to a rear part of the fuselage by the rear tilt axis, rotational speeds of the two front motor rotors and the rear motor rotor are independently controlled, to achieve vertical take-off and landing mode and a fixed wing mode,
• wherein the propeller and the two tail vanes are connected to a lower part of the rear part of the fuselage, the two tail vanes are symmetrical with respect to the longitudinal axis, and the propeller is located on the longitudinal axis;
• and the two tail vanes are rotatable to change a sailing direction, and a rotational speed of the propeller is controlled to change a sailing speed in water, and
• wherein the air, sea and underwater tilt tri-rotor UAV includes four operation modes in total:
• (1) vertical take-off and landing mode:
• in a vertical take-off and landing mode, when the two front motor rotors and the rear motor rotor of the UAV are vertically upward, an attitude control of the UAV by simultaneously controlling a pushing force magnitude and direction of the two front motor rotors and the rear motor rotor;
• when the two front motor rotors and the rear motor rotor of the UAV are vertically upward, change in a pitch angle by adjusting the difference between pulling forces of the front motor rotors and the rear motor rotor;
• and the UAV is made to pitch by simultaneously reducing the rotational speeds of the front motor rotors or increasing the rotational speed of the rear motor rotor;
• when the two front motor rotors and the rear motor rotor of the UAV are vertically upward, control of a roll angle by adjusting difference between pulling forces of the two front motor rotors of the UAV;
• and the UAV is made to roll by increasing the rotational speed of the front right motor rotor or reducing the rotational speed of the front left motor rotor;
• and
• when the two front motor rotors and the rear motor rotor of the UAV are vertically upward, control of a yaw angle by adjusting the tilt angle of the rear tilt seat;
• and the UAV is made to yaw by tilting the rear motor rotor;
• (2) fixed wing flight mode:
• with increasing of a horizontal speed of the UAV, when the two front motor rotors tilt to a horizontal position and the rear motor rotor stops operating, the UAV is controlled by the ailerons and the vertical tails;
• and by controlling pushing force magnitude of the two front motor rotors and a control surface angle of the ailerons;
• (3) water surface sailing mode:
• the two front motor rotors and the rear motor rotor of the UAV stop operating, the air cylinder fills the right rear airbag, the left rear airbag and the front airbag with air though the airbag controller so that the UAV floats on the water surface, the tail vanes rotate leftwards and rightwards to control heading of the UAV, and the propeller controls advancing or withdrawing speed of the UAV;
• and
• (4) underwater sailing mode:
• the two front motor rotors and the rear motor rotor of the UAV stop operating, and the air cylinder fills an amount of air into the right rear airbag, the left rear airbag and the front airbag through the airbag controller to provide an underwater depth of the UAV;
• an underwater pitch angle of the UAV is controlled by controlling difference between air storage capacities of the right rear airbag and the left rear airbag, and the front airbag by the airbag controller;
• and the UAV is made to pitch by increasing the air storage capacity of the right rear airbag and the air storage capacity of the left rear airbag or by reducing the air storage capacity of the front airbag;
• and
• the underwater roll angle of the UAV is controlled by controlling a difference between air storage capacities of the right rear airbag and the left rear airbag by the airbag controller;
• the UAV is made to roll by increasing the air storage capacity of the right rear airbag or reducing the air storage capacity of the left rear airbag;
• and the tail vanes rotate leftwards and rightwards to control the heading of the UAV, and the propeller controls the advancing or withdrawing speed of the UAV.