Drone having multi-degree-of-freedom flight mode

1 . A drone with a multiple DOF flight mode, comprising:

a fuselage in which a battery is mounted and a forward direction is set in an x-axis;

a first rotor and a second rotor each having its rotational axis aligned in a z-axis direction, and disposed to face each other about the fuselage at a first position when viewed in an x-axis direction;

a third rotor and a fourth rotor each having its rotational axis aligned in the z-axis direction and disposed to face each other in a y-axis direction at a second position of the fuselage when viewed in the x-axis direction;

a first frame shaft rotatably supported with respect to the fuselage about a y1-axis parallel to the y-axis at the first position and supporting the first rotor and the second rotor by respective support shafts parallel to the x-axis at both end portions;

a second frame shaft rotatably supported with respect to the fuselage about a y2-axis parallel to the y-axis at the second position and supporting the third rotor and the fourth rotor by respective support shafts parallel to the x-axis at both end portions;

a third frame shaft disposed to be spaced apart from the first frame shaft in the z-axis direction by a plurality of first rod parts and formed to tilt the first rotor and the second rotor about each axis parallel to the x-axis while being moved by a force acting in parallel to the y-axis;

a fourth frame shaft disposed to be spaced apart from the second frame shaft in the z-axis direction by a plurality of second rod parts and formed to tilt the third rotor and the fourth rotor about each axis parallel to the x-axis while being moved by a force acting in parallel to the y-axis;

a first drive motor unit connected through a first conversion mechanism unit and providing a force to the third frame shaft and the fourth frame shaft in a direction parallel to the y-axis;

a second drive motor unit connected through a second conversion mechanism unit and providing a force to rotate the first frame shaft and the second frame shaft about the y1-axis and the y2-axis, respectively; and

a control unit configured to implement a plurality of flight modes by controlling the first rotor, the second rotor, the third rotor, the fourth rotor, the first drive motor unit, and the second drive motor unit,

wherein the plurality of flight modes include:

a first flight mode in which both the first drive motor unit and the second drive motor unit are stopped by inhibiting drive signals to the first drive motor unit and the second drive motor unit such that tilting angles of the first to fourth rotors are maintained and the speeds of the first to fourth rotors are individually controlled; and

a second flight mode in which the first drive motor unit and the second drive motor unit are individually controlled and operated to change tilting angles of the first to fourth rotors, and the speeds of the first to fourth rotors are individually controlled,

wherein the first flight mode includes:

a 1-1th flight mode in which the fuselage is tilted in the x-axis direction or the fuselage moves in the y-axis direction;

a 1-2th flight mode in which the fuselage is tilted in the y-axis direction or the fuselage moves in the x-axis direction;

a 1-3th flight mode in which the fuselage rotates about the z-axis; and

a 1-4th flight mode in which the fuselage moves in the z-axis direction, and wherein the second flight mode includes:

a 2-1th flight mode in which the fuselage moves in the y-axis direction by maintaining the fuselage horizontally and tilting the first to fourth rotors about each axis parallel to the x-axis;

a 2-2th flight mode in which the fuselage moves in the y-axis direction by maintaining the fuselage horizontally and tilting the first to fourth rotors about each axis parallel to the y-axis;

a 2-3th flight mode in which the fuselage rotates about the z-axis by maintaining the fuselage horizontally and individually controlling the speeds of the first to fourth rotors;

a 2-4th flight mode in which the fuselage rotates in the z-axis direction by maintaining the fuselage horizontally and individually controlling the speeds of the first to fourth rotors;

a 2-5th flight mode in which the fuselage rotates about the x-axis by rotating the first to fourth rotors about each axis parallel to the x-axis; and

a 2-6th flight mode in which the fuselage rotates about the y-axis by rotating the first to fourth rotors about each axis parallel to the y-axis, wherein the control unit is further configured to:

detect an angular difference between (i) a heading angle of the fuselage and (ii) a track angle of the drone in a trajectory, the track angle being determined from a velocity vector having a magnitude corresponding to a traveling speed of the drone in the trajectory;

compare the detected angular difference to a predetermined angular threshold value; and

control the tilting angles of the rotors to reduce the angular difference so that the heading angle is adjusted only when the detected angular difference is greater than or equal to the angular threshold value.

2 . The drone of claim 1 , wherein the first conversion mechanism unit includes a first transmission rod configured to simultaneously transmit a driving force of the first drive motor unit to the third frame shaft and the fourth frame shaft.

3 . The drone of claim 1 , wherein the second conversion mechanism unit includes a second transmission rod configured to simultaneously transmit a driving force of the second drive motor unit to the first frame shaft and the second frame shaft.

4 . The drone of claim 1 , wherein the 2-5th flight mode includes a posture in which each rotational axis of the first to fourth rotors is parallel to the z-axis, and the fuselage rotates about the x-axis to maintain a tilted state with respect to the ground.

5 . The drone of claim 1 , wherein the 2-6th flight mode includes a posture in which each rotational axis of the first to fourth rotors is parallel to the z-axis, and the fuselage rotates about the y-axis to maintain a tilted state with respect to the ground.

6 . A drone with a multiple DOF flight mode, comprising:

a fuselage in which a battery is mounted and a forward direction is set in an x-axis;

a plurality of rotors disposed about the fuselage in four or more, each rotational axis of which is aligned in a z-axis direction;

an x-axis tilting mechanism unit formed to tilt the plurality of rotors about an axis parallel to the x-axis;

a y-axis tilting mechanism unit formed to tilt the plurality of rotors about an axis parallel to the y-axis;

a first drive motor unit driving the y-axis tilting mechanism unit;

a second drive motor unit driving the x-axis tilting mechanism unit; and

a control unit configured to implement a plurality of flight modes by controlling the first rotor, the second rotor, the third rotor, the fourth rotor, the first drive motor unit, and the second drive motor unit,

wherein the plurality of flight modes include:

a first flight mode in which both the first drive motor unit and the second drive motor unit are stopped by inhibiting drive signals to the first drive motor unit and the second drive motor unit such that tilting angles of the first to fourth rotors are maintained and the speeds of the first to fourth rotors are individually controlled; and

a second flight mode in which the first drive motor unit and the second drive motor unit are individually controlled and operated to change tilting angles of the first to fourth rotors, and the speeds of the first to fourth rotors are individually controlled,

wherein the first flight mode includes:

a 1-1th flight mode in which the fuselage is tilted in the x-axis direction or the fuselage moves in the y-axis direction;

a 1-2th flight mode in which the fuselage is tilted in the y-axis direction or the fuselage moves in the x-axis direction;

a 1-3th flight mode in which the fuselage rotates about the z-axis; and

a 1-4th flight mode in which the fuselage moves in the z-axis direction, and wherein the second flight mode includes:

a 2-1th flight mode in which the fuselage moves in the y-axis direction by maintaining the fuselage horizontally and tilting the first to fourth rotors about each axis parallel to the x-axis;

a 2-2th flight mode in which the fuselage moves in the y-axis direction by maintaining the fuselage horizontally and tilting the first to fourth rotors about each axis parallel to the y-axis;

a 2-3th flight mode in which the fuselage rotates about the z-axis by maintaining the fuselage horizontally and individually controlling the speeds of the first to fourth rotors;

a 2-4th flight mode in which the fuselage rotates in the z-axis direction by maintaining the fuselage horizontally and individually controlling the speeds of the first to fourth rotors;

a 2-5th flight mode in which the fuselage rotates about the x-axis by rotating the first to fourth rotors about each axis parallel to the x-axis; and

a 2-6th flight mode in which the fuselage rotates about the y-axis by rotating the first to fourth rotors about each axis parallel to the y-axis,

wherein the control unit is further configured to:

detect an angular difference between (i) a heading angle of the fuselage and (ii) a track angle of the drone in a trajectory, the track angle being determined from a velocity vector having a magnitude corresponding to a traveling speed of the drone in the trajectory;

compare the detected angular difference to a predetermined angular threshold value; and

control the tilting angles of the rotors to reduce the angular difference so that the heading angle is adjusted only when the detected angular difference is greater than or equal to the angular threshold value.

7 . The drone of claim 6 , wherein the 2-5th flight mode includes a posture in which each rotational axis of the first to fourth rotors is parallel to the z-axis, and the fuselage rotates about the x-axis to maintain a tilted state with respect to the ground.

8 . The drone of claim 6 , wherein the 2-6th flight mode includes a posture in which each rotational axis of the first to fourth rotors is parallel to the z-axis, and the fuselage rotates about the y-axis to maintain a tilted state with respect to the ground.