Coaxial tilt-rotor unmanned aerial vehicle and control method thereof

Patent metadata

Field	Value
Publication number	US-11993370-B2
Application number	US-202017414715-A
Country	US
Kind code	B2
Filing date	May 13, 2020
Priority date	May 13, 2020
Publication date	May 28, 2024
Grant date	May 28, 2024

Abstract

A coaxial tilt-rotor unmanned aerial vehicle (CTRUAV) and a control method thereof. The CTRUAV includes three rotor modules, five rotors with motors and a control system. The three rotor modules are in an inverted triangle layout. The left and right coaxial tiltable rotor modules in the front of the CTRUAV can rotate around the plane of a fuselage. A rear rotor is installed on the rear fixed-axis rotor module. Two pairs of coaxial rotors are respectively installed on the left and right coaxial tiltable rotor modules. The left and right coaxial tiltable rotor modules include an upper rotor and a lower rotor respectively; the upper rotor and the lower rotor have opposite rotation directions and the same rotation speed during the flight. In the two pairs of coaxial rotors, the rotors on the same layers have opposite rotation directions, and the rotors on different layers have the same rotation directions.

First claim

The invention claimed is:

1. A coaxial tilt-rotor unmanned aerial vehicle (CTRUAV), comprising:
three rotor modules positioned in an inverted triangle layout, the three to rotor modules comprising:
a left coaxial tiltable rotor module;
right coaxial tiltable rotor module located at a front of the CTRUAV; and
a fixed-axis rear rotor module located at a rear of the CTRUAV;

five rotors with motors, comprising:
a rear rotor installed on the rear fixed-axis rotor module and driven by a motor installed on the rear fixed-axis rotor module; and
two pairs of coaxial rotors respectively installed on the left coaxial tiltable rotor module and the right coaxial tiltable rotor module, each pair of coaxial rotors being driven by a pair of coaxial motors; and

a control system installed on the CTRUAV and used to receive position and attitude information of the CTRUAV, perform control operation, and drive the three rotor modules to control the motion of the CTRUAV,
wherein the left coaxial tiltable rotor module and the right coaxial tiltable rotor module are configured to rotate around a plane of a fuselage;
wherein the two motors of a pair of coaxial motors have a same rotation speed and opposite rotation directions,
wherein in the two pairs of coaxial rotors, rotors on same layers have opposite rotation directions, and rotors on different layers have the same rotation directions,
wherein the CTRUAV can roll around an X-axis, pitch around a Y-axis and yaw around a Z-axis, wherein, taking a positive direction of the X-axis as a forward direction; taking the positive direction of the Z-axis as a takeoff direction, and taking the positive direction of the Y-axis as a direction perpendicular to the positive direction of the X-axis,
wherein the CTRUAV has three modes comprising:
a vertical takeoff and landing (VTOL) mode;
a fixed-wing mode; and
a transition mode,

wherein the VTOL mode and the fixed-wing mode are switched through the transition mode,
wherein, when the CTRUAV is in the VTOL mode, the CTRUAV places the three rotor modules perpendicular to the plane of the fuselage, and uses the five rotors to provide lift forces to take off or land quickly, and
wherein, when the CTRUAV is in the fixed-wing mode, the CTRUAV tilts the left and right coaxial tiltable rotor modules parallel to the plane of the fuselage to provide horizontal forward thrust forces, and places the rear fixed-axis rotor module perpendicular to the plane of the fuselage to provide the lift force to ensure the smooth forward flight.

2. A control method of the coaxial tilt-rotor unmanned aerial vehicle (CTRUAV) of claim 1 , comprising steps of:
step 1: according to target and current positing and attitude, obtaining error between the target and current value, and then getting a set of forces and torques vectors [F x F z τ Φ τ θ τ ψ ] T after operation by the control system; wherein F x is a resultant force of three rotor modules in the x direction; F z is a resultant force of three rotor modules in the z direction; τ Φ is a resultant torque of three rotor modules around the x direction; τ θ is a resultant torque of three rotor modules around the y direction; and τ ψ a resultant torque of three rotor modules around the z direction;
step 2: calculating a set of forces [F 5z F 2z F 2x F 1z F 1x ] T which are produced by the left, right and rear rotor modules respectively through the equations (1);

[

F
x

F
z

τ
ϕ

τ
θ

τ
ψ

]

=

[

0

0

1

0

1

1

1

0

1

0

0

-

L
1

0

-

L
1

0

L
3

L
2

0

-

L
2

0

Assignees

• Univ Dalian Tech

Inventors

• Wu Yuhu
• Lv Zongyang
• Sun Ximing
• Shen Xiangyu
• Wang Rui

Classifications

• B64C29/0033 Primary

  the propellers being tiltable relative to the fuselage · CPC title

• B64U10/25 Primary

  Fixed-wing aircraft (VTOL aircraft B64U10/20) · CPC title

• B64U30/297

  Tilting rotors · CPC title

• B64U30/24

  Coaxial rotors · CPC title

• B64C11/48

  Units of two or more coaxial propellers · CPC title