# US 10,871,785 B2 · Method and system for controlling attitude of rotor unmanned aerial vehicle

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- Number: US 10,871,785 B2
- Document ID: US10871785B2
- Status: Granted
- Kind: B2
- Application number: 16/104,893
- Filed: 2018-08-18
- Published: 2019-01-03
- Granted: 2020-12-22
- Earliest claimed: 2017-08-18
- Assignees: Haoxiang Electric Energy (Kunshan) Co., Ltd.
- Applicants: Haoxiang Electric Energy (Kunshan) Co., Ltd.
- Inventors: Yu Tian; Wenyan Jiang
- Web page: https://patentgrep.com/patent/US10871785B2

## CPC

- G05D 1/0816: {to ensure stability}
- G05D 1/0669: {specially adapted for vertical take-off}
- B64U 30/20: Rotors; Rotor supports
- B64U 2201/10: autonomous, i.e. by navigating independently from ground or air stations, e.g. by using inertial navigation systems [INS]
- B64U 2201/20: Remote controls
- G08G 5/55: for a single aircraft
- G08G 5/57: for unmanned aircraft
- G05D: SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- B64U: UNMANNED AERIAL VEHICLES [UAV]; EQUIPMENT THEREFOR
- G08G: TRAFFIC CONTROL SYSTEMS (guiding railway traffic, ensuring the safety of railway traffic B61L; arrangement of road signs or traffic signals E01F9/00; radar or analogous systems, sonar systems, lidar systems specially adapted for traffic control G01S13/91, G01S15/88, G01S17/88; {radar or analogous systems, sonar systems, lidar systems specially adapted for anti-collision purposes G01S13/93, G01S15/93, G01S17/93})

## Abstract

A method for controlling an attitude of a rotor UAV (unmanned aerial vehicle) includes judging whether the rotor UAV is in a first attitude on a support base; and starting a first thrust generating device which is offset from a first side of a center of gravity of the rotor UAV, the first thrust generating device generating a thrust that faces away from the support base while working, the first side moving away from the support base, flipping the rotor UAV and switching the rotor UAV from the first attitude to a second attitude. Also, a system for controlling the attitude of the rotor UAV is provided. According to the method and the system, the rotor UAV can be switched between different attitudes without artificially assisting in adjusting a current attitude of the rotor UAV, so that the convenience in use and the satisfaction of experience are improved.

## Claims

### Claim 1

A method for controlling an attitude of a rotor unmanned aerial vehicle (UAV), the method comprising steps of:
judging whether the rotor UAV is in a first attitude on a support base;
starting a first thrust generating device which is offset from a first side of a center of gravity of the rotor UAV, and the first thrust generating device generating a thrust that faces away from the support base while working for moving the first side away from the support base to flip the rotor UAV, so that the rotor UAV is switched from the first attitude to a second attitude;
obtaining an inclined direction and an inclined angle of the rotor UAV relatively to the support base when the rotor UAV is in the first attitude;
obtaining a continuous first predetermined duration of the rotor UAV in the first attitude, judging and excluding instantaneous inclination of the rotor UAV, and determining that the rotor UAV is in the first attitude; and
before starting the first thrust generating device, starting a second thrust generating device which is offset from a second side of the center of gravity of the rotor UAV; or simultaneously starting both the first thrust generating device and the second thrust generating device, wherein:
the first thrust generating device is opposite to the second thrust generating device; the second thrust generating device generates a thrust facing towards ground; a flip torque from the thrust generated by the second thrust generating device which applies to the rotor UAV is smaller than a flip torque from the thrust generated by the first thrust generating device which applies to the rotor UAV the first side is opposite to the second side based on the center of gravity of the rotor UAV;
when the rotor UAV switches to the second attitude, at least one of the first thrust generating device and the second thrust generating device is stopped;
an X-axis and a Y-axis, acting as virtual reference axes, are provided and perpendicular to each other, the inclined direction comprises a first direction inclining relatively to the X-axis and a second direction inclining relatively to the Y-axis, the inclined angle comprises an angle between the Y-axis and the support base and an angle between the X-axis and the support base.

### Claim 2 (depends on 1)

The method, as recited in claim 1, wherein: a Z-axis is provided and is perpendicular to both the X-axis and the Y-axis; the method further comprises collecting an accelerating speed in the Z-axis and determining a current state of the rotor UAV.

### Claim 3 (depends on 2)

The method, as recited in claim 2, wherein: when the accelerating speed is in a range of −g m/s2 to 0 m/s2, the rotor UAV is in an overturned attitude; when the accelerating speed is g m/s2, the rotor UAV is in a right-side up attitude; the first attitude is the overturned attitude, and the second attitude is the right-side up attitude, here, g is acceleration of gravity.

### Claim 4

A system for controlling an attitude of a rotor unmanned aerial vehicle (UAV), the system comprising:
an attitude processor for judging whether the rotor UAV is in a first attitude on a support base;
a controller for starting a first thrust generating device which is offset from a first side of a center of gravity of the rotor UAV, wherein: the first thrust generating device generates a thrust that faces away from the support base while working, so as to move the first side away from the support base for flipping the rotor UAV to switch the rotor UAV from the first attitude to a second attitude;
a location processor for obtaining an inclined direction and an inclined angle of the rotor UAV relatively to the support base when the rotor UAV is in the first attitude; and
a timer for obtaining a predetermined duration of the rotor UAV in the first attitude, wherein:
according to the predetermined duration of the rotor UAV in the first attitude, the attitude processor determines and excludes instantaneous inclination of the rotor UAV for determining that the rotor UAV is in the first attitude;
the controller is also adapted for before starting the first thrust generating device, starting the second thrust generating device which is offset from a second side of the center of gravity of the rotor UAV or simultaneously starting both the first thrust generating and the second thrust generating device;
the first thrust generating device is opposite to the second thrust generating device, the second thrust generating device generates a thrust facing towards ground, a flip torque from the thrust generated by the second thrust generating device which applies to the rotor UAV is smaller than a flip torque from the thrust generated by the first thrust generating device which applies to the rotor UAV, the first side is opposite to the second side based on the center of gravity of the rotor UAV;
when the rotor UAV switches to the second attitude, the controller is also adapted for controlling at least one of the first thrust generating device and the second thrust generating device to stop working;
an X-axis and a Y-axis, acting as virtual reference axes, are provided and perpendicular to each other, the inclined direction comprises a first direction inclining relatively to the X-axis and a second direction inclining relatively to the Y-axis, the inclined angle comprises an angle between the Y-axis and the support base and an angle between the X-axis and the support base.

### Claim 5 (depends on 4)

The system, as recited in claim 4, further comprising: an acceleration processor, a Z-axis is provided and is perpendicular to both the X-axis and the Y-axis, the acceleration processor is adapted for collecting an accelerating speed in the Z-axis to judge a current state of the rotor UAV.

### Claim 6 (depends on 5)

The system, as recited in claim 5, wherein: when the accelerating speed is in a range of −g m/s2 to 0 m/s2, the rotor UAV is in an overturned attitude; when the accelerating speed is g m/s2, the rotor UAV is in a right-side up attitude; the first attitude is the overturned attitude, and the second attitude is the right side up attitude, here, g is acceleration of gravity.

### Claim 7 (depends on 6)

The system, as recited in claim 6, further comprising: a timer for obtaining a predetermined duration of the rotor UAV in the second attitude, wherein: according to the predetermined duration of the rotor UAV in the second attitude, the attitude processor determines that the rotor UAV is in the second attitude.