METHOD FOR THE INTUITIVE PILOTING OF A DRONE BY MEANS OF A REMOTE CONTROL

• US 20130173088A1
• Filed: 01/03/2013
• Published: 07/04/2013
• Est. Priority Date: 01/04/2012
• Status: Active Grant

• Current Assignee: Parrot Drones
• Original Assignee: Parrot SA
• Inventors: Callou, Francois, Foinet, Gilles
• Granted Patent: US 8,594,862 B2
• Time in Patent Office: Days
• US Class Current: 701/2
• CPC Class Codes: A63H 27/12 Helicopters A63H27/04 takes precedence; Flying tops
• CPC Class Codes: A63H 30/04 using wireless transmission
• CPC Class Codes: B64C 39/024 of the remote controlled vehicle type, i.e. RPV
• CPC Class Codes: B64U 10/14 with four distinct rotor axes, e.g. quadcopters
• CPC Class Codes: G05D 1/0033 by having the operator tracking the vehicle either by direct line of sight or via one or more cameras located remotely from the vehicle

Abstract

The user inclines the apparatus (16) according to the pitch (32) and roll (34) axes to produce inclination signals (θ_I, φ_I) which are transformed into corresponding command setpoints (θ_d, φ_d) for the drone (10) in terms of attitude of the drone according to the pitch (22) and roll (24) axes of the drone. The drone and the apparatus each determine the orientation of their local reference frame (X_lY_lZ_l; X_bY_bZ_b) in relation to an absolute reference frame linked to the ground (X_NEDY_NEDZ_NED), to determine the relative angular orientation of the drone in relation to the apparatus. Then, the reference frame of the apparatus is realigned on the reference frame of the drone by a rotation that is a function of this relative angular orientation. The realigned values thus correspond to user commands referenced in the reference frame of the apparatus and no longer in that of the drone, which allows for more intuitive piloting when the user is watching the drone.

Claims

1. A method for piloting, by means of a remote control apparatus, a rotary wing drone with multiple rotors driven by respective motors that can be controlled in a differentiated manner to pilot the drone attitude-wise and speed-wise, comprising the following steps:

by the apparatus (16);

inclination of the apparatus according to the pitch (32) and roll (34) axes of this apparatus, and production of corresponding inclination signals (θ

_I, φ

_I); and

transformation of these inclination signals of the apparatus into piloting commands and sending of these commands to the drone, and

by the drone (10);

reception of the piloting commands and generation from these commands of setpoint values (θ

_d, φ

_d) for a drone motor control loop, these setpoint values being suitable for controlling the attitude of the drone according to the pitch (22) and roll (24) axes of the drone,

wherein this method comprises the following additional steps;

acquisition of first orientation data (ψ

_iP) of a local reference frame linked to the apparatus (X_lY_lZ_l) in relation to an absolute reference frame linked to the ground (X_NEDY_NEDZ_NED);

acquisition of second orientation data (ψ

_drone) of a local reference frame linked to the drone (X_bY_bZ_b) in relation to said absolute reference frame (X_NEDY_NEDZ_NED);

computation of a relative angular orientation datum (Δ

ψ

) of the drone in relation to the apparatus, from said first and second orientation data; and

realignment of the reference frame of the apparatus on the reference frame of the drone, by application to the piloting commands of a rotation that is a function of said relative angular orientation datum,

so as to thus produce realigned setpoint values according to the pitch and roll axes of the drone which are a function of the inclinations, applied to the apparatus by the user according to the pitch and roll axes thereof, considered in the local reference frame linked to the apparatus and no longer in that linked to the drone.

2. The method of claim 1, in which the first and the second orientation data are obtained from respective heading angles (ψ

_drone, ψ

_iP) of the apparatus and of the drone in relation to the north.

3. The method of claim 2, in which said rotation that is a function of said relative angular orientation datum is of the type:

4. The method of claim 3, in which the computation of said rotation is performed within the drone, directly from data received from the apparatus, these data comprising the values of the inclinations applied to the apparatus and a heading angle datum of the apparatus.

5. The method of claim 2, in which said rotation that is a function of said relative angular orientation datum is of the type:

6. The method of claim 5, in which the computation of said rotation is performed partially within the apparatus and partially within the drone with:

within the apparatus, computation of a first rotation from the values of the inclinations θ

_I and φ

_I applied to the apparatus and of a heading angle datum ψ

_iP of the apparatus;

7. The method of claim 2, in which the absolute reference frame linked to the ground is a geomagnetic reference frame, and the heading angles are the angles measured in relation to the magnetic north.

8. The method of claim 7, in which the determination of the heading angle of the drone comprises the acquisition of a magnetic heading measurement delivered by a magnetometric sensor (116) of the drone.

9. The method of claim 8, in which the heading angle of the drone is acquired by the combination:

of a magnetic heading measurement delivered by a magnetometric sensor (116) of the drone with application of a low-pass filtering (152), and

of a gyroscopic heading measurement delivered by an inertial unit of the drone (102) with application of a high-pass filtering (154) complementing said low-pass filtering.

10. The method of claim 8, also comprising a preliminary step of calibration of the magnetometric sensor of the drone.

11. The method of claim 10, in which said calibration step comprises the substeps of:

ordering a complete rotation of the drone in flight, flat around a yaw axis;

recording of the measurements delivered by the magnetometric sensor;

determination of a global offset value representative of the surrounding disturbing magnetic fields and of the specific offset of the magnetometric sensor.