Parrot

Parrot Drones

Gilles Foinet

Francois Callou

Mathieu Babel

Yoni Benatar

A new method of dynamic control of a rotary-wing drone in throw start includes the steps of: a) initializing a predictive-filter altitude estimator; b) the user throwing the drone in the air with the motors turned off; c) detecting the free fall state; d) upon detecting the free fall state, fast start with turn-on of the motors, open-loop activation of the altitude control means, and closed-loop activation of the attitude control means; e) after a motor response time, stabilizing the drone by closed-loop activation of the altitude control means, and closed-loop activation of the attitude control means; f) detecting a stabilization state such that the total angular speed of the drone is lower than a predetermined threshold; and g) upon detecting the stabilization state, switching to a final state in which the drone is in a stable lift condition and pilotable by the user.

Method of dynamic control of a rotary- wing drone in throw start

The attitude and speed of the drone are controlled by angular commands applied to a control loop () for controlling the engines of the drone according to the pitch and roll axes. A dynamic model of the drone, including, in particular, a Kalman predictive filter, represents the horizontal speed components of the drone on the basis of the drone mass and drag coefficients, the Euler angles of the drone relative to an absolute terrestrial reference, and the rotation of same about a vertical axis. The acceleration of the drone along the three axes and the relative speed of same in relation to the ground are measured and applied to the model as to estimate () the horizontal speed components of the cross wind. This estimation can be used to generate corrective commands () that are combined with the angular commands applied to the control loop of the drone in terms of pitch and roll.

Method for controlling a multi-rotor rotary-wing drone, with cross wind and accelerometer bias estimation and compensation

The user inclines the apparatus () according to the pitch () and roll () axes to produce inclination signals (&#x3b8;, &#x3c6;) which are transformed into corresponding command setpoints (&#x3b8;, &#x3c6;) for the drone () in terms of attitude of the drone according to the pitch () and roll () axes of the drone. The drone and the apparatus each determine the orientation of their local reference frame (XYZ; XYZ) in relation to an absolute reference frame linked to the ground (XYZ), 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.

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Paris, France

Gilles Foinet