Rotary-wing drone provided with a video camera supplying stabilised image sequences

Abstract

The drone (10) comprises a camera with a hemispherical-field lens of the fisheye type pointing to a fixed direction (Δ) with respect to the drone body. A capture area (36) of reduced size is extracted from the image formed by this lens (42), the position of this area being function of the signals delivered by an inertial unit measuring the Euler angles characterizing the attitude of the drone with respect to an absolute terrestrial reference system. The position of this area is dynamically modified in a direction (44) opposite to that of the changes of attitude (38) of the drone detected by the inertial unit. The raw pixel data are then processed to compensate for the geometric distortions introduced by the fisheye lens in the image acquired in the region of the capture area.

Description

technical field [0001] The present invention relates to rotary-wing unmanned aerial vehicles such as quadrotor helicopters. Background technique [0002] Rotary-wing UAVs such as quadcopters are already in widespread use. Such drones are provided with a plurality of rotors servo-controlled by corresponding motors which can be controlled in different ways to steer the drone in terms of attitude and speed. [0003] A typical example of this type of drone is Parrot AR. Drone 2.0, a quadrotor helicopter equipped with a series of sensors (accelerometer, three-axis gyroscope, altimeter) , a front-facing camera that captures images of the scene the drone is being directed towards, and a vertical view camera that captures images of the ground it is flying over. [0004] Documents WO2010 / 061099A2 and EP2364757A1 (Garrot AG) describe such drones and their use via a phone or multimedia player (e.g. a cellular phone of the iphone type, or a multimedia tablet device of the iPad type) w...

AI Technical Summary

Problems solved by technology

[0023] However, these image stabilization techniques are possible only because the camera in question is a camera with a low resolution CCD sensor (640x480 pixels, or 0.3 megapixels)

On the other hand, they will not apply to the stabilization of useful HD-quality (1920x1080 pixels, or 2 megapixels) images which themselves are windowed on very high-resolution raw fisheye images, e.g. Image formed on a sensor with a resolution of 14 megapixels (4608x3288 pixels)

In these conditions, if the entirety of the original image was passed for processing, this would correspond to a pixel data stream of 14 megapixels per image, resulting in a resolution of 6 images per second (ips) at this resolution. frame rate, which is insufficient for fluid video sequences requiring frame rates close to 30ips

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