Patent ID: 9641810
Date: 2017-05-02
CPC Classifications: B64D,G05D,H04N

Claim:
1. A method for acquiring images of a photographic target from arbitrary perspectives with an unmanned aerial vehicle (UAV) equipped with at least one image acquisition device having a fixed acquisition direction with respect to the vehicle, said UAV having an automatic navigation system that allows the UAV to reach an arbitrary location and automatic attitude control system that allows the UAV to transiently reach an arbitrary orientation in space, said photographic target being outside a current field of view of the acquisition device while the UAV flies along a predefined flying path, the method comprising the steps of: computing a target UAV position and an orientation in space required to acquire a desired slanted image from a set of parameters pertaining to the desired photographic target, a desired perspective and a relative orientation of the image acquisition device with respect to the UAV; determining an anticipatory location at a target UAV altitude and spaced apart from the target UAV position at a distance determined by one or more flight dynamics of the UAV, the anticipatory location being on a line between the target UAV position and the photographic target; and navigating, using the automatic navigation system, to said anticipatory location before navigating to the target UAV position; navigating, after reaching the anticipatory location, using the automatic navigation system, to said target UAV position; modifying an attitude, which comprises modifying at least one of a pitch or roll of the UAV in order to modify the acquisition direction to point toward the photographic target, thereby deviating from the predefined flying path into a transient phase of flight; acquiring images during the transient phase of flight when the acquisition direction points toward the photographic target with the desired perspective; and starting a recovery phase by controlling the UAV back to the predefined flying path.