Detection of close encounters with obstacles by aerial vehicles

At least one non-transitory machine-readable storage medium storing instructions that, when executed by a processing system of an unmanned aerial vehicle (UAV) will cause the UAV to perform operations comprising:

• acquiring a video stream of a ground area below the UAV with a camera system;
• monitoring a flight motion of the UAV using an onboard motion sensor while acquiring the video stream;
• determining flow velocities of first image pixels from the video stream by comparing pixel motions of the first image pixels between consecutive image frames in the video stream with an optical flow processing pipeline;
• calculating optical flow depth estimates for the first image pixels based on both the flow velocities and the flight motion of the UAV;
• and
• asserting an encounter flag indicting that a close encounter between the UAV and an obstacle rising from the ground area occurred based at least on the optical flow depth estimates.

At least one non-transitory machine-readable storage medium storing instructions that, when executed by a processing system of an unmanned aerial vehicle (UAV), will cause the UAV to perform operations comprising:

• acquiring a video stream of a ground area below the UAV with a stereovision camera system disposed onboard the UAV;
• generating a depth perception map indicating stereovision depth estimates of first image pixels from the video stream with a stereovision processing pipeline;
• generating an optical flow map indicating optical flow depth estimates of second image pixels from the video stream with an optical flow processing pipeline;
• comparing the depth perception and optical flow maps;
• and
• asserting an encounter flag indicting that a close encounter between the UAV and an obstacle occurred based at least on the comparing.