Abstract: A method comprises determining an occupancy grid of an area for unmanned aerial vehicle (UAV) navigation. The method further comprises determining, based on the occupancy grid, a candidate flyable airspace through which to permit UAV navigation and determining, by a UAV route planner, a plurality of UAV flight paths through the candidate flyable airspace. The method further comprises determining, based on the occupancy grid, a probability value of the plurality of UAV flight paths intersecting an occupied volume. The method additionally comprises determining whether the probability value of the plurality of UAV flight paths intersecting the occupied volume is below a threshold value and, based on determining that the probability value of the plurality of UAV flight paths intersecting the occupied volume is below the threshold value, validating the candidate flyable airspace for the UAV route planner to plan a route for a UAV to navigate through the area.

Abstract: A method includes, during a delivery process of an unmanned aerial vehicle (UAV), receiving, by an image processing system, a depth image captured by a downward-facing stereo camera on the UAV. One or more pixels are within a sample area of the depth image and are associated with corresponding depth values indicative of distances of one or more objects to the downward-facing stereo camera. The method also includes determining, by the image processing system an estimated depth value representative of depth values within the sample area. The method further includes determining that the estimated depth value is below a trigger depth. The method further includes, based at least on determining that the estimated depth value is below the trigger depth, aborting the delivery process of the UAV.

Abstract: A method includes, during a delivery process of an unmanned aerial vehicle (UAV), receiving, by an image processing system, a depth image captured by a downward-facing stereo camera on the UAV. One or more pixels are within a sample area of the depth image and are associated with corresponding depth values indicative of distances of one or more objects to the downward-facing stereo camera. The method also includes determining, by the image processing system an estimated depth value representative of depth values within the sample area. The method further includes determining that the estimated depth value is below a trigger depth.

Abstract: A method includes receiving a digital surface model of an area for unmanned aerial vehicle (UAV) navigation. The digital surface model represents an environmental surface in the area. The method includes determining, for each grid cell of a plurality of grid cells in the area, a confidence value of an altitude of the environmental surface at the grid cell and determining a terrain clearance value based at least on the confidence value of the altitude of the environmental surface at the grid cell. The method includes determining a route for a UAV through the area such that the altitude of the UAV is above the altitude of the environmental surface at each grid cell of a sequence of grid cells of the route by at least the terrain clearance value determined for the grid cell. The method includes causing the UAV to navigate through the area using the determined route.