Autonomous Navigation for Low-Altitude UAVs in Urban Areas

Authors: Thomas Castelli, Aidean Sharghi, Don Harper, Alain Tremeau, Mubarak Shah


Safe Autonomous Navigation

In this paper, we present a novel approach towards enabling safe operation of such vehicles in urban areas. Our method uses geodetically accurate dataset images with Geographical Information System (GIS) data of road networks and buildings provided by Google Maps, to compute a weighted A* shortest path from start to end locations of a mission. Weights represent the potential risk of injuries for individuals in all categories of land-use, i.e. flying over buildings is considered safer than above roads. We enable safe UAV operation in regards to 1- land-use by computing a static global path dependent on environmental structures, and 2- avoiding flying over moving objects such as cars and pedestrians by dynamically optimizing the path locally during the flight.

Colors represent costs in the weight map, red, transparent and green respectively represent dangerous, neutral, and safer areas.

As all input sources are first geo-registered, pixels and GPS coordinates are equivalent, it therefore allows us to generate an automated and user-friendly mission with GPS waypoints readable by consumer drones’ autopilots. We simulated 54 missions and show significant improvement in maximizing UAV’s standoff distance to moving objects with a quantified safety parameter over 40 times better than the naive straight line navigation.

 
 

Comparison of the number of detected objects in the FOV as function of UAV-to-objects ground distance between 0 and 10m for all nine paths executed at 5, 8, and 11 m/s. The perfect solution would be 0 objects for all distances. Left: WPAFB. Right: PVLabs.