Multi‐UAV‐based stereo vision system without GPS for ground obstacle mapping to assist path planning of UGV

A multi‐unmanned aerial vehicle (UAV)‐based stereo vision system is proposed to assist global path planning of an unmanned ground vehicle (UGV) even in GPS‐denied environments. The proposed system can optimally generate the depth map of ground objects and robustly detect obstacles. The proposed multi‐UAV‐based system with a movable baseline overcomes the limitations of a single‐UAV‐based stereo vision system with a fixed baseline. Thus, the performance of the proposed system does not degrade significantly based on the altitude of UAVs. The relative position and altitude estimation, multi‐agent formation control and image processing techniques are considered to implement a prototype system. The experimental results demonstrate the performance of the implemented system for various baseline conditions between UAVs.