Incremental coverage path planning method for UAV ground mapping in unknown area

Coverage in unknown environment is a commonly concerned problem in ground mapping field of Unmanned Aerial Vehicle (UAV). Based on the concept of incremental cell construction, a practical online coverage path planning method is proposed for mapping in unknown environments with obstacles and boundaries. This method consists of the Boustrophedon motion and D* algorithm. Based on the information from onboard ranging sensor, the UAV uses Boustrophedon motion to incrementally construct coverage cells while exploring the environment. When there are no alternative cells for Boustrophedon motion, the D* algorithm is utilized to plan the backtracking path to the next starting point. Particularly, the backtracking path replanning will be carried out if an unknown obstacle suddenly appears on the path. The static and hardware-in-loop dynamic simulation results show that the proposed method can achieve near-complete coverage in complex unknown environments with low computational and sensor accuracy requirements.