Time-optimal UAV trajectory planning for 3D urban structure coverage

In this paper, we study the time-optimal trajectory planning of a sensor attached to an unmanned aerial vehicle (UAV) to provide complete 3-dimensional coverage with applications to urban environments with 2.5-dimensional features. The basic approach is to approximate the features of interest with a set of non planar coverage surfaces and to design a motion plan that guarantees the coverage surface is swept completely with a conical-field-of-view sensor. We establish a lower bound on time for a UAV to achieve complete coverage and derive the analytical coverage plan whose duration is a constant times this lower bound. Our hardware-in-the-loop simulation results verify the effectiveness of the proposed algorithm.