Strategies of Path-Planning for a UAV to Track a Ground Vehicle

In this paper, we present a strategy of path-planning for an unmanned aerial vehicle (UAV) to follow a ground vehicle. The ground vehicle may change its heading and vary its speed from a standstill up to the velocity of the UAV, while the UAV will maintain a fixed airspeed and will maneuver itself to track the ground vehicle. The algorithm also allows the UAV to track the ground vehicle with an offset vector (i.e. the user may wish the UAV to stay ahead of the ground vehicle or to its sides). Since the ground vehicle may operate in a range of velocities, the algorithm must plan the UAV's path with the appropriate schemes for the various ground vehicle speeds. The natural effect of wind injects a disturbance into the system, and so wind compensation techniques had to be developed. In order to maintain the focus of this project on path-planning strategies, the path-planning algorithm was implemented on top of a system that already controls the dynamics of the UAV. Simulation of aircraft and ground vehicles was performed with a hardware-in-the-loop simulation environment to test for mission feasibility. After attaining satisfactory simulation results, an experiment was conducted to confirm the path-planning strategy.