Cooperative Target Tracking using a Fleet of UAVs with Collision and Obstacle Avoidance

In this paper, our earlier results on cooperative target tracking using a fleet of unmanned aerial vehicles (UAVs) is enhanced with both collision and obstacle avoidance capability. The existing control input that has two decoupled control efforts with one handling the tracking and the other dedicated for formation is now further augmented with a repulsion term that resolves collision with other team members and obstacles nearby. Assuming that each UAV takes the same and constant velocity. This newly-added control component adjusts the UAV’s heading angle to the opposite direction in relation to the UAV’s closet neighbors and obstacles where collision may occur. This repulsion term can also be expressed as a function of relative bearing angles alone, making it possible to be estimated/measured by onboard vision sensors in the presence of communication loss. Regarding communication topologies, an all-to-all communication, a ring topology, and a cyclic pursuit topology are studied. The effectiveness of the proposed collision/obstacle avoidance scheme is demonstrated by numerical simulation examples.