Reconfiguration Control with Collision Avoidance Framework for Unmanned Aerial Vehicles in Three-Dimensional Space

This work concerns a collision-free fixed-time formation reconfiguration control method for unmanned aerial vehicles (UAVs). The reconfiguration to the new formation in three-dimensional space is specified based on the target final states of each UAV. A reference reconfiguration trajectory is generated from a Bolza optimization solution of simplified dynamics of the vehicle. A sliding controller is then utilized to track the reconfiguration trajectory. Collision avoidance is achieved by modeling the detection region of each UAV as a potential field. Such a field generates control signals that are inversely proportional to the square of the distance between the UAV and a moving or stationary object within its detection region. Altered optimal trajectories are generated online as the UAV avoids collision with another UAV or other obstacles. Simulations confirm that the control scheme developed is able to produce satisfactory results. This paper examines the stability (in the sense of Lyapunov) and performance of the controller under the influence of the avoidance control command. The results of this study provide useful insights to the behavior of the UAV formation under tracking command and a collision avoidance system.