Formation Reconfiguration Based on Backstepping-PID Controller for Collaborative Quadrotors

Formation reconfiguration is one of the most significant subjects of the collaborative quadrotors unmanned aerial vehicles (UAVs). In this paper, a backstepping-PID (proportional-integral-derivative) controller is used with a group of multiple collaborative quadrotors to track desired predesigned trajectory. The proposed backstepping-PID controller composed of two-loops of control. First loop is an external-loop for the higher-controller for position control, and the second loop is an internal-loop for the lower-controller for attitude control. The proposed controller uses a backstepping controller as a higher-controller and an PID controller as a lowercontroller. The main contribution in this paper is resolving the formation reconfiguration issue for the collaborative quadrotors in dynamic moving obstacles-loaded environment. Simulation results of collaborative quadrotors show that the proposed backstepping-PID controller enables formation reconfiguration of the collaborative quadrotors to keep a desired formation guaranteeing the obstacle-avoidance operation. The results show the split-rejoin capability of the backstepping-PID controller to retain the original formation configuration of the group. The results of the backstepping-PID controller are compared to a studied earlier backstepping controller in presence and absence of model uncertainty.