Cyclic Leader-Follower Quadrotor Formation Control with Squared Fiducial Marker Guides

The study investigates the swarm capabilities of quadrotors, focusing on the cyclic leader-follower (LF) method. Unlike conventional LF, where a leader's failure aborts the entire swarm, cyclic LF replaces a failing leader with a follower. This process continues until one quadrotor remains, ensuring task completion. The system employs ArUco squared fiducial markers (SFM) as guiding media and first-order plus time delay (FOPTD) models for velocity dynamics. Based on this model, each quadrotor's proportional derivative (PD) controller and the cyclic LF swarm configurations are designed and simulated. The simulation results are verified through real-time flight assignment using three quadrotors to trace reference points along an 800 cm route. Its guiding media are 60 SFM ArUco distributed over an 840 × 270 cm area on the ground. The cyclic LF formation is assessed by simulating a fault of the battery during the course. The cyclic LF system with no battery failure completes the assignment in 19.2 seconds, with the root means square of tracing error (RMSTE) of 73.6 cm. In comparison, the system with two battery failures completes in 27 seconds, with the RMSTE of 156.9 cm, 159.3 cm, and 273.7 for the first, the second, and the last leader, respectively. The flight duration and the tracing errors increase due to leader changes and formation adjustments. In all test cases, at least one quadrotor completes the assignment.