3D Observer-based Connectivity Preserving Flocking Control of UAVs with Velocity-free Measurement and Disturbances

This paper studies the distributed three-dimensional (3D) flocking control problem of multi-UAVs subject to velocity-free measurement and disturbances. The whole flocking control structure is divided into two layers. In the upper layer, an extended state observer (ESO) is designed to deal with unmeasured states, disturbances and nonlinearity. In the lower layer, considering only partial UVAs have access to the information of the virtual leader, an improved flocking control law is proposed to make all UVAs track the trajectory of leader while maintaining collision avoidance and connectivity. Meanwhile, an integral backstepping control law is designed to guarantee the good robustness and stability of the attitude subsystem of UVAs. Simulation results are given to demonstrate the validity of the proposed approach.