Nonlinear Disturbance Observer-Based Bearing-Only Unmanned Aerial Vehicle Formation Control

This article primarily investigates nonlinear disturbance observer-based bearing-only formation tracking control for unmanned aerial vehicle (UAV) systems that encounter uncertainties and disturbances. The employed distributed control strategy relies solely on the relative bearing information of neighboring UAVs. To tackle the challenges posed by unknown disturbances and system uncertainties, a novel nonlinear disturbance observer is proposed to effectively mitigate their impact. Moreover, the issue of unknown controller orientation arising from controller singularities is addressed by introducing a Butterworth low-pass filter. This filter ensures a consistent controller gain and enhances disturbance suppression, ultimately transforming the controller gain function into a constant value of 1. Subsequently, a bearing-only formation tracking controller is developed using the backstepping control approach. The stability of the closed-loop control systems is rigorously proven using Lyapunov theory. Finally, numerical simulations are conducted to validate the effectiveness of the proposed scheme in achieving formation control objectives.