Bearing‐only formation tracking control with a predefined‐time disturbance observer

This paper addresses the formation problem relying solely on angle measurements under unknown bounded disturbances. First, a predefined‐time disturbance observer is proposed, which renders the disturbance estimation error convergent to zero in a predefined time. Then, relying on disturbance estimates and the maximum values of both the disturbances and the leaders' acceleration, a formation control scheme using angle measurements is designed to achieve the preset formation. The proposed control scheme does not require relative velocity or relative acceleration measurements, and no communication is needed among agents. Furthermore, rigorous stability analysis of the system is provided. Finally, the results of simulations verify the effectiveness of the designed method.