Fully distributed anti-disturbance formation tracking control for multi-UAVs

Considering the multi-UAVs(Unmanned Aerial Vehicle) formation problem with time-varying uncertainty and directional communication topology, a fully distributed anti-disturbance formation tracking control method based on TVGESO(Time-Varying Gain Extended State Observer) is pro-posed. The multi-UAVs systems are divided into outer-loop formation subsystem and inner-loop attitude subsystem using hierarchical control strategy. Then the TVGESO is constructed to estimate the time-varying uncertainty, and the anti-disturbance formation tracking protocol and the anti-disturbance attitude cooperative controller are designed respectively. The proposed distributed TVGESO can effectively suppress the peaking widely existing in constant ESO through dynamic gain, which greatly reduce the requirement of UAV control input and improve the system stability. Moreover, the scheme also loosens the requirement of the exact upper bound of the first derivative of uncertainty that is required in the finitetime convergent ESO, which significantly reduces the conservatism of the controller design in addition to enhancing the anti-disturbance formation tracking. Finally, the effectiveness of the method is verified by MATLAB simulation.