Distributed Formation Centroid Tracking Control of Clustered Rotorcraft

We design a distributed control algorithm for clustered rotorcraft to cooperatively realize the formation centroid tracking objective in this article. In particular, the rotorcraft cluster are capable of constructing a prescribed configuration while making the configuration centroid track a reference trajectory. However, constrained by decentralization, each rotorcraft has no idea where the configuration centroid is. Besides, the reference trajectory information is just available to parts of rotorcraft. To begin with, resorting to the cascaded system stability theory, the original formation centroid tracking problem of clustered rotorcraft is translated into designing a bounded transition force and an applied torque for the respective stabilization of the nominal position error dynamics and attitude error dynamics of each individual. Then, by introducing two feasible distributed observers to accurately estimate the configuration centroid and reference acceleration, respectively, a transition force with saturation attribute is designed such that the nominal position error dynamics is stabilized. With such a saturated transition force, a choice criterion of control parameters that is independent of system states is built for the nonsingular demand attitude extraction. Next, an applied torque is designed such that the attitude error dynamics is stabilized. A detailed stability analysis using the generalized Lyapunov theory is carried out. Simulation results verify the effectiveness of the designed distributed control algorithm.