Control and Estimation for Coordinated Transport of an Unknown Slung Load by a Team of Multirotors

In recent years, multirotor UAVs are becoming prevalent, in particular for payload transportation tasks. In this work, cooperative payload transportation by a team of multirotors is studied, for the case of an unknown slung payload. A nonlinear geometric controller is designed and coupled with an on-line parameter estimator, to reduce high levels of uncertainty in the payload parameters, namely its mass, inertia moments and cable-payload attachment points. It is shown that system parameter identification and thus the reduction in parameter uncertainty contributes greatly to the robustness and tracking performance of the system.