Cooperative Transport of a Suspended Payload via Two Aerial Robots with Inertial Sensing

In this article, we address the problem of aerial transport of a suspended payload by two vehicles with minimal sensing and computational requirements. Herein, the leader-follower paradigm is adopted, allowing the follower robot to estimate and stabilize the formation using only feedback from its onboard inertial sensor. This is achieved through an analysis of the underlying dynamics of the coupled system. The gained insights lead to the introduction of a two-stage Kalman-based estimation strategy and the linear control laws that are capable of robustly dealing with the underactuated leader-payload-follower system. The vision-less methods have been verified through a series of flight experiments. The efficiency and the robustness of the schemes enable the cooperative payload transport to be accomplished by two sub-100-g robots with highly limited computational power in both indoor and outdoor environments.