Carrying a flexible payload with multiple flying vehicles

This paper introduces a method for carrying a flexible payload with multiple attached flying vehicles. A model for a particular class of flexible structures is presented, and an estimator is derived that observes the pose of the structure in space as well as the magnitude of some characteristic deformation modes. A control strategy that controls the flexible payload to a desired pose while also controlling the deformations to zero is introduced. The presented methods are validated in the ETH Zurich Flying Machine Arena by flying with a thin, flexible ring that is carried by six quadrocopters.