Design and Analysis of a Payload-Centric Controller for Collaborative Aerial Manipulation of a Slender Object

This paper presents the development of a payloadcentric controller for manipulating a slender object with two multirotor UAVs. The paper formulates a 2.5D planar problem that allows the payload to be oriented and positioned in the horizontal plane while independently controlling the height. The aim is to enable abstracted dynamics of the UAVs providing the lift, to allow for simple control of the payload whilst enabling disproportionate control effort between the two UAVs. The control system has been experimentally implemented with two Crazyflie UAVs connected by a lightweight slender payload. In comparison to a combined position setpoint controller, the payload-centric control system shows a reduction in steady-state error for hover tests and reference tracking, and a reduction in oscillations caused by the UAVs competing to hold position. Reference tracking testing validates the performance of the reference tracking controller. The payload-centric controller is tested in simulation with a heterogeneous multilift system to demonstrate the versatility of the controller.