Tracking of a target payload via a combination of input shaping and feedback control

This paper investigates the use of the combination of a feedback controller and input shaping to align a crane hoist with a desired, moving payload. The motivating application example is the retrieval of an autonomous surface vessel (ASV) by a larger, host vessel following the completion of the ASV's unmanned mission. Both the ASV and the larger vessel are subject to disturbances that make control of the crane-based operation difficult. This work focuses on the motion of the ASV and proper alignment of the host-vessel's hoist with it leading to the initiation of the lift. This alignment is maintained via a feedback mechanism as well as a preview of incoming conditions. Input shaping greatly simplifies the design of this controller by reducing commanded-motion-induced oscillation.