Time-Delay Algorithms for Damping Oscillations of Suspended Payload by Adjusting the Cable Length

This paper deals with damping oscillations of a payload suspended to a fixed position base (e.g., a standing crane trolley). The damping is done by utilizing the Coriolis force generated by synchronizing translational and rotational motion of the payload. After revising existing approaches mainly based on approximating the payload motion by the motion of a mathematical pendulum, several nonlinear time-delay algorithms are proposed to handle the given task efficiently. The key benefit of the proposed methods is the feedback character of the algorithms guaranteeing the required synchronization of the cable length adjustment with the payload swing motion under the varying oscillation period and even under the effect of external disturbances. Note that the preceding algorithms were of open-loop character where such a synchronization was not guaranteed. The theoretical design is validated by simulations. The implementation aspects are discussed by relaxing the simplifying assumptions. Finally, the proposed time-delay feedback method is experimentally verified on a laboratory setup. The achieved results demonstrate viability of the proposed method for payload oscillation damping, e.g., in crane applications.