A Robust Control Approach for Double-Pendulum Overhead Cranes With Unknown Disturbances

In some situations, underactuated overhead crane systems suffer from double-pendulum effects. Until now, for double-pendulum crane systems, most existing studies propose open-loop approaches, which are generally sensitive to uncertainties. Also, most feedback controllers do not consider unmodeled dynamics or unknown disturbances. In practice, such uncertainties make the control environment unfavorable or even lead to control failure. This paper presents a robust tracking control for double-pendulum overhead cranes, which achieves accurate trolley transportation and effectively eliminates unexpected residual swings. The system stability is theoretically proven, and the satisfactory robustness against unknown uncertainties is verified through numerical simulation results.