A gantry cranes is generally modeled as a simple-pendulum with a point mass attached to the end of a massless rigid link. Numerous control systems have been developed to reduce payload oscillations in order to improve safety and positioning accuracy of crane operations. However, large-size payloads transforms the crane model from a simple-pendulum system to a double-pendulum system. Control systems that consider only one mode of oscillations of a double-pendulum may excite large oscillations in the other mode. In multi-degrees-of-freedom systems, command-shaping controllers designed for the first mode may eliminate oscillations of higher modes provided that their frequencies are odd integer multiples of the first mode frequency. In this work, a hybrid command-shaping controller is designed to generate acceleration commands to suppress travel and residual oscillations of a highly accelerated double-pendulum gantry crane. It is shown that the suggested hybrid command-shaper is capable of minimizing oscillations of both modes of a scaled experimental double-pendulum model of a gantry crane. Results show that the hybrid command-shaper produces a reduction of 95% in residual oscillations in both modes of the double-pendulum over the time-optimal rigid-body commands.

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