Patent attributes
A method and a system for controlling a crane drive unit so as to suppress sway of a load suspended by a rope of a crane, which sway occurs when the load has been transported from a first position to a second position, the control being made by operating a controller having a filter unit by using a feedforward control program. The method is to control the crane drive unit so that the load does not greatly sway when it is transported from the first position to the second position by removing a component near a resonance frequency by the filter unit from a transportation command for the load, in which command the maximum value among at least one of a transportation speed, transportation acceleration, and transportation jerk is limited, under the resonance frequency sequentially computed from a rope length that is a distance from the center of rotation of the sway of the rope to the center of gravity of the load and under parameters that relate to a control unit of the crane drive unit and that are previously calculated so as not to exceed the performance of the crane drive unit, and by inputting in the crane drive unit the transportation command, from which the component near the resonance frequency is removed.
