Crane

Abstract

Provided is a crane in which it is possible to suppress vibration pertaining to a resonant frequency of horizontal shaking produced in a suspended load, and vibration pertaining to the characteristicfrequency of a telescopic boom, produced in a suspended load. The resonant frequency [omega]z(n) of horizontal shaking of a suspended load W suspended from the distal end of a telescopic boom 9 via wire ropes 14,16 is calculated on the basis of the suspension length Lm(n).Ls(n) of the wire ropes 14,16; the characteristic frequency [omega]y(n) in the raising and lowering direction of the telescopicboom 9 is calculated; and, in accordance with an operation for raising and lowering the telescopic boom 9, the filtering control signal Cd(n) of an actuator is generated in which a frequency component in a discretionary frequency range is attenuated at a discretionary ratio with reference to the resonant frequency [omega]x(n) of the suspended load W, and in which a frequency component in a discretionary frequency range is attenuated at a discretionary ratio with reference to the characteristic frequency [omega]y(n) in the raising and lowering direction of the telescopic boom 9.

Description

technical field [0001] The present invention relates to cranes. Specifically, it relates to a crane that attenuates a resonance frequency component based on a control signal. Background technique [0002] Conventionally, in cranes, on the lifting load during transportation, the acceleration applied during transportation is used as a vibrating force to generate a simple pendulum with the lifting load suspended at the tip of the cable as the mass point or a hook part as the fulcrum. vibration of the double pendulum. In addition, vibrations caused not only by single pendulums or double pendulums but also by deflection of structures constituting the crane, such as telescopic arms and cables, occur in lifting loads conveyed by cranes equipped with telescopic arms. When the hoisting load suspended on the cable vibrates at the resonant frequency of the single pendulum or double pendulum, and at the natural frequency of the undulating direction of the telescopic arm, the natural f...

AI Technical Summary

Problems solved by technology

However, the crane described in Patent Document 1 has disadvantages such as being unable to suppress the vibration of the arm itself which fluctuates according to the heave angle of the arm.

Images