Method for extracting fault features of gantry crane lifting mechanism under variable speed

Abstract

The invention relates to a method for extracting fault features of a gantry crane lifting mechanism under the variable speed. The method comprises the steps of firstly collecting an original vibrationsignal of the gantry crane lifting mechanism under the variable speed, performing low-pass filtering and downsampling on the original vibration signal according to the speed of the lifting mechanism,then analyzing the undersampled vibration signal by using a time-frequency analysis method to obtain a time-frequency cloud map, extracting the instantaneous rotating frequency according to a frequency ridge extraction method, obtaining an estimated instantaneous rotating frequency curve through polynomial fitting, performing uniform angle sampling on the original vibration signal according to the estimated instantaneous rotating frequency curve, carrying out order ratio analysis by using the uniform angle sampled vibration signal to obtain an order ratio spectrum, and judging whether the gantry crane lifting mechanism breaks down or not according to the order ratio spectrum. The method solves a problem that it is difficult to extract fault features for the existing gantry crane lifting mechanism under the variable speed.

Description

technical field [0001] The invention belongs to the technical field of fault diagnosis of port equipment portal cranes, and in particular relates to a method for extracting fault features of a hoisting mechanism of a portal crane under variable speed. Background technique [0002] The lifting mechanism of portal crane, also called "lifting mechanism", is the basic structure necessary for portal crane to lift and lower objects. The hoisting mechanism is driven by the hoisting motor through the coupling through the hollow shaft of the reducer to rotate the reel, so that the wire rope / cable wound on the reel drives the hook device to rise or fall. The quality of the lifting mechanism will directly affect the working performance of the whole crane. . [0003] The hoisting mechanism of the portal crane often works under the condition of variable speed. When the hoisting mechanism is in the state of non-stable speed change, a large transient impact force is generated between the...

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is to provide a method for extracting fault features of the hoisting mechanism of a portal crane under variable speed. The method utilizes the time-frequency analysis method to estimate the time-frequency nephogram of the vibration signal after down-sampling to obtain its instantaneous speed curve. The defects of inaccurate estimation of instantaneous speed curve in existing methods are overcome

Images