A load extrapolation method for CNC machine tools based on time-domain load expansion

Abstract

The invention relates to a technical method applied to the field of load spectrums of numerical control machine tools, in particular to a time domain load extension-based load extrapolation method for a numerical control machine tool, and solves the problem that a conventional time domain load extension method does not consider difference of time intervals of an extreme load and selection of an optimal extreme value threshold at present. The method comprises the following steps of 1, adopting an MCMC-based time domain load extension method; 2, determining a threshold range by utilizing an MEF graph; 3, selecting an optimal threshold based on grey relational analysis; and 4, obtaining an extrapolated time domain load. According to the method, the time interval between adjacent extreme values of a cutting load is fully considered, the time domain load can be extended more accurately, grey correlation degrees of GPD fitting of overshoots corresponding to different thresholds are subjected to comparative analysis through the grey relational analysis method, and the threshold corresponding to the GPD fitting with the maximum grey correlation degree is selected as the optimal threshold.

Description

technical field [0001] The invention relates to a technical method applied in the field of load spectrum of a numerically controlled machine tool, more precisely, the invention relates to a method for extrapolating time domain load POT on the basis of expanding the time domain load of a numerically controlled machine tool. Background technique [0002] The load spectrum is the load time history of the whole machine or parts of the product. Because it can reflect the change law of random loads, the load spectrum is widely used in the reliability test of the component structure, fatigue life prediction, reliability design, and accelerated test. etc. [0003] CNC machine tools have different cutting loads under different cutting conditions and working modes. Compared with other mechanical products, their loads are more complex and changeable. In addition, CNC machine tools themselves do not have the function of load testing. If the corresponding testing device is installed, it ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the problems that the current traditional time-domain load extension method does not consider the difference in the time interval of extreme loads and the selection of the optimal test quantity for GPD fitting, etc., and proposes a method based on time-domain load extension Extrapolation Method of CNC Machine Tool Load

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