Cutter abrasion monitoring method based on co-integration modeling

Abstract

The invention relates to a cutter abrasion monitoring method based on co-integration modeling. The cutter abrasion monitoring method comprises the steps of: extracting a plurality of characteristics of a cutting force signal by means of a cutter cutting experiment; primarily selecting characteristic time sequences with the same trend with a cutter in abrasion loss by using a coorelation coefficient matrix; carrying out an ADF (Augmented Dickey-Fuller) test on each selected characteristic time sequence to judge whether the selected characteristic time sequences are I (1); carrying out co-integration analysis under the condition of guaranteeing that all the selected characteristic time sequences are I (1); solving characteristic values and a co-integration matrix beta; then carrying out Johansen test so as to determine a co-integration order r and related co-integration coefficients; establishing a co-integration relational expression of innovation variables according to the co-integration coefficients; determining an optimal co-integration model by comparing calculated values of the expression; carrying out ADF test on the determined innovation variables; and if the innovation variables are stable, judging that the established co-integration model is correct, and further predicting the abrasion loss of the cutter by using the model. By means of the cutter abrasion monitoring method, the abrasion state of the cutter can be monitored accurately so as to reduce the dimensional deviation of a processed workpiece, caused by the cutter abrasion.

Description

technical field [0001] The invention belongs to the field of tool wear monitoring and relates to a tool wear monitoring method based on co-integration modeling. Background technique [0002] During the cutting process of the workpiece, the tool will be worn, and the wear of the tool will cause the geometric shape of the tool to change, so that the workpiece will have a dimensional deviation and affect the processing quality of the workpiece. In order to avoid excessive deviation of the workpiece and improve the processing quality, it is necessary to monitor the wear of the tool, and determine whether to change the tool according to the monitoring results. [0003] Commonly used monitoring tool wear methods can be divided into direct monitoring method and indirect monitoring method. The direct monitoring method is to directly measure the average wear amount of the middle part of the flank wear zone; the indirect monitoring method is to measure the physical quantities related...

AI Technical Summary

Problems solved by technology

However, in actual monitoring, due to the interference of vibration and random noise, it is easy to make mistakes when using this method to judge tool wear, resulting in misjudgment; and because the boundary between normal wear and abnormal wear of the tool has certain uncertainty, the threshold It is more difficult and must be determined based on experience and more experiments, and the threshold is not stable in different occasions

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