Laser measurement system-based taper thread data processing algorithm

Abstract

The invention discloses a laser measurement system-based taper thread data processing algorithm. The method comprises the following steps of (1) removing gross errors in thread profile data collected by a displacement sensor through adopting a variable coefficient adaptive Laiyite criterion; (2) removing random noise points in the data subjected to the gross error removal by applying an improved wavelet threshold denoising method; (3) fitting the denoised data by applying a robustified least square method; and (4) performing segmentation according to a fitted profile derivative condition and extracting feature points; finally calculating thread parameters through the extracted feature points. According to the algorithm, a drill pipe thread is taken as a research object; the collected thread profile original point cloud data is subjected to the gross error removal and the denoising in combination with the improved wavelet adaptive threshold algorithm through the adaptive Laiyite criterion; the denoised data is fitted through the robustified least square method; a thread profile curve is obtained, the segmentation is performed according to the fitted profile derivative condition, and the feature points are extracted; and finally the thread parameters are calculated through the extracted feature points. Therefore, efficient and quick data processing after taper thread data collection can be realized and the taper thread detection efficiency is improved.

Description

[0001] Technical field: [0002] The invention relates to a thread data processing algorithm, in particular to a taper thread data processing algorithm based on a laser measuring system with the thread of an oil drill pipe as the research object. Specifically, the coarse error and noise reduction are performed on the collected original point cloud data of the thread profile through the adaptive Leite criterion combined with the improved wavelet adaptive threshold algorithm, and then the noise-reduced data is simulated by the robust least squares method. The feature points are extracted according to the slope of the fitting curve, and the thread parameters are calculated according to the feature points. [0003] Background technique: [0004] Oil drill pipes are connected together by internal and external tapered pipe threads. Due to the large force and high temperature of the drill pipe during drilling, coupled with the scour friction of high-pressure mud, the shoulder surface...

AI Technical Summary

Problems solved by technology

Due to the large force and high temperature of the drill pipe during drilling, coupled with the scour friction of high-pressure mud, the shoulder surface of the drill pipe and the thread profile are easily deformed, worn or partially damaged. At present, the characteristics of taper threads are used in China. Machining repairs to allow multiple reuses of the drill pipe, but current methods are not ideal

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