Method for determining ground mark time of inner detector of pipeline

Abstract

The invention discloses a method for determining the ground mark time of an inner detector of a pipeline, relating to the technical field of inner detection of the pipelines. The method comprises the following steps of: acquiring a friction sound signal which is generated by the friction between the inner detector and the pipe wall and meets a preset rule by an acoustic ground mark system; acquiring an envelope signal through band-pass filtering, full-wave shaping and enveloping acquiring processing; establishing a mathematical model that the amplitude of the friction sound signal of the inner detector, which is received by the ground marker, changes along with the time; substituting the vertical distance between a sensor of the ground marker and a pipeline, the operation speed of the inner detector of the pipeline within a signal time period as well as the obtained envelope signal into the established mathematical model; and acquiring the ground mark time through least square fitting. Proved by experiments, the error of the acquired ground mark time obtained through the method is little; the acquired ground mark time is more accurate and can meet the requirement of projects; and the odometer wheel error of the inner detector of the pipeline can be corrected more accurately.

Description

technical field [0001] The invention relates to the technical field of in-pipeline detection, in particular to a method for determining the ground marking time of an in-pipeline detector. Background technique [0002] Pipeline defects are caused by factors such as material defects, external force damage, construction defects, and corrosion. These defects cause potential danger to the safe operation of the pipeline, and if they are not dealt with in time, once an accident occurs, it will cause huge loss of life and property and environmental pollution. In order to ensure the safe operation of the pipeline, it is necessary to carry out defect detection on the pipeline. [0003] The in-pipeline detection technology is to place the in-pipeline detector equipped with non-destructive testing equipment and data acquisition, processing and storage systems in the pipeline, and run in the pipeline under the impetus of the fluid medium to detect the defects of the pipe body and accura...

AI Technical Summary

Problems solved by technology

[0006] In the envelope extraction, the existing methods are based on the principle of extreme value interpolation, relying on the extreme value of the friction sound signal, and the friction sound signal is a complex and changeable broadband signal, the envelope extraction based on the principle of extreme value interpolation The envelope obtained by this method is not smooth, it is difficult to accurately judge the peak time, and the accurate ground marking time cannot be obtained, so that the mileage wheel error of the detector in the pipeline cannot be accurately corrected

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