Ground marking method for eliminating time drift of crystal oscillator

Abstract

The invention discloses a ground marking method for eliminating time drift of a crystal oscillator and relates to the field of detection in pipelines. The method comprises the following steps of: coding ground markers before an internal detector is sent into a pipeline; performing time synchronization on the internal detector and the ground markers through a master clock; sending the internal detector into the pipeline for operation; placing the ground markers on ground marking piles; starting the ground markers to acquire data when the internal detector is close to the ground markers; recording the time when the internal detector passes through the ground markers; storing the recorded time when the internal detector passes through the ground markers into the ground markers; taking the internal detector out of the pipeline, and calibrating each ground marker for the second time; and transmitting the internal detector passing time recorded by the ground markers and data recorded by the internal detector to a supervisory computer for processing so as to realize the positioning of pipeline defects. By the method, the influence of clock drift is effectively eliminated, the detection precision of the ground markers is improved, and the positions of the pipeline defects are accurately positioned.

Description

technical field [0001] The invention relates to the field of detecting ground markings in pipelines, in particular to a ground marking method for eliminating crystal oscillator time drift. Background technique [0002] With the rapid development of the pipeline transportation industry, the increase of pipelines, the increase of pipe age, the manufacturing defects, construction defects and corrosion of the pipeline itself, and man-made damage, etc., pipeline accidents occur frequently, seriously affecting the normal operation of the pipeline and the surrounding natural environment. , the safety and reliability of the pipeline has become increasingly prominent. The in-pipeline detection technology uses high-precision non-destructive detection equipment, advanced signal processing and digital storage systems to move forward under the impetus of oil and gas, complete the step-by-step scanning of the pipeline, and realize the precise positioning of pipeline defects such as pipeli...

AI Technical Summary

Problems solved by technology

This method must accurately measure the time when the inner detector passes through welding, and the subsequent processing needs to calculate linear calibration factors for multiple welds. The hardware is relatively complex and the algorithm is difficult, which cannot meet the requirements of portability, low power consumption and low cost. ; Due to the influence of the transmission delay and the structure of the internal detector itself, the time for the internal detector to pass through the same welding place measured by the ground marking system and the internal detector is different. This scheme calibrates the two times to be equal, thus introducing errors. Affects the accuracy of defect location

Images