Research on Above Ground Marker System of Pipeline Internal Inspection Instrument Based on Geophone Array

Abstract

The above ground marker system (AGM) is an important part of pipeline internal inspection instrument, which can reduce the mileage error and improve the positioning precision. A AGM based on geophone array was proposed aiming at increasing depth problem of the pipeline. It can record and amplify the sound of an approaching pipeline pig's cups striking the welds of a pipe to an easily discernible level. The seismic signals generated by the different targets around the pipeline were gathered. These signals were pre-processed and the targets features were extracted, by the EMD (Empirical Mode Decomposition) based signal feature extraction method, to identify different the targets. After estimating the time difference of signal arrival on different sensors by cross correlation-phase transform (GCC-PHAT) method , the the spacial location of internal inspection instrument can be realized, according to the time difference and relative position between the sensor array and the pipe. The proposed method above was verified through the outside simulated experiments and data analysis.

New Research on MEMS Acoustic Vector Sensors Used in Pipeline Ground Markers

“…When PIGs run in pipes, errors of about 1 m per 1 km will be produced. The longer the pipe, the greater the cumulative error, and the defect positioning is less accurate, thus requiring more repair work, manpower and material resources in the future [ 11 ], so for long distance pipeline defect detection, it is necessary to mark the PIG every kilometer. When the PIG works in the pipe, it will produce two kinds of acoustic signal: one kind is a friction sound signal because of friction between the PIG and pipe, the other is the crash sound signals induced by the PIG and welding (as shown in Figure 1 ).…”

“…When the PIG works in the pipe, it will produce two kinds of acoustic signal: one kind is a friction sound signal because of friction between the PIG and pipe, the other is the crash sound signals induced by the PIG and welding (as shown in Figure 1 ). In general, the friction sound signal frequency is concentrated in the 150 Hz∼380 Hz range, and crash sound signal frequency is concentrated in the dozens of Hertz range [ 11 ].…”

Design and Numerical Simulation of an Odometer Wheel Used in an Ultrasonic In-Line Inspection Tool

“…e accuracy of locating a detector was improved e ectively [11]. e abovementioned studies mainly focus on improving the performance of an odometer wheel's locating function, while the structural stability of an odometer wheel as well as its antiskid performance [12] is not analyzed considering extreme conditions during in-line inspection [13].…”

High-Sensitivity Real-Time Tracking System for High-Speed Pipeline Inspection Gauge

“…Pipeline inspection gauges (PIGs) are periodically used for pipeline in-line inspections (ILIs) to minimize these risks and maintain pipeline integrity [11,12,13,14,15,16]. However, during the pipeline ILI operation, the PIG is likely to be blocked by the deformed pipelines, while an odometer installed in the PIG can only record the PIG position offline, because the shielding effect of the steel pipe wall makes it difficult to transmit the position information from inside the pipeline to the ground through wireless communication technologies, such as Wi-Fi, Bluetooth, or 3G and 4G networks [17,18]. Thus, the pipeline ILI usually needs the use of above-ground-marker (AGM) technologies to track the position of the PIG in real time [19,20].…”