阅读说明：本技术 一种管道内检测器示踪定位方法 (Tracing and positioning method for detector in pipeline ) 是由 黄新敬 王垣 曾周末 封皓 李健 张宇 周乾 于 2020-08-03 设计创作，主要内容包括：本发明公开了一种管道内检测器示踪定位方法,包括：构建管道内检测器示踪定位装置；基于所述装置进行示踪定位；装置包括：管道内检测器在充液管道内运行,每隔1s就发射一串超声脉冲信号,贴在管壁上的接收器将接收到的声信号转换为电信号,通过信号调理盒对其进行放大、滤波处理,数据采集卡在GPS模块发出的触发脉冲作用下,将采集到的电信号传输到上位机中；上位机使用动态阈值法计算超声脉冲信号的到达时刻,并结合已知的信号发出时刻和超声波在充液管道内的传播速度,计算管道内检测器和接收器之间的距离,进而对管道内检测器进行定位。本发明由内检测器主动发声、在管道外壁远距离实时侦听导波脉冲,从而计算内检测器与监测点的距离。(The invention discloses a tracing and positioning method for a detector in a pipeline, which comprises the following steps: constructing a tracing and positioning device of a detector in a pipeline; performing tracing positioning based on the device; the device comprises: the detector in the pipeline runs in the liquid filling pipeline, a series of ultrasonic pulse signals are transmitted every 1s, a receiver attached to the wall of the pipeline converts received acoustic signals into electric signals, the electric signals are amplified and filtered through a signal conditioning box, and a data acquisition card transmits the acquired electric signals to an upper computer under the action of trigger pulses sent by a GPS module; the upper computer calculates the arrival time of the ultrasonic pulse signal by using a dynamic threshold method, and calculates the distance between the detector in the pipeline and the receiver by combining the known signal sending time and the propagation speed of the ultrasonic wave in the liquid filling pipeline, thereby positioning the detector in the pipeline. The invention actively sounds by the inner detector and remotely monitors the guided wave pulse on the outer wall of the pipeline in real time, thereby calculating the distance between the inner detector and a monitoring point.)

1. A method for tracing and positioning a detector in a pipeline, the method comprising:

constructing a tracing and positioning device of a detector in a pipeline; performing tracing positioning based on the device;

wherein, detector tracer positioner in the pipeline includes: a detector in the pipeline is arranged in the pipeline,

the detector in the pipeline runs in the liquid filling pipeline, a series of ultrasonic pulse signals are transmitted every 1s, a receiver attached to the wall of the pipeline converts received acoustic signals into electric signals, the electric signals are amplified and filtered through a signal conditioning box, and a data acquisition card transmits the acquired electric signals to an upper computer under the action of trigger pulses sent by a GPS module;

the upper computer calculates the arrival time of the ultrasonic pulse signal by using a dynamic threshold method, and calculates the distance between the detector in the pipeline and the receiver by combining the known signal sending time and the propagation speed of the ultrasonic wave in the liquid filling pipeline, thereby positioning the detector in the pipeline.

2. The method for tracing and positioning an in-pipe detector according to claim 1, wherein the in-pipe detector is a cylindrical inner detector or a spherical inner detector.

3. The method as claimed in claim 2, wherein the spherical inner detector comprises: the double-layer spherical shell is composed of two different materials, the outer spherical shell is made of polyurethane, the inner spherical shell is made of aluminum,

punching a polyurethane layer to enhance the transmission of sound waves and reduce signal distortion, placing piezoelectric ceramics on a platform with a pre-polished bottom, and fixing the piezoelectric ceramics on the bottom of the spherical shell by using a stainless steel plate;

insulating resin sheets are adhered to the upper surface and the lower surface of the piezoelectric ceramic to serve as insulating layers, a stainless steel plate is used for exerting pretightening force, and the contact force between the piezoelectric ceramic and the spherical shell is enhanced to enhance the sound production intensity;

further comprising: and the core circuit board is used for detecting damage of the liquid filling pipeline and controlling the piezoelectric ceramics to send out ultrasonic signals for tracing and positioning.

4. The tracing and positioning method for the in-pipe detector as recited in claim 1, wherein the in-pipe detector is synchronized with a time reference of the receiver, and the timing uses a rising edge of a PPS signal sent out when the GPS module is used for positioning to trigger an acquisition process of the receiver.

5. The method for tracing and positioning a detector in a pipeline according to claim 1, wherein the method further comprises:

when the signal of the detector in the pipeline is at the moment t₁When known, according to the time t at which the signal arrives at the receiver₂Acquiring the transmission time delta t of a signal;

wherein the time t at which the signal arrives at the receiver₂The acquisition specifically comprises the following steps:

the receiver receives the sound pressure signal from the detector in the pipeline, converts the sound pressure signal into an electric signal, and then performs primary amplification, filtering and secondary amplification on the obtained electric signal through the signal conditioning box to filter a high-frequency noise signal;

then envelope detection, rectification and peak value processing are carried out in sequence, and finally the arrival time t of the sound wave is determined by using a dynamic threshold value method₂。

Technical Field

The invention relates to the field of detectors in pipelines, in particular to a tracing and positioning method for a detector in a pipeline.

Background

By 2019, the total mileage of oil and gas pipelines in China reaches 13.9 kilometers and is in the front of the world. Of these, about 60% of pipelines have been in service for more than 20 years, have severe aging corrosion, and are currently in the high-incidence of rupture and leakage accidents. Once the pipeline leaks, serious environmental pollution, economic loss and casualties are caused. Therefore, it is necessary to periodically inspect the oil and gas pipelines to find the defect and the high-risk leakage part in time. The inner detector of the pipeline is the most commonly used pipeline defect detection means, and the principle of the inner detector is that the inner detector carrying nondestructive detection equipment is placed in the pipeline, moves under the pushing of fluid in the pipeline, collects and stores pipeline detection information at the same time, takes out the inner detector after the detection is finished, downloads data, and carries out off-line analysis and processing, thereby judging the type and the position of the pipeline defect. When the internal detector is operated in a pipe, for safety and economic reasons, its position must be tracked in real time to prevent accidental jamming or loss. Meanwhile, the acquired real-time position information has important significance for auxiliary positioning of pipeline defects. The tracer location system is therefore an integral part of the internal detector.

There are two types of in-line detectors commonly used today: conventional cylindrical internal detectors and emerging spherical internal detectors. The column-shaped inner detector, the leather cups and the pipe wall are in close contact before and after operation, and the inner detector is pushed to advance by the pressure difference between the front and the back of the detector, and the common tracing and positioning methods thereof comprise the following methods:

the mileage rotation method. Usually, several mileage wheels are installed at the tail of the inner detector, and the distance traveled by the inner detector is calculated by counting pulse signals emitted by the mileage wheels. However, due to the structural defects of the mileage wheel and the unavoidable slippage, the method can generate larger accumulated errors, has low positioning accuracy and is not suitable for long-distance detection;

(ii) a collision acoustics method. And judging the passing time of the inner detector according to the friction and impact sound of the inner detector, the pipe wall and the welding seam. However, the acoustic positioning method is very easy to be interfered by environmental noise to generate a large amount of false reports, and can not track the blocked internal detector;

③ magnetostatic field method. The inner detector carries a permanent magnet, and whether the inner detector passes through is judged by detecting a leakage magnetic signal passing through the pipe wall. The static magnetic field method needs to carry huge permanent magnets, and the detected pipe wall cannot be too thick, so the application range is small;

and fourthly, a very low frequency electromagnetic pulse method. An electromagnetic signal transmitter is arranged in the inner detector and transmits an extremely low frequency electromagnetic signal within 30Hz to be detected by a receiver outside the tube. However, due to the weak and instantaneous properties of the extremely low frequency signals, the detection method is extremely easy to miss and report by mistake on the whole, and the actual engineering requirements are difficult to meet. Therefore, a new method for tracing and positioning the detector in the pipeline is needed.

Disclosure of Invention

The invention provides a tracing and positioning method for a detector in a pipeline, which is characterized in that an inner detector actively sounds and remotely monitors guided wave pulses in real time on the outer wall of the pipeline so as to calculate the distance between the inner detector and a monitoring point, and the following description is provided:

a method of in-pipe detector tracer location, the method comprising:

constructing a tracing and positioning device of a detector in a pipeline; performing tracing positioning based on the device;

wherein, detector tracer positioner in the pipeline includes: a detector in the pipeline is arranged in the pipeline,

the detector in the pipeline runs in the liquid filling pipeline, a series of ultrasonic pulse signals are transmitted every 1s, a receiver attached to the wall of the pipeline converts received acoustic signals into electric signals, the electric signals are amplified and filtered through a signal conditioning box, and a data acquisition card transmits the acquired electric signals to an upper computer under the action of trigger pulses sent by a GPS module;

the upper computer calculates the arrival time of the ultrasonic pulse signal by using a dynamic threshold method, and calculates the distance between the detector in the pipeline and the receiver by combining the known signal sending time and the propagation speed of the ultrasonic wave in the liquid filling pipeline, thereby positioning the detector in the pipeline.

Wherein the in-pipe detector is a cylindrical or spherical inner detector.

Further, the spherical inner detector includes: the double-layer spherical shell is composed of two different materials, the outer spherical shell is made of polyurethane, the inner spherical shell is made of aluminum,

punching a polyurethane layer to enhance the transmission of sound waves and reduce signal distortion, placing piezoelectric ceramics on a platform with a pre-polished bottom, and fixing the piezoelectric ceramics on the bottom of the spherical shell by using a stainless steel plate;

insulating resin sheets are adhered to the upper surface and the lower surface of the piezoelectric ceramic to serve as insulating layers, a stainless steel plate is used for exerting pretightening force, and the contact force between the piezoelectric ceramic and the spherical shell is enhanced to enhance the sound production intensity;

further comprising: and the core circuit board is used for detecting damage of the liquid filling pipeline and controlling the piezoelectric ceramics to send out ultrasonic signals for tracing and positioning.

The pipeline detector is synchronous with the time reference of the receiver, and the rising edge of a PPS signal sent out when the GPS module is used for positioning in timing triggers the acquisition process of the receiver.

Further, the method further comprises:

when the signal of the detector in the pipeline is at the moment t₁When known, according to the time t at which the signal arrives at the receiver₂Acquiring the transmission time delta t of a signal;

wherein the time t at which the signal arrives at the receiver₂The acquisition specifically comprises the following steps:

the receiver receives the sound pressure signal from the detector in the pipeline, converts the sound pressure signal into an electric signal, and then performs primary amplification, filtering and secondary amplification on the obtained electric signal through the signal conditioning box to filter a high-frequency noise signal;

then envelope detection, rectification and peak value processing are carried out in sequence, and finally the arrival of the sound wave is determined by using a dynamic threshold value methodTime t₂。

The technical scheme provided by the invention has the beneficial effects that:

1. the method can track and position the spherical internal detector in real time, and is particularly used for monitoring the process of receiving and dispatching the ball and judging the fixed-point trafficability;

2. aiming at the difficult problem of tracing and positioning of the spherical internal detector, the method provides a tracing and positioning method of the spherical internal detector based on active acoustics, and the implementation key points are determined through simulation and experiments, and the effectiveness is proved;

3. the polyurethane vibration damping layer of the internal detector has a great attenuation effect on the sound wave emission intensity, and the aluminum ball shell is contacted with water by opening holes in the polyurethane layer, so that the enough sound production intensity can be ensured.

Drawings

FIG. 1 is a schematic diagram of a tracking and positioning process of a spherical internal detector;

FIG. 2 is a schematic diagram of the internal structure of a spherical internal detector;

FIG. 3 is a schematic diagram of a field device in an actual experiment;

FIG. 4 is a graph of raw signal data for an accelerometer;

wherein, (a) is an acceleration-time signal diagram in the process that the spherical inner detector is far away from a monitoring point; (b) the acceleration-time signal diagram of the spherical inner detector in the process of approaching the monitoring point is shown.

FIG. 5 is a graph comparing accelerometer positioning and ultrasonic positioning;

fig. 6 is a schematic view of the sound pressure of the lower surface of the imperforate spherical inner detector 3;

fig. 7 is a schematic view of the sound pressure of the lower surface of the holed spherical inner detector 3;

fig. 8 is a graph of the results of sound pressure versus time at different distances.

Wherein, (a) is a sound pressure-time result graph at a distance of 0 m; (b) the sound pressure-time result chart at the distance of 2 m; (c) the sound pressure-time result chart at the distance of 4 m; (d) is a sound pressure-time result graph at a distance of 6 m; (e) the sound pressure-time results are plotted for a distance of 8 m.

In the figure:

1: soil; 2: a ground surface;

3: an in-pipe detector; 4: a liquid-filled pipe;

5: a receiver; 6: a signal conditioning box;

7: a data acquisition card; 8: GPS module

9: an upper computer 10: a suspension device.

Wherein the content of the first and second substances,

3-1: a polyurethane layer; 3-2: an aluminum layer;

3-3: an insulating resin sheet; 3-4: piezoelectric ceramics;

3-5: a core circuit board.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention are described in further detail below.

1. Integral structure device

Referring to fig. 1, the apparatus includes: the device comprises an in-pipeline detector 3, a liquid filling pipeline 4, a receiver 5, a signal conditioning box 6, a data acquisition card 7, a GPS module 8 and an upper computer 9.

When the in-line detector 3 is operating in the liquid-filled line 4, a series of ultrasonic pulse signals is transmitted every 1 s. The receiver 5 attached to the pipe wall converts the received acoustic signals into electrical signals, then the electrical signals are amplified and filtered through the signal conditioning box 6, the data acquisition card 7 transmits the acquired electrical signals to the upper computer 9 under the action of trigger pulses sent by the GPS module 8, the arrival time of ultrasonic pulse signals is calculated by using a dynamic threshold method, the distance between the detector 3 in the pipe and the receiver 5 is calculated by combining the known signal sending time and the propagation speed of ultrasonic waves in the liquid filling pipe 4, the detector 3 in the pipe is positioned, and the working device of the device is shown in figure 1. If the liquid filling pipe 4 is a subsea pipe, the receiver 5 may also be arranged near the subsea pipe, since water may also act as an acoustic couplant.

The method does not limit the shape of the in-pipe detector 3, i.e. the method is applicable to both cylindrical and spherical internal detectors. The essential internal components are described below in terms of a spherical internal detector.

The structure of the spherical inner detector 3 is shown in fig. 2, the spherical shell is a double-layer spherical shell formed by two different materials, the material used for the spherical shell is a polyurethane layer 3-1, and the aluminum layer 3-2 is used for the spherical inner shell. The sound wave is greatly attenuated after passing through the spherical shell, and the spherical shell generates residual vibration to distort the sound signal. Therefore, the polyurethane layer 3-1 under the spherical shell is perforated to enhance the transmission of sound waves and reduce signal distortion, but the aperture is not too large or the normal smooth rolling of the spherical inner detector 3 is affected, and finally the aperture is determined to be 35 mm. The piezoelectric ceramics 3-4 is arranged on a platform which is polished in advance at the bottom of the spherical internal detector 3, and a stainless steel plate is used as a clamping device to be fixed at the bottom of the spherical shell. Due to the acoustic impedance mismatch between the piezoelectric ceramic 3-4 and the aluminum layer 3-2, a couplant needs to be applied as an acoustic wave coupling layer. Insulating resin sheets 3-3 are adhered to the upper surface and the lower surface of the piezoelectric ceramics 3-4 to serve as insulating layers, and meanwhile, a stainless steel plate is used for exerting pretightening force to enhance the contact force between the piezoelectric ceramics 3-4 and the spherical shell so as to enhance the sound intensity. The core circuit boards 3-5 are used for detecting the damage of the liquid filling pipeline 4, and are also used for controlling the piezoelectric ceramics 3-4 to send out ultrasonic signals to trace and position the spherical inner detector 3.

Before the spherical internal detector 3 is placed in the liquid filling pipe 4, the timing is first required to ensure that the time references of the spherical internal detector 3 and the receiver 5 are synchronized. The timing is performed by using a PPS (Pulse Per Second) signal transmitted by the GPS module 8 during positioning. The PPS signal is a pulse wave with a duty cycle of 10% and a frequency of 1Hz, and its rising edge corresponds to the time of the GPS module 8 in whole second, and has an accuracy of ns. Before the spherical inner detector 3 is placed into the liquid filling pipeline 4, the PPS pulse is used for timing the spherical inner detector 3, the clock of the spherical inner detector is made to be consistent with the time of the GPS module 8, and then the rising edge of the PPS signal is used for triggering the acquisition process of the receiver 5 in the detection process.

2. Aspects of data processing

The position of the detector 3 within the sphere is described with reference to the receiver 5, and the basic calculation formula is x ═ c Δ t ═ c (t ═ c ═ t ═ c (t ═ c (t-₂-t₁) Where x is the distance between the spherical internal detector 3 and the receiver 5, c is the propagation velocity of the ultrasonic signal in the liquid-filled pipe 4, Δ t is the propagation time of the signal, t₁Is the time of signal emission and is known as the whole second, t₂Is the time at which the signal arrives at the receiver 5 and has an integer part equal to t₁The fractional part is equal to deltat because the speed of sound wave transmission inside the pipe is fast and the detection distance usually does not exceed several hundred meters, so the propagation time of sound wave must be less than 1 s.

When the signal of the spherical inner probe 3 is at time t₁When known, the time t at which the signal arrives at the receiver 5 is obtained₂The transmission time deltat of the signal can be obtained. When receiving the sound pressure signal from the spherical inner detector 3, the receiver 5 converts the sound pressure signal into an electric signal, and then the obtained electric signal is preliminarily amplified, filtered and amplified again through the signal conditioning box 6 to filter a high-frequency noise signal; then envelope detection, rectification and peak value determination processing are sequentially carried out, and finally the arrival time t of the sound wave is determined by using a dynamic threshold value method₂。

The specific implementation manner of the dynamic threshold method is to determine the maximum amplitude, i.e. peak value, of a group of received signals, and then according to a certain proportion of the peak value (in the embodiment of the present invention, the following steps are taken to describe

For example, the detection threshold is not limited in specific implementation) to determine the detection threshold, and the time when the amplitude of the received signal first exceeds the threshold is regarded as the signal arrival time. The method solves the problem of amplitude fluctuation of the ultrasonic signals, and has the advantages of simple principle, easy realization and higher real-time property and accuracy.

Wherein, the sound velocity c is obtained by fitting data obtained through experiments or simulation. The implementation process comprises the steps of placing two receivers 5 at different axial positions of a liquid filling pipeline 4, wherein the axial position of a first receiver 5 is fixed, the axial distance of a second receiver 5 relative to the first receiver is changed, carrying out a plurality of groups of experiments repeatedly, then calculating the time when a signal reaches the first receiver 5 by using a dynamic threshold method to obtain corresponding time delays at different distances, drawing a time delay-distance scatter diagram, carrying out linear fitting on the scatter diagram, and obtaining the reciprocal of the slope of a fitting straight line as the sound velocity c.

Fig. 3 is a schematic structural diagram of a field device in an actual experiment, and the specific experiment process includes that firstly, the spherical inner detector 3 provided with the piezoelectric sounding device and the accelerometer is placed at the right end of the liquid filling pipe 4, the right end of the liquid filling pipe 4 is lifted up through the suspension device 10, and the spherical inner detector 3 slowly rolls to the left end of the liquid filling pipe 4; and staying for a period of time, wherein the suspension device 10 is adjusted to the left end of the liquid filling pipeline 4, the left end of the pipeline is lifted, and the spherical inner detector 3 slowly rolls back to the right end of the liquid filling pipeline 4. The acceleration signal is used to determine the mileage of the spherical internal detector 3, compared with the results of localization using the ultrasonic signal.

In fig. 4, (a) is the original signal of the accelerometer when the spherical inner detector 3 is far away from the monitoring point, and (b) is the original signal of the accelerometer when the spherical inner detector 3 is close to the monitoring point, the spherical inner detector 3 is in a static state before reaching the other end of the pipeline and returning to the monitoring point, the spherical inner detector 3 rolls in the liquid filling pipeline 4 more stably, the time for moving from one end to the other end is about 40s, the number of rolling turns is 15-16, the rolling distance is calculated to be about 7 m according to the perimeter of the spherical inner detector 3, and the distance is consistent with the actual distance; FIG. 5 is a comparison of accelerometer and ultrasound positioning: the spherical inner detector 3 is firstly far away from the monitoring point, and after the spherical inner detector is static for a period of time, the spherical inner detector starts to approach the monitoring point again, which is identical with the rolling process of the spherical inner detector 3 in the experimental process and is basically equal to the positioning result of the accelerometer. Fig. 6 and 7 are graphs showing the simulation results of the sound pressure on the lower surfaces of the imperforate spherical internal detector 3 and the perforate spherical internal detector 3, respectively, when the piezoelectric ceramics 3-4 are excited by the same modulation voltage signal, which are confirmed by comparison.

Due to frequency dispersion of the ultrasonic guided waves, along with the increase of the propagation distance, the time domain width of a wave packet is gradually widened, the time delay between the starting point time and the peak value time of a signal is larger and larger, and the two signals are two modes of the guided waves and are divided into fast waves and slow waves. The guided waves of the two modes of the ultrasonic signal speed and the ultrasonic signal speed have definite initial characteristics and stable propagation speed, and can be used for calculating the guided wave propagation distance and positioning the spherical internal detector 3; however, the amplitude of the slow wave is far larger than that of the fast wave, and the arrival time of the signal can be determined by the slow wave.

Fig. 8 (a), (b), (c), (d), and (e) show simulation result graphs of sound pressure-time at distances of 0m, 2m, 4m, 6m, and 8m after the spherical internal detector 3 sends out the ultrasonic signal, and when the start time of timing is 0s, the arrow indicates the time when the fast wave and the slow wave reach the position at the specified distance.

In the embodiment of the present invention, except for the specific description of the model of each device, the model of other devices is not limited, as long as the device can perform the above functions.

Those skilled in the art will appreciate that the drawings are only schematic illustrations of preferred embodiments, and the above-described embodiments of the present invention are merely provided for description and do not represent the merits of the embodiments.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.