A ground positioning device, method and system for a pipeline magnetic flux leakage internal detector

Abstract

The application discloses a ground positioning device, method and system for a pipeline magnetic flux leakage internal detector, the ground positioning device comprises a control module and a magnetic sensor module and a calculation module connected with the control module, the magnetic sensor module is used for detecting magnetic field information of the pipeline, the magnetic field information comprises a magnetic field strength, the control module is used for reading the magnetic field information and sending a first calculation instruction to the calculation module; whether the difference between the magnetic field strength and a reference value is greater than a threshold value; if yes, the calculation module sends a determination signal to the control module; the control module is used for sending a second calculation instruction to the calculation module after receiving the determination signal; whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value, according to the calculation instruction, whether the current is the magnetic flux leakage internal detector passing can be accurately calculated, so that the false judgment caused by external interference is avoided, and the detection accuracy is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pipeline magnetic flux leakage external detection, and particularly to a ground positioning device, method and system for a pipeline magnetic flux leakage internal detector. BACKGROUND

[0002] With the increase of the service life of the pipeline, the pipeline will have different degrees of damage, and the detection of the pipeline is crucial. However, due to its own reasons, the pipeline of oil, natural gas and the like cannot be repaired by opening the pipeline, so the magnetic flux leakage internal detector arranged inside the pipeline becomes the main detection means. The magnetic flux leakage internal detector moves along the conveying direction of the pipeline and detects the damage of the pipeline during the movement. By collecting the passing information of the magnetic flux leakage internal detector during the movement, the condition of the magnetic flux leakage internal detector itself can be analyzed, the magnetic flux leakage internal detector can be effectively prevented from being blocked in the pipeline, and a basis is provided for subsequent analysis of the quality of the pipeline.

[0003] The detection equipment mainly realizes the marking positioning of the magnetic flux leakage internal detector by detecting the magnetic field information of the magnetic flux leakage internal detector. However, in the detection process, there is a lack of corresponding algorithm for positioning the magnetic flux leakage internal detector, which cannot accurately position the magnetic flux leakage internal detector, resulting in low detection accuracy. SUMMARY

[0004] The present application provides a ground positioning device, method and system for a pipeline magnetic flux leakage internal detector to solve the problem of low positioning accuracy of the magnetic flux leakage internal detector.

[0005] The first aspect of the present application provides a ground positioning device for a pipeline magnetic flux leakage internal detector, which is buried above the pipeline and used for collecting the magnetic field information of the magnetic flux leakage internal detector inside the pipeline and positioning the magnetic flux leakage internal detector, comprising: a control module, a magnetic sensor module and a calculation module, the magnetic sensor module and the calculation module being connected with the control module; the magnetic sensor module is used for detecting the magnetic field information of the pipeline, and the magnetic field information includes the magnetic field strength; the control module is used for reading the magnetic field information and sending a first calculation instruction to the calculation module; the calculation module is used for calculating whether the difference between the magnetic field strength and a reference value is greater than a threshold value according to the first calculation instruction after receiving the first calculation instruction; if yes, the calculation module sends a determination signal to the control module; the control module is used for sending a second calculation instruction to the calculation module after receiving the determination signal; the calculation module is used for calculating whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value according to the second calculation instruction after receiving the second calculation instruction; if the frequency amplitude is less than the preset value, it is determined that the magnetic flux leakage internal detector passes, and the magnetic field information is collected to position the magnetic flux leakage internal detector.

[0006] In some embodiments of the present application, the computing module is further configured to calculate the frequency amplitude of the magnetic field information collected by the magnetic sensor module through a discrete Fourier formula after receiving the second computing instruction.

[0007] In some embodiments of the present application, the ground positioning device further comprises an RTC real-time clock module; the RTC real-time clock module is connected to the control module, and the control module is further configured to send a time synchronization and timing instruction to the RTC real-time clock module; the RTC real-time clock module is configured to receive the time synchronization and timing instruction and record the current time when the magnetic sensor module acquires the magnetic field information.

[0008] In some embodiments of the present application, the control module adopts a Riscv chip; and the magnetic sensor module is an AMR magnetoresistance sensor.

[0009] In some embodiments of the present application, the ground positioning device further comprises a GPS module; the GPS module is connected to the control module and is configured to determine the coordinate position and time of the ground positioning device; wherein the coordinate position is the embedding coordinate of the ground positioning device; the GPS module has a time service function and is configured to synchronize the satellite time of the ground marking device; the control module performs a time service operation on the RTC real-time clock module through the GPS module, and after the time service operation is completed, the GPS module is turned off.

[0010] In some embodiments of the present application, the ground positioning device further comprises a storage module and a wireless communication module; the control module is connected to the storage module and the wireless communication module respectively; the storage module is configured to store the magnetic field information of the magnetic flux leakage internal detector, the coordinate position, and the current time triggered by the magnetic flux leakage internal detector when passing through; the control module is configured to receive the transmission instruction of the control device and control the wireless communication module to send the magnetic field information of the magnetic flux leakage internal detector, the coordinate position, and the current time stored in the storage module to the control device according to the transmission instruction.

[0011] The second aspect of the present application provides a ground positioning method for a pipeline magnetic flux leakage internal detector, comprising: detecting the magnetic field information of the pipeline, the magnetic field information comprising a magnetic field strength; reading the magnetic field information and sending a first computing instruction; in response to the first computing instruction, calculating whether the difference between the magnetic field strength and a reference value is greater than a threshold value according to the first computing instruction; if yes, sending a determination signal; in response to receiving the determination signal, sending a second computing instruction according to the determination signal; in response to receiving the second computing instruction, calculating whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value according to the second computing instruction, and when the frequency amplitude is less than the preset value, determining that the magnetic flux leakage internal detector passes through, collecting the magnetic field information to position the magnetic flux leakage internal detector.

[0012] In some embodiments of the present application, the step of determining whether the frequency amplitude of the magnetic field strength at the preset frequency is less than the preset value according to the second calculation instruction comprises: calculating the frequency amplitude by a discrete Fourier formula.

[0013] The third aspect of the present application provides a ground positioning system for a pipeline magnetic flux leakage internal detector, comprising the ground positioning device of the first aspect;

[0014] In the present application, the calculation module calculates whether the difference between the magnetic field strength and the reference value is greater than the threshold value in response to the calculation instruction, and continues to calculate whether the frequency amplitude at the preset frequency is less than the preset value if it is greater than the threshold value. If the frequency amplitude is less than the preset value, it is determined that the magnetic flux leakage internal detector passes, and the magnetic field information when the magnetic flux leakage internal detector passes is collected. The calculation instruction can accurately calculate whether the current is the passage of the magnetic flux leakage internal detector, thereby avoiding false judgments caused by external interference and improving the detection accuracy. The sampling speed of 1ms can ensure the collection accuracy, and the information is stored when it is determined that the magnetic flux leakage internal detector passes, which can effectively utilize the storage space. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0016] Figure 1 The module structure diagram of the ground positioning device in the embodiments of the present application;

[0017] Figure 2 The flowchart of the ground positioning device in the embodiments of the present application;

[0018] Figure 3 The flowchart of the ground positioning device in the embodiments of the present application;

[0019] Figure 4 The flowchart of the ground positioning device in the embodiments of the present application;

[0020] Figure 5 The flowchart of the ground positioning device in the embodiments of the present application; DETAILED DESCRIPTION

[0021] The embodiments will be described in detail below, and examples are shown in the drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following embodiments do not represent all embodiments consistent with the present application. They are only examples of systems and methods consistent with some aspects of the present application as described in detail in the claims.

[0022] The pipeline magnetic flux leakage internal detector is a special detection instrument used in the engineering and technical science basic disciplines and the safety science and technology field, is the most key important equipment in pipeline detection, uses the magnetic principle, combines the advanced electronic technology, big data technology and transmission storage technology into one, and is a high-precision equipment which can adapt to the complex and changeable environment in the pipeline. Since the pipeline is deeply buried underground, the specific position of the pipeline cannot be observed on the ground.

[0023] Generally, the pipeline is overhauled by using the magnetic flux leakage internal detector, the magnetic flux leakage internal detector is arranged in the pipeline to be detected, and the magnetic flux leakage internal detector slides along the extension direction of the pipeline to detect the pipeline. The collection of various information of the magnetic flux leakage internal detector is also particularly important, and these information has a crucial influence on the subsequent pipeline detection.

[0024] In order to ensure the safety of the pipeline environment, before detection, a ground positioning device is buried directly above the pipeline to determine the position and time of the magnetic flux leakage internal detector passing through, so that the magnetic flux leakage internal detector can locate the defects by comparing the time.

[0025] Embodiment 1

[0026] Reference Figure 1 , Figure 1 It is a structure diagram between various modules of the ground positioning device for the pipeline magnetic flux leakage internal detector in the embodiment.

[0027] The ground positioning device for the pipeline magnetic flux leakage internal detector provided in the embodiment is buried above the pipeline and is used for positioning the magnetic flux leakage internal detector in the pipeline. The ground positioning device comprises a control module, a magnetic sensor module connected to the control module and a calculation module connected to the control module. The magnetic sensor module is used for detecting magnetic field information, and the magnetic field information comprises a magnetic field strength. The control module is used for reading the magnetic field information and sending a first calculation instruction to the calculation module. After receiving the first calculation instruction from the control module, the calculation module calculates whether the difference between the magnetic field strength and a reference value is greater than a threshold value. The first calculation instruction is: whether the difference between the magnetic field strength and the reference value is greater than the threshold value, specifically whether the difference between the magnetic field strength and the reference value is greater than the threshold value. If the calculation result is greater than the threshold value, the calculation module sends a determination signal to the control module, wherein the determination signal represents that the calculation result is greater than the threshold value. After receiving the determination signal from the control module, the calculation module sends a second calculation instruction to the control module. According to the second calculation instruction, the calculation module calculates whether the frequency amplitude of the magnetic field strength collected by the sensor at a preset frequency is less than a preset value. If the frequency amplitude is less than the preset value, it indicates that the magnetic flux leakage internal detector passes through at this time, and the magnetic field information at this time is stored to position the magnetic flux leakage internal detector.

[0028] It can be seen that the application determines whether the difference between the magnetic field strength and the reference value is greater than the threshold value first. That is, if the difference between the magnetic field strength and the reference value is greater than the threshold value, the subsequent frequency amplitude determination is performed, so that the determination result is more accurate. At the same time, the calculation of the frequency amplitude of all data is avoided, the calculation amount is reduced, and the calculation efficiency is improved.

[0029] Specifically, when the calculation result is that the frequency amplitude is less than the preset value, it is determined that the magnetic flux leakage internal detector passes, and the magnetic field information at this moment is collected. When the calculation result is that the frequency amplitude is greater than or equal to the preset value, it is determined that the magnetic flux leakage internal detector does not pass at this moment, but other external interference objects pass, such as a car driving on the ground.

[0030] It is worth noting that when the first calculation instruction is executed, it can be understood as the first screening of the data, avoiding the execution of the second calculation instruction on all data. After the first calculation, when the difference between the magnetic field strength and the reference value is greater than the threshold value, the second calculation instruction is executed again, which can be understood as the second screening of the data. Therefore, in the process of determining whether the magnetic flux leakage internal detector passes, the data is screened twice, avoiding the increase of workload caused by the execution of the first calculation instruction and the second calculation instruction on all data. The second calculation under the premise that the first calculation meets certain conditions can effectively improve the calculation speed, thereby improving the recognition efficiency. When the first calculation instruction is executed, if the calculation result is that the difference between the magnetic field strength and the reference value is less than the threshold value, it means that the determination condition is not met at this moment, and the second calculation instruction is not executed. At this moment, the magnetic flux leakage internal detector is not the cause of the change of the magnetic field. After the second calculation instruction is executed, when the calculated frequency amplitude is greater than the preset value, it means that the magnetic flux leakage internal detector is not the cause of the change of the magnetic field.

[0031] That is, by judging whether the two calculation results are the passing of the magnetic flux leakage internal detector, the accuracy of detecting the passing of the magnetic flux leakage internal detector can be effectively improved, and the misjudgment of the passing of the magnetic flux leakage internal detector caused by other factors can be avoided.

[0032] Specifically, the size of the reference value, the threshold value, the preset frequency and the preset value is determined according to the actual detection requirement, which is not limited here. That is, the values of the reference value, the threshold value, the preset frequency and the preset value can be adjusted according to the actual situation.

[0033] In some embodiments, after receiving the second calculation instruction, the calculation module calculates the frequency amplitude of the magnetic field information collected by the magnetic sensor module through the discrete Fourier formula, and determines whether the current is the passing of the magnetic flux leakage internal detector according to the frequency amplitude.

[0034] In some embodiments, the control module adopts an MCU (Microcontroller Unit; MCU) control module. In some embodiments, the magnetic sensor module is used to collect environmental magnetic field information, the magnetic field information including X-axis magnetic field strength and magnetic field direction, and the MCU control module reads the magnetic field information of the magnetic sensor module every 1 ms. The MCU control module is used to monitor whether the magnetic field information is abnormal, and if the monitored magnetic field value minus the reference value exceeds the set threshold value, the environmental magnetic field information, time information, and GPS geographic coordinate information are continuously collected for 10 seconds. After the collection is completed, the control storage module is used for data storage.

[0035] Specifically, the magnetic field information further includes a magnetic field direction, which is reflected in the data collected by the magnetic sensor. After processing the data, the waveform change can be used to determine the passing direction of the magnetic sensor. For example, it is determined that the magnetic flux leakage internal detection passes from the right side of the ground positioning device, or it is determined that the magnetic flux leakage internal detection passes from the left side of the ground positioning device.

[0036] The main control MCU of the MCU control module is a Riscv chip. The magnetic sensor module is data collected every 10 ms, and when the collected X-axis magnetic field information exceeds the set threshold value, the MCU control module controls the storage module to record the magnetic field information data for 10 seconds.

[0037] The reference value of the magnetic field collection changes every 10 seconds. Weighted filtering is used, and the filtering formula is target reference value = 0.99*(last reference value) + 0.01*(current collected magnetic field value). The initialized reference value is the average value of 1000 point magnetic field collection values.

[0038] The magnetic sensor module is an AMR magnetic resistance sensor. Based on the most advanced high-resolution magnetic resistance technology, 16-bit analog-to-digital conversion, it has the advantages of low noise, high precision, low power consumption, offset compensation, and temperature compensation.

[0039] In some embodiments, the ground positioning device further comprises an RTC real-time clock module, which is connected with the control module, and the control module sends time synchronization and timing instructions to the RTC real-time clock module. The RTC real-time clock module records the current time when the magnetic sensor module acquires the magnetic field information, so as to record the time when the magnetic flux leakage detector passes. The RTC real-time clock module is used to synchronize and track the satellite time.

[0040] In some embodiments, the control module adopts a Riscv chip. The Riscv chip is low in energy consumption, suitable for efficient design, and flexible in application requirements. Different parts can be connected together in a modular manner to achieve the satisfaction of various applications through a unified architecture. The Riscv chip adopted by the control module in the embodiments of the application and other chips working together are all domestic chips.

[0041] In the Riscv chip, Reduced Instruction Set Computing is a reduced instruction set, and "V" contains two layers of meaning. One is that it is the fifth generation instruction set architecture designed by Berkeley starting from RISC I, and the other is that it represents variation and vectors.

[0042] The magnetic sensor module adopts an AMR (Anisotropic magnetoresistance, anisotropic magnetoresistance effect) magnetoresistance sensor. The AMR magnetoresistance sensor is used to detect the magnetic field by using the magnetoresistance effect. The anisotropic magnetoresistance (AMR) effect refers to that when the external magnetic field and the built-in magnetic field of the magnet are zero-degree angle, the resistance does not change with the external magnetic field. However, when the external magnetic field and the built-in magnetic field of the magnet have a certain angle, the internal magnetization vector of the magnet will be offset, and the resistance will be reduced.

[0043] In a feasible embodiment, the control module adopts a ZFM32F103CB model and an embedded MCU (Microcontroller Unit) based on the Riscv instruction set. The magnetic sensor module adopts a QMC5883L model AMR magnetoresistance sensor. The QMC5883L is a sensor developed by using the third generation AMR magnetic sensing technology. It has the characteristics of high precision, low power consumption, high reliability, small package, and the like. It integrates offset cancellation and temperature compensation functions, and efficiently realizes the detection purpose.

[0044] In some embodiments, the ground positioning device further comprises a GPS (Global Positioning System) module, the GPS module being connected to the control module, and the geographic coordinate position of the ground positioning device is determined by setting the GPS module. It can be understood that, on the one hand, the ground positioning device is arranged above the pipeline just to detect whether the magnetic flux leakage internal detector passes through, and the GPS module can mark the geographic position of the ground positioning device, and when the magnetic flux leakage internal detector passes through the ground positioning device, that is, the magnetic flux leakage internal detector passes through the geographic coordinate position. On the other hand, since the ground positioning device needs to be buried underground during the detection of the magnetic flux leakage detector, the coordinate position positioned by the GPS is also convenient for the staff to retrieve it. It can be understood that, by burying the ground positioning device underground, not only the detection distance can be reduced, but also the loss can be avoided.

[0045] In a feasible embodiment, the GPS module adopts a time-providing positioning module, and the model is BD-357ZF. By adopting the GPS time-providing positioning module with time-providing function, the function of synchronizing time can be played, and the positioning time of the ground positioning device can be recorded. The control module performs time-providing operation on the RTC real-time clock module through the GPS module, and after the time-providing operation is completed, the GPS module is turned off.

[0046] The time-providing positioning module comprises one-way time-providing and two-way time-providing, and one-way time-providing can be adopted in the present application. It is worth noting that the selection of one-way time-providing and two-way time-providing can be adjusted according to the actual working condition, and is not specifically limited.

[0047] In some embodiments, the ground positioning device further comprises a storage module and a wireless communication module, the storage module being connected to the control module, and when it is determined that the magnetic flux leakage internal detector passes through, the magnetic field information of the magnetic flux leakage internal detector detected by the magnetic sensor module, the coordinate position positioned by the GPS, and the current time recorded by the RTC real-time clock module are stored in the storage module. Compared with a large amount of storage data, the storage module only stores the effective data of the magnetic flux leakage internal detector passing through, avoids the occupation of invalid data in the memory, and improves the storage efficiency.

[0048] Specifically, the storage module is used for storing the magnetic field information of the magnetic flux leakage internal detector, the coordinate position, and the time information when the continuous 10-second acquisition is triggered.

[0049] It can be understood that the storage module in the application does not trigger storage of data in the whole time period, but stores effective data when it is determined that the magnetic flux leakage internal detection is passed, and the ineffective data is deleted or not stored. That is to say, after the collected data is executed by the first calculation instruction and the second calculation instruction, the data that meets the condition of the magnetic flux leakage internal detection passed is stored, instead of storing all data, which can effectively guarantee the storage space of the storage module and improve the working efficiency of the ground positioning device.

[0050] In a feasible embodiment, the storage module is a data storage module GD25Q64, the GD25Q64 (64M bits) serial flash memory supports a standard serial peripheral interface (SPI, serial peripheral interface) and supports double / four SPI: serial clock, chip selection, serial data I / O0 (SI, Serial Interface), I / O1 (SO, Serial Output), I / O2 (WP, Write Protect) and I / O3 (HOLD, hold). The application adopts a standard SPI, has four signal lines, which are CLK, CS, MOSI and MISO. The data line works at a full-duplex communication rate of 10Mbit / s, is reliable and has a high rate, so as to meet the application requirements.

[0051] The wireless communication module is connected with the control module and the storage module, respectively, and is used for receiving the transmission instruction sent by the control module, transmitting the data in the storage module to the control device, so as to facilitate the staff to analyze and process the data. The storage module in the application has a small storage capacity, and outputs a graphical interface on the host computer, which is convenient for data analysis and processing. The application provides an effective reference for improving the ground positioning of the magnetic flux leakage internal detector.

[0052] It can be understood that the control device can include a host computer and a lower computer. In the same control instruction, the host computer and the lower computer are different, but in different control instructions, the host computer and the lower computer can be the same or different.

[0053] For example, the host computer is a computer that can directly send a control command, so as to facilitate the control of the ground positioning device.

[0054] In one possible embodiment, the wireless communication module adopts A78-C2G4A20S2b, which is a wireless communication module working in the 2.4G ISM (Industrial Scientific Medical) frequency band. It supports multiple protocols including BLE (Bluetooth Low Energy), BLE Mesh (Bluetooth Low Energy Mesh), Zigbee (a wireless network protocol for low-speed short-range transmission) and RF4CE (Radio Frequency four Consumer Electronics, a standard and protocol for home appliance remote control), and is light in weight, small in size and convenient to integrate.

[0055] The wireless communication module is used for receiving a transmission instruction of the terminal device, judging the instruction by the MCU control module, reading information of the storage module, and returning to the terminal device.

[0056] Embodiment 2

[0057] Figure 2 A flowchart of a ground positioning method for a pipeline magnetic flux leakage internal detector is provided for an exemplary embodiment of the present application. As shown in Figure 2 The ground positioning method provided by the present embodiment includes:

[0058] S11, detecting magnetic field information of the pipeline, the magnetic field information including magnetic field strength;

[0059] The magnetic sensor module is used for detecting the magnetic field information of the pipeline,

[0060] The ground positioning device is buried above the pipeline, and the magnetic field information is sensed by the magnetic sensor module. It can be understood that after the ground positioning device is buried at a specific position, the ground positioning device is turned on. Since the passage of objects will cause changes in the magnetic field of the surrounding environment, the magnetic field strength of the surrounding environment will change, so that whether the magnetic flux leakage internal detector passes through is represented by detecting the magnetic strength, and the specific detection is realized by the following steps.

[0061] The control module periodically reads the information collected by the magnetic sensor, and judges whether the magnetic field is abnormal. The magnetic field information may be generated by the pipeline below, or may be caused by the passage of some objects through the pipeline, such as the magnetic flux leakage internal detector inside the pipeline, the car driving on the road, etc.

[0062] S12, reading the magnetic field information and sending a first calculation instruction;

[0063] The control module is used for reading the magnetic field information and sending a first calculation instruction to the calculation module;

[0064] S13, in response to the first calculation instruction, calculating whether the difference between the magnetic field strength and the reference value is greater than the threshold value according to the first calculation instruction; if yes, executing step S14, if no, executing step S11;

[0065] The calculation module is configured to calculate whether the difference between the magnetic field strength and the reference value is greater than the threshold value according to the first calculation instruction after receiving the first calculation instruction;

[0066] S14, sending a determination signal;

[0067] The calculation module sends the determination signal to the control module;

[0068] S15, in response to receiving the determination signal, sending a second calculation instruction according to the determination signal;

[0069] The control module is configured to send a second calculation instruction to the calculation module after receiving the determination signal

[0070] S16, in response to the second calculation instruction, calculating whether the frequency amplitude of the magnetic field strength is less than a preset value according to the second calculation instruction; if yes, executing step S17; if no, executing step S11;

[0071] The calculation module is configured to calculate whether the frequency amplitude of the magnetic field strength at the preset frequency is less than the preset value according to the second calculation instruction after receiving the second calculation instruction;

[0072] After the calculation module receives the calculation instruction, it calculates whether the frequency amplitude of the magnetic field strength is less than the preset value according to the calculation instruction, and judges whether the magnetic flux leakage internal detector passes according to the calculation result.

[0073] When the judgment result is that the frequency amplitude is less than the preset value, it is judged that the magnetic flux leakage internal detector passes, and the magnetic field information at this time is collected.

[0074] S17, determining that the magnetic flux leakage internal detector passes, collecting the magnetic field information to position the magnetic flux leakage internal detector.

[0075] The control module is configured to read the magnetic field information and send a first calculation instruction to the calculation module. After receiving the first calculation instruction from the control module, the calculation module calculates whether the difference between the magnetic field strength and the reference value is greater than the threshold value. The first calculation instruction is to calculate whether the difference between the magnetic field strength and the reference value is greater than the threshold value, specifically whether the difference between the magnetic field strength and the reference value is greater than the threshold value. If the calculation result is greater than the threshold value, the calculation module sends a determination signal to the control module, wherein the determination signal represents that the calculation result is greater than the threshold value. After the control module receives the determination signal, the control module sends a second calculation instruction to the calculation module. The calculation module calculates whether the frequency amplitude of the magnetic field strength collected by the sensor at the preset frequency is less than the preset value according to the second calculation instruction. If the frequency amplitude is less than the preset value, it indicates that the magnetic flux leakage internal detector passes at this time, and the magnetic field information at this time is stored to position the magnetic flux leakage internal detector.

[0076] It can be seen that the application is judged under the premise that the difference between the magnetic field strength and the reference value is greater than the threshold value. That is, if the difference between the magnetic field strength and the reference value is greater than the threshold value, the subsequent frequency amplitude judgment is performed, so that the judgment result is more accurate. At the same time, the calculation of the frequency amplitude of all data is avoided, the calculation amount is reduced, and the calculation efficiency is improved.

[0077] When the calculation result is that the frequency amplitude of the magnetic field strength is greater than or equal to the preset value, it is judged that the magnetic flux leakage internal detector does not pass at this time, but other external interference objects pass, such as a car driving on the ground, and the step of detecting the magnetic field information of the pipeline is re-executed.

[0078] It is worth noting that the preset value range is adaptively set according to different types of magnetic flux leakage internal detectors, and is not a fixed value, which can be adjusted according to factors such as working conditions.

[0079] Figure 3 The flow chart of the ground positioning method provided by the embodiment of the application is shown in FIG. 1. Figure 3 As shown in FIG. 1, the ground positioning method provided by the embodiment of the application is a flowchart for judging that the magnetic flux leakage internal detector passes, which includes the following steps:

[0080] S21, calculating the frequency amplitude of the magnetic field strength;

[0081] The frequency amplitude is calculated by the Fourier formula.

[0082] In some embodiments, the discrete Fourier formula calculates the 50HZ frequency amplitude.

[0083] S22, if the frequency amplitude is less than the preset value;

[0084] The frequency amplitude is compared and analyzed.

[0085] S23, collect the magnetic field information.

[0086] When the result meets the condition that the frequency amplitude is less than the preset value, it is determined that the magnetic flux leakage internal detector passes at this time, and the magnetic field change at this time is caused by the magnetic flux leakage internal detector, and the magnetic field information at this time is collected.

[0087] In some embodiments, when the frequency amplitude cannot simultaneously meet the condition that the frequency amplitude is less than the preset value, it is determined that the external object interferes at this time, and the magnetic field change is not caused by the magnetic flux leakage internal detector, but by the external object, such as a moving car. At this time, no data is collected, but the step of receiving the magnetic field information of the detection pipeline is returned to execute, that is, when it is determined that the non-magnetic flux leakage internal detector passes, the detection continues until the magnetic flux leakage internal detector passes, and then the magnetic field strength information is collected.

[0088] As shown in Figure 4 , it is a feasible implementation, and the flowchart of calculating the frequency amplitude is shown.

[0089] S31, read the ground positioning device storage information;

[0090] S32, RC first-order low-pass filtering;

[0091] S33, mean filtering;

[0092] S34, 20-point DTF discrete Fourier transform, remove power frequency interference;

[0093] In combination with the DFT (Discrete Fourier Transform) algorithm, the frequency amplitude is extracted to determine whether it exceeds the preset value; the sensor sampling frequency is 1000HZ, and the DFT operation of 20 points is sequentially taken out to calculate the specific amplitude at 50HZ frequency. If it exceeds the threshold value (such as 1000), it is power frequency interference.

[0094] S35, if the condition is met, it is target data.

[0095] S36, record the time when the detector passes through the collection device.

[0096] In the process of calculating the frequency amplitude, first, RC (Resistor, Capacitance) first-order low-pass filtering and mean operation are performed, and the data is divided into three sections according to the maximum value and the minimum value, so that multiple groups of data can be processed, and the data processing speed is improved. After being divided into three sections, the frequency amplitude is calculated, wherein the frequency amplitude is calculated by the DFT algorithm.

[0097] S32, the RC first-order low-pass filtering formula is: u0(n) = u0(n-1) + Ts2πfc(u i(n)-u0(n-1)). Where, u i u0(n) is the input, u0(n) is the output, Ts is the sampling interval (in actual detection, data is collected once every 1ms, but other time intervals are also possible. The specific sampling interval can be adjusted according to the actual working conditions), and fc is the filter cutoff frequency, which is specifically taken as twice the sampling frequency.

[0098] The low-pass filter formula is a discrete iterative equation derived from the Laplace transform and Z-transform.

[0099] Then perform S33 and mean filtering. Where X1, X2, ..., Xn are all actual sampling points, and the average value is calculated by adding several of them together.

[0100] S34. The frequency amplitude is obtained by using the Fourier transform formula. If the value exceeds the preset value, it is considered an interference.

[0101] The Discrete Fourier Transform (DFT) of an N-point sequence x(n) in the time domain is defined as follows: Where (0≤k≤N-1), j is the imaginary unit.

[0102] Since the system sampling frequency is 1kHz, 20 sampling points are selected sequentially for Discrete Fourier Transform.

[0103] Ultimately, the fundamental frequency amplitude at 50Hz can be extracted. If it exceeds the threshold, it indicates 50Hz power frequency interference.

[0104] If the frequency amplitude is less than the preset value (meeting the requirement that it does not exceed the threshold), then it is the target data. The target data is the magnetic field strength generated when the leakage magnetic field detector passes through.

[0105] like Figure 5 The diagram shown is a schematic representation of the data transmission process in this embodiment.

[0106] S41. Should data transmission be performed? If yes, then execute S42; otherwise, then execute S43.

[0107] S42, Data transmission;

[0108] S43. Has GPS positioning and RTC synchronization been successful? If yes, proceed to S44; otherwise, repeat S43.

[0109] S44. Is the magnetic field information initialization successful? If yes, proceed to S45; otherwise, repeat S44.

[0110] S45. Enter the main program and begin loop monitoring;

[0111] S46. Is data collection triggered? If yes, proceed to S47; otherwise, proceed to S45.

[0112] S47. Data acquisition and data storage.

[0113] In the process of determining whether to transmit data, such as Figure 5 As shown, upon power-on, the system checks whether data transmission is required. If so, data transmission occurs; otherwise, GPS positioning, RTC clock synchronization, and magnetic field information initialization are initiated. After successful GPS positioning, RTC clock synchronization, and magnetic field information initialization, the main program begins looping and detecting information. If the difference between the monitored magnetic field information and the reference value exceeds a threshold, data acquisition is triggered. After data algorithm analysis, the monitored information is stored. Then, the main program continues looping and monitoring (the detection process of the internal magnetic leakage detector). In other words, this implementation provides a ground positioning method comprising two workflows: real-time detection and data transmission.

[0114] Example 3

[0115] This application provides a ground positioning system for a pipeline magnetic flux leakage detector, which includes the ground positioning device described in Embodiment 1. Therefore, it includes all the beneficial technical effects of the ground positioning device in Embodiment 1, which will not be repeated here.

[0116] Specifically, the ground positioning system is used to monitor the passage information of the magnetic flux leakage detector, which is installed in the pipe being inspected and can move inside the pipe along its extension direction, while the ground positioning device is buried underground and located above the pipe.

[0117] Specifically, the internal magnetic flux leakage detector is equipped with a magnetic steel brush, which means that the internal detector moves with a magnetic field to detect the pipe being tested. When the internal magnetic flux leakage detector passes through the pipe, it will cause a change in the magnetic field of the pipe. Therefore, by detecting whether the difference between the magnetic field strength of the pipe and the reference value is greater than the threshold, the relationship between the frequency amplitude and the preset value can be further judged to determine whether the current passage is a ground positioning device.

[0118] In some embodiments, there are multiple ground positioning devices, which are positioned above the pipeline at preset distances.

[0119] In one feasible embodiment, the preset distance is one kilometer. That is, ground positioning devices are arranged at one-kilometer intervals. By setting up multiple ground positioning devices, multiple devices can upload data simultaneously, which is fast, reliable, and convenient. It is understood that the specific preset distance can be adaptively adjusted according to the actual working conditions and the type of pipeline.

[0120] The similar parts among the embodiments provided in the application can be referred to each other, the specific embodiments provided above are only several examples under the general concept of the application, and do not constitute the limitation of the protection scope of the application. Any other embodiments extended according to the application scheme without creative labor for those skilled in the art shall fall within the protection scope of the application.

Claims

1. A ground positioning device for a pipeline magnetic flux leakage detector, buried above the pipeline, for collecting magnetic field information of the internal magnetic flux leakage detector inside the pipeline and locating the detector, characterized in that, include: The system includes a control module, a magnetic sensor module, and a computing module, wherein the magnetic sensor module and the computing module are respectively connected to the control module. The magnetic sensor module is used to detect the magnetic field information of the pipeline, and the magnetic field information includes the magnetic field strength; The control module is used to read the magnetic field information and send a first calculation instruction to the calculation module; The calculation module is used to calculate, after receiving the first calculation instruction, whether the difference between the magnetic field strength and the reference value is greater than a threshold. If so, the calculation module sends a confirmation signal to the control module; The control module is used to send a second calculation instruction to the calculation module after receiving the determination signal; The calculation module is used to calculate, after receiving the second calculation instruction, whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value according to the second calculation instruction; If the frequency amplitude is less than the preset value, it is determined that the magnetic flux leakage detector has passed, and the magnetic field information is collected to locate the magnetic flux leakage detector.

2. The ground positioning device according to claim 1, characterized in that, The calculation module is also used to calculate the frequency amplitude of the magnetic field information collected by the magnetic sensor module using the discrete Fourier formula after receiving the second calculation instruction.

3. The ground positioning device according to claim 2, characterized in that, Also includes: RTC real-time clock module; The RTC real-time clock module is connected to the control module, and the control module is also used to send time synchronization and timing commands to the RTC real-time clock module; The RTC real-time clock module is used to receive the time synchronization and timing commands, and to record the current time when the magnetic sensor module acquires the magnetic field information.

4. The ground positioning device according to claim 3, characterized in that, The control module uses a Riscv chip; The magnetic sensor module is an AMR magnetoresistive sensor.

5. The ground positioning device according to claim 4, characterized in that, Also includes: GPS module; The GPS module is connected to the control module and is used to determine the coordinates and time of the ground positioning device; Wherein, the coordinate position is the embedded coordinate of the ground positioning device; The GPS module has a time synchronization function, which is used to synchronize the ground positioning device with satellite time; the control module performs time synchronization operation on the RTC real-time clock module through the GPS module, and shuts down the GPS module after the time synchronization operation is completed.

6. The ground positioning device according to claim 5, characterized in that, Also includes: Storage module and wireless communication module; The control module is connected to the storage module and the wireless communication module respectively. The storage module is used to store the magnetic field information of the magnetic flux leakage detector, the coordinate position, and the current time when the magnetic flux leakage detector triggers the acquisition when it passes by. The control module is used to receive transmission instructions from the control device and control the wireless communication module to send the magnetic field information of the leakage magnetic field detector, the coordinate position and the current time stored in the storage module to the control device according to the transmission instructions.

7. A ground positioning method, characterized in that, include: The magnetic field information of the pipeline is detected, including the magnetic field strength; Read the magnetic field information and send the first calculation command; In response to the first calculation instruction, calculate whether the difference between the magnetic field strength and the reference value is greater than a threshold. If so, send a confirmation signal; In response to receiving the determination signal, a second calculation instruction is sent according to the determination signal; In response to receiving the second calculation instruction, the system calculates whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value according to the second calculation instruction. If the frequency amplitude is less than the preset value, the system determines that the internal magnetic leakage detector has passed and collects the magnetic field information to locate the internal magnetic leakage detector.

8. The ground positioning method according to claim 7, characterized in that, The step of calculating whether the frequency amplitude of the magnetic field strength at a preset frequency is less than a preset value according to the second calculation instruction includes: The frequency amplitude is calculated using the Discrete Fourier Transform formula.

9. A ground positioning system, characterized in that, The ground positioning device includes any one of claims 1-6.

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