Pipeline detection device, method and system

Abstract

The invention provides a pipeline detection device, method and system, and belongs to the technical field of pipeline detection. The pipeline detection device comprises a magnetic array ring, a multi-core optical cable and an optical signal processing device; the magnetic array ring comprises a plurality of optical fiber channels and magneto-optical crystals wrapping the optical fiber channels; the multi-core optical cable is configured to receive a to-be-modulated optical signal generated by the optical signal processing device, transmit the to-be-modulated optical signal to the magnetic array ring for polarization modulation, receive a return optical signal after the magnetic array ring modulates the to-be-modulated optical signal, and transmit the return optical signal to the optical signal processing device; the optical signal processing device comprises a positioning module which is configured to determine the deformation position and the deformation degree of the pipeline in response to the returned optical signal and the position information, provided by the positioning module, of the magnetic array ring. Through the pipeline detection device provided by the invention, the defects of the inner wall of the pipeline can be detected under the condition that the original magnetic field of the inner wall of the pipeline is not damaged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pipeline detection, and particularly relates to a pipeline detection device, method and system. BACKGROUND

[0002] In the pipeline detection of urban water plants, the current commonly used magnetic flux leakage detection method and the out-of-pipe distributed detection method have certain limitations. The magnetic flux leakage detection method needs to actively magnetize the pipeline, which may destroy the original magnetic field inside the pipeline, resulting in that the collected magnetic field signal is a magnetized signal, rather than the actual magnetic field inside the pipeline. The out-of-pipe distributed detection method is limited to monitoring defects on the outer wall of the pipeline, and cannot detect corrosion of the inner wall of the pipeline. Therefore, there is an urgent need for a detection means that does not destroy the original magnetic field of the inner wall of the pipeline and can detect the inner wall of the pipeline. SUMMARY

[0003] In view of the above problems, the present application provides a pipeline detection device, method and system to overcome the above problems or at least partially solve the above problems.

[0004] In a first aspect of the present application, a pipeline detection device is provided, comprising a magnetic array ring, a multi-core optical cable and an optical signal processing device; The magnetic array ring comprises a plurality of optical fiber channels and a magneto-optical crystal wrapped around each optical fiber channel; wherein the magneto-optical crystal is configured to rotate the polarization direction of the optical signal; One end of the multi-core optical cable is connected to the magnetic array ring, and the other end is connected to the optical signal processing device. The multi-core optical cable is configured to receive the modulated optical signal generated by the optical signal processing device, transmit the modulated optical signal to the magnetic array ring for polarization modulation, and receive the return optical signal after the magnetic array ring modulates the modulated optical signal, and transmit the return optical signal to the optical signal processing device; The optical signal processing device comprises a positioning module configured to determine the deformation position and degree of the pipeline in response to the return optical signal and the position information of the magnetic array ring provided by the positioning module.

[0005] Further, the magnetic array ring is configured to move in the pipeline along the axial direction of the pipeline, and the optical signal processing device further comprises a modulation module and a demodulation module; wherein, The modulation module is configured to generate the modulated optical signal, which is transmitted to the magnetic array ring through the multi-core optical cable, so that the magnetic array ring generates the return optical signal; The positioning module is configured to detect the position information of the magnetic array ring in the pipeline and transmit the position information to the demodulation module; The demodulation module is configured to determine the deformed position and the deformation degree of the pipeline in response to the return light signal and the position information.

[0006] Further, the modulation module comprises a light source, a polarization polarizer and a beam splitter; wherein the polarization polarizer is connected between the light source and the beam splitter, and the beam splitter is further connected with the multi-core optical cable; The light source is configured to generate a light signal output to the polarization polarizer; The polarization polarizer is configured to respond to the light signal, first depolarize the light signal, then convert it into linearly polarized light of a preset polarization angle, and transmit the linearly polarized light to the beam splitter; The beam splitter is configured to respond to the linearly polarized light and split the linearly polarized light into a plurality of channels of the to-be-modulated light signal, which is transmitted into each of the optical fiber channels through the multi-core optical cable.

[0007] Further, the position information includes the moving distance of the magnetic array ring in the pipeline, and the demodulation module comprises a balanced photodetector, a lock-in amplifier and a demodulation unit; The balanced photodetector is configured to synchronously detect the biaxial polarization component optical power intensity of the parallel polarization component and the vertical polarization component of the return light signal, and output the biaxial polarization component optical power intensity to the lock-in amplifier; The lock-in amplifier is configured to denoise and amplify the biaxial polarization component optical power intensity, and output the amplified optical power intensity to the demodulation unit; The demodulation unit is configured to determine the magnetic induction intensity of the return light signal based on the amplified biaxial polarization component optical power intensity and the moving distance.

[0008] Further, the polarization polarizer is provided with a depolarizer, a Wollaston prism and a 45-degree Faraday rotator.

[0009] Further, the plurality of optical fiber channels in the magnetic array ring are arranged in a ring array, and the diameter of the magnetic array ring is smaller than the diameter of the pipeline.

[0010] The second aspect of the embodiment of the present application provides a pipeline detection method applied to the pipeline detection device of the first aspect of the embodiment of the present application, comprising: In response to the to-be-modulated light signal generated by the light signal processing device, the to-be-modulated light signal is transmitted to the magnetic array ring by the multi-core optical cable; In response to the to-be-modulated optical signal, a magneto-optical crystal in the magnetic array ring modulates the to-be-modulated optical signal, and a returned optical signal obtained after modulation is returned to the optical signal processing device through the multi-core optical cable; In response to the returned optical signal and position information of the magnetic array ring provided by a positioning module in the optical signal processing device, a deformed position and a deformation degree of the pipeline are determined.

[0011] Further, in response to the returned optical signal and the position information of the magnetic array ring provided by the positioning module in the optical signal processing device, the deformed position and the deformation degree of the pipeline are determined, including: Based on the returned optical signal, a biaxial polarization component optical power intensity of each optical fiber channel position is determined; Based on the biaxial optical power intensity, a polarization angle of the optical signal is determined; Based on the polarization angle of the optical signal, a magnetic induction intensity of the returned optical signal is determined; Based on the magnetic induction intensity and the position information, and a preset force-magnetic coupling model, the deformed position and the deformation degree of the pipeline are determined; wherein the preset force-magnetic coupling model represents the influence of different deformation degrees of the pipeline on the magnetic induction intensity.

[0012] Further, based on the magnetic induction intensity and the preset force-magnetic coupling model, and the position information, the deformed position and the deformation degree of the pipeline are determined, including: Based on the magnetic induction intensity and the position information, a pulse signal of each optical fiber channel at different positions is determined; wherein the pulse signal represents the amplitude change of the magnetic induction intensity at the pipeline position corresponding to the position information; Based on the pulse signal of each optical fiber channel at different positions, the deformed position of the pipeline is determined; Based on the deformed position and the preset force-magnetic coupling model, the deformation degree of the pipeline is determined.

[0013] In a third aspect, a pipeline detection system is provided, including the pipeline detection device and a pig according to the first aspect of the present application, one end of the pig is connected to one end of the magnetic array ring in the pipeline detection device; The pig is configured to control the magnetic array ring to move in the pipeline.

[0014] Further, it further includes a three-way valve; wherein one end of the multi-core optical cable in the pipeline detection device passes through the three-way valve and is connected to the optical signal processing device of the pipeline detection device, and the other end of the multi-core optical cable is connected to the other end of the magnetic array ring.

[0015] The pipeline detection device provided by the embodiment comprises a magnetic array ring, a multi-core optical cable and an optical signal processing device. The magnetic array ring comprises a plurality of optical fiber channels and a magneto-optical crystal wrapped on each optical fiber channel. The magneto-optical crystal is configured to rotate the polarization direction of the optical signal. Since the rotation angle is proportional to the magnetic field strength, the magnetic field strength inside the pipeline can be accurately measured by detecting the change in the polarization of the light without destroying the original magnetic field inside the pipeline.

[0016] Secondly, since one end of the multi-core optical cable is connected with the magnetic array ring and the other end is connected with the optical signal processing device, the multi-core optical cable can simultaneously transmit the optical signals of the plurality of optical fiber channels, each channel corresponding to a detection point, thereby realizing the multi-point synchronous detection of the pipeline and improving the detection efficiency in cooperation with the magnetic array ring.

[0017] In addition, the multi-core optical cable is configured to receive the to-be-modulated optical signal generated by the optical signal processing device, transmit the to-be-modulated optical signal to the magnetic array ring for polarization modulation, receive the return optical signal after the to-be-modulated optical signal is modulated by the magnetic array ring, and transmit the return optical signal to the optical signal processing device. Therefore, the stable bidirectional transmission of the optical signals (the to-be-modulated optical signal and the return optical signal) can be realized through the multi-core optical cable, so as to ensure the low loss and low interference of the optical signals in the transmission process.

[0018] In addition, since the optical signal processing device comprises a positioning module configured to determine the deformation position and degree of the pipeline in response to the return optical signal and the position information of the magnetic array ring provided by the positioning module. Therefore, by connecting the optical signal processing module with the magnetic array ring and the multi-core optical cable, the magneto-optical crystal in the magnetic array ring can be used to perform polarization modulation on the to-be-modulated optical signal under the action of the external magnetic field, detect the polarization change of the return optical signal, and inversely deduce the change in the magnetic field strength. Finally, in combination with the position information of the magnetic array ring, the deformation position and degree of the pipeline inside can be determined without destroying the magnetic field inside the pipeline. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a schematic diagram of a pipeline detection device provided by an embodiment of the present application; Figure 2 is a schematic diagram of a magnetic array ring provided by an embodiment of the present application; Figure 3 is a schematic diagram of another pipeline detection device provided by an embodiment of the present application; Figure 4 is a step flow chart of a pipeline detection method provided by an embodiment of the present application; Figure 5 is a schematic diagram of a magnetic field change trend of a pipeline axis provided by an embodiment of the present application; Figure 6 is a schematic diagram of a magnetic induction intensity change of multiple optical fiber channels under an applied magnetic field provided by an embodiment of the present application; Figure 7 is a schematic diagram of a pipeline detection system that can be provided by an embodiment of the present application. DETAILED DESCRIPTION

[0021] Exemplary embodiments of the present application will be described herein below with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present application can be more thoroughly understood and so that the scope of the present application can be accurately conveyed to those skilled in the art.

[0022] Reference Figure 1 , Figure 1 is a pipeline detection device provided by an embodiment of the present application, from Figure 1 It can be known from the pipeline detection device that the pipeline detection device comprises a magnetic array ring, a multi-core optical cable, and an optical signal processing device; the magnetic array ring comprises multiple optical fiber channels and a magneto-optical crystal wrapped on each of the optical fiber channels; wherein the magneto-optical crystal is configured to rotate the polarization direction of an optical signal; one end of the multi-core optical cable is connected to the magnetic array ring, and the other end is connected to the optical signal processing device; the multi-core optical cable is configured to receive a to-be-modulated optical signal generated by the optical signal processing device, transmit the to-be-modulated optical signal to the magnetic array ring for polarization modulation, and receive a return optical signal after the to-be-modulated optical signal is modulated by the magnetic array ring and transmit the return optical signal to the optical signal processing device; the optical signal processing device comprises a positioning module configured to determine a deformation position and a deformation degree of the pipeline in response to the return optical signal and position information of the magnetic array ring provided by the positioning module.

[0023] In the present embodiment, the magnetic array ring is a ring structure arranged in a specific manner by multiple magnet units, used to generate a specific distribution of magnetic field, composed of multiple optical fiber channels, and each optical fiber is wrapped with a magneto-optical crystal. The magneto-optical crystal is configured to rotate the polarization direction of the optical signal, so that the magnetic array ring can adjust the polarization state of the to-be-modulated optical signal generated by the optical signal processing device, facilitating subsequent detection of the deformation position and the deformation degree of the pipeline.

[0024] Reference Figure 2 ,Figure 2 is a schematic diagram of a magnetic array ring provided by an embodiment of the present application, from Figure 2 It can be known that the magnetic array ring in the embodiment can contain 16 fiber channels, and the 16 magneto-optical crystals are wrapped around the optical fibers and fixed by mechanical devices, referring to the cross-sectional view of Figure 2 , forming a ring-shaped array. Referring to the perspective view of Figure 2 , taking a 16-channel ring-shaped array as a standard, wherein the top is provided with a sensor 1, and the sensors are sequentially defined as 2, 3, …, 16 in a clockwise direction. The magnetic array ring includes a fiber magnetic field sensor, which contains magneto-optical crystals and can be immune to electromagnetic interference based on optical signal transmission.

[0025] The multi-core optical cable can be a communication cable integrating multiple optical fibers in the same sheath. The multi-core optical cable contains multiple independent fiber cores in the same optical cable, and each fiber core can independently transmit an optical signal. Since one end of the multi-core optical cable is connected to the magnetic array ring and the other end is connected to the optical signal processing device, the multi-core optical cable is configured to: receive the to-be-modulated optical signal generated by the optical signal processing device, and transmit the to-be-modulated optical signal to the magnetic array ring for polarization modulation, and receive the return optical signal after the magnetic array ring modulates the to-be-modulated optical signal. Therefore, the multi-core optical cable can transmit the to-be-modulated optical signal generated by the optical signal processing device to the magnetic array ring through the independent fiber cores in parallel. Then the magnetic array ring performs polarization modulation on the to-be-modulated optical signal, which can controllably rotate or change the polarization direction of the to-be-modulated optical signal according to a preset change. Then the multi-core optical cable transmits the to-be-modulated optical signal with the rotated polarization direction as the return optical signal to the optical signal processing device.

[0026] The optical signal processing device can generate the to-be-modulated optical signal, and receive the return optical signal, and is an electronic device or device for analyzing and confirming the deformation position and deformation degree of the pipeline. The optical signal processing device includes a positioning module, which can position the position of the magnetic array ring. Therefore, the deformation position and deformation degree of the pipeline can be determined by the return optical signal and the position of the pipeline where the magnetic array ring is located reflected by the positioning module. Specifically, the magnetic array ring is arranged to move in the pipeline. During the movement of the magnetic array ring, the return optical signal at different positions in the pipeline is returned to the optical signal processing device in real time, and the positioning module feeds back the position information of the magnetic array ring corresponding to the return optical signal. Finally, the optical signal processing device analyzes the return optical signal at different positions in the pipeline, measures the polarization rotation angle of the return optical signal, and determines whether the deformation occurs inside the pipeline and the degree of deformation according to the size of the polarization rotation angle of the return optical signal when the pipeline is bent or extruded. Then, according to the position information provided by the positioning module, the position where the deformation of the pipeline occurs is determined.

[0027] For example, assume that the initial θ0 of the magnetic array ring is 15° and the position x is 200 m. The detected return light signal is θ' = 25° and k = 0.5° / mm. k is the pipe deformation variable corresponding to the unit polarization rotation angle.

[0028] Deformation calculation: Δα = (25°-15°) / 0.5 = 20 mm (bending subsidence), corresponding to the pipe subsidence of 20 mm at 200 m.

[0029] In summary, the pipeline detection device provided in the embodiment includes a magnetic array ring, a multi-core optical cable, and an optical signal processing device. The magnetic array ring contains a plurality of optical fiber channels, and each optical fiber channel is covered with a magneto-optical crystal. The magneto-optical crystal causes the passing light to produce polarization rotation under the action of an external magnetic field, and the rotation angle is proportional to the magnetic field strength, so that the magnetic field size can be measured by detecting the polarization change without destroying the original magnetic field. One end of the multi-core optical cable is connected to the magnetic array ring, and the other end is connected to the optical signal processing device. The multi-core optical cable can simultaneously and in parallel transmit the signals of all optical fiber channels. Each channel corresponds to a detection point, and full-line synchronous monitoring is achieved. The multi-core optical cable is responsible for sending the modulated light from the optical signal processing device to each magneto-optical crystal and sending the polarization-modulated return light back to the processor with low loss and low interference. The optical signal processing device is built-in with a laser source, a polarization analyzer, and a positioning module: first, emit laser light to each magnetic array ring through the optical cable; then, receive the return light, measure the polarization angle change, and obtain the magnetic field information; at the same time, use the position type of the magnetic array ring given by the positioning module to associate the magnetic field data with the position information, and determine the deformation position and degree of the pipeline.

[0030] In a specific embodiment, the magnetic array ring is configured to move in the pipeline along the axial direction of the pipeline, and the optical signal processing device further includes a modulation module and a demodulation module. The modulation module is configured to generate the modulated light signal, which is transmitted to the magnetic array ring through the multi-core optical cable to make the magnetic array ring generate the return light signal. The positioning module is configured to detect the position information of the magnetic array ring in the pipeline and transmit the position information to the demodulation module. The demodulation module is configured to determine the deformation position and degree of the pipeline in response to the return light signal and the position information.

[0031] In the embodiment, the magnetic array ring is configured to move in the pipeline along the axial direction of the pipeline. Specifically, a pusher can be installed in the magnetic array ring to push the magnetic array ring to move in the pipeline along the axial direction of the pipeline. Alternatively, the magnetic array ring can be connected with a propeller to be pushed by the propeller to move in the pipeline along the axial direction of the pipeline. Figure 3 is a schematic diagram of another pipeline detection device provided in the embodiment of the application, from Figure 3It can be known that the optical signal processing device further comprises a modulation module and a demodulation module. The modulation module can generate a to-be-modulated optical signal. Specifically, a broadband light source is emitted by a light source, and the natural light of the light source is polarized and modulated by a polarization polarizer to generate linearly polarized light of a specific angle of polarization, that is, the to-be-modulated optical signal, and the to-be-modulated optical signal is transmitted to the magnetic array ring through the multi-core optical cable to enable the magnetic array ring to modulate the to-be-modulated optical signal to generate a return optical signal.

[0032] A positioning module is configured to detect position information of the magnetic array ring in the pipeline and transmit the position information to the demodulation module. The positioning module can be a position sensor installed on the magnetic array ring to detect the position information of the magnetic array ring in real time. The position information includes a moving distance and a moving direction. The positioning module can be a position sensor installed inside the pipeline to determine the position information of the magnetic array ring by detecting the distance between the magnetic array ring and the position sensor. In addition, the positioning module can also be a position sensor for detecting the elongation length of the multi-core optical cable. The moving distance of the magnetic array ring is indirectly obtained by detecting the elongation length of the multi-core optical cable.

[0033] The demodulation module is a device for determining the deformation position and deformation degree of the pipeline according to the return optical signal and the position information. Specifically, the deformation position and deformation degree are determined according to the polarization rotation angle in the return optical signal, the magnetic induction intensity of the return light, the moving distance of the magnetic array ring, and the moving direction.

[0034] In a specific embodiment, the modulation module comprises a light source, a polarization polarizer, and a beam splitter. The polarization polarizer is connected between the light source and the beam splitter, and the beam splitter is further connected with the multi-core optical cable. The light source is configured to generate an optical signal output to the polarization polarizer. The polarization polarizer is configured to convert the optical signal into linearly polarized light of a specific angle of polarization in response to the optical signal, and transmit the linearly polarized light to the beam splitter. The beam splitter is configured to split the linearly polarized light into a to-be-modulated optical signal, and the to-be-modulated optical signal is transmitted to each of the optical fiber channels through the multi-core optical cable.

[0035] In this embodiment, the modulation module comprises a light source, a polarization polarizer, and a beam splitter. The polarization polarizer is connected between the light source and the beam splitter, and the beam splitter is further connected with the multi-core optical cable. The light source is configured to generate an optical signal output to the polarization polarizer. The polarization polarizer is configured to convert the optical signal into linearly polarized light of a specific angle of polarization in response to the optical signal, and transmit the linearly polarized light to the beam splitter.

[0036] In a specific embodiment, the polarization polarizer is provided with a depolarizer, a Wollaston prism, and a 45-degree Faraday rotator.

[0037] In the present embodiment, in the present example, the polarization polarizer is provided with a depolarizer, which can depolarize the light source signal containing any noise into natural white light; provided with a Wollaston prism, which can decompose any white light into two beams of orthogonal polarized linearly polarized light, and the two beams of light are the parallel polarization component and the vertical polarization component of the natural white light respectively. The power of the light signal after the depolarizer is defined as , and the light vector is defined as , wherein After the Wollaston prism, the two beams of light are split into two orthogonal linearly polarized lights, i.e. the parallel polarization component and the vertical polarization component , and the light vector is defined as In the present example, in order to “quantize” the polarization rotation caused by the subsequent magnetic field into a single variable change, only the polarization component in the direction can be extracted, without the polarization component in the direction, and therefore is defined as , i.e. the parallel polarization component linearly polarized light.

[0038] A 45-degree Faraday rotator is also provided in the polarization polarizer, which can rotate the polarization angle of any incident polarization state by 45°. If only the polarization component in the direction is extracted, without the polarization component in the direction, a 45-degree Faraday rotator can be included in the polarization polarizer to form linearly polarized light with a specific polarization angle. Formula (1) is the Jones matrix: Formula (1) The beam splitter is a passive optical device that splits a beam of incident light into two or more output beams according to a specified ratio. Therefore, the beam splitter can respond to linearly polarized light with a specific polarization angle, and split the linearly polarized light with a specific polarization angle into a one-to-one correspondence between the modulated light signal and the optical fiber channel. For example, if the magnetic array ring includes 16 optical fiber channels, the beam splitter can uniformly split the linearly polarized light with a specific polarization angle into 16 identical modulated light signals, and then the modulated light signals are transmitted to each optical fiber channel through a multi-core optical cable.

[0039] In a specific embodiment, the position information includes a moving distance of the magnetic array ring in the pipeline, the demodulation module includes a balanced photodetector, a lock-in amplifier and a demodulation unit; the balanced photodetector is configured to detect a biaxial polarization component light power intensity of the return light signal and output the biaxial polarization component light power intensity to the lock-in amplifier; the lock-in amplifier is configured to denoise and amplify the biaxial polarization component light power intensity and output the amplified light power intensity to the demodulation unit; and the demodulation unit is configured to determine a magnetic induction intensity of the return light signal based on the amplified biaxial polarization component light power intensity and the moving distance.

[0040] In the embodiment, the position signal includes a moving distance of the magnetic array ring in the pipeline, the demodulation module includes a balanced photodetector, a lock-in amplifier and a demodulation unit, and the balanced photodetector is configured to detect a biaxial polarization component light power intensity of the return light signal, i.e. the power of the parallel polarization component and the vertical polarization component of the return light can be measured, and output a differential current.

[0041] The lock-in amplifier is configured to amplify the biaxial polarization component light power intensity and output the amplified light power intensity to the demodulation unit, take the modulation frequency as a reference, narrow-band amplify and suppress noise of the differential current, and obtain a power signal with high signal-to-noise ratio, and the demodulation unit is configured to determine a magnetic induction intensity of the return light signal based on the amplified light power intensity, a light signal direction and the moving distance, convert the power change into the magnetic induction intensity B at the point according to the amplified power-direction data and the real-time moving distance (position information) of the magnetic array ring by using a calibration curve, and complete a single measurement. The magnetic array ring continues to move, and the magnetic induction intensity distribution at each position in the pipeline can be obtained point by point along the whole length of the pipeline.

[0042] For example, in the demodulation module of the light signal processing device, assuming that the return light signal is a 16-way signal, each way of signal is set as wherein n = 1, 2, 3, …, 16, the signal is preprocessed through a polarization polarizer first, and then the light power intensity of two axes in x direction (parallel polarization component) and y direction (vertical polarization component) is detected through a balanced photodetector, i.e. formula (2): Formula (2) After simplification, the output result is: Formula (3) The corresponding light power detected by the balanced photodetector and is: Formula (4) The voltage data output by the balanced photodetector is and According to the conversion formula of the balanced photodetector, V = α P， wherein, α is the conversion gain coefficient in the balanced photodetector. Formula (5) can be obtained: [ Formula (5) Therefore, the relationship between θ and the Vx and Vy of the optical power detection can be calculated according to formula (6).

[0043] Formula (6) Thus, the magnetic field at the position is calculated according to the Faraday effect, and the formula is: Formula (7) wherein, V represents the Verdet constant of the magneto-optical crystal material (rad / m•T), which is only related to the wavelength and temperature of the input light of the magneto-optical crystal material; H is the magnetic field strength (A / m); B is the magnetic induction intensity (T); and L is the optical path length of the linearly polarized light in the magneto-optical material (m). For a long straight optical fiber, the formula can be simplified as = V B L. Thus, formula (8) can be calculated: Formula (8) The magnetic field data of each optical fiber channel wherein, n=1, 2, 3, …, 16. The magnetic induction intensity at each channel position in the entire pipeline is collected by fusing the positioning data x(t) of the positioning module.

[0044] In a specific embodiment, the plurality of optical fiber channels in the magnetic array ring are arranged in a ring array, and the diameter of the magnetic array ring is smaller than the diameter of the pipeline.

[0045] In this embodiment, the plurality of optical fiber channels in the magnetic array ring are arranged in a ring shape to form a circular array. This arrangement allows each optical fiber channel to be evenly distributed along the circumference of the ring, thereby enabling uniform detection of the entire circumference of the pipeline and ensuring that no area inside the pipeline is missed. The diameter of the magnetic array ring is smaller than the diameter of the pipeline, which allows the magnetic array ring to be installed inside the pipeline and to move or be fixed along the inner wall of the pipeline, ensuring that the magnetic array ring maintains a certain distance from the inner wall of the pipeline and thus does not interfere with the normal operation (e.g., fluid flow) inside the pipeline.

[0046] This embodiment also provides a pipeline detection method, which is described with reference to Figure 4 , Figure 4 ​is a step flow chart of a pipeline detection method provided by the embodiment, applied to the pipeline detection device in the first aspect of the embodiment, from Figure 4 It can be known that the method comprises: Step S401: in response to the to-be-modulated light signal generated by the light signal processing device, the to-be-modulated light signal is transmitted to the magnetic array ring by the multi-core optical cable.

[0047] In the embodiment, when the inside of the pipeline is detected, first, the to-be-modulated light signal generated by the light signal processing device is transmitted to the magnetic array ring by the multi-core optical cable, so that the magnetic array ring modulates the to-be-modulated light signal.

[0048] Step S402: in response to the to-be-modulated light signal, the magneto-optical crystal in the magnetic array ring modulates the to-be-modulated light signal, and the returned light signal obtained after modulation is returned to the light signal processing device through the multi-core optical cable.

[0049] In the embodiment, the magnetic array ring can modulate the to-be-modulated light signal through the magneto-optical crystal in the magnetic array ring in response to the to-be-modulated light signal, and return the returned light signal obtained after modulation to the light signal processing device through the multi-core optical cable, so that the light signal processing device identifies the deformation position and deformation degree of the inside of the pipeline through the returned light signal.

[0050] Step S403: in response to the returned light signal and the position information of the magnetic array ring provided by the positioning module in the light signal processing device, the deformation position and deformation degree of the pipeline are determined.

[0051] In the embodiment, according to the returned light signal and the position information of the multi-core optical cable provided by the positioning module in the light signal processing device, the light signal processing device analyzes the returned light signal at different positions in the pipeline, can measure the polarization rotation angle of the returned light signal, and because the polarization rotation angle of the returned light signal changes when the pipeline is bent or extruded, the position information corresponding to the magnetic array ring when the polarization rotation angle changes is determined together to determine the deformation position and deformation degree of the pipeline.

[0052] In a specific embodiment, the deformed position and the deformed degree of the pipeline are determined based on the return light signal, the position information of the magnetic array ring provided by the positioning module in the light signal processing device, and a preset force-magnetic coupling model, wherein the preset force-magnetic coupling model represents the influence of different deformed degrees of the pipeline on the magnetic induction intensity.

[0053] In the embodiment, in order to determine the deformed position and the deformed degree of the pipeline, since the linearly polarized light inside each optical fiber is deflected due to the Faraday effect caused by the magnetic field at the magneto-optical crystal during the movement of the magnetic array ring, the deflection angle of the linearly polarized light is determined based on the biaxial polarization component light power intensity of each optical fiber channel position determined by the balanced photodetector, and then the magnetic induction intensity of the return light signal is determined. θ Then the return light signal is transmitted to the light signal processing device through the multi-core optical cable, the balanced photodetector can determine the biaxial polarization component light power intensity of each optical fiber channel position, then the deflection angle of the linearly polarized light is determined based on the biaxial polarization component light power intensity, and then the magnetic induction intensity of the return light signal is determined, finally, the deformed position and the deformed degree of the pipeline are determined based on the magnetic induction intensity, the position information, and the preset force-magnetic coupling model, wherein the preset force-magnetic coupling model represents the influence of different deformed degrees of the pipeline on the magnetic induction intensity.

[0054] In a specific embodiment, the deformed position and the deformed degree of the pipeline are determined based on the return light signal, the position information of the magnetic array ring provided by the positioning module in the light signal processing device, and a preset force-magnetic coupling model, wherein the preset force-magnetic coupling model represents the influence of different deformed degrees of the pipeline on the magnetic induction intensity.

[0055] In the embodiment, the magnetic field data of each fiber channel is analyzed. When the pipeline is not subjected to internal and external active magnetization, the pipeline retains its residual magnetism. Due to the magnetic shielding of the pipeline, the internal magnetic field of the pipeline maintains stability in the same geographical direction. In an ideal state, according to the sensor distribution rule, the electromagnetic induction intensity of the 16 fiber channels presents the same change trend with the moving distance of the magnetic array ring. In the actual situation, due to the influence of the geomagnetic field, the magnetic signal of each channel does not have an alternating component, but the direct current component has a certain offset in the overall curve due to the different detection positions of the sensors. Due to the defects in the actual pipe wall, the magnetic signal close to the corresponding pipe wall has a pulse signal, and the magnetic signal away from the position does not have a pulse signal, which can be used for the positioning of the pipe wall defects and direction. In order to realize the monitoring of the deformation of the pipeline, all the pulse signals of the channels are filtered out by filtering or difference. Secondly, the magnetic field of the stress concentration area of the pipeline has the following characteristics: the tangential component of the magnetic field strength of the magnetic field has a zero point, the magnetic signal curve is symmetrical about the zero point; the normal component has a maximum value; the midline of the peak-valley value of the tangential component and the midline of the peak value of the normal component are consistent with the position where the crack occurs in the stress concentration area.

[0056] Therefore, based on the magnetic induction intensity and the position information, the pulse signal of each fiber channel at different positions can be determined, and the pulse signal represents the amplitude change of the magnetic induction intensity at the position corresponding to the position of the pipeline; and then based on the pulse signal of each fiber channel at different positions, the deformation position of the pipeline can be determined. Specifically, when the pipeline does not deform, in an ideal state, the pulse signal of each fiber channel at different positions is the same, but due to the deformation, the pulse signal at the deformation position will have a sharp peak pulse signal that is obviously different from other positions. Therefore, the deformation position of the pipeline can be determined according to the pulse signal, and then the deformation degree of the pipeline can be determined according to the deformation position and the preset force magnetic coupling model. Since the preset force magnetic coupling model represents the influence of different deformation degrees of the pipeline on the magnetic induction intensity, the preset force magnetic coupling model can be expressed as follows: Formula (9) wherein E is the Young's modulus, ξ is the energy correlation coefficient, is the non-hysteresis magnetization intensity, is the stress, M is the magnetization intensity, and the preset force magnetic coupling model can also be expressed as the stress causing the deformation and the magnetization intensity changing.

[0057] According to the formula (10) of the magnetic induction intensity, it can be known that Formula (10) wherein M is the magnetization intensity, is the vacuum permeability, H is the external magnetic field (the magnetic field intensity in free space), and it can be known that when the magnetization intensity M changes, the magnetic induction intensity B also changes.

[0058] If the pipeline of ferromagnetic material is taken as the research object, the stress change of the arbitrarily direction displacement deformation pipeline can cause the change of the magnetic properties of the pipe wall and the magnetic field in the pipeline space according to the magneto-elastic effect. Referring to Figure 5 , Figure 5 is a schematic diagram of the magnetic field change trend of the pipeline axial provided by the embodiment of the application, Figure 5 The horizontal axis is the pipeline axial distance, the vertical axis is the magnetic flux density, H represents the axial magnetic field at different distance values from the stress position, and from Figure 5 It can be known from the above that when stress concentration occurs in a certain area, deformation occurs, and the magnetic field change trend of the pipeline axial.

[0059] Specifically, the stress change of the pipeline can cause the change of the magnetic properties of the pipe wall and the magnetic field in the pipeline space, and the modulus of the magnetization intensity of each part is different, the magnetization intensity distribution is different, and theoretically the magnetization intensity of the deformation position is enhanced, which further affects the magnetic field in the pipeline space, and the magnetic field intensity of the corresponding position in the whole internal space is enhanced in amplitude, and the magnetic field intensity amplitude change near the deformation stress direction is larger. Referring to Figure 6 , Figure 6 is a schematic diagram of the magnetic induction intensity change of multiple optical fiber channels under an applied magnetic field provided by the embodiment of the application, the horizontal axis is the pipeline axial distance, and the vertical axis is the magnetic flux density. The magnetic signal data of the multiple optical fiber channels is represented as, compared with the normal state inspection data, the magnetic induction intensity value of the multiple optical fiber channels at the deformation position rises as a whole, the magnetic signal amplitude change degree of different channels is inconsistent, and the data is represented as the significant change of the dispersion degree of each channel. Based on this, the pipeline deformation is monitored.

[0060] The third aspect of the embodiment further provides a pipeline detection system, which comprises the pipeline detection device of the first aspect of the application and a pig, one end of the magnetic array ring in the pipeline detection device is connected with the pig; the pig is configured to control the magnetic array ring to move in the pipeline.

[0061] In the embodiment, referring to Figure 7 , Figure 7 is a schematic diagram of a pipeline detection system that can be provided by the embodiment of the application, from Figure 7 It can be known from the above that one end of the magnetic array ring in the pipeline detection device is connected with the pig; The pig is configured to control the magnetic array ring to move in the pipeline. The pig is usually equipped with a driving mechanism such as a motor and a driving wheel, can move along the inner wall of the pipeline, and therefore can drive the magnetic array ring to move forward along the liquid flow in the pipeline. In addition, the pig can be installed with a travel sensor, which is connected to the optical signal processing device through a signal line and a collection card to feed back the position information of the magnetic array ring in real time.

[0062] In a specific embodiment, the pipeline detection system further comprises a three-way valve; wherein one end of the multi-core optical cable in the pipeline detection device passes through the three-way valve and is connected with the optical signal processing device in the pipeline detection device, and the other end of the multi-core optical cable is connected with the other end of the magnetic array ring.

[0063] In this embodiment, with reference to Figure 6 , the pipeline detection system further comprises a three-way valve, which can disconnect the multi-core optical cable when the pipeline is in normal operation, ensuring the normal flow of fluid in the pipeline and not affecting the daily operation of the pipeline. When pipeline detection is needed, the three-way valve is operated to connect the multi-core optical cable to the optical signal processing device, and the detection process is started. In addition, the three-way valve can prevent high-pressure fluid in the pipeline from directly impacting the multi-core optical cable and the magnetic array ring, protecting the multi-core optical cable and the magnetic array ring. Figure 6 In this embodiment, by bending the multi-core optical cable inside the magnetic array ring and returning, the effective length of the multi-core optical cable can be increased. When the magnetic array ring moves, the multi-core optical cable has sufficient redundant length to adapt to its movement, thereby expanding the movement range of the magnetic array ring in the pipeline. In addition, the multi-core optical cable is connected to the magnetic array ring and the optical signal processing device in the form of multiple turns, which can ensure that the optical cable and the connection point always maintain good contact during the movement of the magnetic array ring, avoiding signal interruption or unstable transmission.

[0064] The following will describe the process of detecting the pipeline by a specific embodiment of the pipeline detection system provided in this embodiment: First, to maintain the health of the internal space of the sewage pipeline and the drainage pipeline, the water plant regularly carries out cleaning work on the in-service pipeline, and often uses a pipe cleaner. The pipe cleaner can perform cleaning work while the pipeline is in normal operation.

[0065] The device is intended to work synchronously with the pipe cleaner. During regular cleaning operations, the magnetic field in the pipeline is regularly recorded, and the deformation defects of the pipeline are monitored and located by comparing with the past magnetic field data.

[0066] When the pig starts, the to-be-modulated light signal generated by the optical signal processing device is transmitted to the magnetic array ring for polarization modulation through the multi-core optical cable, the magnetic array ring modulates the to-be-modulated light signal, and transmits the modulated return light signal to the optical signal processing device. Due to the magnetization effect of the pipe wall residual magnetism and the earth magnetic field on the space inside the pipe, the magnetic field in the space inside the pipe tends to be stable under no stress, and the magnetic induction signals of the 16 optical fiber channels represented by the return light signal have a certain dispersion, but the trend is consistent. If there is deformation, the deformation position has stress concentration, which leads to the emergence of magnetic anomalies, which is manifested as the overall rise of the magnetic induction intensity values of multiple optical fiber channels, and the change degree of the magnetic signal amplitude of different channels is inconsistent. The data shows that the dispersion of each channel changes significantly, which is judged as a pipe strain anomaly. Therefore, based on this, combined with the moving distance of the magnetic array ring reflected by the positioning module, the pipe deformation position can be determined, and then further analysis is performed according to the preset force-magnetic coupling model to determine the deformation degree corresponding to the pipe deformation position. If the pipe deformation is relatively high, the normal operation effect cannot be achieved by continuing to use, and the detection personnel can be informed to replace in time to ensure that the fluid in the pipe passes normally.

[0067] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same and similar parts between each embodiment can be referred to each other.

[0068] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the method and device according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams can be implemented by computer program instructions, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing terminal equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal equipment realize the functions specified in the flows and / or blocks. Figure 1 The device for realizing the functions specified in one flow or multiple flows and / or blocks. Figure 1 The device for realizing the functions specified in one flow or multiple flows and / or blocks.

[0069] Although the preferred embodiments of the embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to include the preferred embodiments and all changes and modifications falling within the scope of the embodiments of the present application.

[0070] Finally, it needs to be pointed out that in this document, relational terms such as first and second and the like can only be used to distinguish one entity or action from another entity or action, without necessarily requiring or implying that there is any such actual relationship or order between these entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, so that a process, method, article, or terminal device including a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or terminal device. Without more limitations, an element defined by the statement "comprising a" does not exclude the existence of additional identical elements in the process, method, article, or terminal device including the element.

[0071] The above describes in detail the pipeline detection device, method and system provided by the present application. The principles and implementation manners of the present application are described by using specific examples. The above description of the examples is only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation manners and application ranges can be changed according to the idea of the present application. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A pipeline inspection device, characterized in that, Includes magnetic array rings, multi-core optical cables, and optical signal processing devices; The magnetic array ring includes multiple optical fiber channels and a magneto-optical crystal wrapped around each of the optical fiber channels; wherein the magneto-optical crystal is configured to rotate the polarization direction of the optical signal. One end of the multi-core optical cable is connected to the magnetic array ring, and the other end is connected to the optical signal processing device. The multi-core optical cable is configured to: receive the optical signal to be modulated generated by the optical signal processing device, transmit the optical signal to be modulated to the magnetic array ring for polarization modulation, and receive the return optical signal after the magnetic array ring modulates the optical signal to be modulated, and transmit the return optical signal to the optical signal processing device. The optical signal processing device includes a positioning module configured to determine the deformation location and degree of the pipeline in response to the returned optical signal and the position information of the magnetic array ring provided by the positioning module.

2. The pipeline inspection device according to claim 1, characterized in that, The magnetic array ring is configured to move along the axial direction of the pipe within the pipe, and the optical signal processing device further includes a modulation module and a demodulation module; wherein... The modulation module is configured to generate the optical signal to be modulated, which is transmitted to the magnetic array ring via the multi-core optical cable, so that the magnetic array ring generates the return optical signal. The positioning module is configured to detect the position information of the magnetic array ring in the pipeline and transmit the position information to the demodulation module; The demodulation module is configured to determine the deformation location and degree of the pipe in response to the returned optical signal and the position information.

3. The pipeline inspection device according to claim 2, characterized in that, The modulation module includes: a light source, a polarizer, and a beam splitter; wherein the polarizer is connected between the light source and the beam splitter, and the beam splitter is also connected to the multi-core optical cable; The light source is configured to generate an optical signal output to the polarizer; The polarization polarizer is configured to, in response to the optical signal, convert the optical signal into linearly polarized light with a preset polarization angle, and transmit the linearly polarized light to the beam splitter; The beam splitter is configured to split the linearly polarized light into a multi-channel modulated optical signal in response to the linearly polarized light, and the modulated optical signal is transmitted to each of the optical fiber channels via the multi-core optical cable.

4. The pipeline inspection device according to claim 3, characterized in that, The location information includes the distance the magnetic array ring moves in the pipe, and the demodulation module includes a balanced photodetector, a lock-in amplifier, and a demodulation unit. The balanced photodetector is configured to synchronously detect the power intensity of the dual-axis polarization component of the parallel polarization component and the vertical polarization component of the returned optical signal, and output the power intensity of the dual-axis polarization component to the lock-in amplifier. The lock-in amplifier is configured to reduce noise and amplify the optical power intensity of the dual-axis polarization component, and output the amplified optical power intensity to the demodulation unit; The demodulation unit is configured to determine the magnetic flux density of the returned optical signal based on the amplified power intensity of the dual-axis polarization component and the moving distance.

5. The pipeline inspection device according to claim 3, characterized in that, The polarizer includes a depolarizer, a Wollaston prism, and a 45-degree Faraday rotator.

6. The pipeline inspection device according to claim 1, characterized in that, The multiple optical fiber channels in the magnetic array ring are arranged in a ring array, and the diameter of the magnetic array ring is smaller than the diameter of the pipe.

7. A pipeline inspection method, applied to the pipeline inspection device according to any one of claims 1-6, characterized in that, include: In response to the optical signal to be modulated generated by the optical signal processing device, the optical signal to be modulated is transmitted to the magnetic array ring via a multi-core optical cable; In response to the optical signal to be modulated, the magneto-optical crystal in the magnetic array ring modulates the optical signal to be modulated, and the resulting return optical signal is returned to the optical signal processing device via the multi-core optical cable. In response to the returned optical signal and the position information of the magnetic array ring provided by the positioning module in the optical signal processing device, the deformation position and degree of the pipeline are determined.

8. The pipeline inspection method according to claim 7, characterized in that, The determination of the deformation location and degree of the pipeline in response to the returned optical signal and the position information of the magnetic array ring provided by the positioning module in the optical signal processing device includes: Based on the returned optical signal, determine the dual-axis polarization component optical power intensity at each fiber channel location; Based on the biaxial optical power intensity, the polarization angle of the optical signal is determined; The magnetic flux density of the returned optical signal is determined based on the polarization angle of the optical signal. Based on the magnetic induction intensity and the location information, as well as a preset force-magnetic coupling model, the deformation location and degree of the pipeline are determined; wherein, the preset force-magnetic coupling model characterizes the influence of different degrees of deformation of the pipeline on the magnetic induction intensity.

9. The pipeline inspection method according to claim 8, characterized in that, Based on the magnetic induction intensity and the preset force-magnetic coupling model, as well as the position information, the deformation location and degree of the pipeline are determined, including: Based on the magnetic induction intensity and the position information, a pulse signal for each optical fiber channel at different positions is determined; wherein, the pulse signal characterizes the amplitude change of the magnetic induction intensity at the pipe position corresponding to the position information; The deformation location of the pipe is determined based on the pulse signals at different positions of each optical fiber channel; The degree of deformation of the pipeline is determined based on the deformation location and the preset force-magnetic coupling model.

10. A pipeline inspection system, characterized in that, Includes the pipeline inspection device and the pipeline pig as described in any one of claims 1-6, wherein the pipeline pig is connected to one end of the magnetic array ring in the pipeline inspection device; The pig is configured to control the movement of the magnetic array ring in the pipeline.

11. The pipeline inspection system according to claim 10, characterized in that, Also includes: A three-way valve; wherein, one end of the multi-core optical cable in the pipeline detection device passes through the three-way valve and is connected to the optical signal processing device of the pipeline detection device, and the other end of the multi-core optical cable is connected to the other end of the magnetic array ring.

Images