A method and system for detecting underground pipelines using efficient electromagnetic wave transmission

Abstract

The application provides a kind of underground pipeline detection method using efficient electromagnetic wave transmission, comprising: step S1, transmitter is connected or coupled with pipeline;Step S2, receiving system is segmented in place, starting from the beginning of pipeline, and the initial judgment of the trajectory of underground pipeline is carried out on the ground above to segment;Step S3, start transmitter and receiver, find the strongest point by receiver;Step S4, after confirming that the current signal is an effective distance signal, input electromagnetic wave signal into computer;Step S5, convert electromagnetic wave signal into distance, and accumulate to form the curve growth point of pipeline trajectory;The application loads electromagnetic wave signal with suitable frequency and large enough intensity on underground pipeline, and receives and detects positioning with the detection machine with high sensitivity frequency selection receiving for the frequency signal on the ground, compared with prior art, high-precision detection data of underground pipeline position can be obtained at the same depth, which provides construction safety guarantee for trenchless directional drilling pipe laying project.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electromagnetic wave emission and reception, in particular to a method and system for detecting underground pipelines using efficient electromagnetic wave transmission. BACKGROUND

[0002] Up to now, a certain scale of underground pipelines have been built in most cities and towns, including power, communication, gas, water, sewage and other pipelines, the number of which is almost proportional to the development of cities and towns. Their burial depth is generally within 30m, pipeline diameter varies from tens of millimeters to several meters, and pipeline materials are mainly metal, plastic, rubber and concrete. However, due to various reasons, a considerable number of pipelines do not have position (trajectory) data, or the data is not accurate enough and has changed. Therefore, in non-excavation directional drilling pipeline construction, the original underground pipeline position is often unknown, and the pipelines may be damaged by drilling. In a deeper sense, the construction of a large database of urban underground pipeline distribution is also an important trend of economic development.

[0003] By loading electromagnetic waves on the underground pipeline (another method of loading through a conductor, loading through a conductor without current in the pipeline, loading through a metal pipe wall, coupling excitation method, pipeline current conductor detection method, blind body excitation induction method, etc.), the received electromagnetic wave signals are received by the ground receiver, and the distance from the transmitting pipeline position to the receiver is calculated according to the strength of the received electromagnetic wave signals, so that the pipeline position can be detected and the three-dimensional trajectory curve of the underground pipeline can be fitted.

[0004] However, the intensity (degree of attenuation) of electromagnetic waves of different frequencies propagating in different media is quite different. The attenuation of conventional wireless communication signals in air by rock and soil layers is extremely serious for high frequency (several hundred kilohertz to several hundred megahertz). The effective propagation distance of high frequency electromagnetic waves in rock and soil is greatly shortened. SUMMARY

[0005] The purpose of the present application is to provide a method and system for detecting underground pipelines using efficient electromagnetic wave transmission.

[0006] In order to achieve the above purpose, the technical solution of the present application is as follows:

[0007] A method for detecting underground pipelines using efficient electromagnetic wave transmission, characterized by comprising the following steps:

[0008] Step S1, connecting or coupling the transmitter with the pipeline;

[0009] Step S2, segmenting and positioning the receiving system, starting from the beginning of the pipeline and segmenting along the initial trajectory of the underground pipeline on the ground surface;

[0010] Step S3, turn on the transmitter and receiver, find the strongest point of the signal by the receiver;

[0011] Step S4, after confirming that the current signal is a valid distance signal, input the electromagnetic wave signal into the computer;

[0012] Step S5, convert the electromagnetic wave signal into distance, and accumulate the curve growth points to form the pipeline track;

[0013] Wherein, the electromagnetic wave penetrates through the rock stratum to the ground, and the maximum electromagnetic wave propagation intensity is obtained at a certain frequency between 50Hz-50kHz as the resonance frequency, the farthest transmission distance is obtained, and the quantitative relationship between the transmission distance r, the transmission current intensity I and the received voltage v is:

[0014]

[0015] k is a coefficient determined by the stratum material, the transmission frequency and the receiver quality, and is calibrated and valued by experimental measurement.

[0016] Further, the step S1 comprises,

[0017] For the loading case of directly connected metal pipe wall and directly connected pipe conductor, the exposed metal conductors at both ends of the outcrop pipeline are respectively connected with the two output conductors of the transmitter.

[0018] For the loading case of insulated clamping pipe, line coupling, the transmitter is connected with the coupling clamp, and the coupling clamp is clamped to the end of the measured pipeline.

[0019] For the loading case of wireless excitation blind body coupling, a coupling excitation transmitter is arranged on the ground above the underground metal pipeline.

[0020] Further, the step S2 comprises, the receiver, the data acquisition card and the computer are sequentially connected to form a receiving system, and the computer is installed with a detection program.

[0021] Further, in the step S2, starting from the beginning of the pipeline, the initial judgment direction of the underground pipeline track is segmented along the ground above, and the interval is equally distributed along the track.

[0022] Further, in the step S3, at each segment point, the receiver is moved left and right on the ground surface along the direction perpendicular to the pipeline track direction with the track axis as the center, to find the strongest point of the electromagnetic wave signal.

[0023] The application discloses an underground pipeline detection system using high-efficiency electromagnetic wave transmission, which is characterized by comprising an excitation signal transmitter and a wireless receiving system, wherein the excitation signal transmitter comprises a sine wave signal generating circuit and an excitation signal power amplification circuit, and the wireless receiving system comprises a magnetic antenna, a mixing amplification module, a frequency conversion filtering module, an intermediate frequency amplification module, a power amplification module, a power module and a data processing system.

[0024] Further, the excitation signal power amplification circuit comprises push-pull field effect tubes and a magnetic tank coupling transformer, and the excitation signal power amplification circuit is in contact with the underground pipeline conductor, or is connected with a magnetic force wrapping clamp of a ring-shaped winding, or cooperates with a magnetic rod antenna to conduct non-contact electromagnetic wave coupling transmission on the underground pipeline.

[0025] The application loads electromagnetic wave signals with a suitable frequency and a large enough intensity on the underground pipeline, and receives and detects the position of the underground pipeline by using a detection machine with high sensitivity and frequency selection on the ground, so that high-precision detection data of the position of the underground pipeline can be obtained at the same depth compared with the prior art, and construction safety guarantee is provided for trenchless directional drilling pipe laying engineering. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a flow chart of the underground pipeline detection method of the application;

[0027] Figure 2 It is a schematic diagram of the underground pipeline detection system of the application;

[0028] Figure 3 It is a schematic diagram of the composition of the excitation signal transmitter of the application;

[0029] Figure 4 It is a schematic diagram of the composition of the excitation signal transmitter of the application;

[0030] Figure 5 It is a schematic diagram of the composition of the excitation signal transmitter of the application;

[0031] Figure 6 It is a schematic diagram of the composition of the excitation signal transmitter of the application;

[0032] Reference signs:

[0033] U1 operational amplifier, U2555 timer, U3 active filter, C1 capacitor,

[0034] D1 switch diode, R1 potentiometer, C1 capacitor, L inductor,

[0035] Q1 first field effect tube, Q2 second field effect tube, Q3 first triode, Q4 second triode. DETAILED DESCRIPTION

[0036] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0037] The present application discloses a kind of underground pipeline detection method using efficient electromagnetic wave transmission, as shown in Figure 1 The present application discloses a kind of underground pipeline detection method using efficient electromagnetic wave transmission, as shown in

[0038] Step S1, transmitter is connected or coupled with pipeline;

[0039] Step S2, receiving system is segmented in place, and from the beginning of pipeline, it is segmented along the preliminary judgment direction of underground pipeline track on the ground above;

[0040] Step S3, start transmitter and receiver, and find the strongest point by receiver;

[0041] Step S4, after confirming that the current signal is a valid distance signal, input electromagnetic wave signal into computer;

[0042] Step S5, convert electromagnetic wave signal into distance, and accumulate to form the curve growth point of pipeline track.

[0043] Wherein, electromagnetic wave penetrates through rock stratum to ground, and the maximum electromagnetic wave propagation intensity is obtained at a certain frequency between 50Hz-50kHz as resonance frequency, the farthest transmission distance is obtained, and the quantitative relationship among transmission distance r, transmission current intensity I and received voltage v is as follows:

[0044]

[0045] K is a coefficient determined by stratum material, transmission frequency and receiver quality, and is calibrated and valued by experiment.

[0046] Step S1 includes,

[0047] For the loading condition of straight metal pipe wall and straight pipe conductor, the exposed metal conductors at both ends of the outcrop pipeline are connected with the two output conductors of the transmitter respectively.

[0048] For the loading condition of insulated wrapping clamp pipe and line coupling, the transmitter is connected with the coupling clamp, and the coupling clamp is wrapped and clamped to the end of the measured pipeline.

[0049] For the loading condition of wireless excitation blind body coupling, coupling excitation transmitter is arranged on the ground above the underground metal pipeline.

[0050] Step S2 includes, in sequence, connecting the receiver, the data acquisition card and the computer to form a receiving system, and the computer is installed with a detection program.

[0051] In step S2, starting from the beginning of the pipeline, the initial judgment of the trajectory of the underground pipeline is segmented on the ground above, with 10 meters as a segment point, and the intervals of the continuous detection along the trajectory are distributed at equal intervals.

[0052] In step S3, at each segment point, the receiver is moved left and right on the ground level along the direction perpendicular to the trajectory of the pipeline with the trajectory axis as the center to find the strongest point of the electromagnetic wave signal.

[0053] In implementation, the data processing system transmits the original electromagnetic wave signal to the computer, and the transmission interface is completed by using the SmarCord usb-1252A type data acquisition card, the frequency of the multi-channel acquisition of the card can reach 200 kHz, and according to the requirement of the undistorted data sampling rate which is greater than or equal to 2 times the signal frequency, the requirement of the frequency range of the project is met.

[0054] Through the data imported through this step, the storage record, operation and display functions of the computer are used to calculate and display (numerical sequence and graphics) the position parameters and the trajectory of the underground pipeline.

[0055] The signal strength value, i.e. the voltage, is converted into the distance value of the receiver to the pipeline and the pipeline burial depth value, i.e. the pipeline position, according to the aforementioned quantization relationship, and the positions Di(xi, yi, zi) of each point measured along the pipeline are obtained through spatial geometric connection to obtain the pipeline trajectory graph.

[0056] The geometric connection can use the straight line method between two points to obtain the interpolation value of any intermediate point, or use the three-dimensional arc cutting method to accurately calculate and determine the intermediate interpolation value.

[0057] The application further discloses an underground pipeline detection system using efficient electromagnetic wave transmission, which comprises an excitation signal transmitter and a wireless receiving system. Figure 3 As shown in the figure, the excitation signal transmitter 1 comprises a sine wave signal generating circuit and an excitation signal power amplification circuit, and the output of the excitation signal power amplification circuit is adjustable at a frequency of 50 Hz to 100 kHz.

[0058] Figure 2 For an embodiment of the detection system, the receiver 2 is arranged on the ground, the plastic pipe 4 is buried in the underground rock-soil layer, and the excitation signal transmitter 1 is further arranged on the ground, and the two ends of the excitation signal transmitter 1 are connected to the underground wire 5 through the ground wire 3, the underground wire 5 is arranged through the plastic pipe 4, and the excitation signal transmitter 1, the ground wire 3 and the underground wire 5 form a closed loop.

[0059] Referring to Figure 4The sine wave signal generating circuit adopts 741 operational amplifier U1, the inverting input end of the operational amplifier U1 is connected with one end of inductor L, the other end of the inductor L is connected with the anode of switch diode D1, the cathode of the switch diode D1 is connected with one end of potentiometer R1, the other end of the potentiometer R1 is connected with the non-inverting input end of the operational amplifier U1, the switch diode D1 is connected with capacitor C1 in parallel, wherein the capacitor C1 is 16 μF, the maximum value of the potentiometer R1 is 2KΩ, and the inductor L is 10H.

[0060] The sine wave signal generating circuit generates a sine wave alternating signal with a certain frequency (50Hz-50kHz adjustable), and then a high-power excitation signal power amplifier loads the signal to the pipeline conductor (peak-peak voltage 30v, maximum current 3.5A).

[0061] The oscillation frequency of the sine signal is 25Hz, and the values of the inductor L and the capacitor C can be changed to make the oscillation frequency change from 15Hz to 100kHz, and the total harmonic distortion is less than 0.5%, and the upper limit frequency is limited by the operational amplifier.

[0062] The potentiometer R1 adjusts the amount of positive feedback added to the series resonance circuit, and the oscillation condition is that the resistance R1 is equal to the sum of the direct current resistance RL and the inductive reactance of the inductor, and the diode D1 limits the signal voltage to prevent the inductor or the operational amplifier from being saturated. The circuit generates a sine wave with small distortion, and the oscillation center frequency is:

[0063]

[0064] Referring to Figure 5 The excitation signal power amplifier circuit includes a first transistor Q3, a first field effect transistor Q1 and a second field effect transistor Q2. The collector of the first transistor Q3 is connected with the primary of a first transformer T1. The secondary of the first transformer T1 is connected with the gate of the first field effect transistor Q1 and the gate of the second field effect transistor Q2 respectively. The first field effect transistor Q1 and the second field effect transistor Q2 are connected in reverse series, that is, the source of the first field effect transistor Q1 and the source of the second field effect transistor Q2 are connected with each other, and the drain of the first field effect transistor Q1 and the drain of the second field effect transistor Q2 are connected with the primary of a second transformer T2. The secondary of the second transformer T2 is used as the output of the excitation signal power amplifier circuit.

[0065] The power amplifier circuit amplifies the sine wave signal in input by the signal generator by the first transistor Q39013 for the first time, and then the signal is coupled to the first field effect transistor Q1 and the second field effect transistor Q2 by the core transformer, that is, the first transformer T1, for power (current) amplification. Finally, the signal is resonantly amplified for the second time by the second transformer T2, that is, the porcelain tank type transformer. The first field effect transistor Q1 and the second field effect transistor Q2 adopt push-pull field effect transistors 8N60C.

[0066] The second transformer T2 is a magnetic tank coupling transformer (manganese-zinc ferrite material), with a diameter of 30 mm, a height of 19 mm, a primary coil of 16*2 turns, a secondary coil of 600 turns, a peak-peak emission voltage of 600 V, and an emission power of 50 W. The second transformer T2 can be directly contacted and conducted with the underground pipeline conductor (at this time, a resistance is connected in series), or the second transformer T2 can be connected to a magnetic force clamp with a ring winding or a straight type high-power magnetic rod antenna for non-contact electromagnetic wave coupling and conduction of the underground pipeline.

[0067] The wireless receiving system comprises a magnetic antenna, a mixed frequency amplification module, a frequency conversion and filtering module, an intermediate frequency amplification module, a power amplification module, a power supply module and a data processing system.

[0068] Referring to Figure 6 The mixed frequency amplification module comprises a second triode Q4, which is a 9018 triode. The emitter of the second triode Q4 is connected with a 555 timer U2, and a 24 KHz square wave signal is inputted by the 555 timer.

[0069] The frequency conversion and filtering module comprises an active filter U3, which is a UAF42. The collector of the triode Q4 is connected to the input end of the active filter U3 as the output of the mixed frequency amplification module.

[0070] The excitation signal power amplification circuit comprises push-pull field effect tubes and a magnetic tank coupling transformer. The excitation signal power amplification circuit is contacted and conducted with the underground pipeline conductor, or connected with the magnetic force clamp with a ring winding, or cooperated with the magnetic rod antenna for non-contact electromagnetic wave coupling and conduction of the underground pipeline.

[0071] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An underground pipeline detection system using efficient electromagnetic wave transmission, characterized by, The utility model relates to a kind of underground pipeline detection system using high-efficiency electromagnetic wave transmission, including excitation signal transmitter and wireless receiving system, the excitation signal transmitter includes sine wave signal generating circuit and excitation signal power amplifier circuit, the excitation signal power amplifier circuit includes push-pull field effect transistor and magnetic tank coupling transformer, the excitation signal power amplifier circuit is contacted with underground pipeline conductor and is conducted, or with the magnetic force of ring-shaped winding and is wrapped around pincers connection, or with magnetic rod antenna cooperation underground pipeline is carried out non-contact electromagnetic wave coupling conduction, the wireless receiving system includes magnetic antenna, mixing frequency amplification module, frequency conversion filter module, intermediate frequency amplification module, power amplifier module, power module and data processing system; The underground pipeline detection method using the underground pipeline detection system using high-efficiency electromagnetic wave transmission includes the following steps: Step S1, connect or couple the transmitter with the pipeline; Step S2, segmentally position the receiving system, start from the beginning of the pipeline, and segmentally position along the preliminary judged direction of the underground pipeline track on the ground above; Step S3, turn on the transmitter and the receiver, and find the strongest point by the receiver; Step S4, after confirming that the current signal is a valid distance signal, input the electromagnetic wave signal into the computer; Step S5, convert the electromagnetic wave signal into distance, and accumulate to form the curve growth point of the pipeline track; Wherein, the electromagnetic wave penetrates through the rock stratum to the ground, takes a certain frequency between 50Hz-50kHz as the resonance frequency, obtains the maximum electromagnetic wave propagation intensity, obtains the farthest transmission distance, and the quantitative relationship among the transmission distance r, the transmission current intensity I and the received voltage v is as follows: ； k is a coefficient determined by the stratum material, the transmission frequency and the receiver quality, and is calibrated and valued by experiment measurement; The step S1 includes, For the loading condition of directly connected metal pipe wall and directly connected pipe conductor, connect the exposed metal conductors at both ends of the outcrop pipeline with the two output conductors of the transmitter respectively; For the loading condition of insulated wrapping pipe and line coupling, connect the transmitter with the coupling clamp, and wrap the coupling clamp to the end of the measured pipeline; For the loading condition of wireless excitation blind body coupling, set the coupling excitation transmitter on the ground above the underground metal pipeline; The step S2 includes, Serially connect the receiver, the data acquisition card and the computer to constitute the receiving system, and the computer is installed with a detection program; Start from the beginning of the pipeline, segmentally position along the preliminary judged direction of the underground pipeline track on the ground above, and continuously detect the interval along the track at equal intervals with 10 meters as a segment point; The step S3 includes, At each segment point, move the receiver left and right on the ground level along the direction perpendicular to the pipeline track direction with the track axis as the center to find the strongest point of the electromagnetic wave signal.

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