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CN-121977485-A - Municipal pipeline internal blockage three-dimensional positioning and quantitative assessment method based on cooperation of pulse pressure wave and ultrasonic guided wave

CN121977485ACN 121977485 ACN121977485 ACN 121977485ACN-121977485-A

Abstract

The invention discloses a three-dimensional positioning and quantitative assessment method for internal blockage of a municipal pipeline based on cooperation of a pulse pressure wave and an ultrasonic guided wave. The method comprises the steps of S1, initializing a basic parameter acquisition and propagation model of a target pipeline, S2, exciting pressure waves and acquiring multi-point signals, S3, establishing a pressure wave propagation model in the pipeline and introducing blocking equivalent impedance, S4, carrying out inversion and preliminary quantification on blocking degree based on blocking axial positions of pulse pressure waves, S5, exciting ultrasonic guided waves and acquiring circumferential signals, S6, enabling blocking objects attached to the inner wall of the pipeline to be equivalent to a local contact stiffness-additional mass-damping system, and calculating blocking annular position angles through constructing circumferential abnormal indexes so as to realize blocking annular accurate positioning based on torsional wave characteristics and without reflection echo, S7, fusing pressure waves and guided wave information and carrying out three-dimensional schematic reconstruction on blocking positions, and S8, carrying out joint inversion and correction on blocking degree.

Inventors

  • WANG FACHENG
  • Ni Anchen
  • DUAN JINSONG

Assignees

  • 清华大学

Dates

Publication Date
20260505
Application Date
20251230

Claims (9)

  1. 1. A municipal pipeline internal blockage three-dimensional positioning and quantitative assessment method based on the cooperation of pulse pressure waves and ultrasonic guided waves comprises the following steps: S1, basic parameter acquisition and propagation model initialization of a target pipeline; step S2, pressure wave excitation and multipoint signal acquisition: setting a pulse pressure wave generator at one end of a detected pipeline, and arranging at least one pressure sensor at the pipeline or a position close to the near end of the other end of the pipeline for collecting pressure time-course signals of incident pressure waves and reflected pressure waves caused by blockage in the pipeline; S3, establishing a pressure wave propagation model in the pipe and introducing blocking equivalent impedance; step S4, performing inversion and preliminary quantification on the blocking axial position and the blocking degree based on the pulse pressure wave: Obtaining a blockage position and a blockage degree which are most matched with an actual measurement spectrum by constructing a fitting error objective function of the reflected pressure wave and minimizing the fitting error objective function of the reflected pressure wave on a frequency set; S5, ultrasonic guided wave excitation and circumferential signal acquisition: Arranging a torsional ultrasonic guided wave excitation array on the outer wall of one end of a pulse pressure wave generator on a pipeline to emit torsional guided wave beams, recording time-course responses of transmission guided waves in all directions through ultrasonic guided wave receiver array elements arranged on the outer side of the pipeline wall farther from a blocking position, and obtaining frequency domain responses through Fourier transformation; S6, equivalent the blocking object attached to the inner wall of the pipe to a local contact stiffness-additional mass-damping system, and calculating the circumferential position angle of the blocking object by constructing a circumferential anomaly index so as to realize the circumferential accurate positioning of the blocking object based on the torsional wave characteristic without reflecting echo; S7, fusing the pressure wave and the guided wave information and performing three-dimensional schematic reconstruction of the blocking position; And S8, joint inversion and correction of the blockage degree, namely constructing a joint objective function through a fitting error objective function and a guided wave error term of the reflected pressure wave, and solving a joint optimization problem of the joint objective function so as to perform joint inversion and correction on the blockage degree and the blockage three-dimensional position by utilizing the sensitivity of the guided wave to the local contact stiffness and the circumferential coverage on the basis of the axial positioning result of the pressure wave, thereby improving the accuracy and the robustness of the blockage degree assessment.
  2. 2. The method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves as set forth in claim 1, wherein the specific process of the step S1 is that geometric and physical parameters of a target pipeline are obtained, including pipeline inner diameter D i , pipeline outer diameter D o and pipeline wall thickness Tube elastic modulus E p , poisson ratio v p , fluid density ρ f in tube, bulk elastic modulus K f to calculate the tube internal cross-sectional area: and the equivalent pressure wave propagation speed c under the coupling action of the fluid and the pipe wall, when the high-order effect is not considered, the following approximate relation is adopted: Wherein the first item Characterizing the influence of fluid compressibility on wave velocity, a second term The influence of the deformation of the pipe wall on the wave speed is characterized.
  3. 3. The method for three-dimensional positioning and quantitative evaluation of the internal blockage of the municipal pipeline based on the cooperation of the pulse pressure wave and the ultrasonic guided wave as set forth in claim 2, wherein the specific content of the step S2 is as follows: A pulse pressure wave generator is arranged at one end of a detected pipeline, and a pressure pulse signal P in (t) with specific frequency or frequency band is excited at a time t 0 to be P in (t)＝P 0 s(t-t 0 ) (3), wherein P 0 is excitation amplitude, and s (t) is a preset standardized waveform function; During the pressure wave transmission process, at least one pressure sensor is arranged at the other end of the pipeline or near the near end of the other end of the pipeline and is used for collecting pressure time domain signals of incident pressure waves and reflected pressure waves caused by the blockage in the pipeline; To build a mathematical model of the propagation and reflection of pressure waves in the pipe, N p virtual probes are axially arranged along the pipe in the modeling process, the axial seating of each virtual probe is marked as x i (i＝1,2,...,N p ), and the corresponding pressure response of each virtual probe is as follows: p i (t)＝p(x i ,t) (4) the corresponding pressure response p i (t) of each virtual probe is subjected to preprocessing including detrending, bandpass filtering, time window interception, and the frequency domain spectrum p i (ω) of the reflected pressure wave is obtained by discrete fourier transform: p i (ω)＝F{p i (t)} (5)
  4. 4. The method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves according to claim 3, wherein the specific process of the step S3 is as follows: Where α is the equivalent damping coefficient for describing the along-path energy loss, introducing a local abrupt impedance change at the center axial position x=x b of the blockage for the presence of a blockage, defining the cross-sectional acoustic impedance Z 0 without blockage as: Clogging results in a reduction of the effective flow area a b to: A b ＝(1-η)A 0 (8) wherein η ε (0, 1) is the blockage area ratio, i.e. the blockage degree, then the equivalent impedance Z b at the blockage section is:
  5. 5. the method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves, as set forth in claim 4, is characterized in that the specific process of the step S4 is as follows: Wherein Z b is equivalent impedance of a blocking position, R is a reflection coefficient, T is a transmission coefficient, and when the pressure sensor is arranged at a position for separating an incident wave amplitude A in and a reflected wave amplitude A ref , the pressure sensor comprises: solving the effective flow area and the blocking degree of the blocking section according to the formulas (7) - (11), substituting the formula (9) into the formula (10), and combining the formulas (11) to obtain the composite material: In the time domain, assuming that the moment when the pressure wave first appears a significant reflection peak at the sensor is y, the axial coordinate x b of the blocking position under the conditions of single-end excitation and single-end reception is approximately as follows: under the basic configuration of single-end excitation and single-end reception, the axial coordinate of the blocking position is directly estimated according to the arrival time of the first significant peak of the reflected pressure wave, so that the blocking position is rapidly positioned; The arrival moments of the reflected waves at different axial positions are accurately identified through a cross correlation method, a parameter inversion method in the least square sense is adopted, the wave speed parameter c and the blocking position x b in a pressure wave propagation model are jointly corrected, so that the axial positioning accuracy is improved, and the method is realized by constructing a fitting error objective function J p of the reflected pressure waves: Wherein P i,meas is the measured reflected pressure wave frequency domain spectrum, and P i,mod is the model-derived reflected pressure wave frequency domain spectrum; Minimizing a fitting error objective function J p of the reflected pressure wave over the frequency set Ω, thereby obtaining a plug position value X b 'that best matches the measured spectrum and a plug level value η' that best matches the measured spectrum;
  6. 6. the method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves, as set forth in claim 5, is characterized in that the step S5 comprises the specific contents of arranging a torsional ultrasonic guided wave excitation array on the outer wall of one end of a pipeline pulse pressure wave generator, wherein the ultrasonic guided wave excitation array consists of a plurality of piezoelectric sheets closely arranged along the circumferential direction of the pipeline wall, and a torsional guided wave beam leading in a T (0, 1) mode is formed through phase difference control, and excitation signals are as follows: wherein the amplitude of the excitation signal A, f 0 is the central frequency of the guided wave, tau is the time width parameter of the Gaussian window and meets the requirement of the torsional mode frequency thick product; n ultrasonic guided wave receiver array elements are uniformly distributed on the outer side of the pipe wall far away from the blocking position along the circumferential direction, and the time domain response of the transmitted guided waves in all directions is recorded: s i (t),i=1,...,N (16) And obtaining a frequency domain response S i (omega) through Fourier transformation: S i (ω)＝F{s i (t)} (17)
  7. 7. The method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves, as set forth in claim 6, is characterized in that the step S6 comprises the specific process of selecting a group of array elements far away from a blockage influence area as a reference area omega r when a T (0, 1) mode propagates to a blockage section, and calculating a reference transfer function: s exc is an excitation end frequency domain signal; for any receiving azimuth i, its transfer function is: Constructing a circumferential anomaly index: the method comprises the steps of (1) determining the circumferential direction azimuth of a target object, wherein W (omega) is a frequency weight function, [ omega 1 ,ω 2 ] is a selected torsional mode analysis frequency band, and the greater the D value is, the greater the deviation degree of the guided wave propagation characteristic at the circumferential direction azimuth relative to a reference area is, and the more obvious the corresponding blockage influence is; finally, the angular position θ * of the blockage satisfies: thus, the precise positioning of the blocking ring direction based on the torsional wave characteristic and without the reflection echo is realized.
  8. 8. The method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves as claimed in claim 7, wherein the specific process of the step S7 is as follows: Establishing a pipeline coordinate system O-XYZ taking a pipeline axis as a z axis, and marking the radius of the inner wall of the pipeline as: The plugging position value x' b which is the best match with the measured spectrum and obtained in the step S4, the plugging circumferential azimuth angle θ b and the coordinates of the plugging center point in the three-dimensional coordinate system are expressed as: X b ＝R i cosθ b ,Y b ＝R i sinθ b ,Z b ＝x b (23) Under the condition that the blocking length and the circumferential coverage range are unknown, the blocking area is regarded as a small section of space voxel taking the point (X b ,Y b ,Z b ) as the center, and the effective length L b of the blocking along the axial direction and the circumferential coverage angle delta theta b are further estimated by combining the energy attenuation distribution of the guided wave signal along the circumferential direction and the axial direction, so that a blocking voxel area model v b is constructed: The method comprises the steps of graphically rendering a blocking voxel region v b in a three-dimensional coordinate system, inputting a blocking voxel region model v b obtained in a formula (25) into MATLAB 3D, creating a corresponding geometric grid according to parameters of the blocking voxel region model v b , converting a definition from a cylindrical coordinate system to a three-dimensional Cartesian coordinate system for final display, endowing color, transparency and material visual properties to the geometric body so as to facilitate clear identification in a three-dimensional graph, and carrying out illumination calculation and projection on the geometric body from a specific view angle in a three-dimensional scene to obtain the three-dimensional space schematic reconstruction of the blocking region.
  9. 9. The method for three-dimensional positioning and quantitative evaluation of municipal pipeline internal blockage based on cooperation of pulse pressure waves and ultrasonic guided waves as set forth in claim 8, wherein the specific process of the step S8 is as follows: in order to comprehensively utilize two types of information of pressure waves and guided waves, a combined objective function is constructed, specifically: J(x b ,η,θ b )＝αJ p (x b ,η)+βJ g (θ b ,η) (25) Where α, β is a weight coefficient, J g (x b , η) is a fitting error objective function of the reflected pressure wave defined in step S4, and the fitting error objective function of the guided wave J g (θ b , η) is expressed as: H k ,mod(ω;θ b , η) is a theoretical transfer function calculated by a guided wave propagation model taking into account a blocking circumferential azimuth angle θ b and a blocking degree value η' which is the best match with the measured spectrum; And solving a joint optimization problem of the joint objective function: The joint inversion and correction can be carried out on the blockage degree eta and the blockage three-dimensional position by utilizing the sensitivity of the guided wave to the local contact rigidity and the circumferential coverage on the basis of the pressure wave axial positioning result, so that the accuracy and the robustness of the blockage degree evaluation are improved.

Description

Municipal pipeline internal blockage three-dimensional positioning and quantitative assessment method based on cooperation of pulse pressure wave and ultrasonic guided wave Technical Field The invention belongs to the technical field of municipal underground pipe network nondestructive testing, and particularly relates to a municipal pipeline internal blockage three-dimensional positioning and quantitative evaluation method based on pressure wave and guided wave cooperation. Background In many fields of petroleum, natural gas, municipal water supply and drainage, etc., pipeline systems are used as key infrastructure of conveying media, and smoothness and integrity are directly related to production safety and operation efficiency. However, local clogging is frequently observed due to corrosion of medium in the pipe, particle deposition, invasion of foreign matter, etc., and serious accidents such as leakage and explosion are caused by light weight and reduced conveying efficiency. Clogging defects such as sediment deposition, garbage accumulation, grease condensation, root invasion, solid foreign matter retention and the like are easy to occur in the long-term operation process of municipal drainage, water supply and sewage pipelines. The blockage causes the reduction of the effective overflow area, causes the increase of hydraulic loss, abrupt change of flow velocity, and secondary disasters such as backflow, water immersion, pavement structure damage and the like, and seriously affects the operation safety and reliability of the urban drainage system. The existing pipeline blockage detection technology mainly comprises traditional methods such as ray detection, penetration detection, magnetic powder detection, ultrasonic detection and the like. Although each of these techniques has advantages, there are significant limitations. For example, the radiation detection has low detection sensitivity to plane defects and corrosion, low detection efficiency, and weak operability of penetration detection and magnetic powder detection in the pipeline, while the traditional ultrasonic detection technology can realize long-distance in-service detection, is often limited in the aspect of identifying the blockage in the pipeline by relying on the characteristic of reflection echo, and has poor detection effect on weak reflection blockage or blockage in the pipeline with a complex structure. In addition, in the prior art, a single detection mode is adopted, so that the axial position and the circumferential distribution information of the blocking point are difficult to obtain accurately at the same time, and the accurate quantification of the blocking degree cannot be realized. In recent years, ultrasonic guided wave detection technology has been attracting attention because of the ability to scan a pipeline over long distances and over a wide range. For example, by arranging the horizontal and oblique circumferential probes, the circumferential ultrasonic guided wave detection method for the thick-wall pipeline can detect axial and circumferential defects respectively, so that the condition of missed detection is reduced. However, the method still has the problems of high directivity control difficulty, easy interference by working conditions and the like for a deeply buried underground or pipeline system with a complex structure. In addition, although detection methods based on acoustic principles (such as voiceprint recognition) have potential in identifying pipe blockage, identifying blockages, tee pieces, and the like by analyzing acoustic pressure signals, positioning accuracy and quantitative evaluation capability are still relatively limited. Therefore, the invention aims to provide a multi-mode collaborative detection method, which realizes accurate three-dimensional positioning and degree quantification of pipeline blockage by combining the advantages of pressure waves and ultrasonic guided waves and establishing a corresponding inverse problem solving model. Disclosure of Invention In order to achieve the technical aim, the invention provides a three-dimensional positioning and quantitative evaluation method for internal blockage of a municipal pipeline based on cooperation of pulse pressure waves and ultrasonic guided waves, which comprises the following steps: s1, basic parameter acquisition and propagation model initialization of a target pipeline. Step S2, pressure wave excitation and multipoint signal acquisition: setting a pulse pressure wave generator at one end of a detected pipeline, and arranging at least one pressure sensor at the pipeline or a position close to the near end of the other end of the pipeline for collecting pressure time-course signals of incident pressure waves and reflected pressure waves caused by blockage in the pipeline; S3, establishing a pressure wave propagation model in the pipe and introducing blocking equivalent impedance; and S4, performing inversion and preliminary quan