Non-contact measuring device and method for pressure of medium in pipeline based on ultrasonic surface wave array

Abstract

The invention provides a non-contact measuring device and method for medium pressure in a pipeline based on an ultrasonic surface wave array, and the device comprises an ultrasonic surface wave array transmitting module, an ultrasonic surface wave receiving module, a signal amplification circuit, a high-speed signal collection card, a drive circuit, and an industrial control computer. Respectively sending driving instructions to the driving circuit when the medium pressure in the test pipeline is zero and the test pipeline is in a working state; after the amplified ultrasonic surface wave signals are received, extracting frequency signals including a zero-pressure state ultrasonic surface wave array frequency f0 and a working state ultrasonic surface wave array frequency f, calculating to obtain an ultrasonic surface wave array frequency difference value, and calculating a pressure indicating value through a pressure calculation formula; based on the ultrasonic surface wave array, the pressure of the medium in the pipeline is inverted by measuring the frequency of the ultrasonic surface wave, high-precision non-contact measurement of the pressure of the medium in the pipeline can be realized, and the sensor belongs to a novel mechanical sensor.

Description

Technical Field

[0001] The present invention relates to a non-contact measurement device and method for the pressure of a medium inside a pipeline based on an ultrasonic surface wave array, belonging to the technical field of pressure measurement. Background Art

[0002] Achieving non-contact detection of pressure is an urgent scientific problem to be solved in the process of economic development and an inevitable trend in the development of the metrology and testing technology discipline. Non-contact measurement of ultrasonic pressure can obtain the medium pressure information by detecting ultrasonic signals, and has the advantages of not destroying the fluid flow field, having no mechanical inertia, fast transient response, strong dynamic measurement ability, convenient installation, etc. By studying the different acoustic characteristics of the liquid in the pipeline under different pressures, the relationship between pressure and ultrasonic sound velocity is established through a large amount of test data, and finally the pressure value in the pipeline liquid is deduced by measuring the ultrasonic propagation velocity.

[0003] The most main problem existing in the existing ultrasonic detection technology is that whether the longitudinal wave or the transverse wave is adopted as the measurement means, its data processing method is based on the time difference method, that is, the transmission time of ultrasonic waves under different pressure conditions is measured. However, the change in ultrasonic velocity caused by the medium pressure is very small, and due to the influence of various noises in the measurement process, the measurement accuracy of the ultrasonic transmission time is relatively low, resulting in a relatively low accuracy of the pressure value inversion result. Currently, the highest is only about ±2%, and it is even not as good as the commonly used ordinary pointer pressure gauge, so its application is greatly limited, which is also an important reason why it cannot be widely promoted. Summary of the Invention

[0004] The purpose of the present invention is to provide a non-contact measurement device and method for the pressure of a medium inside a pipeline based on an ultrasonic surface wave array to solve the problem of relatively low measurement accuracy existing in the prior art when using ultrasonic longitudinal waves or transverse waves for measurement.

[0005] The technical solution of the present invention is as follows: A non-contact measurement device for the pressure of a medium inside a pipeline based on an ultrasonic surface wave array includes an ultrasonic surface wave array transmitting module, an ultrasonic surface wave receiving module, a signal amplification circuit, a high-speed signal acquisition card, a driving circuit, and an industrial control computer. The ultrasonic surface wave array transmitting module and the ultrasonic surface wave receiving module are fixed on the test pipeline and are arranged parallel to the central axis of the test pipeline. Ultrasonic surface wave array transmitting module: simultaneously activates a plurality of transmitting sub-units to send ultrasonic surface wave signals to the ultrasonic surface wave receiving module; Ultrasonic surface wave receiving module: after receiving the ultrasonic surface wave signal, sends it to the signal amplification circuit; Signal amplification circuit: amplifies the ultrasonic surface wave signal and then sends it to the high-speed signal acquisition card; High-speed signal acquisition card: acquires the amplified ultrasonic surface wave signal and sends it to the industrial control computer; Industrial control computer: Send drive instructions to the drive circuit respectively when the medium pressure in the test pipeline is zero and in the working state; respectively extract the frequency signals including the ultrasonic surface wave array frequency in the zero-pressure state after receiving the amplified ultrasonic surface wave signals f 0 and the ultrasonic surface wave array frequency in the working state f , calculate the difference in the ultrasonic surface wave array frequencies, and calculate the pressure indication value through the pressure calculation formula; Drive circuit: Drive the ultrasonic surface wave array emission module according to the drive instructions of the industrial control computer.

[0006] Furthermore, the industrial control computer uses the refined fast Fourier transform method ZoomFFT to extract the frequency signals.

[0007] Furthermore, the distance between the ultrasonic surface wave array emission module and the ultrasonic surface wave receiving module is 10 cm - 15 cm.

[0008] Furthermore, the ultrasonic surface wave array emission module adopts a one-dimensional emission array structure formed by multiple identical emission sub-units with the same spacing, and the emission sub-units are respectively arranged along the parallel direction of the central axis of the test pipeline.

[0009] Furthermore, in the industrial control computer, the pressure calculation formula is: P = k △ f , where △ f is the difference in the ultrasonic surface wave array frequencies, that is, the ultrasonic surface wave array frequency in the working state f and the ultrasonic surface wave array frequency in the zero-pressure state f 0 difference, k is the comprehensive proportionality coefficient between the ultrasonic array surface wave propagation frequency and the pipeline pressure.

[0010] Furthermore, the comprehensive proportionality coefficient k between the ultrasonic array surface wave propagation frequency and the pipeline pressure is obtained by the following steps: Conduct a pressure test in the test pipeline, change the internal pressure magnitude through a standard pressure source, obtain multiple sets of propagation data of ultrasonic surface waves in the pipe wall, extract the frequency signals, and perform linear fitting by the least squares method to obtain the comprehensive proportionality coefficient k value of.

[0011] A non-contact measurement method for the medium pressure in a pipeline based on an ultrasonic surface wave array using the device described in any one of the above, includes the following steps, When the medium pressure in the test pipeline is zero, perform a pressure zeroing operation. The industrial control computer controls each transmitting subunit in the ultrasonic surface wave array transmitting module to simultaneously transmit surface wave pulses through the drive circuit, collects the surface wave array signals of the ultrasonic surface wave receiving module, extracts the zero-pressure state frequency, and after repeating the set number of times and taking the average, obtains the ultrasonic surface wave array frequency in the zero-pressure state. f 0 ; When the test pipeline is in the working state, that is, when the pipeline medium is pressurized, start the measurement. The industrial control computer controls each transmitting subunit in the ultrasonic surface wave array transmitting module to simultaneously transmit surface wave pulses through the drive circuit, collects the surface wave array signals of the ultrasonic surface wave receiving module, extracts the working state frequency, and after repeating the set number of times and taking the average, obtains the ultrasonic surface wave array frequency in the working state. f ; Calculate the difference in the ultrasonic surface wave array frequency, and calculate the pressure indication value through the pressure calculation formula.

[0012] The beneficial effects of the present invention are: First, this non-contact measurement device and method for the medium pressure in a pipeline based on an ultrasonic surface wave array, based on the ultrasonic surface wave array, inversely calculates the medium pressure in the pipeline by measuring the ultrasonic surface wave frequency shift, and can achieve high-precision non-contact measurement of the medium pressure in the pipeline.

[0013] Second, this non-contact measurement device and method for the medium pressure in a pipeline based on an ultrasonic surface wave array uses ultrasonic surface wave array signals. The signal propagation does not need to penetrate the medium in the pipeline and does not require special calibration for different media.

[0014] Third, the present invention first proposes to use the ultrasonic surface wave frequency shift method. An ultrasonic surface wave one-dimensional array is used to excite surface waves on the pipeline surface, and the pipeline stress is obtained by measuring the surface wave frequency shift. The pipeline stress reflects the internal medium pressure of the pipeline. Compared with the time difference method, the frequency shift method is less affected by random factors such as the environment and has higher accuracy.

[0015] Fourth, this non-contact measurement device and method for the medium pressure in a pipeline based on an ultrasonic surface wave array uses the ZoomFFT method to achieve high-precision and high-resolution measurement of the ultrasonic surface wave signal frequency, ensuring the accuracy of the inversion calculation result of the pipeline medium pressure. Description of the Drawings

[0016] Figure 1 is a schematic illustration of the non-contact measurement device for the medium pressure in a pipeline based on an ultrasonic surface wave array according to an embodiment of the present invention; Figure 2 Schematic illustration of the ultrasonic surface wave array transmitting module and the ultrasonic surface wave receiving module fixedly arranged in parallel on the axis of the pipe wall of the test pipeline in the embodiment; Figure 3 Schematic diagram for explaining the transmitting sub - unit in the ultrasonic surface wave array transmitting module in the embodiment; Figure 4 It is a schematic flow chart of the method for non - contact measurement of the pressure of the medium in the pipeline based on the ultrasonic surface wave array in the embodiment; Wherein: 1 - ultrasonic surface wave array transmitting module; 2 - ultrasonic surface wave receiving module; 3 - test pipeline, 4 - transmitting sub - unit. Specific implementation manner

[0017] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] The embodiment provides a non - contact measurement device for the pressure of the medium in the pipeline based on the ultrasonic surface wave array, including an ultrasonic surface wave array transmitting module 1, an ultrasonic surface wave receiving module 2, a signal amplification circuit, a high - speed signal acquisition card, a driving circuit, and an industrial control computer. The ultrasonic surface wave array transmitting module 1 and the ultrasonic surface wave receiving module 2 are fixed on the test pipeline 3 and are arranged parallel to the central axis of the test pipeline 3, as Figure 1 : Ultrasonic surface wave array transmitting module 1: Simultaneously excites multiple transmitting sub - units 4 to send ultrasonic surface wave signals to the ultrasonic surface wave receiving module 2; Ultrasonic surface wave receiving module 2: After receiving the ultrasonic surface wave signal, it sends it to the signal amplification circuit; Signal amplification circuit: Amplifies the ultrasonic surface wave signal and then sends it to the high - speed signal acquisition card; High - speed signal acquisition card: Collects the amplified ultrasonic surface wave signal and sends it to the industrial control computer; Industrial control computer: Sends driving instructions to the driving circuit respectively when the pressure of the medium in the test pipeline 3 is zero and in the working state; respectively, after receiving the amplified ultrasonic surface wave signal, extracts the frequency signals including the ultrasonic surface wave array frequency in the zero - pressure state f 0 and the ultrasonic surface wave array frequency in the working state f , calculates the difference in the ultrasonic surface wave array frequencies, and calculates the pressure indication value through the pressure calculation formula; Driving circuit: Drives the ultrasonic surface wave array transmitting module 1 according to the driving instructions of the industrial control computer.

[0019] This non - contact measurement device for the pressure of the medium in the pipeline based on the ultrasonic surface wave array, based on the ultrasonic surface wave array, inversely calculates the pressure of the medium in the pipeline by measuring the ultrasonic surface wave frequency shift, and can realize high - precision non - contact measurement of the pressure of the medium in the pipeline.

[0020] The industrial control computer uses the refined Fast Fourier Transform method ZoomFFT to extract frequency signals. The ultrasonic surface wave array transmitting module 1 adopts a one-dimensional transmitting array structure with the same spacing composed of several identical transmitting sub-units 4, and the transmitting sub-units 4 are respectively arranged along the parallel direction of the central axis of the test pipeline, as Figure 3 , which contains 6 completely identical transmitting sub-units 4 inside, and the spacing between two adjacent transmitting sub-units 4 is 1 cm. The spacing between the ultrasonic surface wave array transmitting module 1 and the ultrasonic surface wave receiving module 2 is 10 cm - 15 cm, parallel to the central axis of the pipeline.

[0021] In the industrial control computer, the pressure calculation formula is: P = k △ f , where △ f is the frequency difference of the ultrasonic surface wave array, that is, the frequency of the ultrasonic surface wave array in the working state f and the frequency of the ultrasonic surface wave array in the zero-pressure state f 0 The difference, k is the comprehensive proportionality coefficient between the propagation frequency of the ultrasonic surface wave on the array and the pipeline pressure.

[0022] The derivation process of the above pressure calculation formula is as follows: 1) Since there is a theoretically linear relationship between the pressure P of the internal medium of the pipeline and the internal stress σ of the pipe wall:

[0023] Among them, σ 0 is the pipe wall stress in the zero-pressure state, k 1 is the proportionality coefficient between the internal pressure of the pipeline and the pipe wall stress; 2) According to the acoustoelastic principle and through experimental verification, it is obtained that the pipe wall stress is linearly related to the ultrasonic surface wave velocity:

[0024] Among them, △σ is the stress change, △ v is the velocity change, k 2 is the proportionality coefficient between the ultrasonic surface wave propagation velocity and the pipe wall stress, where v 0 is the ultrasonic surface wave propagation velocity in the zero-pressure state, σ, v is the pipe wall stress and the ultrasonic surface wave propagation velocity when the pipeline pressure is P ; 3) Since the spacing between adjacent transmitting sub-units 4 in the array ultrasonic surface wave array transmitting module 1 is λ, the time interval for the ultrasonic surface wave receiving module 2 to receive the signals of two adjacent transmitting sub-units 4 is: , which receives the array surface wave signal with a frequency of , that is:

[0025] Among them, f 0 is the frequency of the ultrasonic surface wave array in the zero-pressure state. In summary, it can be obtained that:

[0026] Among them, k is the comprehensive proportionality coefficient between the propagation frequency of the ultrasonic array surface wave and the pipeline pressure.

[0027] The comprehensive proportionality coefficient between the propagation frequency of the ultrasonic array surface wave and the pipeline pressure k is obtained through the following steps: Conduct a pressure test in the test pipeline 3, change the internal pressure through a standard pressure source, obtain multiple sets of propagation data of ultrasonic surface waves in the pipe wall, extract the frequency signal, and perform linear fitting by the least squares method to obtain the comprehensive proportionality coefficient k of the propagation speed of the ultrasonic array surface wave and the pipeline pressure.

[0028] For example Figure 4 , the embodiment also provides a non-contact measurement method for the pressure of the medium in the pipeline based on the ultrasonic surface wave array using the device described in any one of the above, including the following steps, When the pressure of the medium in the test pipeline 3 is zero, perform a pressure zeroing operation. The industrial control computer controls each transmitting subunit 4 in the ultrasonic surface wave array transmitting module 1 to simultaneously transmit surface wave pulses through the drive circuit, collect the surface wave array signals of the ultrasonic surface wave receiving module 2, extract the zero-pressure state frequency, and after repeating the set number of times, such as 5 times, and taking the average, obtain the ultrasonic surface wave array frequency in the zero-pressure state f 0 ; When the test pipeline 3 is in the working state, that is, when the pipeline medium is pressurized, start the measurement. The industrial control computer controls each transmitting subunit 4 in the ultrasonic surface wave array transmitting module 1 to simultaneously transmit surface wave pulses through the drive circuit, collect the surface wave array signals of the ultrasonic surface wave receiving module 2, extract the working state frequency, and after repeating the set number of times, such as 5 times, and taking the average, obtain the ultrasonic surface wave array frequency in the working state f ; Calculate the difference in the ultrasonic surface wave array frequency, and calculate the pressure indication value through the pressure calculation formula.

[0029] The present invention first proposes to adopt the ultrasonic surface wave frequency shift method. An ultrasonic surface wave one-dimensional array is used to excite surface waves on the pipeline surface, and the stress of the pipeline is obtained by measuring the surface wave frequency shift. The pipeline stress reflects the internal medium pressure of the pipeline. Compared with the time difference method, the frequency shift method is less affected by random factors such as the environment and has higher accuracy. Tests are carried out in the laboratory within the range of (0 - 20) MPa by selecting different standard pressure values, and the deviation between the system display value and the standard pressure value is better than ±1%, and the measurement accuracy has been greatly improved.

[0030] The non-contact measurement device and method for the internal medium pressure of a pipeline based on an ultrasonic surface wave array belong to a new type of mechanical sensor. Ultrasonic surface wave array signals are adopted, and the signal propagation does not need to penetrate the internal medium of the pipeline, and there is no need for special calibration for different media. The ultrasonic surface wave detection is greatly affected by environmental factors. By adopting the method of 5 repeated measurements, while ensuring the measurement speed, the influence of random factors can be greatly eliminated, the consistency of the measurement results can be ensured, and the accuracy of the measurement results can be improved.

[0031] The non-contact measurement device and method for the internal medium pressure of a pipeline based on an ultrasonic surface wave array adopt the ZoomFFT method to achieve high-precision and high-resolution measurement of the ultrasonic surface wave signal frequency, ensuring the accuracy of the inversion calculation result of the pipeline medium pressure.

[0032] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array, characterized in that: It includes an ultrasonic surface wave array transmitting module, an ultrasonic surface wave receiving module, a signal amplifying circuit, a high-speed signal acquisition card, a driving circuit and an industrial computer. The ultrasonic surface wave array transmitting module and the ultrasonic surface wave receiving module are fixed on the test pipeline and arranged parallel to the central axis of the test pipeline. Ultrasonic surface wave array transmitting module: simultaneously excites multiple transmitting sub-units to send ultrasonic surface wave signals to the ultrasonic surface wave receiving module; Ultrasonic surface wave receiving module: receives the ultrasonic surface wave signal and sends it to the signal amplifying circuit; Signal amplification circuit: amplifies the ultrasonic surface wave signal and sends it to the high-speed signal acquisition card; High-speed signal acquisition card: collects the amplified ultrasonic surface wave signal and sends it to the industrial computer; Industrial computer: sends driving instructions to the driving circuit when the medium pressure in the test pipeline is zero and in the working state; extracts the frequency signal including the ultrasonic surface wave array frequency in the zero pressure state after receiving the amplified ultrasonic surface wave signal. f 0 and working state ultrasonic surface wave array frequency f , calculate the frequency difference of the ultrasonic surface wave array, and calculate the pressure indication through the pressure calculation formula; Driving circuit: drives the ultrasonic surface wave array transmitting module according to the driving instructions of the industrial computer.

2. The non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array according to claim 1, characterized in that: The industrial computer uses the refined fast Fourier transform method ZoomFFT to extract the frequency signal.

3. The non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array according to claim 1, characterized in that: The distance between the ultrasonic surface wave array transmitting module and the ultrasonic surface wave receiving module is 10cm-15cm.

4. The non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array according to any one of claims 1 to 3, characterized in that: The ultrasonic surface wave array transmitting module adopts a plurality of identical transmitting subunits to form a one-dimensional transmitting array structure with the same spacing, and the transmitting subunits are respectively arranged in a direction parallel to the central axis of the test pipeline.

5. The non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array according to any one of claims 1 to 3, characterized in that: In industrial computers, the pressure calculation formula is: P = k △ f , where △ f is the ultrasonic surface wave array frequency difference, that is, the ultrasonic surface wave array frequency in the working state f The frequency of ultrasonic surface wave array in zero pressure state f The difference of 0, k It is the comprehensive proportionality coefficient between the ultrasonic array surface wave propagation frequency and the pipeline pressure.

6. The non-contact measuring device for medium pressure in a pipeline based on an ultrasonic surface wave array as claimed in claim 5, characterized in that: The comprehensive proportionality coefficient between the propagation frequency of ultrasonic array surface waves and the pipeline pressure k The results are obtained by the following steps: a pressurized test is conducted in the test pipeline, the internal pressure is changed by a standard pressure source, multiple sets of ultrasonic surface wave propagation data in the pipe wall are obtained, the frequency signal is extracted, and a linear fit is performed by the least squares method to obtain the comprehensive proportional coefficient between the ultrasonic array surface wave propagation velocity and the pipe pressure. k The value of .

7. A non-contact measurement method for medium pressure in a pipeline based on an ultrasonic surface wave array using the device according to any one of claims 1 to 6, characterized in that: The following steps are included: When the medium pressure in the test pipeline is zero, the pressure is reset. The industrial computer controls each transmitting subunit in the ultrasonic surface wave array transmitting module through the driving circuit to simultaneously transmit surface wave pulses, collects the surface wave array signal of the ultrasonic surface wave receiving module, extracts the zero pressure state frequency, and obtains the zero pressure state ultrasonic surface wave array frequency after averaging after repeating the set number of times. f 0; When the test pipeline is in working state, i.e., when the pipeline medium is pressurized, the measurement starts. The industrial computer controls each transmitting subunit in the ultrasonic surface wave array transmitting module to transmit surface wave pulses simultaneously through the driving circuit, collects the surface wave array signal of the ultrasonic surface wave receiving module, extracts the working state frequency, and obtains the working state ultrasonic surface wave array frequency after averaging after repeating the set number of times. f ; The frequency difference of the ultrasonic surface wave array is calculated, and the pressure indication is calculated using the pressure calculation formula.

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