Liquid micro-pressure measurement method, device, storage medium and equipment

Abstract

The present invention provides a liquid micro-pressure measurement method, device, storage medium and equipment. A liquid micro-pressure measurement method is applied to a liquid micro-pressure measurement device, the liquid micro-pressure measurement device includes a micro-pressure measurement unit, the micro-pressure measurement unit includes a plurality of pressure measuring tubes arranged in parallel, each pressure measuring tube is connected to a pressure-taking hole to be measured through a correspondingly arranged pressure-leading tube, the method includes: obtaining an image of a liquid column in each pressure measuring tube; obtaining liquid surface pixel coordinate information of a liquid column in each pressure measuring tube in the image, the liquid surface pixel coordinate information includes pixel coordinates of boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface; calculating the height of the liquid surface caused by the surface tension of the liquid surface based on the liquid surface pixel coordinate information; calculating the pressure difference at the pressure taking holes connected to different pressure measuring tubes based on the height. The present invention has a fast measurement speed while ensuring high pressure measurement accuracy, and can simultaneously measure the pressure difference between multiple pressure taking holes.

Description

Technical Field

[0001] The present invention relates to the field of micro-pressure measurement, and in particular to a liquid micro-pressure measurement method, device, storage medium and equipment. Background Art

[0002] The common pressure measurement methods currently used in industry and laboratories include liquid pressure gauges, elastic element pressure gauges, various pressure sensors, and piston pressure gauges for calibrating pressure gauges. Liquid pressure gauges have simple structures, are easy to manufacture, have reliable measurements, and are highly accurate. When measuring pressures in the range of 0 to 10 kPa, liquid pressure gauges are the most suitable choice.

[0003] The accuracy of the liquid pressure gauge mainly depends on the accuracy of the liquid column height reading, and is also affected by the local gravity acceleration and the change in the density of the working medium. The local gravity acceleration has little effect on the accuracy of the liquid pressure gauge and can be ignored in many cases. The change in the density of the working medium also has little effect on the accuracy of the liquid pressure gauge, and can be corrected by measuring the medium temperature. However, since the pressure of a 1 mm standard water column reaches 9.8 Pa, the reading error of the liquid column height will have a great impact on the accuracy of the liquid pressure gauge. Therefore, maximizing the accuracy of the liquid column height reading is the key to improving the accuracy of the liquid pressure gauge, especially when measuring micro-pressures in the hectopascal range.

[0004] The reading error of the liquid column height mainly includes sine error, cosine error, parallax, scale error, zero position error, etc. In order to reduce the reading error of the liquid column height and improve the measurement accuracy of the liquid pressure gauge, the existing liquid micromanometer is equipped with a spiral micrometer mechanism on the liquid pressure gauge device, and even an acoustic device or an optical device is installed to measure the change of the liquid column height of the pressure gauge. Although the introduction of these high-precision liquid column height measurement devices has improved the measurement accuracy of the liquid pressure gauge, it has also greatly complicated the pressure measurement equipment, greatly affecting the simple and easy-to-operate characteristics of the liquid pressure gauge. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a liquid micro-pressure measurement method, device, storage medium and equipment.

[0006] In a first aspect, an embodiment of the present invention provides a liquid micro-pressure measurement method, which is applied to a liquid micro-pressure measurement device, wherein the liquid micro-pressure measurement device includes a micro-pressure measurement unit, wherein the micro-pressure measurement unit includes a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure taking hole to be measured through a correspondingly arranged pressure-guiding tube, and the method includes:

[0007] Acquire images of the fluid columns in each piezometer;

[0008] Obtaining liquid surface pixel coordinate information of the liquid column in each pressure measuring tube in the image, wherein the liquid surface pixel coordinate information includes pixel coordinates of boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface;

[0009] Calculating the height of the liquid surface caused by the liquid surface tension based on the liquid surface pixel coordinate information;

[0010] The pressure difference at the pressure tapping holes to which different pressure measuring tubes are connected is calculated based on the height.

[0011] In some implementations, the obtaining of liquid level pixel coordinate information of the liquid column in each pressure measuring tube in the image includes:

[0012] Reading pixel coordinates of boundaries on both sides of the liquid surface of each liquid column in each pressure measuring tube in the image;

[0013] The pixel coordinates of the vertex at the bottom of the liquid surface are obtained based on the pixel coordinates of the boundaries on both sides of the liquid surface.

[0014] In some implementations, calculating the height of the liquid surface caused by the liquid surface tension based on the liquid surface pixel coordinate information includes:

[0015] The height of the liquid level rise caused by the surface tension of the liquid surface is calculated using a first calculation formula, which represents the relationship between the height of the liquid level rise caused by the surface tension of the liquid surface, the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and the inner diameter of the pressure measuring tube.

[0016] In some implementations, the first calculation formula is:

[0017]

[0018] Among them, H o It represents the height of the liquid level caused by the surface tension of the liquid surface, d represents the inner diameter of the pressure measuring tube, θ represents the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and B represents the Bond number.

[0019] In some implementations, the liquid micro-pressure measuring device further includes two pressure measuring tubes respectively located on both sides of the micro-pressure measuring unit, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit, and are respectively connected to a liquid level adjustment box containing liquid, and the pressure difference at the pressure holes connected to different pressure measuring tubes is calculated based on the height, including:

[0020] Calculate the pressure difference at the pressure holes connected to different pressure measuring tubes based on the height and the correction coefficient;

[0021] The correction coefficient is calculated based on the pixel coordinates of the vertices of the bottom of the liquid surface in the two pressure measuring tubes connected to the liquid surface adjustment box.

[0022] In some implementations, the calculating the pressure difference at the pressure holes connected to different pressure measuring tubes based on the height and the correction coefficient includes:

[0023] Use the second calculation formula to calculate the pressure difference at the pressure holes where the two pressure measuring tubes are connected:

[0024] The second calculation formula is as follows:

[0025] ΔP 1，2 =ρg(H1-H2)

[0026] Among them, ΔP 1，2 It represents the pressure difference at the pressure tapping holes where the two pressure measuring tubes are connected, ρ represents the density of the liquid at the current measurement temperature, g represents the local gravitational acceleration, and H1 and H2 represent the heights of the liquid columns of the two pressure measuring tubes after correction based on the correction coefficients;

[0027] H1=(l v -S1 by +(S1 bx -L bx )k)fH 0，1

[0028] H2=(l v -S2 by +(S2 bx -L bx )k)fH 0，2

[0029] l v represents the total number of vertical pixels of the liquid column image, k represents the correction coefficient, H 0，1 and H 0，2 They respectively represent the heights of the liquid columns in the two pressure measuring tubes caused by the surface tension of the liquid surface;

[0030] k=((R by +H 0，r )-(L by +H 0，l )) / (R bx -L bx )

[0031] (R bx , R by ) represents the pixel coordinates of the rightmost pressure gauge, (L bx , L by ) represents the pixel coordinate of the leftmost pressure gauge, H 0，r and H 0，1 They respectively represent the height of the liquid column in the rightmost pressure tube and the leftmost pressure tube caused by the surface tension of the liquid column.

[0032] In some implementations, before acquiring the image of the liquid column in each pressure measuring tube, the method further includes:

[0033] Adjust the height of the liquid column in the two pressure measuring tubes connected to the liquid level adjustment box so that the height of the liquid column in the two pressure measuring tubes is consistent.

[0034] In a second aspect, an embodiment of the present invention provides a liquid micro-pressure measuring device, which is applied to a liquid micro-pressure measuring device, wherein the liquid micro-pressure measuring device comprises a micro-pressure measuring unit, wherein the micro-pressure measuring unit comprises a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure taking hole to be measured through a correspondingly arranged pressure-leading tube, and the liquid micro-pressure measuring device comprises:

[0035] An image acquisition module, used to acquire images of liquid columns in each pressure measuring tube;

[0036] A coordinate acquisition module, used to acquire liquid surface pixel coordinate information of the liquid column in each pressure measuring tube in the image, wherein the liquid surface pixel coordinate information includes pixel coordinates of the boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface;

[0037] A first calculation module, used for calculating the height of the liquid surface caused by the liquid surface tension based on the liquid surface pixel coordinate information;

[0038] The second calculation module is used to calculate the pressure difference at the pressure holes connected to different pressure measuring tubes based on the height.

[0039] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by one or more processors, the method described in the first aspect is implemented.

[0040] In a fourth aspect, an embodiment of the present invention provides an electronic device, comprising a memory and one or more processors, wherein the memory stores a computer program, and when the computer program is executed by the one or more processors, the method described in the first aspect is implemented.

[0041] In a fifth aspect, an embodiment of the present invention provides a liquid micro-pressure measuring device, comprising:

[0042] The micro-pressure measuring unit comprises a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure-taking hole to be measured through a correspondingly arranged pressure-leading tube;

[0043] A camera, arranged facing the micro-pressure measuring unit, for taking images of the liquid columns in each pressure measuring tube;

[0044] An electronic device as described in the fourth aspect.

[0045] In some implementations, the liquid micro-pressure measuring device further includes:

[0046] Two pressure measuring tubes are respectively located on both sides of the micro-pressure measuring unit. The two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit and are respectively connected to a liquid level adjustment box containing liquid.

[0047] In some implementations, the liquid micro-pressure measuring device further includes:

[0048] A light homogenizing plate, arranged on a side of each pressure measuring tube away from the camera, and used to fix each pressure measuring tube;

[0049] The light homogenizing lamp is arranged on a side of the light homogenizing plate away from each pressure measuring tube, and is used to irradiate uniform light on the light homogenizing plate so that the light homogenizing plate evenly projects the light to each pressure measuring tube.

[0050] One or more embodiments of the present invention can bring at least the following beneficial effects:

[0051] In view of the defects of current liquid micro-manometer measurement equipment, such as complexity, cumbersome operation, and inability to measure the pressure difference between multiple pressure tapping ports at the same time, the present invention introduces digital imaging technology into liquid micro-pressure measurement, and provides a new method for micro-pressure measurement by photographing the pressure measuring liquid column and processing the liquid column image during pressure measurement. When measuring the pressure difference in the range of 0 to 300Pa, the measurement error can be within 0.5Pa. While ensuring high pressure measurement accuracy, the pressure measuring equipment is simple, easy to operate, and has a fast measurement speed, and can measure the pressure difference between multiple pressure tapping ports at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope.

[0053] Figure 1 is a schematic diagram of a liquid micro-pressure measuring device provided by an embodiment of the present invention;

[0054] Figure 2 is a flow chart of a liquid micro-pressure measurement method provided by an embodiment of the present invention;

[0055] Figure 3 is a schematic diagram of a liquid column image provided by an embodiment of the present invention;

[0056] Figure 4 is a schematic diagram of a projection image of a liquid surface on an image provided by an embodiment of the present invention;

[0057] Figure 5 It is a block diagram of a liquid micro-pressure measuring device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present invention.

[0059] Embodiment 1

[0060] This embodiment provides a liquid micro-pressure measurement method, which is applicable to Figure 1 The liquid type micro-pressure measuring device shown in the figure comprises a micro-pressure measuring unit 1, wherein the micro-pressure measuring unit 1 comprises a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure taking hole to be measured through a corresponding pressure-leading tube. Figure 2 As shown, the method may include the following steps:

[0061] Step S101, obtaining images of the liquid columns in each pressure measuring tube.

[0062] The liquid micro-pressure measuring device of this embodiment may further include a camera 3, which is arranged facing the micro-pressure measuring unit and is used to take digital images of the liquid columns in each pressure measuring tube.

[0063] In some implementations, the liquid micro-pressure measuring device of this embodiment may further include two pressure measuring tubes 2 respectively located on the left and right sides of the micro-pressure measuring unit 1, and the two pressure measuring tubes 2 are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit 1, and are respectively connected to the two pressure holes of the liquid level adjustment box, for calculating the correction coefficient according to the pixel coordinates of the bottom vertices of the liquid surface in the two pressure measuring tubes 2 connected to the liquid level adjustment box in subsequent steps.

[0064] In some implementations, the liquid micro-pressure measuring device of this embodiment may further include a light homogenizing plate 4 and a light homogenizing lamp 5; the light homogenizing plate 4 is arranged on the side of each pressure measuring tube (including each pressure measuring tube in the micro-pressure measuring unit 1 and two pressure measuring tubes 2 arranged on the left and right sides of the micro-pressure measuring unit 1) away from the camera 3, and the light homogenizing plate 4 is used to fix each pressure measuring tube; the light homogenizing lamp 5 is arranged on the side of the light homogenizing plate 4 away from each pressure measuring tube, and is used to irradiate uniform light on the light homogenizing plate 4, so that the light homogenizing plate 4 evenly projects the light to each pressure measuring tube.

[0065] Before acquiring the images of the liquid columns in the respective pressure measuring tubes, the method may further include:

[0066] Step S100, adjusting the heights of the liquid columns in the two pressure measuring tubes connected to the liquid level adjustment box so that the heights of the liquid columns in the two pressure measuring tubes are consistent.

[0067] Since the liquid in the liquid level adjustment box is still, the heights of the liquid columns in the leftmost and rightmost pressure measuring tubes 2 are consistent, that is, the liquid levels of the liquid columns in the two pressure measuring tubes are horizontal. The purpose of this setting is to correct the errors caused by the pressure measuring tubes not being installed completely vertically and the captured images not being completely horizontal when processing the images of the liquid columns in the pressure measuring tubes.

[0068] Step S102, obtaining the liquid surface pixel coordinate information of the liquid column in each pressure measuring tube in the image, wherein the liquid surface pixel coordinate information includes the pixel coordinates of the boundaries on both sides of the liquid surface and the pixel coordinates of the vertex at the bottom of the liquid surface.

[0069] In some implementations, obtaining pixel coordinate information of the liquid level of each liquid column in each pressure measuring tube in the image may further include:

[0070] Step S102a, reading the pixel coordinates of the boundaries on both sides of the liquid surface of each liquid column in each pressure measuring tube in the image;

[0071] Step S102b: obtaining the pixel coordinates of the vertex at the bottom of the liquid surface based on the pixel coordinates of the boundaries on both sides of the liquid surface.

[0072] The pressure change at the pressure tapping hole or the pressure difference between the pressure tapping holes can be obtained by processing the digital image of the liquid column in the pressure measuring tube. A typical liquid column image is as follows: Figure 3 As shown, the leftmost and rightmost pressure measuring tubes are represented by Tube-L and Tube-R respectively. These two pressure measuring tubes are connected to the liquid level adjustment box. The micro-pressure measurement unit 1 includes 4 pressure measuring tubes, namely the 4 pressure measuring tubes in the middle of the figure, represented by Tube-1 to Tube-4 respectively. These 4 pressure measuring tubes are connected to 4 pressure tapping holes through pressure tapping tubes. Figure 3 It can be seen that the liquid column image clearly shows the height of the liquid column in the pressure measuring tube, and the black meniscus at the top of the liquid column is the projection of the liquid surface.

[0073] After obtaining the digital image of the liquid column, it is necessary to read the pixel coordinates of the liquid surface of each liquid column. It is necessary to read the pixel coordinates of the left boundary, right boundary and bottom vertex of the liquid surface of each liquid column. Taking the liquid column of Tube-L pressure tube as an example, first read the pixel coordinates of the left boundary (L lx , L ly ) and the right boundary pixel coordinates (L rx , L ry ), and then obtain the horizontal pixel coordinate L of the vertex at the bottom of the liquid surface bx =(L lx +L rx ) / 2, with the horizontal axis being L bxThe vertical pixel coordinate L of the bottom vertex of the meniscus projected by the liquid surface is located on the vertical line by The same method is used to read out the liquid level pixel coordinates of the Tube-R pressure tube and other pressure tube liquid columns in the micro-pressure measurement unit 1. The liquid level pixel coordinates of the Tube-R pressure tube liquid column are represented by R, and the liquid level pixel coordinates of the pressure tube liquid columns connected to the pressure holes are represented by S1 to S4, which will not be repeated here.

[0074] Since the surface tension of the liquid column will cause the liquid column surface to rise, which will bring errors to the micro-pressure measurement, it is necessary to correct the height of the liquid column surface caused by the surface tension of the liquid column surface. The projection image of the liquid column surface in the pressure measuring tube on the image is a meniscus, such as Figure 4 As shown in the figure, d is the inner diameter of the pressure tube, h is the height of the meniscus, θ is the contact angle between the liquid column surface and the inner wall of the pressure tube, and H0 is the height of the liquid column surface caused by the surface tension of the liquid surface. The surface tension of the liquid surface is corrected by the three pixel coordinates of the liquid surface (S 1x , S ly )、(S rx , S ry )、(S bx , S by ) calculates H0 and then realizes error correction when calculating the pressure difference at the pressure tapping holes connected to different pressure measuring tubes.

[0075] Step S103: Calculate the height of the liquid surface caused by the liquid surface tension based on the liquid surface pixel coordinate information.

[0076] In some implementations, calculating the height of the liquid surface caused by the surface tension of the liquid surface based on the liquid surface pixel coordinate information may further include:

[0077] Step S103a, using a first calculation formula to calculate the height of the liquid level caused by the surface tension of the liquid surface, wherein the first calculation formula represents the relationship between the height of the liquid level caused by the surface tension of the liquid surface, the contact angle formed between the liquid surface and the inner wall of the pressure measuring tube, and the inner diameter of the pressure measuring tube.

[0078] In some implementations, the first calculation formula is:

[0079]

[0080] Among them, H o It represents the height of the liquid level caused by the surface tension of the liquid surface, d represents the inner diameter of the pressure measuring tube, θ represents the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and B represents the Bond number.

[0081] B=ρgd 2 / 4σ, σ represents the surface tension coefficient of the liquid surface in the air, and ρ represents the density of the liquid at the current measurement temperature.

[0082] The contact angle θ can be calculated using the following formula:

[0083]

[0084] Where h = f[S by -(S ly +S ry ) / 2].

[0085] f is the ratio of pixel coordinates to length coordinates, m / pixel:

[0086]

[0087] Where D is the outer diameter of the pressure measuring tube, m.

[0088] Step S104: Calculate the pressure difference at the pressure holes to which different pressure measuring tubes are connected based on the height.

[0089] In the case where the liquid micro-pressure measuring device includes two pressure measuring tubes respectively located on both sides of the micro-pressure measuring unit, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit and are respectively connected to two pressure taking holes of the liquid level adjustment box, and the pressure difference at the pressure taking holes connected to different pressure measuring tubes is calculated based on the height, including:

[0090] Step S104a, calculating the pressure difference at the pressure holes connected to different pressure measuring tubes based on the height and the correction coefficient; wherein the correction coefficient is calculated based on the pixel coordinates of the bottom vertices of the liquid surface in the two pressure measuring tubes connected to the liquid level adjustment box.

[0091] In some implementations, calculating the pressure difference at the pressure tapping holes to which different pressure measuring tubes are connected based on the height and the correction coefficient may include:

[0092] Use the second calculation formula to calculate the pressure difference at the pressure holes where the two pressure measuring tubes are connected:

[0093] Calculate Figure 3 The pressure difference between Tube-1 and Tube-2 is ΔP 1，2 For example, the second calculation formula is as follows:

[0094] ΔP 1，2 =ρg(H1-H2)

[0095] Among them, ΔP 1，2 Represents two pressure measuring tubes ( Figure 3 The pressure difference at the pressure holes connected to the two pressure measuring tubes (Tube-1 and Tube-2 in the figure), ρ represents the density of the liquid at the current measurement temperature, g represents the local gravitational acceleration, H1 and H2 represent the pressure of the two pressure measuring tubes ( Figure 3 The height of the liquid column of Tube-1 and Tube-2 in Fig. 1 is corrected based on the correction factor;

[0096] H1=(l v -S1 by +(S1 bx -L bx )k)fH 0,1

[0097] H2=(l v -S2 by +(S2 bx -L bx )k)fH 0,2

[0098] Among them, l v represents the total number of vertical pixels of the liquid column image, k represents the correction coefficient, H 0,1 and H 0,2 Represents two pressure measuring tubes ( Figure 3 The height of the liquid column in Tube-1 and Tube-2) caused by the surface tension of the liquid column;

[0099] k=((R by +H 0,r )-(L by +H 0，l )) / (R bx -L bx )

[0100] Among them, (R bx , R by ) represents the pixel coordinates of the rightmost pressure gauge, (L bx , L by ) represents the pixel coordinates of the leftmost pressure gauge, H 0,r and H 0,1 They respectively represent the height of the liquid column in the rightmost pressure tube and the leftmost pressure tube caused by the surface tension of the liquid column.

[0101] The micro-pressure measurement method of this embodiment is used to measure the pressure difference of four pressure holes with the same pressure. The height position and shape position of the pressure measuring liquid column can be accurately determined to 0.02mm. At the same time, based on the shape of the liquid surface formed by the liquid column in the air during pressure measurement, the pressure measurement error caused by the surface tension of the pressure measuring liquid column is corrected, ensuring that the measurement error does not exceed 0.5Pa when measuring the pressure difference in the range of 0 to 300Pa.

[0102] Embodiment 2

[0103] The present embodiment provides a liquid micro-pressure measuring device, which is applied to a liquid micro-pressure measuring device. The liquid micro-pressure measuring device includes a micro-pressure measuring unit, which includes a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure-taking hole to be measured through a corresponding pressure-leading tube. Figure 5 As shown, the liquid micro-pressure measuring device of this embodiment includes:

[0104] An image acquisition module 201 is used to acquire images of liquid columns in each pressure measuring tube;

[0105] A coordinate acquisition module 202 is used to acquire pixel coordinate information of the liquid surface of the liquid column in each pressure measuring tube in the image, wherein the pixel coordinate information of the liquid surface includes pixel coordinates of the boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface;

[0106] A first calculation module 203 is used to calculate the height of the liquid surface caused by the surface tension of the liquid surface based on the liquid surface pixel coordinate information;

[0107] The second calculation module 204 is used to calculate the pressure difference at the pressure holes connected to different pressure measuring tubes based on the height.

[0108] In some implementations, obtaining the liquid surface pixel coordinate information of each liquid column in each pressure measuring tube in the image may further include: reading the pixel coordinates of the boundaries on both sides of the liquid surface of each liquid column in the image; and obtaining the pixel coordinates of the vertex at the bottom of the liquid surface based on the pixel coordinates of the boundaries on both sides of the liquid surface.

[0109] In some implementations, calculating the height of the liquid level rise caused by the surface tension of the liquid surface based on the liquid surface pixel coordinate information may further include: using a first calculation formula to calculate the height of the liquid level rise caused by the surface tension of the liquid surface, the first calculation formula characterizing the relationship between the height of the liquid level rise caused by the surface tension of the liquid surface, and the contact angle formed by the liquid surface and the inner wall surface of the pressure measuring tube and the inner diameter of the pressure measuring tube.

[0110] In some implementations, the first calculation formula is:

[0111]

[0112] Among them, H o It represents the height of the liquid level caused by the surface tension of the liquid surface, d represents the inner diameter of the pressure measuring tube, θ represents the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and B represents the Bond number.

[0113] B=ρgd 2 / 4σ, σ represents the surface tension coefficient of the liquid surface in the air, and ρ represents the density of the liquid at the current measurement temperature.

[0114] The contact angle θ can be calculated using the following formula:

[0115]

[0116] Where h = f[S by -(S ly +S ry ) / 2].

[0117] f is the ratio of pixel coordinates to length coordinates, m / pixel:

[0118]

[0119] Where D is the outer diameter of the pressure measuring tube, m.

[0120] In the case where the liquid micro-pressure measuring device includes two pressure measuring tubes respectively located on both sides of the micro-pressure measuring unit, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit, and are respectively connected to the two pressure taking holes of the liquid level adjusting box, and the pressure difference at the pressure taking holes connected to different pressure measuring tubes is calculated based on the height, which may further include: calculating the pressure difference at the pressure taking holes connected to different pressure measuring tubes based on the height and the correction coefficient; wherein the correction coefficient is calculated based on the pixel coordinates of the vertices of the bottom of the liquid surface in the two pressure measuring tubes connected to the liquid level adjusting box.

[0121] In some implementations, calculating the pressure difference at the pressure tapping holes to which different pressure measuring tubes are connected based on the height and the correction coefficient may include:

[0122] Use the second calculation formula to calculate the pressure difference at the pressure holes where the two pressure measuring tubes are connected:

[0123] Calculate Figure 3 The pressure difference between Tube-1 and Tube-2 is ΔP 1,2 For example, the second calculation formula is as follows:

[0124] ΔP 1，2 =ρg(H1-H2)

[0125] Among them, ΔP 1，2 Represents two pressure measuring tubes ( Figure 3 The pressure difference at the pressure holes connected to the two pressure measuring tubes (Tube-1 and Tube-2 in the figure), ρ represents the density of the liquid at the current measurement temperature, g represents the local gravitational acceleration, H1 and H2 represent the pressure of the two pressure measuring tubes ( Figure 3 The height of the liquid column of Tube-1 and Tube-2 in Fig. 1 is corrected based on the correction factor;

[0126] H1=(l v -S1 by +(S1 bx -L bx )k)fH 0,1

[0127] H2=(l v -S2 by +(S2 bx -L bx )k)fH 0,2

[0128] Among them, l v represents the total number of vertical pixels of the liquid column image, k represents the correction coefficient, H 0,1 and H 0,2 Represents two pressure measuring tubes ( Figure 3 The height of the liquid column in Tube-1 and Tube-2) caused by the surface tension of the liquid column;

[0129] k=((R by +H 0,r )-(L by +H 0,l )) / (R bx -L bx )

[0130] Among them, (R bx , R by ) represents the pixel coordinates of the rightmost pressure gauge, (L bx , L by ) represents the pixel coordinates of the leftmost pressure gauge, H 0,r and H 0，1 They respectively represent the height of the liquid column in the rightmost pressure tube and the leftmost pressure tube caused by the surface tension of the liquid column.

[0131] It should be understood that the device of this embodiment has all the beneficial effects of the method provided in the embodiment.

[0132] Embodiment 3

[0133] This embodiment provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by one or more processors, the method provided in the above-mentioned embodiment is implemented.

[0134] Among them, the computer-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic storage, flash memory, disk or optical disk.

[0135] Embodiment 4

[0136] This embodiment provides an electronic device, including a memory and one or more processors. The memory stores a computer program, and when the computer program is executed by the one or more processors, the method provided in the above embodiment is implemented.

[0137] The processor can be an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a controller, a microcontroller unit (MCU), a microprocessor or other electronic components to execute the methods in the above embodiments.

[0138] Embodiment 5

[0139] This embodiment provides a liquid micro-pressure measuring device, such as Figure 1 As shown, including:

[0140] The micro-pressure measuring unit 1 comprises a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure-taking hole to be measured through a correspondingly arranged pressure-guiding tube;

[0141] The camera 3 is arranged facing the micro-pressure measuring unit 1 and is used to take images of the liquid columns in each pressure measuring tube;

[0142] And the electronic device provided by the aforementioned embodiment.

[0143] In some implementations, the liquid micro-pressure measuring device further includes:

[0144] Two pressure measuring tubes 2 are respectively located on both sides of the micro-pressure measuring unit 1. The two pressure measuring tubes 2 are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit 1 and are respectively connected to two pressure taking holes of a liquid level adjustment box containing liquid. The purpose of the arrangement of the two pressure measuring tubes 2 is to calculate the correction coefficient according to the pixel coordinates of the bottom vertices of the liquid surface in the two pressure measuring tubes 2 connected to the liquid level adjustment box in the subsequent steps, so as to correct the error caused by the pressure measuring tubes not being installed completely vertically and / or the image being taken not being completely horizontal when processing the image taken by the camera 3.

[0145] In some implementations, the liquid micro-pressure measuring device further includes:

[0146] A light homogenizing plate 4 is arranged on a side of each pressure measuring tube (including each pressure measuring tube in the micro-pressure measuring unit 1 and two pressure measuring tubes 2 arranged on the left and right sides of the micro-pressure measuring unit 1) away from the camera 3, and is used to fix each pressure measuring tube;

[0147] The light homogenizing lamp 5 is arranged on a side of the light homogenizing plate 4 away from each pressure measuring tube, and is used to irradiate uniform light on the light homogenizing plate 4 so that the light homogenizing plate 4 evenly projects the light to each pressure measuring tube.

[0148] In some application examples, the camera 3 can be a high-resolution camera, the homogenizing plate 4 can be a frosted plexiglass plate, the homogenizing lamp 5 can be an LED homogenizing lamp group, and each pressure measuring tube can be an plexiglass tube, but the specific implementation of the homogenizing plate 4 and the homogenizing lamp 5 in this embodiment is not limited to a single one.

[0149] The liquid pressure gauge in the related art is composed of a pressure measuring tube and a scale for measuring the height of the liquid column in the pressure measuring tube, while the liquid micro-pressure measuring device used in this embodiment realizes liquid micro-pressure measurement based on images. It does not need to use a scale to measure the height of the liquid column, but adds a high-resolution camera 3, a homogenizing lamp 5 and a homogenizing plate 4. The pressure measuring tube can be fixed on the surface of the homogenizing plate 4, and the lower end of the pressure measuring tube is connected to one end of the pressure-leading tube, and the other end of the pressure-leading tube is connected to the pressure-taking hole. The liquid at the pressure-taking hole enters the pressure measuring tube through the pressure-leading tube. The homogenizing lamp 5 irradiates uniform light onto the homogenizing plate 4, and the light is further evenly transmitted through the homogenizing plate 4. The light transmitted from the homogenizing plate 4 passes through each pressure measuring tube, and the image of each pressure measuring tube and the liquid column in the pressure measuring tube is projected into the camera 3, which is photographed by the camera 3 to form a digital image. The number of pressure measuring tubes in the micro-pressure measuring unit 1 is determined according to the number of pressure holes to be measured. Each pressure hole requires a pressure measuring tube. A pressure measuring tube 2 is arranged on the leftmost and rightmost sides of the micro-pressure measuring unit 1, respectively. The leftmost and rightmost pressure measuring tubes 2 are not connected to the pressure holes to be measured, but are connected to the pressure holes of the liquid level adjustment box containing a certain volume of liquid. Since the liquid in the liquid level adjustment box is stationary, the heights of the liquid columns in the leftmost and rightmost pressure measuring tubes 2 are the same, that is, the liquid levels of the liquid columns in the two pressure measuring tubes are horizontal. The purpose of such a setting is to correct the errors caused by the pressure measuring tubes not being installed completely vertically and the captured images not being completely horizontal when processing the captured images of the liquid columns in the pressure measuring tubes.

[0150] When using the liquid micro-pressure measuring device of the present embodiment to perform liquid micro-pressure measurement, first turn on the uniform light lamp 5, connect one end of the pressure-guiding tube to the pressure-taking hole to be measured, and the other end to the pressure-gauging tube, and at the same time connect the leftmost pressure-gauging tube and the rightmost pressure-gauging tube 2 fixed on the uniform light plate 4 to the liquid level adjustment box, then remove the bubbles in the pressure-guiding tube, and adjust the height of the liquid level adjustment box so that the height of the liquid column in the leftmost and rightmost pressure-gauging tubes is basically the same as the height of the liquid column in other pressure-gauging tubes. Then adjust the pan / tilt of the camera 3 bracket to the horizontal level, and face the lens of the camera 3 to each pressure-gauging tube, the height of the lens is basically the same as the height of the liquid column in the pressure-gauging tube, and then adjust the focal length of the camera 3 to obtain a clear pressure-gauging tube image. When the working condition to be measured is stable, press the shutter button of the camera 3 to obtain the image of the pressure-gauging tube and its liquid column under the measuring working condition. When the working condition needs to be changed, repeat the previous step and readjust the camera 3. When the working condition changes and causes a significant change in the height of the liquid column in the pressure measuring tube, the height of the camera and the height of the liquid level adjustment box should be adjusted synchronously to make the lens height of camera 3, the height of the liquid column in the leftmost and rightmost pressure measuring tubes fixed on the homogenizing plate 4, and the height of the liquid column in other pressure measuring tubes basically consistent.

[0151] In the several embodiments provided in the embodiments of the present invention, it should be understood that the disclosed system and method can also be implemented in other ways. The system and method embodiments described above are merely illustrative.

[0152] It should be noted that, in this article, the terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. The terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0153] Although the embodiments disclosed in the present invention are as above, the above contents are only embodiments adopted for facilitating the understanding of the present invention and are not intended to limit the present invention. Any technician in the technical field to which the present invention belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A liquid micro-pressure measurement method, characterized in that: Applied to a liquid type micro-pressure measuring device, the liquid type micro-pressure measuring device comprises a micro-pressure measuring unit and two pressure measuring tubes respectively located on both sides of the micro-pressure measuring unit, the micro-pressure measuring unit comprises a plurality of pressure measuring tubes arranged in parallel, each pressure measuring tube is connected to a pressure taking hole to be measured through a correspondingly arranged pressure lead tube, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit, and are respectively connected to a liquid level adjustment box containing liquid, the method comprises: Acquire images of the fluid columns in each piezometer; Obtaining liquid surface pixel coordinate information of the liquid column in each pressure measuring tube in the image, wherein the liquid surface pixel coordinate information includes pixel coordinates of boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface; The height of the liquid surface caused by the surface tension of the liquid surface is calculated using a first calculation formula, wherein the first calculation formula represents the relationship between the height of the liquid surface caused by the surface tension of the liquid surface, the contact angle formed between the liquid surface and the inner wall of the pressure measuring tube, and the inner diameter of the pressure measuring tube; the first calculation formula is: Among them, H o It represents the height of the liquid surface caused by the surface tension of the liquid surface, d represents the inner diameter of the pressure measuring tube, θ represents the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and B represents the Bond number; Use the second calculation formula to calculate the pressure difference at the pressure holes where the two pressure measuring tubes are connected: The second calculation formula is as follows: ΔP 1，2 =ρg(H1-H2) Among them, ΔP 1，2 represents the pressure difference at the pressure tapping hole connected to any two pressure measuring tubes of the micro-pressure measuring unit, ρ represents the density of the liquid at the current measurement temperature, g represents the local gravitational acceleration, H1 and H2 represent the heights of the liquid columns of the two pressure measuring tubes after correction based on the correction coefficient; H1=(l v -S1 by +(S1 bx -L bx )k)fH 0，1 H2=(l v -S2 by +(S2 bx -L bx )k)f-H 0，2 l v represents the total number of vertical pixels of the liquid column image, k represents the correction coefficient, H 0，1 and H 0，2 They represent the height of the liquid column in the two pressure measuring tubes caused by the surface tension of the liquid surface; (S1 by , S1 bx ) represents the pixel coordinates of the vertex at the bottom of the liquid surface in one of the two pressure measuring tubes, (S2 bx , S2 by ) represents the pixel coordinates of the vertex at the bottom of the liquid surface in the other of the two pressure measuring tubes; f represents the ratio of pixel coordinates to length coordinates; k=((R by +H 0，r )-(L by +H 0，l )) / (R bx -L bx ) (R bx , R by ) represents the pixel coordinates of the bottom vertex of the liquid surface in the rightmost pressure measuring tube, and the rightmost pressure measuring tube refers to the pressure measuring tube located on the right side of the micro-pressure measuring unit among the two pressure measuring tubes on both sides of the micro-pressure measuring unit, (L bx , L by ) represents the pixel coordinates of the vertex of the bottom of the liquid surface in the leftmost pressure measuring tube, and the leftmost pressure measuring tube refers to the pressure measuring tube located on the left side of the micro-pressure measuring unit among the two pressure measuring tubes on both sides of the micro-pressure measuring unit, H 0，r and H 0，1 They respectively represent the height of the liquid column in the rightmost pressure tube and the leftmost pressure tube caused by the surface tension of the liquid column.

2. The liquid micro-pressure measurement method according to claim 1, characterized in that: The step of obtaining pixel coordinate information of the liquid level of the liquid column in each pressure measuring tube in the image includes: Reading pixel coordinates of boundaries on both sides of the liquid surface of each liquid column in each pressure measuring tube in the image; The pixel coordinates of the vertex at the bottom of the liquid surface are obtained based on the pixel coordinates of the boundaries on both sides of the liquid surface.

3. The liquid micro-pressure measurement method according to claim 1, characterized in that: Before acquiring the image of the liquid column in each pressure measuring tube, the method further includes: Adjust the height of the liquid column in the two pressure measuring tubes connected to the liquid level adjustment box so that the height of the liquid column in the two pressure measuring tubes is consistent.

4. A liquid micro-pressure measuring device, characterized in that: Applicable to liquid micro-pressure measuring equipment, the liquid micro-pressure measuring equipment includes a micro-pressure measuring unit and two pressure measuring tubes respectively located on both sides of the micro-pressure measuring unit, the micro-pressure measuring unit includes a plurality of pressure measuring tubes arranged in parallel, each pressure measuring tube is connected to a pressure-taking hole to be measured through a correspondingly arranged pressure-leading tube, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit, and are respectively connected to a liquid level adjustment box containing liquid, the liquid micro-pressure measuring device includes: An image acquisition module, used to acquire images of liquid columns in each pressure measuring tube; A coordinate acquisition module, used to acquire liquid surface pixel coordinate information of the liquid column in each pressure measuring tube in the image, wherein the liquid surface pixel coordinate information includes pixel coordinates of the boundaries on both sides of the liquid surface and pixel coordinates of the vertex at the bottom of the liquid surface; The first calculation module is used to calculate the height of the liquid surface caused by the surface tension of the liquid surface by using a first calculation formula, wherein the first calculation formula represents the relationship between the height of the liquid surface caused by the surface tension of the liquid surface, the contact angle formed between the liquid surface and the inner wall of the pressure measuring tube, and the inner diameter of the pressure measuring tube; the first calculation formula is: Among them, H o It represents the height of the liquid surface caused by the surface tension of the liquid surface, d represents the inner diameter of the pressure measuring tube, θ represents the contact angle formed by the liquid surface and the inner wall of the pressure measuring tube, and B represents the Bond number; The second calculation module is used to calculate the pressure difference at the pressure holes connected to the two pressure measuring tubes using a second calculation formula; the second calculation formula is as follows: ΔP 1，2 =ρg(H1-H2) Among them, ΔP 1，2 represents the pressure difference at the pressure tapping hole connected to any two pressure measuring tubes of the micro-pressure measuring unit, ρ represents the density of the liquid at the current measurement temperature, g represents the local gravitational acceleration, H1 and H2 represent the heights of the liquid columns of the two pressure measuring tubes after correction based on the correction coefficient; H1=(l v -S1 by +(S1 bx -L bx )k)fH 0，1 H2=(l v -S2 by +(S2 bx -L bx )k)f-H 0，2 l v represents the total number of vertical pixels of the liquid column image, k represents the correction coefficient, H 0，1 and H 0，2 They represent the height of the liquid column in the two pressure measuring tubes caused by the surface tension of the liquid surface; (S1 by , S1 bx ) represents the pixel coordinates of the vertex at the bottom of the liquid surface in one of the two pressure measuring tubes, (S2 bx , S2 by ) represents the pixel coordinates of the vertex at the bottom of the liquid surface in the other of the two pressure measuring tubes; f represents the ratio of pixel coordinates to length coordinates; k=((R by +H 0，r )-(L by +H 0，l )) / (R bx -L bx ) (R bx , R by ) represents the pixel coordinates of the bottom vertex of the liquid surface in the rightmost pressure measuring tube, and the rightmost pressure measuring tube refers to the pressure measuring tube located on the right side of the micro-pressure measuring unit among the two pressure measuring tubes on both sides of the micro-pressure measuring unit, (L bx , L by ) represents the pixel coordinates of the vertex of the bottom of the liquid surface in the leftmost pressure measuring tube, and the leftmost pressure measuring tube refers to the pressure measuring tube located on the left side of the micro-pressure measuring unit among the two pressure measuring tubes on both sides of the micro-pressure measuring unit, H 0，r and H 0，1 They respectively represent the height of the liquid column in the rightmost pressure tube and the leftmost pressure tube caused by the surface tension of the liquid column.

5. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by one or more processors, the method according to any one of claims 1 to 3 is implemented.

6. An electronic device, characterized in that: The method comprises a memory and one or more processors, wherein a computer program is stored in the memory, and when the computer program is executed by the one or more processors, the method according to any one of claims 1 to 3 is implemented.

7. A liquid micro-pressure measuring device, characterized in that: include: The micro-pressure measuring unit comprises a plurality of pressure measuring tubes arranged in parallel, each of which is connected to a pressure-taking hole to be measured through a correspondingly arranged pressure-leading tube; Two pressure measuring tubes are respectively located on both sides of the micro-pressure measuring unit, the two pressure measuring tubes are arranged in parallel with the pressure measuring tube in the micro-pressure measuring unit, and are respectively connected to a liquid level adjustment box containing liquid; A camera, arranged facing the micro-pressure measuring unit, for taking images of the liquid columns in each pressure measuring tube; The electronic device as claimed in claim 6.

8. The liquid type micro-pressure measuring device according to claim 7, characterized in that: Also includes: A light homogenizing plate, arranged on a side of each pressure measuring tube away from the camera, and used to fix each pressure measuring tube; The light homogenizing lamp is arranged on a side of the light homogenizing plate away from each pressure measuring tube, and is used to irradiate uniform light on the light homogenizing plate so that the light homogenizing plate evenly projects the light to each pressure measuring tube.

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