Liquid film measuring device and method for coupling multi-factor variable interaction

Abstract

The invention provides a liquid film measuring device and method coupled with multi-factor variable interaction, and belongs to the technical field of fire fighting equipment, the liquid film measuring device coupled with multi-factor variable interaction comprises a visual sealed pressure cabin, a pressure gauge is arranged outside the visual sealed pressure cabin, and the pressure gauge is connected with a pressure adjusting module; a humidifying module, a first heating module, a second heating module, a third heating module, a first thermocouple, a second thermocouple, a first telescopic rod, a second telescopic rod, a third telescopic rod, a fourth telescopic rod, a light source, an image acquisition module and a liquid pool are arranged in the visible sealed pressure cabin; the humidifying module is positioned at the top in the cabin; the first heating module and the second heating module are located on the left and right sides of the middle of the cabin inner wall respectively. The third heating module is located at the bottom of the liquid pool. The first thermocouple is positioned at the top in the cabin; the second thermocouple is positioned at the bottom of the liquid pool; the problem that the drainage performance of the foam under different environmental conditions cannot be accurately reflected is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fire-fighting equipment, and in particular relates to a liquid film measuring device and method coupled with the interaction of multiple variables. Background Art

[0002] Foam fire extinguishing agents are an effective means of extinguishing oil fires. Using specialized equipment, foam is generated and can be applied to a wide area of the oil surface. Its fluidity effectively reduces the burning area and cools the fuel by releasing liquid, reducing its evaporation rate. Furthermore, the resulting foam layer isolates the air, thereby reducing the concentration of oxidants and preventing combustion. Numerous studies have shown that foam stability is a key indicator of the effectiveness of foam fire extinguishing agents. After the formation of a gas-liquid two-phase foam, the liquid film between the bubbles thins over time. This thinning of the liquid film accelerates bubble collapse, thus affecting foam stability. Therefore, quantitative measurement of the thinning process can effectively reflect foam stability.

[0003] The invention patent with publication number: CN110715908B (application number: CN201911035343.0) discloses a foam film liquid evaporation measurement device and measurement method. Although it can analyze the changes in film thickness distribution over time as a reference indicator for measuring the liquid evaporation rate of the foam film, changes in ambient temperature and humidity will affect the evaporation rate of the liquid in the foam film; pressure changes will change the gas state inside the foam, affecting the stability of the foam and the stress conditions of the liquid film; in addition, depending on the size of the liquid film, its surface area to volume ratio is also different, which will affect the material exchange and energy transfer between the liquid film and the surrounding environment.

[0004] Therefore, the existing liquid film measurement devices and methods are unable to comprehensively consider the influence of the interaction of multiple factors such as liquid film size, ambient temperature, humidity, and pressure, resulting in deviations between the measurement results and the actual situation, and there is a problem of being unable to accurately reflect the liquid separation performance of the foam under different environmental conditions. Summary of the Invention

[0005] In view of this, the present invention provides a liquid film measurement device and method coupled with the interaction of multiple variables, which solves the problem of being unable to accurately reflect the liquid separation performance of foam under different environmental conditions.

[0006] The present invention is achieved in that:

[0007] The present invention provides a liquid film measuring device coupled with the interaction of multiple variables, which includes a visual sealed pressure cabin, a pressure gauge is provided outside the visual sealed pressure cabin, and the pressure gauge is connected to a pressure regulating module; a humidifying module, a first heating module, a second heating module, a third heating module, a first thermocouple, a second thermocouple, a first telescopic rod, a second telescopic rod, a third telescopic rod, a fourth telescopic rod, a light source, an image acquisition module, and a liquid pool are provided in the visual sealed pressure cabin; the humidifying module is located at the top of the cabin; the first heating module and the second heating module are respectively located at the left and right sides of the middle of the cabin inner wall, and the third heating module is located at the bottom of the liquid pool; the first thermocouple is located at the top of the cabin, and the second thermocouple is located at The bottom of the liquid pool; the first telescopic rod and the second telescopic rod are respectively fixed to the left and right positions above the inner wall of the cabin, and are provided with a first stepping motor and a second stepping motor, and the third telescopic rod and the fourth telescopic rod are respectively fixed to the left and right positions below the inner wall of the cabin; the first stepping motor is provided with a first pulley, and the second stepping motor is provided with a second pulley; the first pulley is connected to the first transmission belt, and the second pulley is connected to the second transmission belt; a liquid film extraction line is connected between the first transmission belt and the second transmission belt; the bottom ends of the first transmission belt and the second transmission belt are respectively connected to the third pulley and the fourth pulley; the third pulley and the fourth pulley are fixed to the third telescopic rod and the fourth telescopic rod; the liquid pool is located at the bottom of the cabin.

[0008] On the basis of the above technical solution, the liquid film measuring device coupled with multi-factor variable interaction of the present invention can also be improved as follows:

[0009] Among them, the visual sealed pressure cabin is made of high-temperature resistant, pressure-resistant and corrosion-resistant materials, and is equipped with an observation window for easy observation of the situation inside the cabin; the pressure regulating module is used to adjust the pressure inside the visual sealed pressure cabin, and display the pressure in real time through a pressure gauge.

[0010] Furthermore, the humidification module is equipped with a humidity sensor for adjusting and monitoring the humidity inside the visible sealed pressure chamber; the first heating module and the second heating module are used to adjust the temperature inside the visible sealed pressure chamber, and monitor the temperature inside the chamber in real time through the first thermocouple; the third heating module is used to adjust the temperature of the liquid in the liquid pool, and monitor the temperature of the liquid through the second thermocouple.

[0011] Furthermore, the first telescopic rod, the second telescopic rod, the third telescopic rod, and the fourth telescopic rod are used to adjust the distance w between the first transmission belt and the second transmission belt by extending and retracting forward and backward.

[0012] Furthermore, the width of the first transmission belt and the second transmission belt is 10 mm; the liquid film extraction line is vertically arranged between the first transmission belt and the second transmission belt, with a diameter of 0.5 mm, and the two ends of the liquid film extraction line are detachably connected to the first transmission belt and the second transmission belt respectively.

[0013] Furthermore, the first stepper motor and the second stepper motor are used to control the rotation of the first pulley and the second pulley respectively, thereby driving the first transmission belt and the second transmission belt.

[0014] Furthermore, the light source is a monochromatic light source with a wavelength greater than or equal to 520 nm.

[0015] Furthermore, the angle between the image acquisition module and the monochromatic light source is 15° to 45°, and the interference fringes between the dark and bright phases of the liquid film are recorded in real time. For the dark fringes, their local thickness δ dark According to formula (1), for bright stripes, the local thickness δ light According to formula (2), we can get:

[0016]

[0017] Where k is the fringe order, α is the incident angle, and n is the refractive index of the solution.

[0018] Furthermore, the liquid pool is 100 mm long, 100 mm wide, and 100 mm high.

[0019] Furthermore, a liquid film measurement method coupled with multi-factor variable interaction includes the following steps:

[0020] S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface;

[0021] S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters;

[0022] S3: Turn on the light source and image acquisition module;

[0023] S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h;

[0024] S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

[0025] Compared with the existing technology, the beneficial effect of the liquid film measurement device and method coupled with the interaction of multiple variables provided by the present invention is: by comprehensively considering the influence of the interaction of multiple factors such as liquid film size, solution temperature, ambient temperature, humidity, and pressure on the liquid film change, and based on the principle of monochromatic light interference, by real-time recording of the liquid film change process, and using computer image processing technology to obtain liquid film thickness data, technical support is provided for the performance testing of foam fire extinguishing agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 The schematic diagram of the structure of a liquid film measuring device coupled with multi-factor variable interaction;

[0028] Figure 2 This is the interference image of the liquid film under monochromatic light in Example 1;

[0029] Figure 3 This is the interference image of the liquid film under monochromatic light in Example 2;

[0030] Figure 4 This is the interference image of the liquid film under monochromatic light in Example 3;

[0031] Figure 5 Schematic diagram of measuring the thickness of the liquid film at different times in Example 1;

[0032] Figure 6 Schematic diagram of measuring the thickness of the liquid film at different times in Example 2;

[0033] Figure 7 Schematic diagram of measuring the thickness of the liquid film at different times in Example 3;

[0034] Figure 8 The flow chart of a liquid film measurement method coupled with multi-factor variable interaction is shown;

[0035] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0036] 1. Visual sealed pressure chamber; 10. First telescopic rod; 11. Second telescopic rod; 12. First transmission belt; 13. Second transmission belt; 14. Liquid film extraction line; 15. First heating module; 16. Second heating module; 17. Third heating module; 18. Light source; 19. Image acquisition module; 2. Pressure gauge; 20. Third telescopic rod; 21. Fourth telescopic rod; 22. Third pulley; 23. Fourth pulley; 24. Second thermocouple; 25. Liquid pool; 3. Humidification module; 4. First thermocouple; 5. Pressure regulating module; 6. First pulley; 7. Second pulley; 8. First stepper motor; 9. Second stepper motor. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] like Figure 1 As shown, an embodiment of a liquid film measuring device coupled with multi-factor variable interaction provided by the present invention is provided. In this embodiment, the device comprises a visual sealed pressure cabin (1), a pressure gauge (2) is provided outside the visual sealed pressure cabin, and the pressure gauge is connected to a pressure regulating module (5); a humidifying module (3), a first heating module (15), a second heating module (16), a third heating module (17), a first thermocouple (4), a second thermocouple (24), a first telescopic rod (10), a second telescopic rod (11), a third telescopic rod (20), a fourth telescopic rod (21), a light source (18), an image acquisition module (19), and a liquid pool (25) are provided inside the visual sealed pressure cabin 1; the humidifying module is located at the top of the cabin; the first heating module and the second heating module are respectively located at the left and right sides of the middle of the cabin inner wall, and the third heating module is located at the bottom of the liquid pool. The invention relates to a liquid tank having a first thermocouple and a second thermocouple. The first telescopic rod and the second telescopic rod are respectively fixed to the left and right positions above the inner wall of the tank, and are provided with a first stepper motor (8) and a second stepper motor (9). The third telescopic rod and the fourth telescopic rod are respectively fixed to the left and right positions below the inner wall of the tank. The first stepper motor is provided with a first pulley (6), and the second stepper motor is provided with a second pulley (7). The first pulley is connected to a first transmission belt (12), and the second pulley is connected to a second transmission belt (13). A liquid film extraction line (14) is connected between the first transmission belt and the second transmission belt. The bottom ends of the first transmission belt and the second transmission belt are respectively connected to a third pulley (22) and a fourth pulley (23). The third pulley and the fourth pulley are fixed to the third telescopic rod and the fourth telescopic rod. The liquid tank is located at the bottom of the tank.

[0039] Among them, in the above technical solution, the visual sealed pressure cabin is made of high-temperature resistant, pressure-resistant and corrosion-resistant materials, and is equipped with an observation window for facilitating observation of the situation inside the cabin; the pressure regulating module is used to adjust the pressure inside the visual sealed pressure cabin, and display the pressure in real time through a pressure gauge.

[0040] Furthermore, in the above technical solution, the body of the visual sealed pressure chamber can be made of 316L stainless steel or corrosion-resistant alloy, the visual observation window can be made of quartz glass or high borosilicate glass, and the sealing parts can be made of fluororubber or polytetrafluoroethylene sealing rings. The pressure regulation module includes a gas source quick connector, a precision pressure reducing valve, a solenoid shut-off valve, a three-way connector, a pressure gauge or pressure sensor, and a connecting air pipe. The gas source quick connector adopts the SMCKQ2H06-M5 type to connect to external compressed air or gas cylinders; the precision pressure reducing valve adopts the SMCIR2020-N02 type to stabilize the gas source pressure within the target range; the solenoid shut-off valve preferably adopts the FESTOVZWM series for air circuit opening and closing control; the pressure gauge can adopt the WIKA232.50 mechanical gauge to monitor and display the air pressure in the visual sealed pressure chamber in real time. Each component is connected in series to form a complete air intake pressure regulation system, which is connected to the gas inlet of the sealed pressure chamber through a high-pressure PU air pipe.

[0041] Furthermore, in the above technical solution, the humidification module is equipped with a humidity sensor for adjusting and monitoring the humidity inside the visible sealed pressure chamber; the first heating module and the second heating module are used to adjust the temperature inside the visible sealed pressure chamber, and monitor the temperature inside the chamber in real time through the first thermocouple; the third heating module is used to adjust the temperature of the liquid in the liquid pool, and monitor the temperature of the liquid through the second thermocouple.

[0042] In the above technical solution, the humidification module includes an ultrasonic humidifier, a water tank, a humidity sensor, and a humidity control controller. The ultrasonic humidifier preferably uses a ceramic oscillating atomization unit with high atomization efficiency and stable operation characteristics. It is fixedly installed on the top of the sealed pressure chamber and sprays atomized particles directly into the chamber through the output port. The water tank is made of stainless steel or high-temperature PC material, with a volume of 500 mL. It is installed on the side of the sealed pressure chamber or under the control cabin of the sealed pressure chamber and is connected to the water inlet of the atomization module through a heat-resistant silicone tube to ensure continuous water supply. The humidity sensor is preferably a Sensirion SHT85 model. The humidity sensor probe is fixed to the inner wall of the pressure chamber top and is used to collect real-time humidity information in the chamber. The humidification module is equipped with a microcontroller for closed-loop control. The controller can optionally use a WHD200 series digital humidity controller. It determines whether to start or stop the humidifier by collecting humidity data in the chamber to achieve stable humidity control. When the humidity in the chamber is lower than the set value, the control unit automatically drives the ultrasonic humidifier to work and continuously increase the humidity. When the target value is reached, it automatically shuts down to ensure the stability and repeatability of the humidity in the liquid film experiment environment.

[0043] Furthermore, in the above technical solution, the first telescopic rod, the second telescopic rod, the third telescopic rod and the fourth telescopic rod are used to adjust the distance w between the first transmission belt and the second transmission belt by extending and retracting forward and backward.

[0044] Furthermore, in the above technical solution, the width of the first transmission belt and the second transmission belt is 10 mm; the liquid film extraction line is vertically arranged between the first transmission belt and the second transmission belt, with a diameter of 0.5 mm, and the two ends of the liquid film extraction line are respectively detachably connected to the first transmission belt and the second transmission belt.

[0045] Furthermore, in the above technical solution, the liquid film extraction line is a prefabricated line segment of various specifications, and the distance w between the first transmission belt and the second transmission belt is adapted by replacing the prefabricated line segments of different lengths.

[0046] In the above solution, magnetic heads are installed at both ends of the liquid film extraction line, which can be fixed to the central connecting pieces of the first and second transmission belts respectively; magnetic mounting bases are installed at the connection points of the transmission belts to facilitate the rapid installation and removal of the liquid film line and stable positioning. The length of the liquid film extraction line is standardized and customized, usually with common spacings such as 8mm, 10mm, 12mm, 14mm, and 16mm. The length mark is placed in the middle of the line for easy identification and recording.

[0047] Before use, the operator selects a liquid film extraction line of corresponding length for replacement according to the currently set transmission belt spacing w, thereby improving the repeatability of the experiment and the convenience of using the device.

[0048] Furthermore, in the above technical solution, the first stepper motor and the second stepper motor are respectively used to control the rotation of the first pulley and the second pulley, thereby driving the first transmission belt and the second transmission belt.

[0049] Furthermore, in the above technical solution, the light source is a monochromatic light source with a wavelength greater than or equal to 520 nm.

[0050] Furthermore, in the above technical solution, the angle between the image acquisition module and the monochromatic light source is 15° to 45°, and the interference fringes between the dark and bright phases of the liquid film are recorded in real time. For the dark fringes, the local thickness δ dark According to formula (1), for bright stripes, the local thickness δ light According to formula (2), we can get:

[0051]

[0052] Where k is the fringe order, α is the incident angle, and n is the refractive index of the solution.

[0053] Furthermore, in the above technical solution, the liquid pool is 100 mm long, 100 mm wide and 100 mm high.

[0054] like Figure 8 As shown, Figure 8The flow chart of a liquid film measurement method coupled with multi-factor variable interaction includes the following steps:

[0055] S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface;

[0056] S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters;

[0057] S2 specifically includes the following sub-steps:

[0058] S21: Adjust the lengths of the first telescopic rod, the second telescopic rod, the third telescopic rod, and the fourth telescopic rod so that the first transmission belt and the second transmission belt are at a target distance w, where w = 12 mm;

[0059] S22: Using the first heating module and the second heating module, adjusting the temperature in the visible sealed pressure chamber to the target temperature, and using the third heating module to adjust the temperature of the solution to the target temperature of about 30° C.;

[0060] S23: Using the pressure regulating module, adjust the pressure in the visible seal pressure chamber to a target pressure of 100 kPa;

[0061] S24: Using the humidification module, adjust the humidity in the sealed pressure chamber to a target humidity of 80%;

[0062] S25: After the temperature, humidity, pressure and solution temperature in the visually sealed pressure chamber all reach the target values and remain stable, proceed to the subsequent steps.

[0063] Furthermore, the steps include:

[0064] S3: Turn on the light source and image acquisition module;

[0065] Among them, the image acquisition module includes a high-resolution industrial camera and a chip, and the chip is electrically connected to the industrial camera, computer, light source, humidification module and heating module respectively; the image acquisition module can realize image enhancement processing through multimodal data acquisition, and combine image feature comparison to assist the computer to output liquid film thickness results more quickly.

[0066] S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h, where h = 15 mm;

[0067] S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

[0068] Example 1:

[0069] S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface;

[0070] S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters;

[0071] Among them, S2 includes the following steps:

[0072] S21: Adjust the lengths of the first telescopic rod, the second telescopic rod, the third telescopic rod, and the fourth telescopic rod so that the first transmission belt and the second transmission belt are at a target distance w, where w = 12 mm;

[0073] S22: Using the first heating module and the second heating module, adjusting the temperature in the visible sealed pressure chamber to the target temperature, and using the third heating module to adjust the temperature of the solution to the target temperature of about 30° C.;

[0074] S23: Using the pressure regulating module, adjust the pressure in the visible seal pressure chamber to a target pressure of 100 kPa;

[0075] S24: Using the humidification module, adjust the humidity in the sealed pressure chamber to a target humidity of 80%;

[0076] S25: After the temperature, humidity, pressure and solution temperature in the visually sealed pressure chamber all reach the target values and remain stable, proceed to the subsequent steps.

[0077] Furthermore, the steps include:

[0078] S3: Turn on the light source and image acquisition module;

[0079] S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h, where h = 15 mm;

[0080] S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

[0081] Among them, Figure 2 As shown in the figure, a monochromatic light source irradiates the liquid film to form interference fringes between dark and bright phases. The image acquisition module is used to record the changes of the interference fringes of the liquid film of specified size under target temperature, humidity and pressure over time in real time, and transmit the image information to the computer. The computer calculates the liquid film thickness data at different times according to formulas (1) and (2), as shown in the figure. Figure 5As shown, the liquid film thickness data are collected at 5s, 10s, 15s, and 20s after the liquid film is formed.

[0082] Furthermore, the image acquisition module enhances the image processing and assists the computer in outputting the liquid film thickness result more quickly by combining the image feature comparison. The specific implementation method is as follows:

[0083] Image data captured by the industrial camera is transmitted to the chip in real time. The preprocessing pipeline algorithm in the chip processing module leverages the chip's hardware acceleration capabilities to rapidly perform image enhancement and threshold segmentation. Next, the FMU unit within the chip, controlled by the chip processing module's feature matching algorithm, queries the template library and outputs matching results. Working together, these two enable efficient completion of image acquisition and chip-side processing tasks, providing high-quality data for subsequent precise computer-side calculations, ultimately achieving accurate measurement of liquid film thickness.

[0084] The specific implementation includes the following stages:

[0085] System initialization and environment preparation; image acquisition and chip-side processing; computer-side thickness calculation and data fusion; result output and verification.

[0086] System initialization and environment preparation:

[0087] Start the heating, pressurization, and humidification components in the cabin; monitor the sensor data in real time. When the parameter fluctuation is less than ±1% for 5 consecutive minutes (such as temperature 30±0.3℃), trigger the data acquisition program of the chip in the image acquisition module to perform image acquisition.

[0088] Image acquisition and chip-side processing:

[0089] Monochromatic image acquisition (real-time chip enhancement):

[0090] The first step is to synchronize the acquisition trigger:

[0091] The computer sends an acquisition command and activates the light source (532 nm) and environmental sensor (sampling frequency 10 Hz) at the same time;

[0092] The industrial camera captures images at 20 fps, and the raw data (2048 × 2048 × 16 bits) is transmitted to the image processing chip in real time.

[0093] The second step is chip-side image enhancement processing:

[0094] Preprocessing pipeline:

[0095] 1. Gaussian filtering (FPGA parallel computing, 4.2μs / frame);

[0096] 2. Adaptive histogram equalization (CLAHE, grid 8×8, contrast limit 4.0, 120μs / frame);

[0097] 3. Dynamic threshold segmentation (based on Otsu algorithm, built-in threshold calculation unit on chip, consuming 5μs / frame).

[0098] Output: enhanced grayscale image (2048×2048) and binary stripe mask (dark / light stripe marks)

[0099] Chip feature extraction and matching (quick retrieval):

[0100] The first step is geometric feature calculation:

[0101] Fringe center coordinates (sub-pixel accuracy, centroid algorithm), fringe width / spacing (converted to nm units):

[0102] Where, the stripe spacing d is:

[0103]

[0104] Where, the stripe width w is:

[0105]

[0106] Where, (Δx is the pixel difference between adjacent stripes, 3.45 μm is the pixel size); w pixel is the pixel width of the stripe in the image (dimensionless).

[0107] The second step is feature matching acceleration:

[0108] Construct a 6-dimensional feature vector: in:

[0109] d: fringe spacing (nm);

[0110] w: stripe width (nm);

[0111] C: Fringe contrast (dimensionless); calculation formula Among them, I max / I min is the maximum / minimum grayscale value of the stripe area;

[0112] Phase gradient (rad / m), the phase difference between adjacent pixels divided by the physical distance;

[0113] k T : Temperature-thickness coefficient (nm / ℃), (Thickness change rate at ΔT = 1°C);

[0114] kP : Pressure-thickness coefficient (nm / MPa), (Thickness change rate when ΔP = 0.1 MPa).

[0115] The chip FMU unit queries the template library to output the most matching historical template (K-NN algorithm, K=5, matching time <200ns).

[0116] Computer-side thickness calculation and data fusion (accurate solution):

[0117] The first step is to calculate the stripe thickness by computer:

[0118] Among them, the thickness of dark lines (k is the order, k≥1):

[0119]

[0120] k: fringe order (positive integer, k = 1, 2, 3, ...), indicating the order of destructive interference fringes;

[0121] λ: wavelength of monochromatic light source (nm), 532nm in this solution;

[0122] n(T,P): liquid film refractive index (dimensionless), a function of temperature and pressure: n(T,P) = 1.333 [1 + 0.0001(T-25) + 0.00005(P-0.1)];

[0123] T: liquid film temperature (℃), reference temperature T0 = 25℃;

[0124] P: ambient pressure (MPa), reference pressure P0 = 0.1 MPa;

[0125] α: refraction angle of light in the liquid film (°), fixed at 60° in this embodiment (calculated using an incident angle of 60° and the law of refraction, cosα = 0.5);

[0126] Among them, the thickness of the bright lines (k is the level, k≥0):

[0127]

[0128] (λ=532nm, n(T,P)=1.333[1+0.0001(T-25)+0.00005(P-0.1)],α=60°)

[0129] k: Bright fringe order (non-negative integer, k = 0, 1, 2, ...), indicating the order of constructive interference fringes, which is 1 less than the order of adjacent dark fringes.

[0130] The second step is mixed area interpolation:

[0131] Calculation based on gray value weight w (0≤w≤1):

[0132] δ mixed =(1-w)δ dark +wδ bright ;

[0133] Grayscale weight w: reflects the relative position of the pixel grayscale value between the peak values of light and dark stripes (0≤w≤1),

[0134] I: current pixel grayscale value (0-255);

[0135] I dark_peak : Grayscale peak value of dark pattern area;

[0136] I bright_peak : Gray level peak value of bright fringe area.

[0137] Deep learning model optimization calculation:

[0138] The first step is to build multi-channel input:

[0139] Input data: enhanced grayscale image (single channel) output by the chip + stripe type mask (dark stripes / light stripes, 2 channels);

[0140] Environmental parameters: Convert [T(℃), P(MPa), H(%RH)] into a 3-dimensional feature vector, where:

[0141] T represents the real-time temperature in degrees Celsius (℃);

[0142] P represents the real-time pressure in MPa;

[0143] H represents the real-time humidity, the unit of which is relative humidity percentage (%RH).

[0144] The second step is model reasoning and fusion:

[0145] Lightweight U-Net model (chip preprocessing + computer-side inference, consuming 1.2ms / frame);

[0146] Dynamic weight allocation:

[0147]

[0148] (σ is the standard deviation, and the initial value k0 of the matching template is used first to reduce the number of iterations by 50%)

[0149] Result output and verification (quality control):

[0150] Spatiotemporal data processing and visualization:

[0151] The first step is gridding and statistical analysis:

[0152] Divide the grid into 100 × 100 grids and calculate the average thickness and coefficient of variation (CV = σ / μ) of each grid;

[0153] Generate thickness time series and calculate the liquid leakage rate:

[0154] Step 2: Visual report generation:

[0155] Pseudo-color image: blue (0nm) → red (1000nm), superimposed stripe outline (dark dashed line, light solid line).

[0156] Excel report: The Excel report contains raw data, statistical parameters, environmental parameter impact analysis (such as temperature coefficient ),in:

[0157] Raw data: records basic information during the measurement process, such as image file name, acquisition time, and environmental parameters.

[0158] Statistical parameters: including average thickness, standard deviation, and coefficient of variation of each grid And other statistical results.

[0159] Analysis of environmental parameter impact: Temperature coefficient k T For example, k T Indicates the degree of influence of temperature change on the thickness of the liquid film, δ is the change in liquid film thickness, and ΔT is the change in temperature.

[0160] Anomaly Detection and Calibration:

[0161] Quality control: When the thickness fluctuation is >100nm or the contrast C is <0.2, the chip will be triggered to re-acquire (up to 3 retries);

[0162] Computer verification: Check whether the number of bright ripples meets k bright =k dark -1, if the deviation is greater than 5%, interpolation correction is performed.

[0163] In the above embodiment, the light source uses 532nm monochromatic light with a light intensity range of 500-1500 lux, which is used to provide stable, single-wavelength lighting conditions for liquid film measurement and ensure the accuracy of interference fringes. During implementation, it is necessary to calibrate with a power meter before each measurement to ensure that the light intensity stability is within ±1%. Otherwise, unstable lighting conditions will affect the quality of fringe imaging.

[0164] The chip processing module includes the chip, firmware, algorithms, and software drivers. The FPGA firmware burned into the chip through the JTAG interface initializes the various functional modules within the chip. The algorithms in the chip processing module, such as the centroid algorithm for calculating the center coordinates of stripes and the K-NN feature matching algorithm, run with the support of the chip hardware resources, realizing a complete processing flow from image acquisition to feature extraction and matching. The chip processing module implements image enhancement in less than 130μs / frame. Through FPGA parallel processing and pre-stored commonly used filter kernels, image preprocessing and feature matching are completed quickly, greatly improving data processing speed. During implementation, it is necessary to ensure that the FPGA firmware is correctly burned and initialized, and that the filter kernel parameters are set reasonably.

[0165] The computer calculation section achieves a thickness resolution accuracy of ±2nm (under 100nm), using double-precision floating-point operations and retaining 6 decimal places to accurately calculate data. The environmental control module maintains temperature accuracy of ±0.5°C, humidity of ±1%, and pressure of ±0.01MPa, providing a stable environment for liquid film measurement and reducing environmental interference. Sensor drift is recorded every 10 minutes and the coefficient is automatically corrected to ensure the accuracy and stability of environmental parameters.

[0166] System initialization and environmental preparation: Precise calibration and calibration of the light source, industrial camera, chip, and environmental control module ensures high-precision hardware operation. Stable environmental parameter control provides consistent external conditions for liquid film measurement, reducing the impact of environmental fluctuations on film thickness and avoiding measurement deviations caused by equipment errors and environmental changes, laying the foundation for subsequent accurate measurements.

[0167] Image acquisition and chip-side processing: The industrial camera and chip work together to achieve high-speed image acquisition and real-time enhanced processing. The on-chip preprocessing pipeline rapidly improves image quality, accurately segmenting light and dark fringes, while simultaneously calculating fringing geometric features and constructing feature vectors. This results in clearer image data and more distinct fringing features, providing high-quality data support for subsequent thickness calculations and improving measurement accuracy and stability.

[0168] Specifically, the principle of this embodiment is that, in the thickness calculation and data fusion stage on the computer side, based on physical formulas and deep learning models, combined with environmental parameters, the liquid film thickness is accurately calculated and dynamically weighted for fusion. The physical relationship between the liquid film thickness and the interference fringes and environmental factors, as well as the reference value of historical data, is fully considered, which can more accurately reflect the actual thickness of the liquid film, effectively reduce calculation errors, and improve measurement accuracy; in the result output and verification stage, through spatiotemporal data processing, visualization and anomaly detection calibration, not only the distribution and change trend of the liquid film thickness can be intuitively presented, but also abnormal measurement data can be discovered and corrected in a timely manner. This helps researchers and operators to fully understand the characteristics of the liquid film, ensure the reliability of the measurement results, and provide strong data support for liquid film-related research and applications.

[0169] Comprehensive technical advantages: The hardware acceleration architecture significantly improves system processing efficiency, monochromatic light adaptability simplifies hardware while ensuring measurement functionality, and template library-driven rapid matching enables significant improvements in the efficiency, accuracy, and applicability of liquid film measurement. This significantly improves the efficiency, accuracy, and applicability of liquid film measurement, meeting the needs of liquid film measurement in diverse scenarios and promoting the development and application of liquid film measurement technology in scientific research and industry.

[0170] Example 2:

[0171] A liquid film measurement method coupled with multi-factor variable interaction specifically comprises the following steps:

[0172] S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface;

[0173] S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters;

[0174] S2 specifically includes the following sub-steps:

[0175] S21: Adjust the lengths of the first telescopic rod, the second telescopic rod, the third telescopic rod, and the fourth telescopic rod so that the first transmission belt and the second transmission belt are at a target distance w, where w = 12 mm;

[0176] S22: Using the first heating module and the second heating module, adjusting the temperature in the visible sealed pressure chamber to the target temperature, and using the third heating module to adjust the temperature of the solution to the target temperature of about 50° C.;

[0177] S23: Using the pressure regulating module, adjust the pressure in the visible seal pressure chamber to a target pressure of 100 kPa;

[0178] S24: Using the humidification module, adjust the humidity in the sealed pressure chamber to a target humidity of 80%;

[0179] S25: After the temperature, humidity, pressure and solution temperature in the visually sealed pressure chamber all reach the target values and remain stable, proceed to the subsequent steps.

[0180] Furthermore, the steps include:

[0181] S3: Turn on the light source and image acquisition module;

[0182] S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h, where h = 15 mm;

[0183] S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

[0184] Among them, Figure 3 As shown in the figure, the interference fringes between dark and bright colors are formed after the monochromatic light source illuminates the liquid film. It can be seen that due to the high temperature accelerating the thinning of the liquid film, a black film appears on the top of the liquid film. The image acquisition module is used to record the change of the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer. The computer calculates the liquid film thickness data at different times according to formulas (1) and (2), as shown in the figure. Figure 6 The figure shows film thickness data collected at different times after film formation. As the temperature increases, the film lifespan shortens, so only film thickness data at 2s, 4s, 6s, and 10s are collected. The narrower film thickness distribution indicates that high temperature accelerates film thinning.

[0185] Example 3:

[0186] A liquid film measurement method coupled with multi-factor variable interaction specifically comprises the following steps:

[0187] S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface;

[0188] S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters;

[0189] S2 specifically includes the following sub-steps:

[0190] S21: Adjust the lengths of the first telescopic rod, the second telescopic rod, the third telescopic rod, and the fourth telescopic rod so that the first transmission belt and the second transmission belt are at a target distance w, where w = 10 mm;

[0191] S22: Using the first heating module and the second heating module, adjusting the temperature in the visible sealed pressure chamber to the target temperature, and using the third heating module to adjust the temperature of the solution to the target temperature of about 30° C.;

[0192] S23: Using the pressure regulating module, adjust the pressure in the visible seal pressure chamber to a target pressure of 100 kPa;

[0193] S24: Using the humidification module, adjust the humidity in the sealed pressure chamber to a target humidity of 80%;

[0194] S25: After the temperature, humidity, pressure and solution temperature in the visually sealed pressure chamber all reach the target values and remain stable, proceed to the subsequent steps.

[0195] Furthermore, the steps include:

[0196] S3: Turn on the light source and image acquisition module;

[0197] S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h, where h = 60 mm;

[0198] S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

[0199] Among them, Figure 4 As shown in the figure, a monochromatic light source irradiates the liquid film to form interference fringes between dark and bright phases. The image acquisition module is used to record the changes of the interference fringes of the liquid film of specified size under target temperature, humidity and pressure over time in real time, and transmit the image information to the computer. The computer calculates the liquid film thickness data at different times according to formulas (1) and (2), as shown in the figure. Figure 7 As shown, the liquid film thickness data are collected at 5s, 10s, 15s, and 20s after the liquid film is formed.

Claims

1. A liquid film measuring device coupled with multi-factor variable interaction, characterized in that: The apparatus comprises a visual sealed pressure cabin, a pressure gauge is provided outside the visual sealed pressure cabin, and the pressure gauge is connected to the pressure regulating module; a humidifying module, a first heating module, a second heating module, a third heating module, a first thermocouple, a second thermocouple, a first telescopic rod, a second telescopic rod, a third telescopic rod, a fourth telescopic rod, a light source, an image acquisition module, and a liquid pool are provided inside the visual sealed pressure cabin; the humidifying module is located at the top of the cabin; the first heating module and the second heating module are respectively located at the left and right sides of the middle of the cabin inner wall, and the third heating module is located at the bottom of the liquid pool; the first thermocouple is located at the top of the cabin, and the second thermocouple is located at the bottom of the liquid pool; the first telescopic rod and the second The telescopic rods are respectively fixed at the left and right positions above the inner wall of the cabin, and are provided with a first stepper motor and a second stepper motor. The third telescopic rod and the fourth telescopic rod are respectively fixed at the left and right positions below the inner wall of the cabin; the first stepper motor is provided with a first pulley, and the second stepper motor is provided with a second pulley; the first pulley is connected to the first transmission belt, and the second pulley is connected to the second transmission belt; a liquid film extraction line is connected between the first transmission belt and the second transmission belt; the bottom ends of the first transmission belt and the second transmission belt are respectively connected to the third pulley and the fourth pulley; the third pulley and the fourth pulley are fixed to the third telescopic rod and the fourth telescopic rod; the liquid pool is located at the bottom of the cabin.

2. The liquid film measuring device coupled with multi-factor variable interaction according to claim 1, characterized in that: The visual sealed pressure cabin is made of high-temperature resistant, pressure-resistant and corrosion-resistant materials, and is equipped with an observation window for easy observation of the situation inside the cabin; the pressure regulating module is used to adjust the pressure inside the visual sealed pressure cabin and display the pressure in real time through a pressure gauge.

3. The liquid film measuring device coupled with multi-factor variable interaction according to claim 2, characterized in that: The humidification module is equipped with a humidity sensor for adjusting and monitoring the humidity inside the visible sealed pressure chamber; the first heating module and the second heating module are used to adjust the temperature inside the visible sealed pressure chamber, and monitor the temperature inside the chamber in real time through the first thermocouple; the third heating module is used to adjust the temperature of the liquid in the liquid pool, and monitor the temperature of the liquid through the second thermocouple.

4. The liquid film measuring device coupled with multi-factor variable interaction according to claim 3, characterized in that: The first telescopic rod, the second telescopic rod, the third telescopic rod and the fourth telescopic rod are used to adjust the distance w between the first transmission belt and the second transmission belt by extending and retracting back and forth.

5. The liquid film measuring device coupled with multi-factor variable interaction according to claim 4, characterized in that: The width of the first transmission belt and the second transmission belt is 10 mm; the liquid film extraction line is vertically arranged between the first transmission belt and the second transmission belt, with a diameter of 0.5 mm, and the two ends of the liquid film extraction line are detachably connected to the first transmission belt and the second transmission belt respectively.

6. The liquid film measuring device coupled with multi-factor variable interaction according to claim 5, characterized in that: The first stepper motor and the second stepper motor are used to control the rotation of the first pulley and the second pulley respectively, thereby driving the first transmission belt and the second transmission belt.

7. The liquid film measuring device coupled with multi-factor variable interaction according to claim 6, characterized in that: The light source is monochromatic.

8. The liquid film measuring device coupled with multi-factor variable interaction according to claim 7, characterized in that: The angle between the image acquisition module and the monochromatic light source is 15° to 45°, and the interference fringes between the dark and bright phases produced by the liquid film are recorded in real time.

9. The liquid film measuring device coupled with multi-factor variable interaction according to claim 8, characterized in that: The liquid pool is 100 mm long, 100 mm wide and 100 mm high.

10. A liquid film measurement method coupled with the interaction of multiple variables, characterized in that: The following measurement steps are implemented using the liquid film measuring device in claim 9: S1: Add the solution to be tested into the liquid pool, adjust the initial position of the liquid film extraction line to the liquid pool and immerse it in the solution 5 cm from the liquid surface; S2: Adjust multiple variables according to demand, including liquid film size, temperature, humidity, and pressure parameters; S3: Turn on the light source and image acquisition module; S4: Turn on the first stepper motor and the second stepper motor to lift the liquid film extraction line out of the solution and generate a liquid film to a target height h; S5: Use the image acquisition module to record the changes in the interference fringes of the liquid film of specified size under the target temperature, humidity and pressure over time in real time, and transmit the image information to the computer, which processes and calculates the liquid film thickness data.

Images