A flow measurement calibration device and method based on high-speed photography and pulsating thermal radiation micro-impact technology

Abstract

The present application relates to a kind of flow measuring device and method, it relates to a kind of flow measuring calibration device and method based on high-speed photography and pulsating heat radiation micro-size impact technology.The present application can measure in real time-Feedback-Revision measurement result, before measurement, first according to flow rate direction, the device is installed on conduit, then measure flow rate parameter, and carry out real-time revision.In the flow rate measurement calibration, it can be suitable for a variety of liquid, fluid and other media, compatibility is good, adaptability is larger.Integrally encapsulated design of ordinary flowmeter, circuit board, high-speed lens and pulse heat radiation generator, structure is small, stability is high.Shape determination of detection heat influence area, pixel level operation is carried out to the image obtained by high-speed camera, can accurately real-time measure the subtle difference of the shape of the heat influence area.For edge detection algorithm, using the Canny operator, can identify the area of temperature change in image, suppress non-edge area, accuracy is high.

Description

Technical Field

[0001] This invention relates to a flow measurement device and method, specifically a flow measurement calibration device and method based on high-speed photography and pulsed thermal radiation micro-impact technology. Background Technology

[0002] Currently, flow measurement is widely used in industrial production to monitor and control the flow of liquids and gases. For example, in industries such as chemical plants, pharmaceutical factories, and food processing, real-time flow monitoring ensures the stability of production processes and product quality. In urban water supply and drainage systems, flow measurement is used to measure and monitor water flow. This helps ensure normal water supply and drainage, optimize pipeline operation, and improve water resource utilization efficiency. In the medical field, flow measurement is used to monitor and control drug delivery, gas flow in ventilators, and other applications. Its use is also common in surgical and laboratory equipment. In scientific research, flow measurement is used in laboratory equipment, such as measuring liquid flow rates in chemical experiments or gas flow rates in biological experiments. In summary, flow measurement has important applications in various fields, including industry, production, environmental monitoring, medicine, and laboratories, providing crucial technical support for ensuring the accurate measurement and control of fluid flow.

[0003] Current flow measurement systems suffer from limitations in accuracy, which can be affected by changes in fluid properties, temperature, and pressure, potentially leading to inaccurate measurements. Different types of flow meters are suited to different flow characteristics, resulting in poor applicability. Noise and external interference can affect sensor readings, leading to inaccurate flow measurements, and the system has poor anti-interference capabilities.

[0004] CN105222838B discloses a flow meter housing and a flow meter. This invention enlarges the internal airflow channel of the housing, enabling the flow meter using this housing to have rectification and noise reduction functions, and reducing the installation footprint of the flow meter. Only its basic structure has been modified.

[0005] CN116519067A discloses a control circuit, control method, medium, and program for a vortex flowmeter, effectively improving the low range ratio problem caused by the inability to separate vortex signals from noise signals when processing signals using a second-order low-pass filter in the prior art, thereby effectively improving the recognition range of vortex signals. The innovation is limited to the control part of the flow system. Summary of the Invention

[0006] In response to the aforementioned technical problems, a flow measurement calibration device and method based on high-speed photography and pulsed thermal radiation micro-impact technology are provided.

[0007] The technical means employed in this invention are as follows:

[0008] A flow measurement calibration device and method based on high-speed photography and pulsed thermal radiation micro-impact technology is characterized by a device housing, on which a liquid crystal display and a circuit board are mounted. The circuit board has a mounting bracket for fixing the device, which can be directly fixed to a conduit. A high-speed lens with a built-in high-precision image acquisition device is mounted on the circuit board via a signal input / output interface. A pulsed thermal radiation generator capable of emitting high-frequency pulses is also mounted on the circuit board via the signal input / output interface. An image processing processor and electrical components capable of processing proprietary image processing algorithms are mounted on the circuit board. The circuit board has a power input interface and a signal I / O interface. The high-speed camera captures the shape of the heat source in real time, and by comparing the relationship between time and pixel points, the liquid flow velocity can be measured with high accuracy.

[0009] The ordinary flow meter is connected to the conduit, and the flow meter is used to calibrate the flow velocity parameters of the liquid in the measured conduit in real time.

[0010] The high-speed camera is mounted on the circuit board via high-speed lens signal input and output. The high-speed camera contains a high-precision imaging device and a data acquisition device, which can capture real-time high-precision images of the area changes of the heat-affected zone through different thermal band ranges. The high-speed camera also has a high-frequency lens signal acquisition port installed at its front end.

[0011] The rear end of the pulsed thermal radiation generator is equipped with a pulsed thermal radiation generator signal input terminal and an output terminal connected to the circuit board, and the front end of the pulsed thermal radiation generator is equipped with a pulsed thermal radiation high-frequency signal emission port.

[0012] The device has a simple outer shell structure, and an LCD screen is installed on the outside of the outer shell. The shape of the heat-affected zone is captured in real time by the high-speed camera, which can measure the liquid flow velocity with high sensitivity.

[0013] The measurement and calibration method is as follows: If there is no liquid flow in the conduit, pulsating thermal radiation is applied to the outside of the conduit, resulting in a circular high-temperature point on the heat-affected zone (HAZ) surface. When fluid flows through the conduit, after the pulsating thermal radiation is applied, the HAZ, initially a high-temperature point, is elongated along the liquid flow direction, forming an elliptical HAZ on the conduit. The elliptical HAZ is proportional to the liquid flow velocity. The shape of the elliptical HAZ can be captured by a high-speed camera, and the image is processed pixel by pixel. The processor processes the pixel-to-time variation, and the relationship between temperature and flow rate data is calibrated using a flow meter. The liquid flow parameters are then displayed on the liquid crystal display screen.

[0014] The area and shape of the heat-affected zone change continuously over time, and the temperature of the heat-affected zone exhibits a gradient change. For the obtained shape of the heat-affected zone, pixel-level operations are used to distinguish the color of the heat-affected zone by channel and to filter the data. Through multiple data acquisitions from the high-frequency camera, the subtle differences in the shape of the heat-affected zone can be accurately measured in real time.

[0015] Edge detection of the area and shape of the heat-affected zone: The edge detection algorithm, using the Canny operator, can identify areas with large temperature changes in the image, calculate the gradient of the heat-affected zone, obtain the gradient intensity and direction of each pixel, retain only pixels with the largest local gradient in the gradient direction, suppress non-edge areas, and use a threshold to classify the pixels in the gradient map into strong edges, weak edges, and non-edges. Then, through edge concatenation, weak edges are connected to strong edges to form the complete edge of the heat-affected zone.

[0016] like Figures 1-6As shown, a flow measurement calibration device based on high-speed photography and pulsed thermal radiation micro-impact technology mainly consists of a conduit, a calibration flow meter, and a high-speed photography and pulsed thermal radiation measurement device. The mounting bracket includes a device housing, on which a circuit board is mounted. The circuit board has mounting bracket I and mounting bracket II connected to the circuit board. A processor is mounted on the circuit board, along with a high-speed lens signal input and output terminal, both connected to a high-speed lens. A pulsed thermal radiation generator signal input and output terminal are also mounted on the circuit board and connected to the pulsed thermal radiation generator. The circuit board also includes a power interface and a main signal I / O interface. A high-frequency pulsed thermal radiation signal emission port is installed at the end of the pulsed thermal radiation generator, and a high-speed lens signal acquisition port is installed at the end of the high-speed lens.

[0017] The high-speed camera is equipped with a small, high-precision lens assembly and an image acquisition execution terminal.

[0018] The pulsed thermal radiation generator is equipped with a pulsed thermal radiation generator energy processing device and a pulsed thermal radiation generator energy generating device.

[0019] In operation: Before processing, a flow measurement and calibration device based on high-speed photography and pulsed thermal radiation micro-impact technology is installed on the conduit in the correct installation orientation. Pulse energy is emitted onto the conduit through the pulsed thermal radiation generator, and the high-speed camera acquires image data of the heat-affected zone. Then, the processor performs pixel processing of the image, statistically analyzes the regional changes in the heat-affected zone over time, and calibrates the flow parameters using data collected from a conventional flow meter. The processor's processing steps are as follows: Original image → Gaussian filtering → Smoothed image → Gradient and direction of each pixel → Temperature gradient map → Retaining pixels with the largest local gradient → Image after non-maximum suppression → Dual threshold method → ​​Pixels in the gradient map are classified as strong edges, weak edges, and non-edges → Image processing completed → Edge changes over time → Flow meter calibration → Flow parameters displayed on the LCD screen. This achieves measurement—calibration—feedback—real-time monitoring, and real-time display of flow parameters.

[0020] The steps for using the flow measurement calibration device based on high-speed photography and pulsed thermal radiation micro-impact technology are as follows:

[0021] S1. Wipe the area of ​​the measuring catheter clean until there are no obvious contaminants on the surface of the clean white cloth.

[0022] S2, open the rear cover of the mounting bracket and install the mounting bracket on the flow rate measuring conduit.

[0023] S3: Connect the power cord to the power interface to turn on the power.

[0024] S4 connects the input signal to the main signal I / O interface at the control end and performs data access control at the control end.

[0025] S5 controls the pulse thermal radiation generator by sending a signal through the pulse thermal radiation generator signal input terminal, and feeds back the execution status to the processor through the pulse thermal radiation generator output terminal.

[0026] S6: The high-speed lens communicates with the processor through the high-speed lens signal input terminal and the high-speed lens signal output terminal, and transmits the heat-affected zone image signal captured by the high-speed lens to the processor.

[0027] The S7 processor processes the image results by analyzing the relationship between the captured image information and the time calibration to obtain appropriate flow parameters.

[0028] To accurately measure the flow parameters within the duct, the high-speed imaging results are processed using a pixel-based method. The specific principle is as follows:

[0029]

[0030] This method takes the position in the image at time t0 as the initial position l0 and the position in the image at time t1 as the final position l1. Using a calibration image with a benchmark between l0 and l1, the scale S between unit length and pixels in the image is obtained through "Calibrate". p m / pix. Then calculate the number of pixels n between l0 and l1.

[0031] Using I to represent pixel coordinates, although both pixel and image coordinate systems lie on the imaging plane, their starting points and units of measurement differ, and the origin is usually located at the top left corner of the image. Therefore, a coordinate system transformation model is needed to convert the pixel coordinates to the image coordinate system. x I y Establish an image coordinate system for the coordinate axes, with the pixel coordinate system oriented in the same direction as the image coordinate axes. The transformation relationship between the two coordinate systems is as follows:

[0032]

[0033] Solve for the scale corresponding to the displacement and actual distance in the pixel coordinate system. When a moving target is detected at pixel (m,n) in the pixel coordinate system, its actual distance ΔO in the world coordinate system can be expressed as:

[0034]

[0035] Among them, O z k is the distance from the lens to the heat-affected zone. x and k y The process parameters for camera calibration.

[0036] S8, through the processor's processing of pixels, obtains the relationship between the corresponding fluid parameters and image changes.

[0037] The S9, through calibration with a standard flow meter, displays fluid parameters in real time on an LCD screen outside the housing.

[0038] The beneficial effects of this invention are:

[0039] 1. The present invention can measure, provide feedback and correct measurement results in real time. Before measurement, the device is installed on the conduit according to the flow velocity direction, and then the flow velocity and other parameters are measured and corrected in real time.

[0040] 2. When calibrating flow velocity measurements, it is applicable to a variety of liquids and fluids, with good compatibility and wide adaptability.

[0041] 3. The design integrates a standard flow meter, circuit board, high-speed lens, and pulsed thermal radiation generator into a single package, resulting in a compact structure and high stability.

[0042] 4. Determine the shape of the heat-affected zone by performing pixel-level operations on the images acquired by the high-speed camera, which can accurately measure the subtle differences in the shape of the heat-affected zone in real time.

[0043] 5. For edge detection algorithms, the Canny operator described above can identify areas with large temperature changes in the image, suppress non-edge areas, and achieve high accuracy.

[0044] 6. The designed device calibrates and feeds back the corresponding flow data by comparing time, pixel data, and data fed back by the flow meter, and can accurately measure the flow parameters. Attached Figure Description

[0045] Figure 1 This is an isometric view of a flow measurement calibration device and method based on high-speed photography and pulsed thermal radiation micro-impact technology in a specific embodiment of the present invention.

[0046] Figure 2 This is a schematic diagram of a flow measurement calibration device and method based on high-speed photography and pulsed thermal radiation micro-size impact technology in a specific embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of the high-speed camera structure in a specific embodiment of the present invention.

[0048] Figure 4 This is a schematic diagram of a pulsed thermal radiation generator in a specific embodiment of the present invention.

[0049] Figure 5 This is a schematic diagram illustrating the detection principle of the method in a specific embodiment of the present invention.

[0050] Figure 6 This is a flowchart of the algorithm processing method in a specific embodiment of the present invention.

[0051] Among them, 1-conduit, 2-device housing, 3-mounting bracket, 4-mounting bracket I and circuit board fixing port, 5-mounting bracket II and circuit board fixing port, 6-circuit board, 7-processor, 8-high-speed lens signal input terminal, 9-high-speed lens signal output terminal, 10-high-speed lens, 11-pulse thermal radiation generator, 12-pulse thermal radiation generator input terminal, 13-pulse thermal radiation generator output terminal, 14-power interface, 15-general signal I / O interface, 16-pulse thermal radiation high-frequency signal transmission port, 17-high-speed lens signal acquisition port, 18-heat-affected zone, 1001 small high-precision lens assembly, 1002 image acquisition execution end, 1101 pulse thermal radiation generator energy processing device, 1102 pulse thermal radiation generator energy generation device. Detailed Implementation

[0052] To achieve the above objectives, the embodiments of this application provide the following technical solutions, which specifically include S1-S9.

[0053] S1. Wipe the area of ​​the measuring catheter clean until there are no obvious contaminants on the surface of the clean white cloth.

[0054] S2, open the rear cover of the mounting bracket 3 and install the mounting bracket 3 on the flow rate measuring conduit.

[0055] S3. Connect the power cord to the power interface 14 to turn on the power.

[0056] S4 connects the input signal to the total signal I / O interface 15 at the control end and performs data access control at the control end.

[0057] S5, the signal is sent to the pulse thermal radiation generator 11 through the signal input terminal 12 of the pulse thermal radiation generator through the control terminal, and the execution status is fed back to the processor 7 through the output terminal 13 of the pulse thermal radiation generator.

[0058] S6,10 The high-speed lens communicates with the processor 7 through the high-speed lens signal input terminal 8 and the high-speed lens signal output terminal 9, and transmits the heat-affected zone image signal captured by the high-speed lens 10 to the processor 7.

[0059] S7, by analyzing the relationship between the captured image information and the time calibration, the processor 7 processes the image results to obtain appropriate flow parameters.

[0060] To accurately measure the flow parameters within the duct, the high-speed imaging results are processed using a pixel-based method. The specific principle is as follows:

[0061]

[0062] This method takes the position in the image at time t0 as the initial position l0 and the position in the image at time t1 as the final position l1. Using a calibration image with a benchmark between l0 and l1, the scale S between unit length and pixels in the image is obtained through "Calibrate". p m / pix. Then calculate the number of pixels n between l0 and l1.

[0063] Use P x ,P y Representing pixel coordinates, although both pixel and image coordinate systems lie on the imaging plane, their starting points and units of measurement differ, and the origin is usually located at the top left corner of the image. Therefore, a coordinate system transformation model is needed to convert the pixel coordinates to the image coordinate system. Let I... x I y Establish an image coordinate system for the coordinate axes, with the pixel coordinate system oriented in the same direction as the image coordinate axes. The transformation relationship between the two coordinate systems is as follows:

[0064]

[0065] Solve for the scale corresponding to the displacement and actual distance in the pixel coordinate system. When a moving target is detected at pixel (m,n) in the pixel coordinate system, its actual distance ΔO in the world coordinate system can be expressed as:

[0066]

[0067] Among them, O z k is the distance from the lens to the heat-affected zone 18. x and k y The process parameters for camera calibration.

[0068] S8, through the processing of pixels by processor 7, obtains the relationship between the corresponding fluid parameters and image changes.

[0069] The S9, through calibration with a standard flow meter, displays fluid parameters in real time on an LCD screen outside the housing.

Claims

1. A flow measurement calibration device based on high speed photography and pulsating thermal radiation micro-impingement technology, characterized in that, The device shell is provided with a liquid crystal display and a circuit board, and a mounting bracket for fixing the device is mounted on the circuit board and can be directly fixed with a catheter; a high-speed camera is mounted on the circuit board through a signal input and output interface, and a high-precision image acquisition device is built in the high-speed camera; a pulse thermal radiation generator is mounted on the circuit board through a signal input and output interface, and the pulse thermal radiation generator can emit high-frequency pulses; a processor and electrical components for image processing are mounted on the circuit board, and the electrical components can process specific picture processing algorithms; the circuit board is provided with a power input interface and a signal I / O interface; the high-speed camera can take real-time photos of the shape of a heat source, and the relationship between the contrast time and the pixel points is measured to measure the liquid flow speed; A common flowmeter is connected with the catheter to calibrate the flow rate parameter of the liquid in the measured catheter in real time. The high-speed camera is mounted on the circuit board through a high-speed camera signal input and output, and has a high-precision imaging device and a data acquisition device built in, and can take real-time high-precision photos of the area change of the thermal influence area through different thermal wave band range changes, and a high-frequency lens signal acquisition port is mounted at the front end of the high-speed camera. The pulse thermal radiation generator signal input end and output end are connected with the circuit board, and a pulse thermal radiation high-frequency signal emission port is mounted at the front end of the pulse thermal radiation generator. A liquid crystal screen is mounted on the outer edge of the device shell, and the high-speed camera takes real-time photos of the shape of the thermal influence area.

2. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 1, characterized in that, The high-speed camera is mounted with a small high-precision lens assembly and an image acquisition execution end.

3. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 1 or 2, characterized in that, The pulse thermal radiation generator is mounted with a pulse thermal radiation generator energy processing device and a pulse thermal radiation generator energy generating device.

4. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 1 or 2, characterized in that, After the high-speed camera (10) collects the image data of the thermal influence area (18), the processor (7) processes the pixels of the image, counts the area change of the thermal influence area and the time relationship, and calibrates the flow rate parameter through the data collected by the common flowmeter.

5. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 3, characterized in that, After the high-speed camera (10) collects the image data of the thermal influence area (18), the processor (7) processes the pixels of the image, counts the area change of the thermal influence area and the time relationship, and calibrates the flow rate parameter through the data collected by the common flowmeter.

6. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 1 or 2 or 5, characterized in that, The processing process of the processor (7) is as follows: original image→Gaussian filter→smoothed image→gradient and direction of each pixel→temperature gradient image→pixel retaining the maximum local gradient→image after non-maximum suppression→double threshold method→pixels in the gradient image are divided into strong edges, weak edges and non-edges→image processing is completed→change of edges over time→flowmeter calibration→flow rate parameter is displayed on the liquid crystal screen; measurement, calibration, feedback and real-time monitoring are achieved, and the flow rate parameter is displayed in real time.

7. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 3, characterized in that, The processor (7) processes as follows: original image→Gaussian filter→smoothed image→gradient and direction of each pixel→temperature gradient image→pixels with the largest local gradient retained→non-maximum suppression image→double threshold method→pixels in the gradient image are divided into strong edges, weak edges and non-edges→image processing is completed→change of edges over time→flow meter calibration→flow parameters are displayed on the liquid crystal screen; achieving measurement-calibration-feedback-real-time monitoring, real-time display of flow parameters.

8. The flow measurement calibration device based on high speed photography and micro- size impulse technology of pulsating thermal radiation according to claim 4, characterized in that, The processor (7) processes as follows: original image→Gaussian filter→smoothed image→gradient and direction of each pixel→temperature gradient image→pixels with the largest local gradient retained→non-maximum suppression image→double threshold method→pixels in the gradient image are divided into strong edges, weak edges and non-edges→image processing is completed→change of edges over time→flow meter calibration→flow parameters are displayed on the liquid crystal screen; achieving measurement-calibration-feedback-real-time monitoring, real-time display of flow parameters.

9. A method of using the flow measurement calibration device based on high speed photography and micro-sized impulsive thermal radiation technology according to any one of claims 1-8, characterized in that, The steps are as follows: S1, wipe the measured catheter position clean until there is no obvious contamination on the clean white cloth surface; S2, open the rear end cover of the mounting bracket (3) and install the mounting bracket (3) on the catheter for measuring flow rate; S3, connect the power cord to the power interface (14) and turn on the power supply; S4, connect the input signal through the total signal I / O interface (15) at the control end and perform data access control at the control end; S5, control the pulse heat radiation generator (11) through the signal input end (12) of the pulse heat radiation generator at the control end, and feed back the execution to the processor (7) through the pulse heat radiation generator output end (13); S6, the high-speed camera (10) communicates with the processor (7) through the high-speed camera signal input end (8) and the high-speed camera signal output end (9), and transmits the heat-affected zone image signal shot by the high-speed camera (10) to the processor (7); S7, the processor (7) processes the picture results through the relationship between the photographed image information and the time calibration, and obtains appropriate flow parameters; The processing of high-speed photography results adopts a pixel point method: The method takes the position in the image at time t0 as the initial position l0, and the position in the image at time t1 as the terminal position l1; the scale S between the unit length and the pixel point on the image is obtained by "Calibrate" from the calibration image of the marker between l0 and l1 p , m / pix; then the number n of pixel points between l0 and l1 is calculated; with (P x , P y ) representing pixel point coordinates, although the pixels and the image coordinate system are located on the imaging plane, the starting points and the measurement units of the two coordinate systems are different, and the origin is located at the top left corner of the image, and a coordinate system conversion model needs to be established to convert it to the image coordinate system; an image coordinate system is established with I x , I y as the coordinate axes, the pixel coordinate system direction is the same as the image coordinate axis direction, and the conversion relationship of the two coordinate systems is as follows: Solve the scale corresponding to the displacement in the pixel coordinate system and the actual distance; when a moving target is detected to move in the pixel coordinate system, the pixel is (m, n), and the actual distance ΔO moved in the world coordinate system is represented as: where O z is the distance of the lens to the thermal influence zone (18), k x and k y are process parameters of the camera calibration; S8, the processor (7) processes the pixel points to obtain the relationship between the corresponding fluid parameters and image changes; S9, through the calibration of the ordinary flow meter, the fluid parameters are displayed in real time on the liquid crystal display screen outside the shell.

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