System and method for measuring bubbles in a specified region of a vessel

Abstract

Embodiments of the present application provide a system and method for measuring bubbles in a specified area of a container. The container is provided with a plurality of measurement windows in the circumferential direction, each measurement window being located on a different surface of the container. The system comprises a plurality of image acquisition devices arranged outside the container, each image acquisition device facing one measurement window, and the field of view of each image acquisition device being able to cover the specified area so as to be able to acquire images containing bubbles in the specified area from different directions respectively. A processor processes the images acquired by each image acquisition device to obtain measurement parameters of the bubbles. According to the embodiments of the present application, the plurality of measurement windows are arranged on different surfaces in the circumferential direction of the container, and the plurality of image acquisition devices arranged outside the container are used to acquire images containing bubbles in the specified area from different directions respectively, so that the images of the bubbles can be obtained more accurately.

Description

Technical Field

[0001] This invention relates to the field of bubble measurement technology, and in particular to a system and method for measuring bubbles in a specified area of ​​a container. Background Technology

[0002] The suction pool of a nuclear power plant pump, serving as the flow passage before the pump inlet, smoothly guides the water flow to the impeller inlet, preventing cavitation and total erosion of the pump and improving the safety of the pumping station. Air can be introduced into the water at the pump suction pool inlet due to air intake vortices, significantly reducing pump efficiency and even affecting the safe operation of nuclear power equipment. Therefore, it is necessary to monitor the amount of air drawn into the water flow.

[0003] Furthermore, many new reactors, such as sodium-cooled fast reactors and lead-bismuth reactors, employ a pool-type structure, with the reactor body, buffer facilities, and purification systems all designed to cover the coolant with an inert gas. During reactor operation, this covering gas can easily be entrained into the main circulation system, leading to damage to equipment such as pumps and heat exchangers. Due to the complex structure of the pool-type reactor body and its critical systems and equipment, it is difficult to accurately obtain the amount and trajectory of entrained gas when it occurs using conventional flow field measurement methods. Moreover, the high coolant flow parameters of the reactor, combined with the complex flow field structure, easily cause entrained bubbles to be dispersed into even smaller micron-sized bubbles, further increasing the difficulty of measurement. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a system and method for measuring bubbles in a specified area of ​​a container.

[0005] In a first aspect, embodiments of this application provide a system for measuring bubbles in a designated area of ​​a container, wherein the container has multiple measurement windows along its circumference, each measurement window being located on a different surface of the container. The system includes: multiple image acquisition devices disposed outside the container, each image acquisition device facing a measurement window, the field of view of the multiple image acquisition devices being able to cover the designated area, so as to be able to acquire images containing bubbles in the designated area from different directions; and a processor, which processes the images acquired by each image acquisition device to obtain measurement parameters of the bubbles.

[0006] Secondly, embodiments of this application provide a method for measuring bubbles in a specified area of ​​a container, implemented using the system of the first aspect of this application. The method includes: calibrating multiple image acquisition devices; controlling the calibrated multiple image acquisition devices to synchronously acquire images containing bubbles in the specified area; and processing the images acquired by each image acquisition device to obtain measurement parameters of the bubbles.

[0007] This application embodiment uses multiple measurement windows along different surfaces of the container's circumference to acquire images of bubbles within a designated area from different directions using multiple image acquisition devices located outside the container, thereby enabling more accurate acquisition of bubble images. Attached Figure Description

[0008] Other objects and advantages of the invention will become apparent from the following description of the invention with reference to the accompanying drawings, and will help to provide a comprehensive understanding of the invention.

[0009] Figure 1 This is a schematic diagram of a system for measuring bubbles in a specified area of ​​a container according to an embodiment of the present invention.

[0010] Figure 2 yes Figure 1 Top view of the system shown;

[0011] Figure 3 This is a schematic diagram of a system for measuring bubbles in a specified area of ​​a container according to an embodiment of the present invention.

[0012] Figure 4 This is a schematic diagram of the structure of a ring light source according to an embodiment of the present invention;

[0013] Figure 5 This is a schematic diagram of the structure of a three-dimensional calibration plate according to an embodiment of the present invention;

[0014] Figure 6 It uses a single camera to acquire control field data from a stereo calibration plate;

[0015] Figure 7 This is a schematic diagram of fitting the trajectory of a single bubble.

[0016] It should be noted that the accompanying drawings are not necessarily drawn to scale, but are shown only in a schematic manner without affecting the reader's understanding.

[0017] Explanation of reference numerals in the attached figures:

[0018] 10. Container; 101. Measuring window;

[0019] 20. Image acquisition device;

[0020] 30. Ring light source;

[0021] 31. Inner ring LED beads grouped; 310. Inner ring LED beads;

[0022] 321, First outer ring LED group; 3210, First outer ring LED;

[0023] 322, Second outer ring LED group; 3220, Second outer ring LED;

[0024] 40. Light source;

[0025] 50. Processor;

[0026] 60. 3D calibration plate; 61. Calibration surface; 610. Marker frame; 611. Marker point. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. Obviously, the described embodiments are one embodiment of this invention, and not all embodiments. Based on the described embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0029] In the description of the embodiments of the present invention, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0030] See Figures 1 to 3 This application provides a system for measuring bubbles in a designated area A within a container 10. The container 10 has multiple measuring windows 101 arranged circumferentially, each window 101 located on a different surface of the container 10. The container 10 contains a liquid, such as water. The liquid in the container 10 can be in a static or flowing state.

[0031] The measurement system includes multiple image acquisition devices 20 and a processor 50. The multiple image acquisition devices 20 are disposed outside the container 10. Each image acquisition device 20 faces a measurement window 101, and the multiple image acquisition devices 20 are configured such that their fields of view all cover a designated area A, enabling them to acquire images of the bubble within the designated area A from different directions. The processor 50 processes the images acquired by each image acquisition device 20 to obtain the measurement parameters of the bubble.

[0032] In this embodiment, multiple measurement windows 101 are provided on different surfaces along the circumference of the container 10. Multiple image acquisition devices 20 are provided outside the container 10 to acquire images of bubbles in a designated area A from different directions, thereby enabling more accurate acquisition of bubble images.

[0033] The image acquisition device 20 can be a high-speed camera with an imaging frequency of several hundred hertz or thousands of hertz, enabling the acquisition of bubbles at high flow rates (greater than or equal to 5 m / s). For example, an industrial measuring camera can be used, with an imaging frequency of 500 hertz.

[0034] Processor 50 can obtain the volume of bubbles and the trajectory fitting of bubbles in a high-speed flow field (flow velocity above 5 m / s) through image processing, thereby quantitatively measuring the air intake of nuclear power plant water pumps and the amount of coolant gas entrained in pool reactors.

[0035] In some embodiments, the measurement system further includes a plurality of light sources 40 disposed outside the container 10, wherein each light source 40 faces a measurement window 101. The light sources 40 are used to provide illumination for the image acquisition device, making the images acquired by the image acquisition device clearer.

[0036] In some embodiments, the container 10 is provided with a first measurement window 101, a second measurement window 101, a third measurement window 101, and a fourth measurement window 101 sequentially along the circumference. The first measurement window 101 and the third measurement window 101 face each other, as do the second and fourth measurement windows 101. The optical axes of the image acquisition device 20 located at the first measurement window 101 and the image acquisition device 20 located at the third measurement window 101 are substantially coincident. The optical axes of the image acquisition device 20 located at the second measurement window 101 and the image acquisition device 20 located at the fourth measurement window 101 are substantially coincident. It is easy to understand that "substantially coincident" here can be understood as the two optical axes having a small angle within 5°, or being parallel and having a distance within 1 cm.

[0037] In some embodiments, the container 10 can be a cuboid or cube-shaped water tank, with four measuring windows 101 located on the four sides of the water tank.

[0038] The four image acquisition devices 20 must ensure the required field of view so that the fields of view a1, a2, a3, and a4 of the four image acquisition devices 20 all cover the designated area A. See [link / reference]. Figure 2 A high-resolution camera fitted with a telephoto lens can be used for measurement to ensure the accuracy of bubble measurement as much as possible.

[0039] Because bubbles are hollow, it is difficult for them to have sharp edges in images when capturing images containing them. Especially when multiple image acquisition devices 20 simultaneously photograph the same bubble, the different devices may interfere with the bubble imaging, leading to a decrease in image quality.

[0040] To address the above issues, in some embodiments of this application, the light source 40 and image acquisition device 20 located at the first measurement window 101 are respectively a green light source 40 and a green light camera; the light source 40 and image acquisition device 20 located at the second measurement window 101 are respectively a red light source 40 and a red light camera; the light source 40 and image acquisition device 20 located at the third measurement window 101 are respectively a green light source 40 and a green light camera; and the light source 40 and image acquisition device 20 located at the fourth measurement window 101 are respectively a red light source 40 and a red light camera. This arrangement ensures that the light sources 40 and 40 located at the first and third measurement windows 101 do not affect the image quality acquired by the image acquisition devices 20 and 20 located at the second and fourth measurement windows 101, thus facilitating the acquisition of bubbles with clear edges by each image acquisition device 20. This application embodiment designs the positions and colors of the four image acquisition devices 20 and the light source 40 to make the bubble prominent and have clear boundaries in the image, and allows for observation from multiple angles and positions, which is beneficial to improving the accuracy of bubble measurement.

[0041] This embodiment of the application deploys a light source system 40 in a designated area A, adjusts the illumination intensity, and coordinates with the image acquisition device 20 to acquire images. By illuminating the bubble from multiple angles and positions with the light source 40, a clear image of the bubble is formed on the image, resulting in a standard, clear outline on the grayscale image—that is, standard imaging. A clear image is formed at a fixed resolution. Based on the imaging state, the grayscale information of the object being imaged can be analyzed, and the brightness can be adjusted according to the image's grayscale to ensure the imaging grayscale is above 80, thereby improving image clarity.

[0042] This design uses opposing lighting, with the light source positioned opposite the camera. When the image acquisition device 20 is measuring at both ends of the water tank, the light source 40 is evenly distributed on both sides of the water tank.

[0043] In some embodiments, the optical axis of the image acquisition device 20 located at the first measurement window 101 and the optical axis of the image acquisition device 20 located at the second measurement window 101 are substantially perpendicular, which helps to further improve the quality of the image acquired by the image acquisition device 20, making the edges of bubbles in the acquired image clearer.

[0044] In some embodiments, the light source 40, located at the same measurement window 101, is situated to the left of the image acquisition device 20. Adjusting the brightness of the light source 40 can make the bubbles in the images acquired by the image acquisition device 20 appear clearer, presenting a standard, clear outline in the grayscale image.

[0045] The light source 40 can be a strip light source 40, such as a lamp tube. The light emitted by the light source 40 can be parallel light, and the light can be substantially parallel to the optical axis of the image acquisition device 20.

[0046] In some embodiments, the measurement system further includes a plurality of ring light sources 30, wherein the lens of each image acquisition device 20 is located radially inside the ring light source 30. The color of the light emitted by the ring light source 30 is adapted to the image acquisition device 20 corresponding to its radially inner lens; for example, for a red light camera, the color of the light emitted by the ring light source 30 is red; for a green light camera, the color of the light emitted by the ring light source 30 is green.

[0047] The ring light source 30 includes an inner ring LED group located in the inner ring and an outer ring LED group located in the outer ring, with the inner ring LED group located radially inside the outer ring LED group.

[0048] The inner ring LED group includes multiple inner ring LEDs 310 distributed circumferentially, and the outer ring LED group includes multiple outer ring LEDs distributed circumferentially. The angle between the optical axis of the inner ring LEDs 310 and the optical axis of the image acquisition device 20 is different from the angle between the optical axis of the outer ring LEDs and the optical axis of the image acquisition device 20.

[0049] The optical axis of each inner ring LED bead 310 forms the same first included angle with the optical axis of the image acquisition device 20.

[0050] The inner ring LED group comprises multiple inner ring LED groups 31 spaced apart. Each inner ring LED group 31 includes two inner ring LEDs 310 whose optical axes are parallel to each other and arranged adjacently. "Adjacently arranged" here can be understood as the distance between the optical axes of the two inner ring LEDs 310 being less than or equal to the radius of the LED.

[0051] The outer ring LED group includes a first outer ring LED group and a second outer ring LED group. The optical axes of each first outer ring LED 3210 in the first outer ring LED group form the same second angle with the optical axis of the image acquisition device 20. The optical axes of each second outer ring LED 3220 in the second outer ring LED group form the same third angle with the optical axis of the image acquisition device 20. The third angle is greater than or equal to the second angle. By configuring the ring light source 30 as described above, it is beneficial for the image acquisition device 20 to acquire clear image data within a microsecond-level exposure time.

[0052] In some embodiments, the first included angle can be 8-12°. The second included angle can be 13-17°; the third included angle can be 13-17°.

[0053] The first outer ring LED group includes a plurality of first outer ring LED groups 321 spaced apart, each first outer ring LED group 321 including two first outer ring LEDs 3210 arranged adjacent to each other with parallel optical axes. The second outer ring LED group includes a plurality of second outer ring LED groups 322 spaced apart, each second outer ring LED group 322 including two second outer ring LEDs 3220 arranged adjacent to each other with parallel optical axes.

[0054] Among them, the first outer ring LED group 321 and the second outer ring LED group 322 are arranged at intervals along the circumference.

[0055] Each first outer ring LED group 321 is located radially outside an inner ring LED group 31 of the inner ring LED group.

[0056] Each LED can have a certain divergence angle. Specifically, the overlap between each group of LEDs and adjacent groups can be up to 60%.

[0057] exist Figure 4 In the illustrated embodiment, the ring light source 30 has a total of 24 LED beads. The inner ring bead group includes 8 LED beads, forming 4 inner ring bead groups 31. These 4 inner ring bead groups 31 are respectively positioned in the top, bottom, left, and right directions of the inner ring. The outer ring bead group includes 16 LED beads, wherein the first outer ring bead group has 8 LED beads, forming 4 first outer ring bead groups 321, and the second outer ring bead group has 8 LED beads, forming 4 second outer ring bead groups 322. The 4 first outer ring bead groups 321 are respectively positioned in the top, bottom, left, and right directions of the outer ring. The 4 second outer ring bead groups 322 are respectively positioned in the upper left, lower left, lower right, and upper right directions of the outer ring.

[0058] The measurement system may also include a synchronization controller and a host computer. The synchronization controller is electrically connected to each image acquisition device 20 and is connected to the host computer to control all image acquisition devices 20 to perform photogrammetry simultaneously.

[0059] The synchronization controller powers each image acquisition device 20 and each light source 40, controls multiple image acquisition devices 20 to take pictures synchronously, and processes the pictures before sending them to the host computer for calculation. The synchronization controller provides multiple high-speed interfaces for connecting each image acquisition device 20 to the host computer. The images (i.e., the photos) acquired by each image acquisition device 20 can be sent back to the synchronization controller for image processing. Finally, the processed files are sent to the host computer system for final calculation via the synchronization controller's high-speed interfaces. When measuring bubbles, the synchronization controller needs to quickly trigger the synchronization of each image acquisition device 20 to ensure synchronized shooting.

[0060] The image acquisition device 20 can be a high-speed industrial camera. The high-speed industrial camera consists of an optical system, an image acquisition and preprocessing module, etc. The optical system is used to collect the reflected light from the marker point. The marker point is a circular reflective marker. The characteristic of a reflective marker is that the emitted light hits the marker and returns along the same path. The image acquisition and preprocessing module is used to convert the received light beam into a digital image signal, perform preprocessing, and transmit it to a computer for analysis and processing via a synchronous controller.

[0061] The image acquisition device 20 can be fixed to the measurement window 101 of the container 10 using a connector. In some embodiments, the measurement window 101 is mounted on the corresponding opening of the container 10 by a flange, and the image acquisition device 20 can be mounted on the flange. The lens of the image acquisition device 20 is in contact with the outer surface of the measurement window 101 to ensure that the field of view of the image acquisition device 20 is sufficient to cover the area to be observed (i.e., the designated area A).

[0062] This application also provides a method for measuring bubbles in a designated area A of a container 10, the method being implemented using the measurement system of any embodiment of this application.

[0063] The measurement method includes: calibrating multiple image acquisition devices 20; controlling the calibrated multiple image acquisition devices 20 to synchronously acquire images containing bubbles in a designated area A; and processing the images acquired by each image acquisition device 20 to obtain the measurement parameters of the bubbles.

[0064] The calibration process will now be explained using the image acquisition device 20 as an example.

[0065] Camera calibration can be divided into intrinsic parameter calibration for each camera and extrinsic parameter calibration for a multi-camera system. Methods such as... Figure 5 The stereo calibration plate shown calibrates 60 pairs of cameras. See also... Figure 5 The three-dimensional calibration plate 60 includes multiple calibration surfaces 61, and an array of marker frames 610 is formed on each calibration surface 61. Each marker frame 610 includes multiple marker points 611. The pattern formed by the multiple marker points 611 in each marker frame 610 is identical. Not all marker points 611 are located in the same row or column of the marker frames 610. In the illustrated embodiment, each marker frame 610 includes 8 marker points 611.

[0066] The number of calibration surfaces 61 can be greater than or equal to the number of cameras. When there are four cameras, the stereo calibration plate 60 can have a cube or cuboid structure, and there can be four calibration surfaces 61, which are formed on the four sides of the cube or cuboid structure.

[0067] Compared with a checkerboard-type calibration plate, this application uses a three-dimensional calibration plate 60 that includes multiple calibration surfaces 61, each calibration surface 61 forming an array of marker frames 610, and each marker frame 610 including multiple marker points 611, which can greatly improve the calibration accuracy.

[0068] Compared to traditional frame calibration objects, the stereo calibration plate 60 is more portable and has higher precision, and can be used for calibration of internal and external parameters of multiple cameras.

[0069] When calibrating intrinsic parameters, each camera can take multiple frames of images containing the stereo calibration plate 60 at different angles and the same distance. Then, each frame of image is processed to obtain the intrinsic parameters of each camera.

[0070] Multi-camera extrinsic parameter calibration is used to determine the relative attitude relationships between camera coordinate systems, including translation and rotation parameters. During extrinsic parameter calibration, each camera photographs a stereo calibration board 60, calibrating all cameras as a whole, unifying the coordinate system, and simultaneously providing the phase and pose relationships of the four cameras.

[0071] During the calibration of multiple cameras, the camera extrinsic parameters can be calibrated by measuring a reference scale. This calibration requires simultaneous measurements of the reference scale by each camera pair. Using multi-angle, multi-position reference scale information, the relative positional relationships of the cameras are calculated through joint adjustment, unifying the coordinate systems of multiple cameras and completing the joint station setup for multiple cameras. Continuous online shooting of the desired area can be performed to acquire data, and the resulting images are then transferred to measurement software for processing.

[0072] When calibrating the extrinsic parameters, the first step is to acquire images of each calibration surface 61 of the stereo calibration plate 60 to obtain the three-dimensional coordinates of each marker point 611 in each marker frame 610 on each calibration surface 61 of the stereo calibration plate 60; the second step is to place the stereo calibration plate 60 within the common field of view of all cameras, so that each camera acquires a frame image containing the stereo calibration plate 60, and obtain the relative pose relationship between each camera and the stereo calibration plate 60 based on the images acquired by each camera; the third step is to determine the relative pose relationship between each camera based on the three-dimensional coordinates of each marker point 611 of the stereo calibration plate 60 obtained in the first step and the relative pose relationship between each camera and the stereo calibration plate 60; the fourth step is to obtain the extrinsic parameters of the multi-camera system.

[0073] Using the extrinsic parameter calibration method of this application embodiment, when calibrating extrinsic parameters, by selecting a stereo calibration plate 60 with a specific structure, the three-dimensional coordinates of each marker point 611 in each marker frame 610 on each calibration surface 61 of the stereo calibration plate 60 are first obtained. Then, by acquiring only one frame image containing the stereo calibration plate 60 from each camera, the extrinsic parameters of the entire camera system can be calculated. Because this application embodiment uses a stereo calibration plate 60 with a specific structure, the calibration accuracy is improved, allowing each camera to acquire only one image when calibrating extrinsic parameters, without needing to rotate the stereo calibration plate 60 and / or change the camera angle, making the operation very simple.

[0074] Extrinsic parameter calibration can be calculated using the principle of spatial resection. Spatial resection is based on point measurement of a single image, and its ideal projection imaging model is the pinhole imaging model in geometrical optics. When multiple cameras perform resection on the same control field, the transformation relationship between the control field coordinate system and each camera is obtained. Then, the transformation relationship between each camera can be calculated, thus completing the multi-camera extrinsic parameter calibration.

[0075] A single camera can be used to acquire data from a stereo calibration plate 60, such as... Figure 6 The control field data shown is illustrated. Four cameras were used simultaneously from four faces. Figure 6 By performing a resection of the stereo control field shown, the transformation relationship between the four camera coordinate systems and the same control field coordinate system can be obtained, thus completing the extrinsic parameter calibration between cameras. Specifically, the steps for calibrating the camera intrinsic parameters may include: taking images of the stereo calibration plate 60 from multiple angles and positions using the camera when it is not installed at the workstation. The number of images should be no less than 35, and the images should be imported into calibration software to calculate the ten intrinsic parameters of the camera. When calibrating the intrinsic parameters, each camera can take multiple frames containing the stereo calibration plate 60 from different angles and at the same distance, and then process each frame to obtain the intrinsic parameters of each camera.

[0076] The steps for camera extrinsic parameter calibration may include: installing and fixing the camera, placing the stereo calibration plate 60 within the camera's field of view. During calibration, it is not necessary for all cameras to capture images of the stereo calibration plate 60 at the same position. Multiple cameras can simultaneously capture images, allowing the relative pose relationship between the cameras and the stereo calibration plate 60 to be calculated. The extrinsic parameter calibration is then completed via coordinate system transfer. While the cameras remain stationary, the stereo calibration plate 60 can be rotated (ensuring it remains within the common field of view of all cameras) to obtain multiple sets of camera extrinsic parameter data. Finally, an average calculation is performed to ensure data accuracy.

[0077] The measurement parameters of the bubble can include at least one of the bubble measurement parameters and the bubble trajectory parameter fitting.

[0078] The volume parameters of a bubble can be measured using envelope 3D reconstruction technology based on contour vision. Assuming the bubble is a standard solid of revolution, edge images of the bubble are obtained through edge detection algorithms. Based on the obtained centroid coordinates of the bubble, the edge image of one side of the bubble is selected as the generatrix of the solid of revolution. The vertical line containing the x-coordinate of the centroid is used as the axis of revolution, and the volume of the bubble can be calculated. The average of the volumes calculated using the two edges as generatrixes is taken as the final bubble volume.

[0079] In some embodiments, when four image acquisition devices 20 acquire images containing the same bubble from different directions, the edges of the bubble in four directions can be obtained, making the measurement and calculation more accurate.

[0080] The trajectory parameter fitting of the bubble can be divided into two steps. The first step involves extracting features of a single bubble from each frame of images acquired by a single image acquisition device 20 according to a time series, and recording the bubble's relative ID, center of gravity, and other relevant information in the current image. The second step involves tracking the bubble trajectory in the inter-frame images after extracting bubble features. First, it is determined whether the y-coordinate (vertical upward direction) of bubble 1 in the current frame is less than the y-coordinate of bubble 1 in the previous frame. If it is less, they are considered to be the same bubble; if it is greater, bubble 1 in the previous frame is considered to have disappeared (e.g., the bubble has moved out of the measurement field of view, or the bubble has merged, or the bubble has dispersed). When a new bubble is generated in the frame image, the entire trajectory of a single bubble is obtained. The fitted trajectory of a single bubble is as follows: Figure 7 As shown.

[0081] When four image acquisition devices 20 acquire images containing the same bubble from different directions, the center coordinates of the bubble can be calculated, and the trajectory of the bubble can be obtained based on the continuous center coordinates.

[0082] In some embodiments, the measurement system may further include a terminal, which may include multiple processing software modules, including five modules: single-camera acquisition software, main camera acquisition software, data playback software, dual-camera calibration software, and parameter measurement software. The single-camera acquisition module controls a single camera to acquire images for qualitative measurements. The main camera acquisition module may run a synchronous control program on the terminal, transmitting signals through a controller to synchronously control four cameras to acquire images. The data playback module is used to play back the images acquired by the cameras. The dual-camera calibration module uses a synchronous controller to control the red and green binocular cameras respectively to acquire stereo images, calibrate camera parameters, and collimate the left and right images. The parameter measurement module uses a synchronous controller to control the four cameras to acquire multiple consecutive frames of underwater bubbles for parameter determination.

[0083] The embodiments of this application can achieve real-time monitoring of the air intake volume and air intake rate of underwater nuclear power equipment by using a four-eye measurement station joint construction, bubble trajectory fitting technology, and bubble volume measurement technology.

[0084] This application's embodiments solve the problem of the difficulty in quantitatively measuring and evaluating the gas entrainment phenomenon in pool reactors by using underwater microbubble volume measurement technology and trajectory fitting technology.

[0085] Regarding the embodiments of the present invention, it should also be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

[0086] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A system for measuring bubbles in a specified area of ​​a container, wherein, The container has multiple measuring windows along its circumference, each measuring window being located on a different surface of the container; the system includes: Multiple image acquisition devices are disposed outside the container, each facing a measurement window. The field of view of all the multiple image acquisition devices can cover the designated area, enabling them to acquire images of bubbles within the designated area from different directions. The processor processes the images acquired by each of the image acquisition devices to obtain the measurement parameters of the bubble; The system further includes: a plurality of light sources disposed outside the container, wherein each light source faces one of the measurement windows; The container is provided with a first measurement window, a second measurement window, a third measurement window and a fourth measurement window in sequence along the circumference. The first measurement window and the third measurement window face each other, and the second measurement window and the fourth measurement window face each other. The light source and the image acquisition device located at the first measurement window are respectively a green light source and a green light camera; The light source and the image acquisition device located at the second measurement window are respectively a red light source and a red light camera; The light source and the image acquisition device located at the third measurement window are a green light source and a green light camera, respectively. The light source and the image acquisition device located at the fourth measurement window are respectively a red light source and a red light camera; The system further includes: multiple ring light sources, with the lens of each image acquisition device located radially inside the ring light source; The ring-shaped light source includes an inner ring of LED beads located in the inner ring and an outer ring of LED beads located in the outer ring. The inner ring of LED beads includes multiple inner ring LED beads distributed circumferentially, and the outer ring of LED beads includes multiple outer ring LED beads distributed circumferentially. The angle between the optical axis of the inner ring LED and the optical axis of the image acquisition device is different from the angle between the optical axis of the outer ring LED and the optical axis of the image acquisition device. The outer ring LED group includes a first outer ring LED group and a second outer ring LED group, wherein... The optical axes of each outer ring LED bead in the first outer ring LED bead group form the same second included angle with the optical axis of the image acquisition device; The optical axes of each outer ring LED bead in the second outer ring LED bead group form the same third included angle with the optical axis of the image acquisition device; The third included angle is greater than or equal to the second included angle.

2. The system according to claim 1, wherein, The optical axis of the image acquisition device located at the first measurement window and the optical axis of the image acquisition device located at the third measurement window are substantially coincident; The optical axis of the image acquisition device located at the second measurement window and the optical axis of the image acquisition device located at the fourth measurement window are substantially coincident.

3. The system according to claim 2, wherein, The optical axis of the image acquisition device located at the first measurement window and the optical axis of the image acquisition device located at the second measurement window are substantially perpendicular.

4. The system according to claim 1, wherein, The light source, located at the same measurement window, is situated to the left of the image acquisition device.

5. The system according to claim 1, wherein, The optical axis of each inner ring LED bead forms the same first included angle with the optical axis of the image acquisition device.

6. The system according to claim 1, wherein, The inner ring LED group includes multiple inner ring LED groups arranged at intervals, and each inner ring LED group includes two inner ring LEDs arranged adjacent to each other with parallel optical axes.

7. The system according to claim 1, wherein, The first outer ring LED group includes multiple first outer ring LED groups arranged at intervals, and each first outer ring LED group includes two outer ring LEDs arranged adjacent to each other with parallel optical axes. The second outer ring LED group includes multiple second outer ring LED groups arranged at intervals, and each second outer ring LED group includes two outer ring LEDs arranged adjacent to each other with parallel optical axes. The first outer ring LED group and the second outer ring LED group are arranged at intervals along the circumference.

8. The system according to claim 7, wherein, Each of the first outer ring LED groups is located radially outside one of the inner ring LED groups of the inner ring LED group.

9. A method for measuring bubbles in a designated area of ​​a container, said method being implemented using the system of any one of claims 1-8, said method comprising: The plurality of image acquisition devices are calibrated; The calibrated multiple image acquisition devices synchronously acquire images containing bubbles within the designated area; The images acquired by each of the image acquisition devices are processed to obtain the measurement parameters of the bubble.

Images