A machine vision-based automatic detection device for liquid phase separation time and phase ratio

Abstract

The application relates to the technical field of automatic analysis detection, and specifically provides a liquid phase separation time and phase ratio automatic detection device based on machine vision. The device comprises a support frame, a detection cavity, a sensor module, a strip-shaped grating plate, a fluid control unit and a control component. The sensor module and the strip-shaped grating plate are arranged on the two sides of the detection cavity to form a pair of light paths, the sensor module adopts a high-speed CMOS industrial camera and is used for high-frequency image acquisition during phase separation; the strip-shaped grating plate is an LED surface light source and provides uniform background illumination. The control component controls the operation of the whole device, processes image data, automatically calculates the phase separation time and the volume ratio of each phase by identifying and tracking the change of the light and dark boundary of the phase interface in the time sequence image. The application solves the problems of strong subjectivity, poor precision and low efficiency of the traditional manual detection method, realizes the objectification, automation and digitization of the detection process, has high repeatability of the measurement result, and can be integrated with a production management system.

Description

Technical Field

[0001] This invention relates to the field of automatic analysis and detection technology, and more specifically, to an automatic detection device for liquid phase separation time and phase ratio based on machine vision. Background Technology

[0002] In industries such as chemical, pharmaceutical, and food processing, phase separation processes (such as extraction and sedimentation) often involve mixing two or more immiscible solutions. Traditional laboratory testing methods mainly rely on manual operation: the operator pours the mixed solution into a graduated cylinder or glass bottle, lets it stand and visually observes the phase separation, manually records the time it takes for the phase separation to complete with a stopwatch, and then estimates the volume ratio of each phase by reading the scale on the graduated cylinder.

[0003] Existing measurement methods typically employ manual measurement, which is subject to subjective differences in the judgment of the visual state of "clear layering" by different operators, leading to inconsistent results. Manual timing and visual reading inevitably introduce human error, making it difficult to guarantee the accuracy and repeatability of the measurement results.

[0004] To avoid introducing human error into the detection results, we propose an automatic detection device for liquid phase separation time and phase ratio based on machine vision. Summary of the Invention

[0005] The purpose of this invention is to provide an automatic detection device for liquid phase separation time and phase ratio based on machine vision, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides an automatic detection device for liquid phase separation time and phase ratio based on machine vision, comprising a support frame, a detection cavity fixedly disposed on the support frame for containing the liquid to be detected, a sensor module disposed on one side of the detection cavity with its detection end facing the interior of the detection cavity, the sensor module being used to acquire high-frequency images of the phase separation process, and a strip grating plate disposed on the side of the detection cavity away from the sensor module, the strip grating plate being used to provide uniform background light into the detection cavity, forming a through-beam optical path with the sensor module.

[0007] As a further improvement to this technical solution, a fluid control unit is also included. The fluid control unit includes a lower liquid outlet connected to the bottom of the detection chamber, a peristaltic pump connected to the lower liquid outlet, and an upper liquid outlet connected to the top of the detection chamber. The upper liquid outlet is connected to at least two containers respectively containing the liquid to be tested and the cleaning liquid through pipelines, and each pipeline is equipped with a solenoid valve. It also includes a control component and a control housing. The control component is electrically connected to the sensor module, peristaltic pump, and solenoid valve. The control component is used to control the operation of the device and process image data to calculate the phase separation time and comparison.

[0008] As a further improvement to this technical solution, the sensor module is an image acquisition unit consisting of a high-speed CMOS industrial camera and a matching optical lens. The object distance and optical axis direction of the optical lens are set so that its imaging field of view completely covers the height range of the entire liquid column in the detection cavity.

[0009] As a further improvement to this technical solution, the strip grating plate is a long strip-shaped LED surface light source, and its light-emitting surface has a grating or diffuse structure, which is used to provide illumination with a uniformity of 85%-98% in the length direction.

[0010] As a further improvement to this technical solution, at least two solenoid valves in the fluid control unit are respectively connected to the test liquid container and the cleaning liquid container, and their opening and closing are controlled by the control component to alternately realize the function of injecting the test liquid or the cleaning liquid into the detection chamber.

[0011] As a further improvement to this technical solution, the control component includes electrical components, and the top outer surface of the control housing is provided with a control knob that is communicatively connected to the electrical components.

[0012] As a further improvement to this technical solution, the bottom of the control housing is provided with a wiring port, and inside it are also provided an air source speed control valve, a heat dissipation air blowing pipe connected to the air source speed control valve, and an air source filter connected to the air source, which are used to regulate the airflow inside the control housing to achieve heat dissipation and dust prevention.

[0013] As a further improvement to this technical solution, an electrical control chamber is fixedly installed on the side of the support frame, and the control housing is located inside the electrical control chamber, thereby isolating the control components from the external environment.

[0014] As a further improvement to this technical solution, the control component is configured to execute an image processing algorithm to analyze the time-series images acquired by the sensor module. By identifying and tracking the pixel position changes of the phase interface light and dark boundaries in the image, the start and end times of the phase separation process and the volume ratio of each phase after stabilization are automatically calculated.

[0015] As a further improvement to this technical solution, the control component supports at least one of RS485 and MODBUS TCP industrial communication protocols, and is used to upload detection data to the production management system.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. In this machine vision-based automatic detection device for liquid phase separation time and comparison, a high-speed camera and image processing algorithm are used to replace human eye observation and manual timing, eliminating subjective judgment differences and human errors, making the measurement results highly repeatable and comparable. The high frame rate (≥30fps) and high resolution camera provide sub-second time resolution and sub-millimeter spatial measurement accuracy, which can accurately capture the phase separation dynamics process.

[0017] 2. This machine vision-based automatic liquid phase separation time and comparison detection device integrates a fluid control unit (peristaltic pump, solenoid valve), realizing unattended operation of the entire process from sample injection, detection, evacuation to cleaning, significantly reducing labor costs and labor intensity. It supports continuous batch detection and adopts a compact modular sealed structure (support frame, electrical control chamber, control housing) to effectively isolate precision components from external corrosive environments, ensuring long-term stable operation in harsh industrial environments. The control components support industrial communication protocols such as RS485 and MODBUS TCP, and the output standard digital signals can be seamlessly connected to the factory production management system (MES) to realize automatic data uploading and process optimization. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure assembly of the present invention; Figure 2 This is a schematic diagram of the control component in this invention; Figure 3 This is a schematic diagram of the structure of the solenoid valve in this invention; Figure 4 This is a schematic diagram of the structure of the strip grating plate in this invention; Figure 5 This is a schematic diagram of the upper liquid outlet structure in this invention; Figure 6 This is a schematic diagram of the peristaltic pump in this invention; Figure 7 This is a schematic diagram of the sensor module in this invention.

[0019] The labels in the diagram represent the following: 1. Sensor module; 2. Detection chamber; 3. Upper liquid outlet; 4. Strip grating plate; 5. Lower liquid outlet; 6. Peristaltic pump; 7. Solenoid valve; 8. Electrical control chamber; 9. Support frame; 10. Control housing; 11. Control components; 1101. Wiring port; 1102. Air source speed control valve; 1103. Cooling air pipe; 1104. Electrical components; 1105. Air source filter. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example 1

[0021] Please see Figures 1-7 As shown, this embodiment provides an automatic detection device for liquid phase separation time and phase ratio based on machine vision, including a support frame 9 and an electrically controlled chamber 8 fixedly installed on the side of the support frame 9. The support frame 9 is provided with feet at the bottom and a fixed base plate is fixedly installed at the bottom of the support frame 9. A support shell is fixedly installed at the center of the fixed base plate and a detection chamber 2 is fixedly installed at the top of the support shell. Several small holes are opened at the bottom of the electrically controlled chamber 8 to facilitate gas flow and heat dissipation. The small holes are covered with a waterproof and breathable membrane to ensure dustproof and waterproof functions while dissipating heat. In traditional experimental testing, operators pour the mixed solution into a graduated cylinder or glass bottle, let it stand, and observe it visually. They manually record the time it takes for the phases to separate using a stopwatch, and then estimate the volume ratio of each phase by reading the graduated cylinder scale. This process suffers from several problems, including: high subjectivity (different operators have different standards for judging "clear phase separation"); poor accuracy and repeatability (human error in manual timing and reading); low efficiency (unable to achieve continuous and batch testing); lack of integration (data cannot be automatically entered into the production management system (MES); and high labor intensity. This solution achieves automatic acquisition of experimental results and automatic recording of time results through automatic sensor detection. At the same time, the detection of experimental results by sensors can avoid the subjective errors that exist in manual data collection. In order to enable the sensor to automatically collect experimental results, a sensor module 1 is fixedly installed on the side of the detection chamber 2. The detection end of the sensor module 1 faces the inside of the detection chamber 2. An upper liquid outlet 3 is provided at the top of the detection chamber 2, and a lower liquid outlet 5 is provided at the bottom of the detection chamber 2. A sealing tube connected to the peristaltic pump 6 is provided at the lower liquid outlet 5. By introducing the liquid to be tested into the detection chamber 2, it is possible to ensure that the detection end of the sensor module 1 can visually acquire the liquid to be tested. By controlling the sensor module 1 to take high-frequency pictures, the change process of the liquid over a certain period of time can be continuously acquired, thereby obtaining an accurate experimental change process. In order to avoid the influence of external light environment on the detection results inside the detection cavity 2, a strip grating plate 4 is also fixedly installed on the side of the detection cavity 2 away from the sensor module 1; Furthermore, the principle of using the strip grating plate 4 is disclosed: A strip grating is essentially a long strip of LED surface light source. Its light-emitting surface is usually composed of a high-density LED array, and it is combined with a diffuser plate or grating structure to transform discrete point light sources into uniform strip light bands.

[0022] In this device, the strip grating plate and the high-speed industrial camera are arranged in a facing configuration: the camera is located on one side of the cuvette, and the strip grating plate is located on the other side. Light passes through the cuvette containing the mixed solution and then enters the camera lens. This backlighting principle utilizes the differences in refractive index, density, and transmittance between different liquid phases.

[0023] When light penetrates a layered solution, a sudden change in refraction or transmittance occurs at the phase interface, creating a clear light-dark boundary in the image sequence captured by the camera. By tracking the changes in the pixel position of this boundary in real time using image processing algorithms, the curve of the interface height evolving over time can be accurately calculated, thus obtaining the phase separation time and phase ratio.

[0024] Liquid phase separation detection requires a consistent brightness background along the entire height of the cuvette (liquid column); any local bright spots or dark areas will lead to edge detection errors. Striped grating plates, through their special diffuse or grating structure, can provide illumination with a uniformity of up to 85%-98% along their length, ensuring consistent image background grayscale and providing stable input for the algorithm. Backlighting maximizes the contrast between the target (phase interface) and the background. On a uniform, bright white background, the immiscible liquid phase interface appears as a clear black silhouette, resulting in extremely drastic changes in edge gradients. This is beneficial for sub-pixel-level edge localization, thereby improving the spatial resolution of interface position measurement. Industrial environments are characterized by complex and variable ambient light. As an active light source, the strip grating plate has a brightness far exceeding that of ambient light. Furthermore, the sealed design of the detection cavity effectively shields the influence of external stray light, ensuring stable image quality under different lighting conditions and improving the system's environmental adaptability and detection reliability.

[0025] To achieve high-precision time result detection, the specific structure of sensor module 1 also needs to be disclosed: The sensor module includes a high-speed CMOS industrial camera and a precision image acquisition unit with matching optical lenses. The image acquisition unit includes the camera body, optical lenses, and mounting and sealing structures. The camera itself is an industrial-grade CMOS camera with high resolution (e.g., 5 megapixels, 2568×1920) and high frame rate (≥30 frames / second), with a pixel size of 2.2μm, to ensure the clarity and dynamic details of the captured images. The optical lens is equipped with an industrial lens of a specific focal length, working in conjunction with the camera. Its mounting position is precisely designed, with the optical axis strictly perpendicular to the wall of the cuvette, and the object distance approximately 61 mm. This distance is calculated to ensure that the imaging field of view completely covers the entire height range of the liquid column within the cuvette, avoiding any gaps or distortion in the field of view. The sensor module 1 and the strip grating plate 4 installed on the other side of the detection cavity form a through-beam optical path. When light penetrates the mixed solution in the cuvette, due to the differences in physical properties such as refractive index and density between the immiscible solution phases, a sudden change in transmittance or refraction occurs at the phase interface, thus forming a clear light-dark boundary (edge) in each frame of the image captured by the camera.

[0026] The camera continuously captures images at a set fixed frame rate (e.g., 30fps), transforming the entire phase separation process—from initial mixing to interface formation, movement, and stabilization—into a series of high-resolution temporal images. This image data is transmitted in real time to the backend computing unit, providing a raw, continuous dynamic information stream for subsequent image processing algorithms.

[0027] By transforming subjective judgments that rely on human eyes into objective calculations based on pixel data, the differences in judgment between different operators and the errors of manual timing and reading are completely eliminated, making the measurement results highly repeatable and comparable. The high frame rate ensures sub-second (e.g., 0.033 seconds) temporal resolution, enabling precise capture of the start and end moments of phase splitting dynamics; the high resolution combined with sub-pixel edge detection algorithms achieves sub-millimeter spatial measurement accuracy, far exceeding manual precision. As the sensing core of the automatic detection cycle, it can work continuously without human intervention, and work in conjunction with the fluid control unit to achieve full-process automation of "sample injection-image capture-drainage-cleaning", providing key data flow for 24 / 7 online real-time monitoring and process optimization of the production process; The output images and processed data are all standard digital signals, which can be seamlessly connected to the factory's MES (Manufacturing Execution System) through industrial protocols such as RS485 and MODBUS TCP, enabling automatic data uploading and traceability, and breaking down the barriers between laboratory testing and production control.

[0028] To achieve an automated process for continuous and rapid testing, the specific working principles of the peristaltic pump 6 and the solenoid valve 7 also need to be disclosed: The support frame 9 contains two sets of solenoid valves 7. One is connected to the container of the liquid to be tested, and the other is connected to the container of cleaning fluid. In use, by opening the solenoid valve 7 connected to the container of cleaning fluid, the internal environment of the detection chamber 2 can be flushed, avoiding interference from residual experimental liquid on the current event results. After cleaning the inside of the detection chamber 2 with the cleaning fluid, the solenoid valve 7 connected to the container of cleaning fluid is closed, and the solenoid valve 7 connected to the container of the liquid to be tested is opened, thereby pumping the liquid to be tested into the detection chamber 2 through the peristaltic pump 6. At this time, the strip grating plate 4 emits a monochromatic light source, and the camera structure in the sensor module 1 takes high-frequency continuous pictures of the changes in the transmitted color of the liquid under the illumination of monochromatic light, and sorts and saves the picture group. By taking high-frequency photos of the liquid under monochromatic light, the experimental results data of the liquid under test can be accurately preserved, avoiding the introduction of human error into the experimental results. After the test is completed, the solenoid valve 7 connected to the cleaning fluid container is opened again to automatically clean the inside of the detection chamber 2. Subsequently, the experimental results of the liquid under test can be continuously and automatically detected, avoiding manual intervention and reducing the labor cost in the experimental work.

[0029] In order to facilitate the control of sensor module 1, peristaltic pump 6 and solenoid valve 7, this solution also needs to include control housing 10, and control component 11 for controlling and adjusting sensor module 1, peristaltic pump 6 and solenoid valve 7 is fixedly installed inside control housing 10. The control component 11 reduces the difficulty of controlling the sensor module 1, peristaltic pump 6 and solenoid valve 7, thereby improving the actual operating efficiency of the device. In order for the control component 11 to achieve accurate control, it is also necessary to disclose the specific structure of the control component 11: The control component 11 includes a wiring port 1101 integrally formed at the bottom of the control housing 10, and an air source speed regulating valve 1102 fixedly installed at the bottom of the inner wall of the control housing 10. The air source speed regulating valve 1102 is connected to a heat dissipation air blowing pipe 1103, and the heat dissipation air blowing pipe 1103 is connected to an air source filter 1105. The air source speed control valve 1102 and the heat dissipation air blowing pipe 1103 can adjust the airflow intensity inside the control housing 10, thereby achieving the effect of adjusting the heat dissipation efficiency inside the control housing 10. The air source filter 1105 filters out impurities in the air source to ensure that the air blown into the instrument is clean. Electrical components 1104 are fixedly installed inside the control housing 10. The electrical components 1104 are connected to the sensor module 1, the peristaltic pump 6 and the solenoid valve 7. The control housing 10 contains a light source controller, a switching power supply and an air switch.

[0030] Before the test begins, the device first activates the solenoid valve 7 connected to the cleaning fluid container, and the peristaltic pump 6 pumps the cleaning fluid into the detection chamber 2 for rinsing. After cleaning, the cleaning fluid valve is closed, the test liquid valve is opened, and the test mixture is injected into the detection chamber 2 via the peristaltic pump 6. After the test liquid is injected, the strip grating plate 4 (white strip LED surface light source) on one side of the detection chamber 2 emits uniform background light. The sensor module 1 (containing a high-speed CMOS industrial camera) located on the other side continuously captures images of the background light passing through the solution at a fixed frame rate. The principle is that when light penetrates the layering solution, a sudden change in transmittance occurs at the phase interface, thus forming a clear light-dark boundary in the image. Sensor module 1 transmits the acquired time-series images to control unit 11. Image processing algorithms automatically identify and track pixel positions at the phase interface edges in each frame. The algorithm analyzes the interface position change curve over time, automatically determines the start and end times of the phase separation process to calculate the total phase separation time, and calculates the phase ratio based on the interface height and cuvette size after stabilization. After detection, the device restarts the cleaning process, draining the waste liquid through the lower outlet 5 to prepare for the next detection cycle.

[0031] By adopting a technical solution based on high-speed time-series image analysis of sensor module 1 and uniform backlighting provided by strip grating plate 4, the entire phase separation process can be objectively recorded with sub-second temporal resolution and sub-millimeter spatial resolution, completely eliminating human subjective error and making the measurement results highly repeatable and comparable. An integrated fluid management system, incorporating a peristaltic pump (6), solenoid valve (7), and piping, enables fully unattended operation from sample introduction, testing, evacuation to cleaning. This significantly reduces labor costs and intensity, and allows for continuous, batch online testing. The device employs a compact, modular, sealed structure (such as an isolation chamber consisting of a support frame 9, an electrical control chamber 8, and a control housing 10), effectively isolating the internal precision sensor module 1 and control components 11 from the external corrosive environment. This ensures long-term stable operation of the device in harsh industrial environments. The device has a compact structure, and the control components 11 can output standard digital signals, allowing for easy integration into existing production lines and rapid access to the factory's intelligent control system (such as MES) to achieve automatic data uploading and process optimization.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A machine vision-based automatic detection device for liquid phase separation time and phase ratio, comprising a support frame (9), characterized in that: The detection cavity (2) is fixedly installed on the support frame (9) and is used to contain the liquid to be tested; The sensor module (1) is located on one side of the detection cavity (2), with the detection end of the sensor module (1) facing the inside of the detection cavity (2). The sensor module (1) is used to acquire high-frequency images of the phase separation process. A strip grating plate (4) is disposed on the side of the detection cavity (2) away from the sensor module (1). The strip grating plate (4) is used to provide uniform background light into the detection cavity (2) and forms a through-beam optical path with the sensor module (1).

2. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 1, characterized in that: It also includes a fluid control unit, which includes a lower outlet (5) connected to the bottom of the detection chamber (2), a peristaltic pump (6) connected to the lower outlet (5), and an upper outlet (3) connected to the top of the detection chamber (2). The upper outlet (3) is connected to at least two containers that respectively hold the liquid to be tested and the cleaning liquid through pipelines, and each pipeline is equipped with a solenoid valve (7). It also includes a control component (11) and a control housing (10), the control component (11) being electrically connected to the sensor module (1), the peristaltic pump (6) and the solenoid valve (7), the control component (11) being used to control the operation of the device and process image data to calculate the phase separation time and comparison.

3. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 2, characterized in that: The sensor module (1) is an image acquisition unit consisting of a high-speed CMOS industrial camera and a matching optical lens. The object distance and optical axis direction of the optical lens are set so that its imaging field of view completely covers the height range of the entire liquid column in the detection cavity (2).

4. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 3, characterized in that: The strip grating plate (4) is a long strip-shaped LED surface light source, and its light-emitting surface has a grating or diffuse structure, which is used to provide illumination with a uniformity of 85%-98% in the length direction.

5. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 4, characterized in that: At least two solenoid valves (7) in the fluid control unit are respectively connected to the test liquid container and the cleaning liquid container. The control component (11) controls their opening and closing to alternately inject the test liquid or cleaning liquid into the detection chamber (2).

6. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 5, characterized in that: The control component (11) includes an electrical component (1104), and the top outer surface of the control housing (10) is provided with a control knob that is communicatively connected to the electrical component (1104).

7. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 6, characterized in that: The bottom of the control housing (10) is provided with a wiring port (1101), and inside it are also provided an air source speed regulating valve (1102), a heat dissipation air blowing pipe (1103) connected to the air source speed regulating valve (1102), and an air source filter (1105) connected to the air source, which are used to regulate the airflow inside the control housing to achieve heat dissipation and dust prevention.

8. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 7, characterized in that: An electrical control chamber (8) is fixedly installed on the side of the support frame (9), and the control housing (10) is located inside the electrical control chamber (8) to isolate the control component (11) from the external environment.

9. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 8, characterized in that: The control unit (11) is configured to execute an image processing algorithm to analyze the time-series images acquired by the sensor module (1), and automatically calculate the start and end times of the phase separation process and the volume ratio of each phase after stabilization by identifying and tracking the pixel position changes of the phase interface light and dark boundaries in the image.

10. The automatic detection device for liquid phase separation time and phase ratio based on machine vision according to claim 9, characterized in that: The control unit (11) supports at least one of RS485 and MODBUS TCP industrial communication protocols and is used to upload detection data to the production management system.

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