Supernatant extraction method and device

Abstract

The present invention discloses a supernatant extraction method and device. In order to solve the technical problem of automation and intelligence of separation of supernatant and sediment, the supernatant extraction method of the present invention includes: calibrating the interface between supernatant and sediment, using a visual sensor to capture key points on the interface between supernatant and sediment, and obtaining the actual physical height of the interface according to the key points; judging whether the stop extraction condition is met according to the actual physical height of the interface and the height information of the current extraction pipeline, and if so, stopping the extraction. The present invention can safely and effectively locate the interface between supernatant and sediment, and realize the automation and intelligence of separation of supernatant and sediment. The present invention is applicable to the field of traditional Chinese medicine manufacturing.

Description

Technical Field

[0001] The invention relates to the field of traditional Chinese medicine manufacturing, and in particular to a supernatant extraction method and device. Background Art

[0002] Water extraction and alcohol precipitation, referred to as alcohol precipitation, is a commonly used liquid purification and refining method, which is often used to remove water-soluble impurities in traditional Chinese medicine decoctions. The principle of this method is to use the difference in physical and chemical properties that the active ingredients can be well dissolved in ethanol, while most impurities are insoluble in ethanol. After adding an appropriate amount of ethanol, as the concentration of ethanol gradually increases, the active ingredients originally dissolved in water will turn to dissolve in ethanol to form a uniform solution, while those impurities insoluble in ethanol will gradually precipitate and settle. In addition, similar precipitation methods may be used in sewage treatment, water purification, water algae identification, solution concentration and solute extraction. The core goal of this type of precipitation method is to effectively remove impurities while retaining the active ingredients to the maximum extent, so as to improve the purity and quality of the active ingredients.

[0003] The operation process of the ethanol precipitation unit and the selection and design of its supporting equipment are crucial to ensure the safety, stability and efficacy of Chinese medicine products. They are not only directly related to the purity and effectiveness of the final product, but also have a profound impact on the dosage form selection and overall quality of the product. They are an indispensable and closely related key link in the modern production of Chinese medicine. Figure 1 It is a schematic diagram of extracting the supernatant in the alcohol precipitation tank in the prior art. After the alcohol precipitation is completed, the effective ingredients and impurities in the medicine solution are fully separated. The upper layer is the purified medicine solution, which is clear and transparent and rich in the required effective ingredients, referred to as the supernatant; and the lower layer is the precipitation waste, which is mainly composed of impurities insoluble in ethanol, referred to as the precipitate.

[0004] However, the separation of supernatant and precipitate requires meticulous management. How to accurately identify the interface between supernatant and precipitate and realize automated extraction to ensure the quality and safety of the final product is a difficult problem faced by this field. In this regard, some existing technologies have been improved on the basis of traditional alcohol precipitation process. For details, please refer to the following existing technologies:

[0005] Prior art 1: CN214844218U;

[0006] Prior art 2: CN203989966U;

[0007] Prior art 3: CN117193444A;

[0008] Prior art 4: CN112393783A.

[0009] Among them, prior art 1 discloses an alcohol precipitation liquid online detection and extraction device, which can detect in real time so as to end the process of collecting supernatant in time, and prior art 2 discloses a floating type automatic supernatant extraction device, but these two methods still have difficulty in realizing the automation of the separation process. Prior art 3 and prior art 4 disclose methods based on multi-sensor information fusion to obtain the handover interface height, but these two methods require multiple sensors to obtain multiple control parameters, and the process is complicated and the cost is high.

[0010] In addition, in the alcohol precipitation process, high-concentration alcohol with an alcohol concentration of more than 70% is usually used as the alcohol precipitation solution. Given the high volatility of alcohol, when it is mixed with air to a certain ratio, it is very easy to form an explosive mixed gas. If this mixed gas encounters an ignition source such as an open flame or an electric spark, it is very easy to cause an explosion, posing a serious physical threat or even life-threatening to the staff, and directly leading to the interruption of the production process, causing significant economic losses to the company. Therefore, when designing an automated alcohol precipitation extraction system, there are extremely strict standards for the explosion-proof safety performance of the equipment used.

[0011] How to safely and effectively locate the supernatant surface and the interface between the supernatant and the precipitate, and realize the automation and intelligence of the separation of the supernatant and the precipitate, is an indispensable and closely related key link in the modern production of traditional Chinese medicine. Summary of the invention

[0012] In order to alleviate or partially alleviate the above technical problems, the solution of the present invention is as follows:

[0013] A method for extracting supernatant, comprising the following steps:

[0014] Step S1, start extracting supernatant;

[0015] Step S2, calibrating the interface between the supernatant and the sediment, and using a visual sensor to capture key points on the interface between the supernatant and the sediment;

[0016] Step S3, obtaining the actual physical height of the interface according to the pixel position of the key point in the pixel plane imaged by the visual sensor;

[0017] Step S4, measuring the height information of the current extraction pipeline;

[0018] Step S5: judging whether the extraction stop condition is met according to the actual physical height of the interface and the height information of the current extraction pipeline, and if so, stopping the extraction.

[0019] Furthermore, in step S2, an infrared optical fiber flashing at a fixed frequency is used to calibrate the interface between the supernatant and the sediment.

[0020] Further, the visual sensor is an event camera.

[0021] Furthermore, in step S3, a camera calibration algorithm is used to calculate the actual physical height of the interface.

[0022] Furthermore, in step S3, the actual physical height of the interface between the supernatant and the sediment is obtained according to the correspondence between the pixel position in the pixel coordinate system and the position information in the world coordinate system.

[0023] Furthermore, the displacement of the extraction pipeline relative to the initial position is measured to obtain the height information of the current extraction pipeline.

[0024] Furthermore, based on the event stream output by the event camera, the height information of the current extraction pipeline is obtained.

[0025] Furthermore, the extraction pipeline begins to slowly descend at a preset rate.

[0026] Furthermore, when the difference between the actual physical height of the interface and the height information of the current extraction pipeline is less than or equal to a preset value, the extraction is stopped.

[0027] The present invention also relates to a supernatant extraction device, comprising:

[0028] An extraction component for extracting or siphoning the supernatant through an extraction pipe;

[0029] A detection component, used to detect the interface between the supernatant and the sediment, and obtain the actual physical height of the interface;

[0030] A displacement metering component measures the displacement of the extraction pipeline relative to the initial position, thereby obtaining the height information of the current extraction pipeline;

[0031] The lifting control component controls the movement state or working state of the extraction component based on the actual physical height of the interface obtained by the detection component and the height information of the current extraction pipeline obtained by the displacement metering component.

[0032] Further, the detection component includes a laser measurement module and a visual detection module;

[0033] The laser measurement module is used to control the infrared optical fiber to flash at a fixed frequency;

[0034] The visual detection module uses an event camera to capture the interface between the supernatant and the sediment, and calculates the actual physical height of the interface based on the pixel positions of key points on the interface obtained by imaging with the event camera.

[0035] Furthermore, a camera calibration algorithm is used to calculate the actual physical height of the interface.

[0036] Furthermore, when the difference between the actual physical height of the interface and the height information of the current extraction pipeline is less than or equal to a preset value, the extraction is stopped.

[0037] Furthermore, the laser measurement module includes a modulated light source and an infrared optical fiber. The modulated light source emits infrared light at a fixed frequency, and the infrared light flashes in the alcohol precipitation tank through the infrared optical fiber.

[0038] Further, the motion state of the extraction pipeline includes one or more of the following: descending, ascending, stopping, descending speed or ascending speed;

[0039] The working state of the extraction pipeline includes one or more of the following: stopping extraction, starting or continuing extraction, or reducing extraction intensity.

[0040] Furthermore, the supernatant is a purified drug solution.

[0041] The technical solution of the present invention has one or more of the following beneficial technical effects:

[0042] (1) The present invention uses brain-like visual technology to perceive the interface between the supernatant and the precipitate in real time and efficiently;

[0043] (2) The present invention does not require manual intervention and realizes the automation and intelligence of the supernatant extraction process;

[0044] (3) In the present invention, the light source is safely installed outside the alcohol precipitation tank, and the optical fiber is only used as a medium for optical signal transmission, thereby improving the safety of the automated extraction equipment;

[0045] (4) The detection components, displacement metering components and lifting control components of the present invention are all placed outside the alcohol precipitation tank, avoiding direct contact between the live components and high-concentration alcohol or alcohol vapor, further reducing the possibility of safety accidents.

[0046] In addition, other beneficial effects of the present invention will be mentioned in the specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of extracting the supernatant in the alcohol precipitation tank in the prior art;

[0048] Figure 2 It is a schematic diagram of the supernatant extraction device of the present invention;

[0049] Figure 3 This is a schematic diagram of the interior of an alcohol precipitation tank in a preferred embodiment of the present invention;

[0050] Figure 4 is a schematic diagram of imaging of an event camera of the present invention;

[0051] Figure 5 It is the conversion principle diagram between pixel coordinate system and world coordinate system;

[0052] Figure 6 is a flow chart of a method for extracting supernatant according to a preferred embodiment of the present invention;

[0053] Figure 7 It is a flow chart of calculating the actual physical height according to the pixel position in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] Event Camera, also known as Dynamic Vision Sensor (DVS), is a new brain-like bionic sensor that can quickly sense changes in light intensity in a scene and output event pulses representing changes in scene light intensity. Compared to ordinary optical cameras, event cameras have extremely high temporal resolution, extremely high dynamic range, extremely low bandwidth and power consumption.

[0056] In the process of supernatant separation and extraction, in order to ensure the purity of the extracted supernatant and avoid mixing with the lower sediment, it is necessary to accurately judge the distance between the current extraction liquid surface and the surface of the lower sediment, and at the same time, avoid dangerous factors such as open flames and electric sparks to improve the safety of the supernatant extraction device. The present invention uses a fixed-frequency scintillation optical fiber combined with an event camera to visually calibrate the interface between the sediment and the supernatant, and detect and control the supernatant extraction process in real time, thereby realizing the safety, automation and intelligence of the supernatant extraction process.

[0057] Figure 2 It is a schematic diagram of the supernatant extraction device of the present invention, which includes an extraction component, a detection component, a displacement metering component and a lifting control component.

[0058] Extraction components, extract or siphon the supernatant through the extraction pipe.

[0059] After the alcohol precipitation process is completed, the extraction component starts to work, and the extraction pipeline is accurately controlled and maintained below the liquid level of the supernatant. Optionally, the extraction component slowly descends at a preset constant rate.

[0060] The detection component is used to detect the interface between the supernatant and the sediment to obtain the actual physical height of the interface.

[0061] Specifically, the detection component includes a laser measurement module and a visual detection module. The laser measurement module includes a modulated light source and an infrared optical fiber. The modulated light source emits infrared light at a fixed frequency, and the infrared light flashes in the alcohol precipitation tank through the infrared optical fiber. The infrared optical fiber enhances the imaging effect of the infrared light in the event camera.

[0062] Optionally, the infrared optical fiber is placed on one side of the alcohol precipitation tank. Preferably, the infrared optical fiber is at the same height as the alcohol precipitation tank.

[0063] Among them, the visual detection module uses an event camera to capture the flickering light source in the alcohol precipitation tank in real time, obtains the pixel position of the key points on the interface between the supernatant and the sediment in the pixel plane of the event camera imaging, and uses the camera calibration algorithm to calculate the actual physical height of the interface.

[0064] The displacement metering component measures the displacement of the extraction pipeline relative to the initial position, thereby obtaining the height information of the current extraction pipeline.

[0065] Specifically, the displacement metering component includes at least one displacement sensor to continuously monitor and instantly feedback the displacement of the extraction component, thereby obtaining the height information of the current extraction pipeline.

[0066] The lifting control component controls the working state of the extraction component, such as changing or maintaining the current motion state, or stopping / starting the extraction action, based on the position information of the interface obtained by the detection component and the height information of the current extraction pipeline obtained by the displacement metering component.

[0067] Optionally, the lifting control component controls the working state of the extraction component based on an electric extraction device or a siphon device.

[0068] When the extraction component reaches the interface between the supernatant and the sediment, the lifting control component controls the extraction component to interrupt or stop extracting the supernatant, wherein reaching means that the height difference between the extraction pipe and the interface is less than or equal to a preset value.

[0069] Figure 3 It is an internal schematic diagram of an alcohol precipitation tank in a preferred embodiment of the present invention. The infrared optical fiber is only used as a transmission medium for optical signals, not the light source itself. The light source generated by the integrated measurement module is safely installed on the outside of the alcohol precipitation tank and is explosion-proofed in strict accordance with the factory explosion-proof specifications to ensure that the live parts have no direct contact with high-concentration alcohol or alcohol vapor, thereby significantly reducing the risk of explosion accidents. In addition, the event camera is also placed outside the alcohol precipitation tank according to the factory explosion-proof requirements, further improving the safety of the alcohol precipitation tank.

[0070] Due to the large difference in light transmittance between the supernatant and the precipitate, the event camera used in the present invention can accurately capture the pixel position of the key points on the interface between the supernatant and the precipitate in the pixel plane of the event camera imaging, that is, the coordinates in the pixel coordinate system. Furthermore, based on the camera calibration algorithm in machine vision, the present invention uses the conversion relationship between the pixel coordinate system and the world coordinate system to obtain the coordinate information of the key points of the interface in the world coordinate system, thereby obtaining the actual physical height of the interface in the alcohol precipitation tank, and then guiding the precise execution of the extraction action.

[0071] Figure 4 This is a schematic diagram of imaging of the event camera of the present invention. Due to the large difference in light transmittance between the supernatant and the sediment, when the infrared optical fiber flashing at a fixed frequency is inserted into the side of the tank and exceeds the interface between the supernatant and the sediment, the infrared optical fiber on the sediment side will be blocked, while the light on the supernatant side will not be greatly affected. Therefore, the infrared light on the sediment side cannot present a clear image in the event camera, while the infrared optical fiber on the supernatant side has a clear image in the event camera.

[0072] According to this difference, the pixel position of the key point on the interface in the pixel plane of the image can be obtained. However, the obtained pixel position information needs to be converted into position information in the world coordinate system to obtain the actual physical height of the interface.

[0073] Figure 5 This is the conversion principle diagram between the pixel coordinate system and the world coordinate system. There are multiple coordinate systems involved in the camera imaging process, including: world coordinate system, camera coordinate system, image coordinate system, and pixel coordinate system.

[0074] World coordinate system: A three-dimensional spatial reference frame customized by the user according to actual needs, used to accurately locate the position and posture of objects and cameras in the real world. The origin of the world coordinate system can be flexibly selected, usually based on the convenience of the problem or the specific application scenario. In the world coordinate system, the position and orientation of an object are accurately described by three-dimensional coordinates relative to the spatial position of the object in the world coordinate system.

[0075] Camera coordinate system: A three-dimensional coordinate system with the camera optical center as the origin, where the camera optical center is also called the focus or projection center of the camera lens. The X-axis and Y-axis of the camera coordinate system are parallel to the X-axis and Y-axis of the image coordinate system, respectively, while the Z-axis of the camera coordinate system is perpendicular to the imaging plane defined by the X-axis and Y-axis of the camera coordinate system, pointing to the front of the camera, representing the direction of the camera's optical axis. The camera coordinate system is a bridge connecting the world coordinate system and the image coordinate system. The conversion between the two can be achieved through the intrinsic and extrinsic parameters of the camera, such as focal length, rotation matrix, translation vector, etc.

[0076] Image coordinate system: A two-dimensional coordinate system corresponding to the imaging plane of the camera. The origin of the image coordinate system is usually set at the intersection of the optical axis and the imaging plane, also known as the principal point or optical center of the image. The X-axis and Y-axis of the image coordinate system are parallel to the two vertical edges of the imaging plane, respectively, and are used to describe the position of each point on the image in the plane. The coordinate values ​​in the image coordinate system represent the horizontal and vertical offsets of a point on the image relative to the principal point.

[0077] Pixel coordinate system: The way an image is represented in computer memory is also a two-dimensional coordinate system. Unlike the image coordinate system, the origin of the pixel coordinate system is located at the vertex in the upper left corner of the imaging plane. The X-axis and Y-axis of the pixel coordinate system are parallel to the X-axis and Y-axis of the image coordinate system, respectively, but the coordinate values ​​of the pixel coordinate system are in pixels. In the pixel coordinate system, each coordinate point corresponds to a pixel position in the image and is used to specify the index of a specific pixel in the image data array. The pixel coordinate system is a commonly used reference frame in fields such as image processing and computer vision, which facilitates digital processing and analysis of images.

[0078] The conversion from the world coordinate system to the camera coordinate system requires a rigid body transformation. Assume that there is a point P in the world coordinate system w (x w , y w , z w ), the conversion from the world coordinate system to the camera coordinate system is a rigid body transformation, which can be achieved through the rotation matrix And the translation matrix T can get the point P in the world coordinate system w (x w , y w , z w ) in the camera coordinate system c (x c , y c ,z c ):

[0079] ;

[0080] Among them, x w , y w , z w Respectively represent the X-axis, Y-axis, and Z-axis of the world coordinate system; c , y c , z c Represent the X-axis, Y-axis, and Z-axis of the camera coordinate system respectively.

[0081] Transforming from the camera coordinate system to the image coordinate system requires perspective projection. According to the following formula, based on the point P in the camera coordinate system c (x c , y c , z c) to get the corresponding point P in the image coordinate system j (x j , y j ):

[0082] ;

[0083] ;

[0084] Where f is the focal length of the camera, x j and j Respectively represent the X-axis and Y-axis of the image coordinate system.

[0085] Affine transformation is required to convert from image coordinate system to pixel coordinate system. According to the corresponding relationship, we can j (x j ,y j ) to get the corresponding point P(u,v) in the pixel coordinate system:

[0086] ;

[0087] ;

[0088] Among them, u and v represent the X-axis and Y-axis of the pixel coordinate system respectively, u 0 and v 0 are the horizontal and vertical coordinates of the center point of the imaging plane in the pixel coordinate system, d x and d y Respectively represent the physical size of each coordinate axis in the pixel coordinate system.

[0089] In summary, the following formula is used to convert from the world coordinate system to the pixel coordinate system:

[0090] ;

[0091] Right now:

[0092] ;

[0093] Among them, f x is the normalized focal length on the x-axis, f y is the normalized focal length on the y-axis. x =f / d x , f y =f / d y , the matrix where the two are located is called the intrinsic parameter matrix, which depends on the internal parameters of the camera; the rotation matrix The matrix containing the translation matrix T is called the extrinsic matrix, which depends on the position of the camera coordinate system and the world coordinate system. Similarly, after an inverse transformation, the pixel coordinate system can be converted to the world coordinate system.

[0094] Because the camera lens is distorted when imaging in the environment. In order to ensure the accuracy of the coordinate system conversion results, it is also necessary to eliminate the influence of lens distortion. The distortion caused by the lens shape is radial distortion, which is corrected using the Taylor series expansion, while the distortion caused by the lens installation not being parallel to the imaging plane is tangential distortion.

[0095] Since the event camera is at a fixed position in the world coordinate system, such as height, the intrinsic parameter matrix and the extrinsic parameter matrix are known during the extraction process. According to the pixel position / coordinates of the key points on the interface in the event camera imaging, combined with the coordinate system conversion method and the distortion correction algorithm, the position information of the key points on the interface in the world coordinate system can be obtained, thereby obtaining the height information of the interface, and then accurately controlling the supernatant extraction.

[0096] Figure 6 : is a flow chart of a method for extracting supernatant according to a preferred embodiment of the present invention, comprising the following steps:

[0097] Step S1, start extracting the supernatant.

[0098] Step S2: calibrate the interface between the supernatant and the sediment, and use a visual sensor to capture key points on the interface between the supernatant and the sediment.

[0099] Preferably, an infrared optical fiber flashing at a fixed frequency is used to calibrate the interface between the supernatant and the sediment.

[0100] Preferably, the visual sensor is an event camera, wherein the event camera can clearly observe the imaging of the infrared optical fiber when the height is fixed.

[0101] Optionally, the visual sensor is an ordinary camera that captures images at a fixed frame rate, but this type of embodiment will significantly increase the data transmission bandwidth, require greater computing power, and reduce the dynamic range, resulting in poor system stability and increased power consumption.

[0102] Step S3, obtaining the actual physical height of the interface between the supernatant and the sediment according to the pixel position of the key point on the interface between the supernatant and the sediment in the pixel plane of the visual sensor imaging.

[0103] In a certain class of preferred embodiments, the actual physical height of the interface between the supernatant and the sediment is calculated using a conversion method between camera imaging and actual physical height.

[0104] Preferably, the conversion method is a camera calibration algorithm. Specifically, the pixel positions of key points on the interface between the supernatant and the sediment in the pixel plane are converted into position information in the world coordinate system by using a coordinate system conversion method, thereby obtaining the actual physical height of the interface.

[0105] Optionally, depending on the lens, a distortion correction algorithm is used to eliminate the distortion effect of the camera lens.

[0106] In another embodiment, the correspondence between any pixel position in the pixel coordinate system and the position information in the world coordinate system is measured in advance, and the actual physical height of the interface between the supernatant and the sediment can be obtained by searching for the correspondence.

[0107] Step S4: measuring the height information of the current extraction pipeline.

[0108] Optionally, a displacement sensor is used to measure the displacement of the extraction pipeline relative to an initial position, thereby obtaining height information of the current extraction pipeline.

[0109] Since the event camera is good at capturing moving objects, optionally, the pixel position of the current extraction pipeline in the pixel plane of the visual sensor imaging can be obtained based on the event stream output by the event camera. Furthermore, the actual physical height of the current extraction pipeline is calculated using the conversion method between camera imaging and actual physical height.

[0110] Preferably, the actual physical height of the current extraction pipeline is calculated using a camera calibration algorithm.

[0111] Preferably, the extraction pipeline descends at a constant speed at a preset rate.

[0112] Step S5: judging whether the stop extraction condition is met according to the actual physical height of the interface and the height information of the current extraction pipeline, if so, stop extraction, otherwise continue extraction. Specifically, when the difference between the actual physical height of the interface and the height information of the current extraction pipeline is less than or equal to a preset value, stop extraction.

[0113] Optionally, the motion state of the extraction pipeline is controlled according to the actual physical height of the interface and the height information of the current extraction pipeline, or the working state of the extraction pipeline is controlled. The motion state of the extraction pipeline includes one or more of the following: descending, ascending, stopping, descending speed or ascending speed. The working state of the extraction pipeline includes one or more of the following: stopping extraction, starting or continuing extraction, or reducing extraction intensity.

[0114] Figure 7 It is a flow chart of calculating the actual physical height according to the pixel position in a preferred embodiment of the present invention.

[0115] According to the pixel positions of the key points on the interface between the supernatant and the sediment in the event camera imaging, the coordinate system conversion method and the distortion correction algorithm are used to obtain the actual physical positions of the key points on the interface in the world coordinate system, thereby obtaining the actual physical height of the interface and accurately controlling the extraction of the supernatant.

[0116] Preferably, the supernatant of the present invention is a purified Chinese medicine liquid. In addition, the present invention can be applied to any scheme of extracting a supernatant from a container in addition to the field of Chinese medicine manufacturing.

[0117] In order to better illustrate the present invention, numerous specific details are provided in the above specific embodiments. It should be understood by those skilled in the art that the present invention can also be implemented without certain specific details. In some examples, methods, means, components and circuits well known to those skilled in the art are not described in detail in order to highlight the subject matter of the present invention.

[0118] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for extracting supernatant, characterized in that: The steps include: Step S1, start extracting supernatant; Step S2, using an infrared optical fiber flashing at a fixed frequency to calibrate the interface between the supernatant and the sediment, and using an event camera to capture key points on the interface between the supernatant and the sediment; Step S3, obtaining the actual physical height of the interface according to the pixel position of the key point in the pixel plane imaged by the visual sensor; Step S4, measuring the height information of the current extraction pipeline; Step S5: judging whether the extraction stop condition is met according to the actual physical height of the interface and the height information of the current extraction pipeline, and if so, stopping the extraction.

2. The supernatant extraction method according to claim 1, characterized in that: In step S3, the actual physical height of the interface is calculated using a camera calibration algorithm.

3. The supernatant extraction method according to claim 1, characterized in that: In step S3, the actual physical height of the interface between the supernatant and the sediment is obtained according to the correspondence between the pixel position in the pixel coordinate system and the position information in the world coordinate system.

4. The supernatant extraction method according to claim 2 or 3, characterized in that: The displacement of the extraction pipeline relative to the initial position is measured to obtain the height information of the current extraction pipeline.

5. The supernatant extraction method according to claim 4, characterized in that: Based on the event stream output by the event camera, the height information of the current extraction pipeline is obtained.

6. The method for extracting supernatant according to claim 5, characterized in that: The extraction pipeline begins to slowly descend at a preset rate.

7. The method for extracting supernatant according to claim 6, characterized in that: When the difference between the actual physical height of the interface and the height information of the current extraction pipeline is less than or equal to a preset value, the extraction is stopped.

8. A supernatant extraction device, characterized in that: include: An extraction component for extracting or siphoning the supernatant through an extraction pipe; A detection component, used to detect the interface between the supernatant and the sediment, and obtain the actual physical height of the interface; A displacement metering component measures the displacement of the extraction pipeline relative to the initial position, thereby obtaining the height information of the current extraction pipeline; A lifting control component controls the motion state or working state of the extraction component based on the actual physical height of the interface obtained by the detection component and the height information of the current extraction pipeline obtained by the displacement measurement component; Wherein, the detection component includes a laser measurement module and a visual detection module; The laser measurement module is used to control the infrared optical fiber to flash at a fixed frequency; The visual detection module uses an event camera to capture the interface between the supernatant and the sediment, and calculates the actual physical height of the interface based on the pixel positions of key points on the interface obtained by imaging with the event camera.

9. The supernatant extraction device according to claim 8, characterized in that: The actual physical height of the interface is calculated using a camera calibration algorithm.

10. The supernatant extraction device according to claim 8 or 9, characterized in that: When the difference between the actual physical height of the interface and the height information of the current extraction pipeline is less than or equal to a preset value, the extraction is stopped.

11. The supernatant extraction device according to claim 10, characterized in that: The motion state of the extraction pipeline includes one or more of the following: descending, ascending, stopping, descending speed or ascending speed; The working state of the extraction pipeline includes one or more of the following: stopping extraction, starting or continuing extraction, or reducing extraction intensity.

12. The supernatant extraction device according to claim 8 or 9, characterized in that: The supernatant is the purified drug solution.

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