A solution refractive index real-time detection method based on amplification imaging and machine vision

Abstract

The application provides a solution refractive index real-time detection method based on amplification imaging and machine vision, which comprises the following steps: step A, illumination light emitted by an illumination light source is irradiated to a microscopic scale, and forms light carrying microscopic scale information, and then sequentially passes through a sample flow cell and a hollow glass block, and is emitted to an image sensor; step B, the emitted light is imaged on the image sensor, the image information of the microscopic scale on the image sensor is recorded, the image sensor is driven to displace through a focusing algorithm, until the imaging of the microscopic scale is a clear image, and the axial position of the image sensor is recorded, and the solution refractive index is analyzed according to the relationship between the axial position of the image sensor and the solution refractive index; step C, the magnification of the object image of the microscopic scale on the imaging system is analyzed through the imaging size of the microscopic scale on the image sensor, and the solution refractive index is inversely calculated, and the solution refractive index obtained in step B is compared, and the redundancy of system measurement is improved.

Description

Technical Field

[0001] This application relates to the field of optical detection technology, and in particular to a method for real-time detection of solution refractive index based on magnified imaging and machine vision. Background Technology

[0002] Existing technologies for detecting transparent solutions have significant shortcomings. Contact-type instruments require direct immersion in the solution, making them susceptible to chemical corrosion and difficult to clean. They also suffer from evaporation errors when detecting volatile solutions such as alcohol. Traditional refractometers, while capable of measuring refractive index, require manual sampling and are highly susceptible to ambient light interference, making them unsuitable for continuous production environments such as winemaking and chemical distillation. Laser interferometry offers high sensitivity to changes in solution refractive index, but its optical path adjustment is complex and its stability is extremely poor under vibration. Current technologies also exhibit weak resolution for low-refractive-index transparent solutions and are easily affected by temperature fluctuations. Summary of the Invention

[0003] To address the problem of weak resolution of low-refractive-index transparent solutions in existing technologies, this invention provides a real-time solution refractive index detection method based on magnified imaging and machine vision. By using scale magnification imaging of the imaging system and machine vision, the refractive index of the solution is inverted, thereby improving the resolution of low-refractive-index transparent solutions and enhancing the detection stability of transparent solutions such as alcohol.

[0004] To address the aforementioned technical problems, this application provides a real-time solution refractive index detection method based on magnified imaging and machine vision, employing the following technical solution:

[0005] A method for real-time detection of solution refractive index based on magnified imaging and machine vision, the method comprising the following steps:

[0006] Step A: The illumination light emitted by the illumination source shines on the micrometer scale and forms light carrying the micrometer scale information. The light carrying the micrometer scale information passes through the hollow glass block containing the sample flow cell. The light carrying the micrometer scale information passes through the sample flow cell and the hollow glass block in sequence, and then is emitted onto the image sensor.

[0007] Step B: The light carrying the microscopic scale information forms an image on the image sensor, and the image information of the microscopic scale on the image sensor is recorded. The image sensor is driven to shift axially using a focusing algorithm until the image of the microscopic scale on the image sensor is clear, and the axial position of the image sensor is recorded. The refractive index of the solution is analyzed based on the relationship between the axial position of the image sensor and the refractive index of the solution. The calculation steps are as follows:

[0008] Let the smallest division of the microscale be... Let the parameters of the hollow glass block and the sample flow cell be: the refractive index of the hollow glass block is... The side of the sample flow cell facing the image sensor is the first arc surface, with a radius of curvature of . The side of the hollow glass block facing the image sensor is the second arc surface, with a radius of curvature of . Assume the refractive index of the solution to be tested is... ;

[0009] According to the principle of ray tracing, let the distance between the ray at a certain point and the optical axis be... The angle between the ray and the optical axis is ;

[0010] Let the ray vector at point A on the micrometer scale be... Let the center thickness of the sample flow cell be... The transmission matrix of light rays from point A to point B on the micrograph is: ;

[0011] Let point B be the exit point of the sample flow cell. Light rays enter the hollow glass block from point B through the solution to be tested. Then the refractive index matrix of the interface at point B is: Let the distance from the center of the first arc surface of the sample flow cell to the center of the second arc surface of the hollow glass block be... Then the transmission matrix for light rays to travel from point B to point C is: ;

[0012] Let point C be the exit point of the insulating glass block. The light ray enters the air from point C of the insulating glass block. Assume the refractive index of air is... Then the refractive index matrix of the interface where point C is located is ;

[0013] Let the distance between the image sensor and the center of the hollow glass block be... The transmission matrix for light rays to travel from point C to point D is: Point D is the incident point of the image sensor;

[0014] By associating the above matrix with the ray tracing calculation, the ray vector at point D can be obtained as follows:

[0015] ;

[0016] Let the transmission matrix of light rays traveling from point A to point D be: ,in , , , For the transmission matrix Middle element;

[0017] From ray tracing, we can obtain: The calculated transmission matrix middle:

[0018] Matrix element ;

[0019] Matrix element ;

[0020] The calculated ray vector at point D ; can be obtained , ;

[0021] Let point D be the image point of point A, then That is, the transmission matrix Matrix elements in , and by The formula for calculating the refractive index of a solution can be obtained as follows:

[0022] ;

[0023] Furthermore, based on the recorded axial position of the image sensor, the distance between the image sensor and the center of the hollow glass block is obtained. Substitute the data into the formula for calculating the refractive index of a solution to obtain the refractive index of the solution. ;

[0024] Step C: Analyze the magnification of the image on the microscale by the imaging system and invert the refractive index of the solution by measuring the image size on the microscale on the image sensor. Compare this with the refractive index of the solution obtained in step B to improve the redundancy of the system measurement.

[0025] In a preferred embodiment, in step C, the calculation steps for the refractive index of the inversion solution are as follows: when the transfer matrix Matrix elements in At this time, it is satisfied , Transmission Matrix Matrix elements in The magnification is the vertical axis magnification, based on the coordinates of point D on the image sensor. ,in The refractive index of the solution can be obtained. and vertical axis magnification The formula for calculating the relationship is:

[0026] ;

[0027] Based on a clear image of the microscopic scale obtained from the image sensor, the size of the microscopic scale image on the image sensor is recorded as follows: The microscale size is Thus, the transverse magnification can be obtained. Substitute the solution refractive index into the solution. and vertical axis magnification The formula for calculating the refractive index of the solution is used. The calculated solution refractive index is then compared with the solution refractive index obtained in step B.

[0028] In a preferred embodiment, the method includes a solution refractive index measuring device, which comprises an illumination source, a hollow glass block containing a sample flow cell, and an image sensor arranged sequentially along the optical path; there is a gap between the hollow glass block and the image sensor, which forms an air gap, and the hollow glass block, the sample flow cell, and the air gap constitute a magnified imaging system.

[0029] In a preferred embodiment, the hollow portion inside the hollow glass block is a sample flow cell containing the solution to be tested; the side of the hollow glass block facing the illumination source is a first plane, the illumination source is disposed in close contact with the first plane, the side of the sample flow cell facing the illumination source is a second plane, and a microscopic scale is disposed outside the second plane; the side of the sample flow cell facing the image sensor is a first arc surface, and the side of the hollow glass block facing the image sensor is a second arc surface.

[0030] In a preferred embodiment, the image sensor is a CMOS image sensor; a circuit system, a motor system, and a position sensor system are connected to the rear of the image sensor. The motor system is used to drive the image sensor to move back and forth along the optical path, and the position sensor system is used to record the position of the image sensor. The image sensor, the motor system, and the position sensor system are electrically connected to the circuit system.

[0031] In a preferred embodiment, the illumination light emitted by the illumination source illuminates the microscopic scale. The light carrying the microscopic scale information passes through the sample flow cell and the hollow glass block and exits onto the image sensor. Then, according to the focusing algorithm, the image sensor is moved by a motor system to make the microscopic scale information focus and form a clear image. The position of the image sensor is recorded by the position sensor system.

[0032] In a preferred embodiment, the refractive index of the solution is calculated based on the relationship between the axial position of the image sensor and the refractive index of the solution.

[0033] In a preferred embodiment, the refractive index of the solution is inverted by the magnification of a microscale on the image sensor.

[0034] In summary, this application has the following beneficial effects:

[0035] 1. This invention introduces an imaging system design, using microscopic scale magnification imaging and machine vision to analyze the magnified image of the scale after the beam is transmitted to achieve refractive index detection. It has the advantages of being non-contact and having a fast response. It can directly measure the increase and decrease of the refractive index of the solution and adds redundancy design, which significantly improves the detection stability of transparent solutions such as alcohol.

[0036] 2. This invention provides a method for real-time detection of the refractive index of a solution. It utilizes a microscopic ruler to image a magnified image on an image sensor to achieve refractive index detection. The method has high measurement sensitivity, is optically measured throughout the process, and does not require contact with the solution. It is suitable for non-contact rapid measurement of the refractive index of liquids, and is especially suitable for the refractive index detection of transparent to semi-transparent liquids such as alcohol and sugar solutions.

[0037] 3. This invention is based on scale magnification imaging with a composite lens and machine vision, which inverses the refractive index of the solution, improves the resolution of transparent solutions with low refractive index, and enhances the detection stability of transparent solutions such as alcohol.

[0038] 4. This invention introduces a composite lens design, incorporating a hollow glass block. This design is easy to manufacture, stable, robust, and reliable. The hollow portion of the glass block forms a convex lens structure, providing magnification and significantly improving the system's detection sensitivity. It also enhances the resolution of low-refractive-index transparent solutions. The entire optical assembly is integrated, preventing optical path misalignment and greatly improving system reliability. It significantly enhances the detection stability of transparent solutions such as alcohol. Because the composite lens is an integrated device, not a separate component, it avoids vibration interference, improves vibration resistance, and prevents thermal drift caused by environmental temperature changes. Attached Figure Description

[0039] Figure 1 This is a structural distribution diagram of the solution refractive index measuring device in a preferred embodiment of the present invention;

[0040] Figure 2 The solution refractive index in the preferred embodiment of the present invention and image sensor position Relationship diagram;

[0041] Figure 3 The solution refractive index in the preferred embodiment of the present invention Size of the micrograph The relationship diagram.

[0042] Explanation of reference numerals in the attached figures: 1. Illumination source; 2. Hollow glass block; 3. Microscopic scale; 4. Sample flow cell; 5. Air gap; 6. Image sensor; 7. Circuit system; 8. Motor system; 9. Position sensor system. Detailed Implementation

[0043] The technical solutions of 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. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed", "equipped", "sleeved / connected", "connected", etc., should be interpreted broadly. For example, "connection" can be a wall-mounted connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0046] The following is in conjunction with the appendix Figures 1-3 This application will be described in further detail.

[0047] This embodiment provides a method for real-time detection of solution refractive index based on magnified imaging and machine vision, which is used for non-contact rapid measurement of liquid refractive index, and is especially suitable for the detection and real-time monitoring of refractive index of transparent to semi-transparent liquids such as alcohol, sugar solutions and electrolyte solutions.

[0048] refer to Figure 1This embodiment also provides a solution refractive index measuring device based on the detection method. The solution refractive index measuring device includes an illumination source 1, a hollow glass block 2 containing a sample flow cell 4, and an image sensor 6 arranged sequentially along the optical path. The illumination source 1, the hollow glass block 2 containing the sample flow cell 4, and the image sensor 6 are coaxially arranged, and there is a gap between the hollow glass block 2 and the image sensor 6, which forms an air gap 5. A circuit system 7, a motor system 8, and a position sensor system 9 are connected to the rear side of the image sensor 6. The image sensor 6 is a CMOS image sensor, and the illumination source 1 is an incoherent light source. The motor system 8 is used to drive the image sensor 6 to move back and forth along the optical path, and the position sensor system 9 is used to record the position of the image sensor 6. The image sensor 6, the motor system 8, and the position sensor system 9 are electrically connected to the circuit system 7.

[0049] The hollow portion inside the hollow glass block 2 is the sample flow cell 4, which is the channel for the solution to be tested, and the solution to be tested contains the solution to be tested. The side of the hollow glass block 2 facing the illumination source 1 is a first plane, and the illumination source 1 is disposed in close contact with the first plane. The side of the sample flow cell 4 facing the illumination source 1 is a second plane, and a microscopic scale 3 is disposed outside the second plane. The side of the sample flow cell 4 facing the image sensor 6 is a first arc surface, and the side of the hollow glass block 2 facing the image sensor 6 is a second arc surface. The hollow glass block 2 and the solution to be tested constitute a composite lens. The hollow glass block 2, the sample flow cell 4, and the air gap 5 constitute a magnified imaging system, and the first arc surface and the second arc surface constitute a convex lens.

[0050] When the illumination light emitted by the illumination source 1 shines on the microscale 3, the light carrying the microscale information passes through the sample flow cell 4 and the hollow glass block 2 and exits onto the image sensor 6. Then, according to the focusing algorithm, the image sensor 6 is moved by the motor system 8 to accurately focus the microscale information, ensuring that the image of the microscale on the image sensor 6 is a clear image. The position of the image sensor 6 is recorded by the position sensor system 9. The refractive index of the solution is calculated based on the relationship between the axial position of the image sensor 6 and the refractive index of the solution, and the refractive index of the solution is inverted by the magnification of the microscale on the image sensor 6.

[0051] The focusing algorithm works as follows: the system employs contrast-based focusing. Circuit system 7 drives image sensor 6, which acquires images in real time. Circuit system 7 calculates the contrast, compares and selects the image with the highest contrast, and determines whether the image is in focus based on the highest contrast value. If the image is not in focus, circuit system 7 drives motor system 8 to move image sensor 6 to achieve focus. Once focused, motor system 8 stops driving, and position sensor system 9 records the position of image sensor 6.

[0052] The specific principle of contrast judgment is as follows: when the object is out of focus, the image is blurred into a series of blur circles superimposed together. At this time, the radius of the blur circles is much larger than the point, so the brightness and contrast are low; while when the focus is accurate, the in-focus area is a series of points, the image is sharp, and therefore the contrast is high.

[0053] refer to Figure 1 Based on the solution refractive index measuring device provided above, the detection method provided in this embodiment includes the following steps:

[0054] Step A: The illumination light emitted by the illumination source shines on the micrometer scale and forms light carrying the micrometer scale information. The light carrying the micrometer scale information passes through the sample flow cell and the hollow glass block and is emitted onto the image sensor.

[0055] Step B: The light carrying the microscale information forms an image on the image sensor, and the image information of the microscale on the image sensor is recorded. The image sensor is driven to move axially by the focusing algorithm until the image of the microscale on the image sensor is clear, and the axial position of the image sensor is recorded. The refractive index of the solution is analyzed based on the relationship between the axial position of the image sensor and the refractive index of the solution.

[0056] Step C: Analyze the magnification of the image on the micro scale by the imaging system and invert the refractive index of the solution by measuring the image size on the micro scale on the image sensor. Compare this with the refractive index of the solution obtained in step B to improve the redundancy of the system measurement.

[0057] In step B, the calculation steps for the solution refractive index are analyzed based on the relationship between the axial position of the image sensor and the solution refractive index, as follows:

[0058] Let the smallest division of the microscale be... ,like Figure 1 The microscopic scale from point O to point A is the smallest graduation; let the parameters of the hollow glass block and the sample flow cell be: the refractive index of the hollow glass block is... The radius of curvature of the first arc surface of the sample flow cell is The radius of curvature of the second arc surface of the hollow glass block is Assume the refractive index of the solution to be tested is... ;

[0059] According to the principle of ray tracing, let the distance between the ray at a certain point and the optical axis be... The angle between the ray and the optical axis (in radians) is ;

[0060] Let the ray vector at point A on the micrometer scale be... ,vector That is, the position vector of the light ray; let the center thickness of the sample flow cell be... The transmission matrix of light rays from point A to point B on the micrograph is: ;

[0061] Let point B be the exit point of the sample flow cell. Light rays enter the hollow glass block from point B through the solution to be tested. Then the refractive index matrix of the interface at point B is: Let the distance from the center of the first arc surface of the sample flow cell to the center of the second arc surface of the hollow glass block be... Then the transmission matrix for light rays to travel from point B to point C is: ;

[0062] Let point C be the exit point of the insulating glass block. Then, the light ray enters the air gap from point C of the insulating glass block. Assume the air refractive index is... Then the refractive index matrix of the interface where point C is located is ;

[0063] Let the distance between the image sensor and the center of the hollow glass block be... , Let be the distance of the air gap. Then the transmission matrix for light rays to travel from point C to point D is: Point D is the incident point of the image sensor;

[0064] By associating the above matrix with the ray tracing calculation, the ray vector at point D can be obtained as follows:

[0065] ;

[0066] Therefore, we can assume that the transmission matrix for light rays traveling from point A to point D is: ,in , , , For the transmission matrix Middle element;

[0067] From ray tracing, we can obtain: The calculated transmission matrix middle:

[0068] Matrix element ;

[0069] Matrix element ;

[0070] The calculated ray vector at point D ; can be obtained , ;

[0071] Let point D be the image point of point A, then That is, the transmission matrix Matrix elements in , and by The refractive index of the solution can be calculated:

[0072] ;

[0073] The refractive index of the solution can be simply remembered. The distance between the image sensor and the center of the hollow glass block is The relationship is: ;refer to Figure 2 Solution refractive index and image sensor position Relationship diagram;

[0074] Then, based on the focusing algorithm, the image sensor is moved to obtain a clear image of the microscopic scale on the image sensor. The moving position of the image sensor is recorded to obtain the distance between the image sensor and the center of the hollow glass block. Substitute the data into The refractive index of the solution was calculated. .

[0075] In step C, the calculation steps for the inversion solution refractive index are as follows: when the transfer matrix... Matrix elements in At this time, it is satisfied , Transmission Matrix Matrix elements in The magnification is the vertical axis magnification, based on the coordinates of point D on the image sensor. ,in The refractive index of the solution can be obtained. and vertical axis magnification The relationship is:

[0076] ;

[0077] The refractive index of the solution can be simply remembered. and vertical axis magnification The relationship is .

[0078] Then, based on the focusing algorithm, the image sensor is moved to obtain a clear image of the microscopic scale on the image sensor, and the size of the microscopic scale image on the image sensor is recorded as follows: The microscale size is Thus, the transverse magnification can be obtained. Substitute again The refractive index of the solution was calculated. . refer to Figure 3 Solution refractive index Size of the micrograph The relationship diagram.

[0079] Then and By comparison, the measurement features a redundant design, improving system stability.

[0080] In step C, it is also possible to use To describe the refractive index of the solution and the size of the microscopic scale image The relationship is as follows: Point D on the image sensor represents the coordinates of the image of point A, based on the magnification of the object image. and solution refractive index The magnitude of the relationship can be calculated by inversion; .

[0081] The above description is merely a preferred embodiment of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention by those skilled in the art within the scope of the technology disclosed in the present invention using this concept shall be deemed as an infringement of the protection scope of the present invention.

Claims

1. A method for real-time detection of solution refractive index based on magnified imaging and machine vision, characterized in that: The detection method includes the following steps: Step A: The illumination light emitted by the illumination source shines on the micrometer scale and forms light carrying the micrometer scale information. The light carrying the micrometer scale information passes through the hollow glass block containing the sample flow cell. The light carrying the micrometer scale information passes through the sample flow cell and the hollow glass block in sequence, and then is emitted onto the image sensor. Step B: The light carrying the microscopic scale information forms an image on the image sensor, and the image information of the microscopic scale on the image sensor is recorded. The image sensor is driven to shift axially using a focusing algorithm until the image of the microscopic scale on the image sensor is clear, and the axial position of the image sensor is recorded. The refractive index of the solution is analyzed based on the relationship between the axial position of the image sensor and the refractive index of the solution. The calculation steps are as follows: Let the smallest division of the microscale be... Let the parameters of the hollow glass block and the sample flow cell be: the refractive index of the hollow glass block is... The side of the sample flow cell facing the image sensor is the first arc surface, with a radius of curvature of . The side of the hollow glass block facing the image sensor is the second arc surface, with a radius of curvature of . Assume the refractive index of the solution to be tested is... ; According to the principle of ray tracing, let the distance between the ray at a certain point and the optical axis be... The angle between the ray and the optical axis is ; Let the ray vector at point A on the micrometer scale be... Let the center thickness of the sample flow cell be... The transmission matrix of light rays from point A to point B on the micrograph is: ; Let point B be the exit point of the sample flow cell. Light rays enter the hollow glass block from point B through the solution to be tested. Then the refractive index matrix of the interface at point B is: Let the distance from the center of the first arc surface of the sample flow cell to the center of the second arc surface of the hollow glass block be... Then the transmission matrix for light rays to travel from point B to point C is: ; Let point C be the exit point of the insulating glass block. The light ray enters the air from point C of the insulating glass block. Assume the refractive index of air is... Then the refractive index matrix of the interface where point C is located is ; Let the distance between the image sensor and the center of the hollow glass block be... The transmission matrix for light rays to travel from point C to point D is: Point D is the incident point of the image sensor; By associating the above matrix with the ray tracing calculation, the ray vector at point D can be obtained as follows: ； Let the transmission matrix of light rays traveling from point A to point D be: ,in , , , For the transmission matrix Middle element; From ray tracing, we can obtain: The calculated transmission matrix middle: Matrix element ; Matrix element ; The calculated ray vector at point D ; can be obtained , ; Let point D be the image point of point A, then That is, the transmission matrix Matrix elements in , and by The formula for calculating the refractive index of a solution can be obtained as follows: ； Furthermore, based on the recorded axial position of the image sensor, the distance between the image sensor and the center of the hollow glass block is obtained. Substitute the data into the formula for calculating the refractive index of a solution to obtain the refractive index of the solution. ; Step C: Analyze the magnification of the image on the microscale by the imaging system and invert the refractive index of the solution by measuring the image size on the microscale on the image sensor. Compare this with the refractive index of the solution obtained in step B to improve the redundancy of the system measurement.

2. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 1, characterized in that: In step C, the calculation steps for the inversion solution refractive index are as follows: when the transfer matrix... Matrix elements in At this time, it is satisfied , Transmission Matrix Matrix elements in The magnification is the vertical axis magnification, based on the coordinates of point D on the image sensor. ,in The refractive index of the solution can be obtained. and vertical axis magnification The formula for calculating the relationship is: ； Based on a clear image of the microscopic scale obtained from the image sensor, the size of the microscopic scale image on the image sensor is recorded as follows: The microscale size is Thus, the transverse magnification can be obtained. Substitute the solution refractive index into the solution. and vertical axis magnification The formula for calculating the refractive index of the solution is used. The calculated solution refractive index is then compared with the solution refractive index obtained in step B.

3. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 1, characterized in that: The invention includes a solution refractive index measuring device for the detection method. The solution refractive index measuring device includes an illumination source, a hollow glass block containing a sample flow cell, and an image sensor arranged sequentially along the optical path. There is a gap between the hollow glass block and the image sensor, which forms an air gap. The hollow glass block, the sample flow cell, and the air gap constitute a magnified imaging system.

4. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 3, characterized in that: The hollow portion inside the hollow glass block is a sample flow cell containing the solution to be tested. The side of the hollow glass block facing the illumination source is a first plane, and the illumination source is disposed in close contact with the first plane. The side of the sample flow cell facing the illumination source is a second plane, and a microscopic scale is disposed outside the second plane. The side of the sample flow cell facing the image sensor is a first arc surface, and the side of the hollow glass block facing the image sensor is a second arc surface.

5. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 4, characterized in that: The image sensor is a CMOS image sensor; a circuit system, a motor system and a position sensor system are connected to the rear of the image sensor. The motor system is used to drive the image sensor to move back and forth along the optical path, and the position sensor system is used to record the position of the image sensor. The image sensor, the motor system and the position sensor system are electrically connected to the circuit system.

6. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 5, characterized in that: The illumination light emitted by the illumination source shines on the microscopic scale. The light carrying the microscopic scale information passes through the sample flow cell and the hollow glass block and is emitted onto the image sensor. Then, according to the focusing algorithm, the image sensor is moved by the motor system to make the microscopic scale information focus and form a clear image. The position of the image sensor is recorded by the position sensor system.

7. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 6, characterized in that: The refractive index of the solution is calculated based on the relationship between the axial position of the image sensor and the refractive index of the solution.

8. The method for real-time detection of solution refractive index based on magnified imaging and machine vision according to claim 6, characterized in that: The refractive index of the solution is inverted by the magnification of the microscale on the image sensor.

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