Laser calibration measurement method and device for planar projection area of fine object

Abstract

The invention discloses a laser calibration measurement method and device for the plane projection area of a fine object. The method comprises the following steps: (1) placing a measured object on a workbench of a microscope; (2) starting a laser emitter to form an initial light spot t1 of which the size is not adjusted; (3) adjusting the laser transmitter to obtain an adjusted light spot t2; (4) acquiring a microscopic image with the light spot t2 and the measurement object through the microscope by the camera; (5) the size of the adjusted light spot t2 is calculated according to the parameters of the laser transmitter, the number of pixel points of the light spot t2 in the image is counted, and the mapping relation ratio r of the size of the light spot t2 and the number of the pixel points of the light spot t2 is obtained; and (6) counting the number of pixel points of the measured object in the image, and calculating the actual area of the measured object in combination with the mapping relation ratio r. According to the laser calibration measurement method, the laser spot is introduced as a reference, and the area of the fine object is reflected by the area of the spot, so that the measurement accuracy is improved.

Description

Technical Field

[0001] The invention relates to a laser measurement method and device, and in particular to a laser calibration measurement method and device for a plane projection area of ​​a micro object. Background Art

[0002] In the study of tiny objects, a microscope is needed to magnify tiny objects so as to observe their various features. In the study of microorganisms, it is often necessary to obtain the area of ​​the research object. The image of the microorganism can be captured through a camera through a microscope, and then the image can be processed and the size of the projection area of ​​the research object can be reflected by calculating the pixel size.

[0003] The above measurement method, because there is no real reference, relies entirely on virtual analysis and calculation, and the results are not accurate enough. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned problems and provide a laser calibration measurement method for the plane projection area of ​​a fine object. The laser calibration measurement method introduces a laser spot as a reference, and the area of ​​the spot reflects the area of ​​the fine object, which is conducive to improving the measurement accuracy.

[0005] Another object of the present invention is to provide a laser calibration and measurement device for the planar projection area of ​​a tiny object.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A laser calibration measurement method for a plane projection area of ​​a microscopic object comprises the following steps:

[0008] (1) Place the object to be measured on the working table of the microscope and ensure that the object to be measured is within the field of view of the microscope;

[0009] (2) starting the laser emitter to form an initial light spot t1 whose size has not been adjusted, and ensuring that the initial light spot t1 is within the field of view of the microscope;

[0010] (3) adjusting the laser emitter to obtain an adjusted light spot t2;

[0011] (4) obtaining a microscopic image with the light spot t2 and the measurement object through a microscope using a camera;

[0012] (5) calculating the size of the adjusted light spot t2 according to the parameters of the laser transmitter, counting the number of pixels of the light spot t2 in the image, and obtaining a mapping relationship ratio r between the size of the light spot t2 and the number of pixels of the light spot t2;

[0013] (6) Count the number of pixels of the measured object in the image, and then calculate the actual area of ​​the measured object based on the mapping relationship ratio r.

[0014] In a preferred embodiment of the present invention, in step (5), the calculation formula of the area of ​​the adjusted light spot t2 is:

[0015]

[0016] In the formula, ω t2 is the diameter of the spot size, ω1 is the size of the adjusted laser waist aperture, which is obtained by adjusting ω0; where the wavelength λ and the beam quality M 2 , working distance z, and waist beam aperture ω0 are all known quantities.

[0017] Furthermore, the actual area S of the light spot t2 is t3 for:

[0018]

[0019] In the formula, S t3 is the area corrected to the elliptical spot t3, and θ is the angle between the laser beam and the plane.

[0020] In the above formula, in order to correct the size and shape of the light spot t2, it is necessary to consider the effect of the incident angle of the light on the light spot. Assuming that the angle between the light and the plane is θ, the projected length of the diameter of the light spot t2 on the plane becomes:

[0021] ω t2，proj =ω t2 cos(θ);

[0022] When light is directed at a plane at a certain angle, the size and shape of the light spot t2 will be affected. The size of the light spot will change due to the angle, from a circle to an ellipse. The size (diameter) of the light spot t2 needs to be multiplied by cos(θ) to obtain the projection length on the plane.

[0023] The shape of the spot t2 will change from a circle to an ellipse. Let the spot that changes to an ellipse be t3, then the major axis length of t3 is ω t2 cos(θ), the minor axis length is ω t2 .

[0024] In a preferred embodiment of the present invention, in step (6), the calculation formula for the actual area of ​​the measured object is:

[0025] real_object = pix_object *r;

[0026] Where real_object is the actual area of ​​the measured object, and pix_object is the number of pixels of the measured object.

[0027] In a preferred embodiment of the present invention, the calculation result is corrected by an infrared light-sensitive distance-measuring mechanism, wherein the infrared light-sensitive distance-measuring mechanism is provided with at least two groups and each group of the infrared light-sensitive distance-measuring mechanism includes an infrared light-sensitive distance-measuring instrument and a distance-measuring adjustment motor;

[0028] When measuring distance, the distance adjustment motors of each group are used to drive the corresponding infrared photosensitive distance meter to adjust the posture so that the measuring point of the infrared photosensitive distance meter coincides with the measured object, and the distance measurement result value is returned: d1cos(θ1), d2cos(θ2)...dncos(θn);

[0029] The error propagation formula is used to calculate the measurement results of each set of infrared photosensitive ranging mechanisms, and d1cos(θ1)=δd1, d2cos(θ2)=δd2…dncos(θn)=δdn is set;

[0030] Then we have:

[0031]

[0032] Determine σ_accept through the learning result. When the total error σtotal is less than or equal to σaCCept, output the ranging result, otherwise repeat the above measurement steps.

[0033] Furthermore, the corrected calculation result is:

[0034]

[0035] Where Final_Result is the final measurement result, pix_object is the pixel size of the measured object, λ is the wavelength, and M is 2 is the beam quality, f is the focal length, Loss(y) is the weight obtained by learning the training set, and σi is the standard deviation of the i-th measurement value.

[0036] A laser calibration and measurement device for the plane projection area of ​​a microscopic object, comprising a microscope, a camera and a laser transmitter;

[0037] The camera is arranged above the eyepiece of the microscope;

[0038] An adjustable mounting frame is provided below the objective lens of the microscope, and the adjustable mounting frame can be movably arranged on the microscope vertically;

[0039] The laser transmitter is arranged on an adjustable mounting frame.

[0040] A preferred embodiment of the present invention, wherein the laser emitter includes a laser source for emitting laser, a focus adjustment component for adjusting the focal length of the light spot, a variable aperture for adjusting the light transmittance of the light spot, and a reflection component for adjusting the position and angle of the light spot, wherein the reflection component includes a reflector and an output adjustment motor.

[0041] A preferred embodiment of the present invention further includes an infrared photosensitive distance measuring mechanism for correcting the calculation results. The infrared photosensitive distance measuring mechanism is provided with at least two groups and is arranged along the circumferential direction on an adjustable mounting frame. Each group of infrared photosensitive distance measuring mechanisms includes an infrared photosensitive distance meter and a distance measuring adjustment motor.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The laser calibration measurement method of the present invention introduces a laser spot as a reference, and infers the area of ​​a fine object from the actual area of ​​the spot, which is beneficial to improving the measurement accuracy.

[0044] 2. By integrating the microscope, camera and laser transmitter together, it is easier to operate under the microscope, which improves the convenience and efficiency of the experiment. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a front view of the laser calibration measurement device for the plane projection area of ​​a fine object of the present invention.

[0046] Figure 2 It is a schematic diagram of the three-dimensional structure of the laser calibration measurement device for the plane projection area of ​​a tiny object of the present invention. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0048] See also Figure 1-2 The laser calibration and measurement device for the plane projection area of ​​a fine object of this embodiment includes a microscope 1, a camera 2 and a laser emitter 3; the camera 2 is arranged above the eyepiece of the microscope 1; an adjustable mounting frame 4 is arranged below the objective lens of the microscope 1, and the adjustable mounting frame 4 can be vertically movably arranged on the microscope 1; the laser emitter 3 is arranged on the adjustable mounting frame 4.

[0049] Specifically, the laser emitter 3 includes a laser source for emitting laser, a focus adjustment component for adjusting the focal length of the light spot, a variable aperture for adjusting the light transmittance of the light spot, and a reflection component for adjusting the position and angle of the light spot, wherein the reflection component includes a reflector and an output adjustment motor.

[0050] See also Figure 1-2 The laser calibration measurement device also includes an infrared photosensitive distance measuring mechanism 5 for correcting the calculation results. The infrared photosensitive distance measuring mechanism 5 is provided with at least two groups and is arranged along the circumferential direction on the adjustable mounting frame 4. Each group of infrared photosensitive distance measuring mechanisms 5 includes an infrared photosensitive distance meter and a distance adjustment motor.

[0051] See also Figure 1-2 The laser calibration measurement method of the plane projection area of ​​a microscopic object of this embodiment comprises the following steps:

[0052] (1) Place the measurement object (e.g., Tetranychus bihemispermum) on the workbench of the microscope 1 , and ensure that the measurement object is within the field of view of the microscope 1 .

[0053] (2) Start the laser emitter 3 to form an initial light spot t1 whose size has not been adjusted, and ensure that the initial light spot t1 is within the field of view of the microscope 1.

[0054] (3) Adjust the laser emitter 3 to obtain an adjusted light spot t2.

[0055] (4) A microscopic image with the light spot t2 and the measurement object is obtained through the microscope 1 by the camera 2.

[0056] (5) The size of the adjusted light spot t2 is calculated according to the parameters of the laser emitter 3, and the number of pixels of the light spot t2 in the image is counted to obtain a mapping ratio r between the size of the light spot t2 and the number of pixels of the light spot t2.

[0057] (6) Count the number of pixels of the measured object in the image, and then calculate the actual area of ​​the measured object based on the mapping relationship ratio r.

[0058] Further, in step (5), the calculation formula of the area of ​​the adjusted light spot t2 is:

[0059]

[0060] In the formula, ω t2 is the diameter of the spot size, ω1 is the size of the adjusted laser waist aperture, which is obtained by adjusting ω0; where the wavelength λ and the beam quality M 2 , working distance z, and waist beam aperture ω0 are all known quantities.

[0061] Furthermore, the actual area S of the light spot t2 is t3 for:

[0062]

[0063] In the formula, S t3is the area corrected to the elliptical spot t3, and θ is the angle between the laser beam and the plane.

[0064] In the above formula, in order to correct the size and shape of the light spot t2, it is necessary to consider the effect of the incident angle of the light on the light spot. Assuming that the angle between the light and the plane is θ, the projected length of the diameter of the light spot t2 on the plane becomes:

[0065] ω t2，proj =ω t2 cos(θ);

[0066] When light is directed at a plane at a certain angle, the size and shape of the light spot t2 will be affected. The size of the light spot will change due to the angle, from a circle to an ellipse. The size (diameter) of the light spot t2 needs to be multiplied by cos(θ) to obtain the projection length on the plane.

[0067] The shape of the spot t2 will change from a circle to an ellipse. Let the spot that changes to an ellipse be t3, then the major axis length of t3 is ω t2 cos(θ), the minor axis length is ω t2 .

[0068] Furthermore, in step (6), the actual area of ​​the measured object is calculated as:

[0069] real_object = pix_object *r;

[0070] Where real_object is the actual area of ​​the measured object, and pix_object is the number of pixels of the measured object.

[0071] Furthermore, the calculation result is corrected by the infrared photosensitive distance measuring mechanism 5. When measuring distance, the distance measuring adjustment motors of each group drive the corresponding infrared photosensitive distance measuring instrument to adjust the posture so that the measuring point of the infrared photosensitive distance measuring instrument coincides with the measuring object, and returns the distance measuring result value: dlcos(θ1), d2cos(θ2)...dncos(θn);

[0072] The measurement results of each group of infrared light sensing distance measuring mechanisms 5 are calculated by using the error propagation formula, and dlcos(γ1)=δd1, d2cos(γ2)=δd2...dncos(θn)=δdn;

[0073] Then we have:

[0074]

[0075] Determine σ_accept through the learning results. When the total error σtotal is less than or equal to σaccept, output the ranging result, otherwise repeat the above measurement steps.

[0076] Furthermore, the corrected calculation result is:

[0077]

[0078] Where Final_Result is the final measurement result, pix_object is the pixel size of the target object, λ is the wavelength, and M is 2 is the beam quality, f is the focal length, Loss(y) is the weight obtained by learning the training set, and σi is the standard deviation of the i-th measurement value.

[0079] Further, the σ_aCCept is obtained by the following method:

[0080] Data collection: Using a calibrated (real-size-measured) grid or pattern, acquire multiple image samples through the system. These images should contain fine objects and their corresponding known real-size grids or patterns.

[0081] The system's approach to extracting size and number of pixels is to extract features of small objects from each image and label the pixels that correspond to a grid or pattern of known size.

[0082] Build an error model: For each image, calculate the difference between the actual measurement of subtle objects in the image and the known calibration value. This will give the error σ for each measurement.

[0083] Statistical analysis: Perform statistical analysis on the errors of all images and calculate the mean, variance, and standard deviation of the errors. These statistics will help determine the distribution characteristics of the errors.

[0084] Determine the error threshold: According to the error distribution, determine a reasonable error threshold σ_accept. This threshold can be determined based on experience, for example, a certain percentile (such as 95%) of the error distribution is selected as the threshold.

[0085] Machine Learning Model Training: Use the extracted features and corresponding error data to train a machine learning model that can predict the errors of subtle objects in new images.

[0086] Model validation and error threshold adjustment: Use the validation set to evaluate the performance of the machine learning model and adjust σ_accept to ensure the accuracy and reliability of the model's predictions.

[0087] Continuous iteration: As new data is added, the model is continuously optimized and the σ_accept value is updated to adapt to new data characteristics and measurement conditions.

[0088] The above is a preferred embodiment of the present invention, but the embodiment of the present invention is not limited to the above content. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A laser calibration measurement method for the plane projection area of ​​a tiny object, characterized in that: The following steps are involved: (1) Place the object to be measured on the working table of the microscope and ensure that the object to be measured is within the field of view of the microscope; (2) starting the laser emitter to form an initial light spot t1 whose size has not been adjusted, and ensuring that the initial light spot t1 is within the field of view of the microscope; (3) adjusting the laser emitter to obtain an adjusted light spot t2; (4) obtaining a microscopic image with the light spot t2 and the measurement object through a microscope using a camera; (5) calculating the size of the adjusted light spot t2 according to the parameters of the laser transmitter, counting the number of pixels of the light spot t2 in the image, and obtaining a mapping relationship ratio r between the size of the light spot t2 and the number of pixels of the light spot t2; (6) Count the number of pixels of the measured object in the image, and then calculate the actual area of ​​the measured object based on the mapping relationship ratio r.

2. The laser calibration measurement method for the plane projection area of ​​a micro object according to claim 1, characterized in that: In step (5), the calculation formula for the area of ​​the adjusted light spot t2 is: In the formula, ω t2 is the diameter of the spot size, ω1 is the size of the adjusted laser waist aperture, which is obtained by adjusting ω0; where the wavelength λ and the beam quality M 2 , working distance z, and waist beam aperture ω0 are all known quantities.

3. The laser calibration measurement method for the plane projection area of ​​a micro-object according to claim 2, characterized in that: The actual area S of the light spot t2 t3 for: In the formula, S t3 is the area of ​​the spot t2 corrected to the elliptical spot t3, and θ is the angle between the laser beam and the plane.

4. The laser calibration measurement method for the plane projection area of ​​a micro object according to claim 1, characterized in that: In step (6), the actual area of ​​the measured object is calculated as: real_object = pix_object *r; Where real_object is the actual area of ​​the measured object, and pix_object is the number of pixels of the measured object.

5. The laser calibration measurement method for the plane projection area of ​​a micro object according to claim 1, characterized in that: The calculation result is corrected by an infrared light-sensing distance-measuring mechanism, wherein the infrared light-sensing distance-measuring mechanism is provided with at least two groups, and each group of the infrared light-sensing distance-measuring mechanism includes an infrared light-sensing distance-measuring instrument and a distance-measuring adjustment motor; When measuring distance, the distance adjustment motors of each group are used to drive the corresponding infrared photosensitive distance meter to adjust the posture so that the measuring point of the infrared photosensitive distance meter coincides with the measured object, and the distance measurement result value is returned: d1cos(θ1), d2cos(θ2)...dncos(θn); The error propagation formula is used to calculate the measurement results of each set of infrared photosensitive ranging mechanisms, and d1cos(θ1)=δd1, d2cos(θ2)=δd2…dncos(θn)=δdn is set; Then we have: Determine σ_accept through the learning results. When the total error σtotal is less than or equal to σaccept, output the ranging result, otherwise repeat the above measurement steps.

6. The laser calibration measurement method for the plane projection area of ​​a micro-object according to claim 5, characterized in that: The corrected calculation result is: Where Final_Result is the final measurement result, pix_object is the pixel size of the measured object, λ is the wavelength, and M is 2 is the beam quality, f is the focal length, Loss(y) is the weight obtained by learning the training set, and σi is the standard deviation of the i-th measurement value.

7. A laser calibration measurement device using the laser calibration measurement method for the plane projection area of ​​a fine object according to any one of claims 1 to 6, characterized in that: Includes microscope, camera and laser transmitter; The camera is arranged above the eyepiece of the microscope; An adjustable mounting frame is provided below the objective lens of the microscope, and the adjustable mounting frame can be movably arranged on the microscope vertically; The laser transmitter is arranged on an adjustable mounting frame.

8. The laser calibration measurement device according to claim 7, characterized in that: The laser transmitter comprises a laser source for emitting laser, a focus adjustment component for adjusting the focal length of the light spot, a variable aperture for adjusting the light flux of the light spot, and a reflection component for adjusting the position and angle of the light spot, wherein the reflection component comprises a reflector and an output adjustment motor.

9. The laser calibration measurement device according to claim 7, characterized in that: It also includes an infrared light-sensitive distance-measuring mechanism for correcting the calculation result. The infrared light-sensitive distance-measuring mechanism is provided with at least two groups and is arranged on an adjustable mounting frame along the circumferential direction. Each group of infrared light-sensitive distance-measuring mechanisms includes an infrared light-sensitive distance-measuring instrument and a distance-measuring adjustment motor.

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