Imaging-based alignment method, device, electronic device and storage medium

Abstract

The present application provides an alignment method, device, electronic device and storage medium based on imaging, which generate a first position control signal and send it to a moving stage, so that the target surface of the object to be measured located on the moving stage moves to the first position indicated by the first position control signal; obtain a first image, determine the first position information of the target surface, so as to generate a second position control signal and send it to the moving stage, so that the target surface moves to the second position indicated by the second position control signal; obtain a second image, the second magnification is greater than the first magnification, determine the second position information of the target surface, so as to generate a third position control signal and send it to the moving stage, so that the imaging of the target surface is aligned with the field of view center of the second sensor, and is used for accurately and quickly aligning the imaging of the object to be measured with the field of view center of the sensor with a smaller field of view when an optical system including a plurality of magnification imaging optical paths with different magnifications is imaging the object to be measured.

Description

Technical Field

[0001] The present application relates to the field of optical technology, and in particular to an alignment method, device, electronic device and storage medium based on imaging. Background Art

[0002] In the prior art, when an optical system has multiple imaging optical paths with different magnifications, the different magnifications result in different fields of view of sensors used to obtain images with different magnifications. Therefore, when using the above optical system to image the object to be measured, it cannot be guaranteed that the image of the object to be measured is simultaneously within the field of view of multiple sensors. Therefore, an accurate and fast alignment method is needed to align the image of the object to be measured with the center of the field of view of the sensor with a smaller field of view. Summary of the invention

[0003] In view of this, the purpose of the present application is to provide an imaging-based alignment method, device, electronic device and storage medium, which are used to accurately and quickly align the image of the object to be measured with the center of the field of view of a sensor with a smaller field of view when an optical system including a plurality of magnified imaging light paths with different magnification factors images the object to be measured.

[0004] In a first aspect, an embodiment of the present application provides an imaging-based alignment method, comprising: responding to a start instruction, generating a first position control signal and sending it to a moving stage, so that the target surface of the object to be measured located on the moving stage moves to a first position indicated by the first position control signal; acquiring a first image of the target surface at the first position after being magnified by a first factor by the optical system, determining the first position information of the target surface, so as to generate a second position control signal and sending it to the moving stage, so that the target surface moves to a second position indicated by the second position control signal; acquiring a second image of the target surface at the second position after being magnified by a second factor by the optical system, the second factor being greater than the first factor, determining the second position information of the target surface, so as to generate a third position control signal and sending it to the moving stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor.

[0005] Preferably, a preset mark is provided on the target surface, and the position information of the target surface indicates the coordinates of the center point of the preset mark. The position information of the target surface is determined in the following manner: a first discrete signal and a second discrete signal are generated according to a target area image corresponding to the preset mark in the image, wherein the first discrete signal represents the sum of the grayscale values ​​of each column of pixels in the target area image, and the second discrete signal represents the sum of the grayscale values ​​of each row of pixels in the target area image; for each discrete signal, two peak coordinate points of the discrete signal and a preset number of sample coordinate points corresponding to each peak coordinate point are determined respectively; for each peak coordinate point, a curve equation corresponding to the peak coordinate point is generated based on the preset number of sample coordinate points corresponding to the peak coordinate point; and the center point coordinates are determined according to the curve equation corresponding to the peak coordinate point.

[0006] Preferably, the first discrete signal and the second discrete signal are generated in the following manner: the grayscale value of each pixel point of the target area image is determined to generate a grayscale matrix; the sum of the pixel points in each column of the grayscale matrix is ​​used as the vertical coordinate, and the column number of the column is used as the horizontal coordinate to generate the first discrete signal; the sum of the pixel points in each row of the grayscale matrix is ​​used as the vertical coordinate, and the row number of the row is used as the horizontal coordinate to generate the second discrete signal.

[0007] Preferably, a preset number of sample coordinate points corresponding to each peak coordinate point is determined in the following manner: a first horizontal coordinate is determined according to the current peak coordinate point; based on the first horizontal coordinate, a second horizontal coordinate and a third horizontal coordinate are determined according to a first preset step size, the second horizontal coordinate is smaller than the first horizontal coordinate, and the first horizontal coordinate is smaller than the third horizontal coordinate; and based on the first horizontal coordinate, a fourth horizontal coordinate and a fifth horizontal coordinate are determined according to a second preset step size, the fourth horizontal coordinate is smaller than the second horizontal coordinate, the third horizontal coordinate is smaller than the fifth horizontal coordinate, and the first preset step size is smaller than the second preset step size; and five sample coordinate points of each horizontal coordinate on the discrete signal corresponding to the current peak coordinate point are determined respectively.

[0008] Preferably, the curve equation includes a first coefficient and a second coefficient. The step of determining the coordinates of the center point according to the curve equation corresponding to the peak coordinate point specifically includes: calculating the mark value corresponding to the peak coordinate point according to the mark value calculation formula according to the first coefficient and the second coefficient of the curve equation corresponding to the peak coordinate point; generating the center point coordinates according to the mark values ​​corresponding to all the peak coordinate points.

[0009] Preferably, the center point coordinates are generated in the following manner: a first mean value between the mark values ​​corresponding to two peak coordinate points of the first discrete signal is used as the horizontal coordinate of the center point coordinates, and a second mean value between the mark values ​​corresponding to two peak coordinate points of the second discrete signal is used as the vertical coordinate of the center point coordinates to generate the center point coordinates.

[0010] Preferably, the image is acquired in the following manner: a first image acquisition signal is generated and sent to a first image acquisition chip to acquire a first image captured by a first sensor; and a second image acquisition signal is generated and sent to a second image acquisition chip to acquire a second image captured by a second sensor.

[0011] In a second aspect, an embodiment of the present application further provides an alignment device based on imaging, comprising:

[0012] A response module, used to respond to the start instruction, generate a first position control signal and send it to the motion stage, so that the target surface of the object to be measured located on the motion stage moves to a first position indicated by the first position control signal;

[0013] A first generating module is used to obtain a first image of a target surface at a first position after being magnified by a first multiple by an optical system, determine first position information of the target surface, generate a second position control signal and send it to the motion stage, so that the target surface moves to a second position indicated by the second position control signal;

[0014] The second generating module is used to obtain a second image of the target surface at a second position after the optical system magnifies the target surface by a second factor, where the second factor is greater than the first factor, and determine the second position information of the target surface to generate a third position control signal and send it to the motion stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor.

[0015] In a third aspect, an embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the processor executes the machine-readable instructions to perform the steps of the above imaging-based alignment method.

[0016] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned imaging-based alignment method are executed.

[0017] An imaging-based alignment method, device, electronic device and storage medium provided in an embodiment of the present application generate a first position control signal in response to a start instruction and send it to a moving stage, so that the target surface of the object to be measured on the moving stage moves to the first position indicated by the first position control signal to ensure that the current imaging of the object to be measured is within the field of view of the first sensor, obtain a first image of the target surface at the first position after being magnified by a first multiple by the optical system, determine the first position information of the target surface, generate a second position control signal and send it to the moving stage, so that the target surface moves to the second position indicated by the second position control signal, so that the current imaging of the object to be measured is within the field of view of the second sensor, obtain a second image of the target surface at the second position after being magnified by a second multiple by the optical system, the second multiple is greater than the first multiple, determine the second position information of the target surface, generate a third position control signal and send it to the moving stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor, and the alignment can be completed through a few simple steps, and the imaging of the object to be measured can be accurately and quickly aligned with the center of the field of view of the sensor with a smaller field of view.

[0018] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A schematic diagram of the structure of an optical system provided in an embodiment of the present application;

[0021] Figure 2 A top view of an optical workpiece provided in an embodiment of the present application;

[0022] Figure 3 A flowchart of an imaging-based alignment method provided in an embodiment of the present application;

[0023] Figure 4 A schematic diagram of a processing flow of a data processing system provided in an embodiment of the present application;

[0024] Figure 5 A flowchart of a method for calculating location information provided in an embodiment of the present application;

[0025] Figure 6 A schematic diagram of a target area image provided in an embodiment of the present application;

[0026] Figure 7 A schematic diagram of a discrete signal provided in an embodiment of the present application;

[0027] Figure 8 A schematic structural diagram of an imaging-based alignment device provided in an embodiment of the present application;

[0028] Fig. 9 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0029] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the drawings in the present application only serve the purpose of explanation and description and are not used to limit the scope of protection of the present application. In addition, it should be understood that the schematic drawings are not drawn in real proportion. The flowchart used in this application shows the operations implemented according to some embodiments of the present application. It should be understood that the operations of the flowchart can be implemented out of sequence, and the steps without logical context can be reversed in order or implemented simultaneously. In addition, those skilled in the art, under the guidance of the content of the present application, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0030] In addition, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0031] In the prior art, when an optical system has multiple imaging optical paths with different magnifications, the different magnifications result in different fields of view of sensors used to obtain images with different magnifications. Therefore, when using the above optical system to image the object to be measured, it cannot be guaranteed that the image of the object to be measured is simultaneously within the field of view of multiple sensors. Therefore, an accurate and fast alignment method is needed to align the image of the object to be measured with the center of the field of view of the sensor with a smaller field of view.

[0032] In response to the above problems, embodiments of the present application provide an imaging-based alignment method, device, electronic device, and storage medium, which are described below through embodiments.

[0033] To facilitate the understanding of the present application, the technical solution provided by the present application is described in detail below in conjunction with specific embodiments.

[0034] See also Figure 1 , is a schematic diagram of the imaging process of an optical system provided in an embodiment of the present application, the optical system is used to magnify and image the target surface of the object to be measured placed on the moving table, and the optical system includes a first optical component, a second optical component, a first mounting plate, a second mounting plate and a total mounting plate. Among them, the first optical component includes a plane reflector 3 and an objective lens 4, and the second optical component includes a periscope lens 5, a first beam splitting prism 6, a second beam splitting prism 8, a tube lens 7, a magnifying lens 9, an illumination component 2, a first sensor 10 and a second sensor 11. The object to be measured can be placed on the stage 1. The first optical components are respectively fixed at the preset positions of the first mounting plate, the second optical components are respectively fixed at the preset positions of the second mounting plate, and the first mounting plate and the second mounting plate are respectively fixed on the total mounting plate. It should be noted here that the preset positions corresponding to each optical device and the positional relationship between the optical devices are all designed in advance, and only need to be installed according to the rules. The optical system can constitute two magnification optical paths with different magnifications.

[0035] The stage 1 can be a position-controllable motion stage for placing the object to be measured. The motion stage is connected to a motion controller, and the motion controller is connected to a data processor. The motion controller is used to drive the motion stage to move in a horizontal plane according to a position control signal sent by the data processor. It should be noted that the relative distance between the motion stage and the plane reflector 3 in the vertical plane remains unchanged.

[0036] A preset mark is set on the target surface, and the position information of the target surface indicates the center point coordinates of the preset mark. The object to be measured here can be an optical workpiece with a measurement mark, and a target surface of the optical workpiece has a preset mark. The preset mark here can be formed by a chrome plating process. Figure 2 A top view of an optical workpiece provided in this application, such as Figure 2 As shown, the shape of the preset mark can be a rectangular frame, which is set at the center of the target surface of the optical workpiece. It should be noted that the part of the preset mark reflects the incident light.

[0037] Specifically, the optical system here is a periscope system, wherein the magnification of the tube lens 7 is five times, and the magnification of the magnifying lens 9 is ten times. The lighting component 2 is used to provide a light source to illuminate the object to be tested.

[0038] The first sensor 10 and the second sensor 11 are used to obtain the image of the object to be measured after being reflected by the optical system. Taking the optical workpiece as an example, the first image obtained by the first sensor 10 is the image of the target surface of the optical workpiece after being magnified five times by the optical system. The second image obtained by the second sensor 11 is the image of the target surface of the optical workpiece after being magnified fifty times by the optical system. Specifically, the sensor here can be a CCD camera.

[0039] The objects to be tested here can be placed on the moving table by a robotic arm, so there may be deviations in the position of the objects to be tested each time, or the objects to be tested themselves may have deviations when they are manufactured. At this time, moving the stage according to a uniformly calibrated position cannot accurately align the imaging of the objects to be tested with the center of the field of view of the second sensor, and the imaging position is not ideal.

[0040] To solve the above problems, Figure 1 The invention comprises an electronic terminal 12 equipped with a data processing system. The electronic terminal 12 here can be a computer. The data processing system collects images and processes the collected images to calculate the coordinates of the center point. The data processing system at least comprises a data processor. Figure 3 An imaging-based alignment method provided in an embodiment of the present application is applicable to the above-mentioned periscope optical system and can be executed by a data processing system. The alignment method includes:

[0041] S101 , in response to a start instruction, generating a first position control signal and sending it to a motion stage, so that a target surface of the object to be measured located on the motion stage moves to a first position indicated by the first position control signal.

[0042] like Figure 4 As shown, it is a processing flow diagram of a data processing system provided by an embodiment of the present application. Specifically, the data processor can respond to the user's start-up instruction, where the start-up instruction is used to instruct the data processing system to generate a first position control signal, and send the first position control signal to the motion controller, and the motion controller drives the motion stage to move to the first position according to the first position control signal. The first position here can be a pre-calibrated position, which can ensure that the imaging of the current optical workpiece is within the field of view of the first sensor 10.

[0043] S102, obtaining a first image of a target surface at a first position after being magnified by a first factor by an optical system, determining first position information of the target surface, generating a second position control signal and sending it to the motion stage, so that the target surface moves to a second position indicated by the second position control signal.

[0044] The data processor may acquire the first image captured by the first sensor 10. Specifically, the first image may be an image of the target surface magnified five times.

[0045] Specifically, the first sensor is connected to the first image acquisition chip, and the image captured by the sensor is obtained by: generating a first image acquisition signal and sending it to the first image acquisition chip to obtain the first image captured by the first sensor.

[0046] like Figure 4 As shown, the data processor sends an image acquisition signal to the first image acquisition chip connected to the first sensor 10, and receives the first image sent by the first image acquisition chip.

[0047] The data processor can determine the first position information of the target surface by a preset position information calculation method. The position information here can be a coordinate point. The first position information can specifically be a coordinate point in the reference coordinate system corresponding to the field of view of the first sensor 10, where the center point of the preset mark in the first image is mapped.

[0048] In one solution, the second position control signal here is generated based on the first position information. The data processor sends the first position information to the motion controller, and the motion controller calculates the coordinate difference between the two coordinate points based on the first position information and the pre-marked coordinates of the center point of the field of view of the second sensor 11. The motion controller converts the coordinate difference into the coordinate difference of the motion stage in the actual reference coordinate system according to the pre-calibrated mapping relationship to determine the moving direction and moving distance of the motion stage. The coordinate difference here indicates the difference in the horizontal and vertical directions.

[0049] In another solution, the data processor first determines the coordinate difference between the two coordinate points based on the first position information and the pre-marked coordinates of the center point of the field of view of the second sensor 11, and then converts the difference into the coordinate difference of the motion stage in the actual reference coordinate system according to a pre-calibrated mapping relationship, and generates a second position control signal. The motion controller determines the moving direction and moving distance of the motion stage according to the second position control signal.

[0050] The second position here indicates a position where the center point of the current preset mark is stabilized within the field of view of the second sensor 11 .

[0051] S103, obtaining a second image of the target surface at a second position after being magnified by the optical system by a second factor, where the second factor is greater than the first factor, determining second position information of the target surface to generate a third position control signal and send it to the motion stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor.

[0052] Specifically, the second image may be an image of the target surface after being magnified fifty times. It should be noted that, since the second magnification is greater than the first magnification, the field of view of the second sensor 11 is smaller than the field of view of the first sensor 10. Therefore, after the alignment in step S102, only coarse-precision alignment is achieved. At this time, the images acquired by the first sensor 10 and the second sensor 11 can both obtain a complete image of the target surface. At this time, step S103 is performed to align the image of the target surface with the center of the field of view of the second sensor 11.

[0053] The second sensor is connected to the second image acquisition chip. Specifically, the second image can be acquired in the following manner: a second image acquisition signal is generated and sent to the second image acquisition chip to acquire the second image captured by the second sensor.

[0054] The data processor sends the second image acquisition signal to the second image acquisition chip connected to the second sensor, and receives the second image sent by the second image acquisition chip. The data processor then determines the second position information in the second image. The second position information here can be the coordinate point of the center point of the preset mark in the second image mapped in the reference coordinate system corresponding to the field of view of the second sensor 11.

[0055] The second position information here is used to indicate the position where the center point of the current preset mark is aligned with the center point of the field of view of the second sensor 11. When the image of the object to be measured is aligned with the center of the field of view of the sensor with a smaller field of view, it can be ensured that the image of the object to be measured is in the center area of ​​the field of view of multiple sensors at the same time, so that each sensor can capture a complete image. The multiple sensors here are used to obtain images after the optical system is magnified at different times.

[0056] Therefore, the second position information can be processed by a data processor, and the second position information can be converted into a coordinate point of the motion stage in the actual reference coordinate system, so as to move the preset point on the motion stage to the position corresponding to the second position information. The preset point here is calculated based on the mapping relationship between the image and the reference coordinate system. Exemplarily, according to the mapping relationship, it can be determined that when the second position information in the corresponding reference coordinate system is (2, 1), it is necessary to move the preset point of the motion stage to the position of the corresponding reference coordinate system (4, 3). To determine the moving direction and moving distance of the motion stage.

[0057] When the moving stage moves to the third position indicated by the third position control signal, the alignment fine-tuning step is completed, and the image of the object to be measured on the moving stage is aligned with the center of the field of view of the second sensor 11. At this time, the complete image of the object to be measured can be obtained by the first sensor 10 or the second sensor 11.

[0058] The imaging-based alignment method provided in the embodiment of the present application realizes the alignment of the optimal imaging position of the object to be measured through the cooperation among the motion stage, the motion controller, the first sensor 10, the second sensor 11 and the data processing system. Compared with the method in the prior art that needs to align by moving the workpiece stage and collecting the energy signal detected by the sensor, it does not need to move the motion stage multiple times, thus reducing the cumulative error and improving the accuracy of the alignment process.

[0059] In one embodiment of the present application, an image processing algorithm is pre-set by a data processor to execute the position information calculation method. Figure 5 , is a flow chart of a method for calculating location information provided in an embodiment of the present application, the method comprising:

[0060] S501. Generate a first discrete signal and a second discrete signal according to a target area image corresponding to a preset mark in an image, wherein the first discrete signal represents the sum of the grayscale values ​​of each column of pixels in the target area image, and the second discrete signal represents the sum of the grayscale values ​​of each row of pixels in the target area image.

[0061] Figure 6 A schematic diagram of a target area image provided for an embodiment of the present application. The image here refers to one of the first image or the second image. It can be understood that the white border is the imaging corresponding to the preset mark. The target area image here can be a rectangular area on the target image including the white border. The target area image here can be a complete image captured by the first sensor 10 or the second sensor 11, or a partial image thereof. When the target area image is a partial image, the resource consumption of the data processor can be reduced and the efficiency of calculating the position information can be improved.

[0062] Specifically, the first sensor or the second sensor here may be a black-and-white CCD camera, and the acquired first image or the acquired second image includes the grayscale values ​​of all pixels in the image.

[0063] The process of generating discrete signals can be understood as the process of projecting and summing the target area image. Figure 7 , which is a schematic diagram of a discrete signal provided by an embodiment of the present application. The target area image is projected and summed in two directions to obtain a first discrete signal and a second discrete signal. For example, if the gray value matrix is:

[0064]

[0065] The obtained first discrete signal can be expressed as X={x1=250, x2=510, x3=250}, and the second discrete signal can be expressed as Y={y1=255, y2=500, y3=255}.

[0066] S502: for each discrete signal, respectively determine two peak coordinate points of the discrete signal and a preset number of sample coordinate points corresponding to each peak coordinate point.

[0067] like Figure 7 As shown in the discrete signals, each discrete signal includes two peaks, one on the left and the other on the left. The peak coordinate point here indicates the coordinate point corresponding to the maximum value of the discrete signal at the peak. For example, when the first discrete signal X = {x1 = 0, x2 = 0, x3 = 500, x4 = 255, x5 = 255, x6 = 255, x7 = 500, x8 = 0, x9 = 0}, the first peak coordinate point (3, 500) on the left half of the discrete signal and the second peak coordinate point (7, 500) on the right half of the discrete signal can be determined.

[0068] S503 . For each wave peak coordinate point, based on a preset number of sample coordinate points corresponding to the wave peak coordinate point, generate a curve equation corresponding to the wave peak coordinate point.

[0069] Specifically, a preset number of sample coordinate points corresponding to each peak coordinate point is determined in the following manner: a first horizontal coordinate is determined according to the current peak coordinate point; based on the first horizontal coordinate, a second horizontal coordinate and a third horizontal coordinate are determined according to a first preset step size, the second horizontal coordinate is smaller than the first horizontal coordinate, and the first horizontal coordinate is smaller than the third horizontal coordinate; and based on the first horizontal coordinate, a fourth horizontal coordinate and a fifth horizontal coordinate are determined according to a second preset step size, the fourth horizontal coordinate is smaller than the second horizontal coordinate, the third horizontal coordinate is smaller than the fifth horizontal coordinate, and the first preset step size is smaller than the second preset step size, and five sample coordinate points of each horizontal coordinate on the discrete signal corresponding to the current peak coordinate point are determined respectively.

[0070] For example, taking the first wave peak coordinate point (3, 500) as an example, the first horizontal coordinate is determined to be 3, then according to the first preset step size of 1 and the second preset step size of 2, the second horizontal coordinate can be determined to be 2, the third horizontal coordinate is 4, the fourth horizontal coordinate is 1, and the fifth horizontal coordinate is 5. Thus, the five sample coordinate points are determined to be S1 (1, 0), S2 (2, 0), S3 (3, 500), S4 (4, 255) and S5 (5, 255).

[0071] S504: Determine the coordinates of the center point according to the curve equation corresponding to the wave peak coordinate point.

[0072] In this step, firstly, the curve equation corresponding to the peak coordinate point is generated according to the five sample coordinate points.

[0073] Specifically, the curve equation can be expressed as Y = Ax 2+Bx+C, the curve equation includes a first coefficient and a second coefficient, and the step of determining the center point coordinates according to the curve equation corresponding to the peak coordinate point specifically includes:

[0074] According to the first coefficient and the second coefficient of the curve equation corresponding to the peak coordinate point, the mark value corresponding to the peak coordinate point is calculated according to the mark value calculation formula. According to the mark values ​​corresponding to all the peak coordinate points, the center point coordinates are generated.

[0075] A in the curve equation corresponding to the peak coordinate point is determined as the first coefficient, and B in the curve equation corresponding to the peak coordinate point is determined as the second coefficient. According to the first coefficient and the second coefficient, the mark value P corresponding to the peak coordinate point is calculated according to the mark value calculation formula, and the mark value calculation formula is:

[0076]

[0077] The mark value P corresponding to each wave peak coordinate point can be calculated by the above formula, which may be P1, P2, P3 and P4 here.

[0078] Wherein, P1 and P2 correspond to the first peak coordinate point of the left half and the second peak coordinate point of the right half of the first discrete signal respectively. P3 and P4 correspond to the third peak coordinate point of the left half and the fourth peak coordinate point of the right half of the second discrete signal respectively.

[0079] Next, generate the center point coordinates in the following way:

[0080] The first mean value between the mark values ​​corresponding to the two peak coordinate points of the first discrete signal is used as the horizontal coordinate of the center point coordinate, and the second mean value between the mark values ​​corresponding to the two peak coordinate points of the second discrete signal is used as the vertical coordinate of the center point coordinate to generate the center point coordinate.

[0081] It can be understood that here, the average of P1 and P2 is taken as X0, and the average of P3 and P4 is taken as Y0, so as to determine the final center coordinates (X0, Y0).

[0082] Based on the same inventive concept, an imaging-based alignment device corresponding to the imaging-based alignment method is also provided in the embodiment of the present application. Since the principle of solving the problem by the imaging-based alignment device in the embodiment of the present application is similar to the above-mentioned imaging-based alignment method in the embodiment of the present application, the implementation of the imaging-based alignment device can refer to the implementation of the method, and the repeated parts will not be repeated.

[0083] See also Figure 8 , Figure 8 This is a schematic diagram of the structure of an imaging-based alignment device provided in an embodiment of the present application. Figure 8As shown in , the imaging-based alignment device 800 includes:

[0084] A response module 810 is used to respond to the start instruction, generate a first position control signal and send it to the motion stage, so that the target surface of the object to be measured located on the motion stage moves to a first position indicated by the first position control signal;

[0085] The first generating module 820 is used to obtain a first image of the target surface at a first position after being magnified by a first multiple by the optical system, determine first position information of the target surface, generate a second position control signal and send it to the motion stage, so that the target surface moves to a second position indicated by the second position control signal;

[0086] The second generating module 830 is used to obtain a second image of the target surface at a second position after the optical system magnifies the target surface by a second factor, where the second factor is greater than the first factor, and to determine the second position information of the target surface to generate a third position control signal and send it to the motion stage so that the imaging of the target surface is aligned with the center of the field of view of the second sensor.

[0087] In a preferred embodiment, a preset mark is set on the target surface, and the position information of the target surface indicates the center point coordinates of the preset mark. The first generation module 820 or the second generation module 830 includes an algorithm module (not shown in the figure), and the algorithm module is used to determine the position information of the target surface in the following manner: according to the target area image corresponding to the preset mark in the image, a first discrete signal and a second discrete signal are generated, wherein the first discrete signal represents the sum of the grayscale values ​​of each column of pixel points in the target area image, and the second discrete signal represents the sum of the grayscale values ​​of each row of pixel points in the target area image; for each discrete signal, two peak coordinate points of the discrete signal and a preset number of sample coordinate points corresponding to each peak coordinate point are determined respectively; for each peak coordinate point, based on the preset number of sample coordinate points corresponding to the peak coordinate point, a curve equation corresponding to the peak coordinate point is generated; according to the curve equation corresponding to the peak coordinate point, the center point coordinates are determined.

[0088] In a preferred embodiment, the algorithm module is specifically used to generate a first discrete signal and a second discrete signal in the following manner: determine the grayscale value of each pixel point in the target area image to generate a grayscale matrix; use the sum of the pixel points in each column of the grayscale matrix as the vertical coordinate and the column number of the column as the horizontal coordinate to generate the first discrete signal; use the sum of the pixel points in each row of the grayscale matrix as the vertical coordinate and the row number of the row as the horizontal coordinate to generate the second discrete signal.

[0089] In a preferred embodiment, the algorithm module is specifically used to: determine a preset number of sample coordinate points corresponding to each peak coordinate point in the following manner: determine a first horizontal coordinate according to the current peak coordinate point; based on the first horizontal coordinate, determine a second horizontal coordinate and a third horizontal coordinate according to a first preset step size, the second horizontal coordinate is smaller than the first horizontal coordinate, and the first horizontal coordinate is smaller than the third horizontal coordinate; based on the first horizontal coordinate, determine a fourth horizontal coordinate and a fifth horizontal coordinate according to a second preset step size, the fourth horizontal coordinate is smaller than the second horizontal coordinate, and the third horizontal coordinate is smaller than the fifth horizontal coordinate; respectively determine five sample coordinate points of each horizontal coordinate on the discrete signal corresponding to the current peak coordinate point.

[0090] In a preferred embodiment, the curve equation includes a first coefficient and a second coefficient, and the algorithm module is specifically used to: calculate the mark value corresponding to the peak coordinate point according to the first coefficient and the second coefficient of the curve equation corresponding to the peak coordinate point according to the mark value calculation formula; generate the center point coordinates according to the mark values ​​corresponding to all the peak coordinate points.

[0091] In a preferred embodiment, the algorithm module is specifically used to generate the center point coordinates in the following manner: using the first mean value between the mark values ​​corresponding to the two peak coordinate points of the first discrete signal as the horizontal coordinate of the center point coordinates, and using the second mean value between the mark values ​​corresponding to the two peak coordinate points of the second discrete signal as the vertical coordinate of the center point coordinates to generate the center point coordinates.

[0092] In a preferred embodiment, it also includes an acquisition module (not shown in the figure) for generating a first image acquisition signal and sending it to the first image acquisition chip to acquire the first image captured by the first sensor; and generating a second image acquisition signal and sending it to the second image acquisition chip to acquire the second image captured by the second sensor.

[0093] See also Fig. 9 , Fig. 9 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Fig. 9 As shown in , the electronic device 900 includes a processor 910 , a memory 920 , and a bus 930 .

[0094] The memory 920 stores machine-readable instructions executable by the processor 910. When the electronic device 900 is running, the processor 910 communicates with the memory 920 via the bus 930. When the machine-readable instructions are executed by the processor 910, the above-mentioned Figure 1 The specific implementation of the steps of the imaging-based alignment method in the method embodiment shown can be found in the method embodiment, and will not be described in detail here.

[0095] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned imaging-based alignment method can be executed. The specific implementation method can be found in the method embodiment, which will not be repeated here.

[0096] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0097] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0098] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0099] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0100] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile computer-readable memory that can be executed by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a memory and includes a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned memory includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0101] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An imaging-based alignment method, characterized in that: The alignment method comprises: In response to the start instruction, a first position control signal is generated and sent to the motion stage, so that the target surface of the object to be measured located on the motion stage moves to a first position indicated by the first position control signal; Acquire a first image of a target surface at a first position after being magnified by a first multiple by an optical system, determine first position information of the target surface, generate a second position control signal and send it to the motion stage, so that the target surface moves to a second position indicated by the second position control signal; Acquire a second image of the target surface at a second position after being magnified by the optical system by a second factor, wherein the second factor is greater than the first factor, determine second position information of the target surface, generate a third position control signal and send it to the motion stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor; A preset mark is set on the target surface, and the position information of the target surface indicates the center point coordinates of the preset mark. The center point coordinates of the target surface are determined by the following method: Generate a first discrete signal and a second discrete signal according to a target area image corresponding to a preset mark in the image, wherein the first discrete signal represents the sum of the grayscale values ​​of each column of pixels in the target area image, and the second discrete signal represents the sum of the grayscale values ​​of each row of pixels in the target area image; For each discrete signal, two peak coordinate points of the discrete signal and a preset number of sample coordinate points corresponding to each peak coordinate point are determined respectively; For each wave peak coordinate point, based on a preset number of sample coordinate points corresponding to the wave peak coordinate point, generate a curve equation corresponding to the wave peak coordinate point; The center point coordinates are determined based on the curve equation corresponding to the peak coordinate point.

2. The alignment method according to claim 1, characterized in that: The first discrete signal and the second discrete signal are generated by: Determine the grayscale value of each pixel of the target area image to generate a grayscale matrix; The sum of the pixels in each column of the gray matrix is ​​used as the ordinate, and the column number of the column is used as the abscissa to generate a first discrete signal; The sum of the pixel points in each row of the gray matrix is ​​used as the ordinate, and the row number of the row is used as the abscissa to generate a second discrete signal.

3. The alignment method according to claim 1, characterized in that: The preset number of sample coordinate points corresponding to each peak coordinate point is determined by: Determine the first horizontal coordinate according to the current wave peak coordinate point; Based on the first horizontal coordinate, determine a second horizontal coordinate and a third horizontal coordinate according to a first preset step size, wherein the second horizontal coordinate is smaller than the first horizontal coordinate, and the first horizontal coordinate is smaller than the third horizontal coordinate; Based on the first horizontal coordinate, a fourth horizontal coordinate and a fifth horizontal coordinate are determined according to a second preset step length, the fourth horizontal coordinate is smaller than the second horizontal coordinate, the third horizontal coordinate is smaller than the fifth horizontal coordinate, and the first preset step length is smaller than the second preset step length; Five sample coordinate points of each abscissa on the discrete signal corresponding to the current peak coordinate point are determined respectively.

4. The alignment method according to claim 1, characterized in that: The curve equation includes a first coefficient and a second coefficient. The step of determining the coordinates of the center point according to the curve equation corresponding to the peak coordinate point specifically includes: Calculate the mark value corresponding to the peak coordinate point according to the first coefficient and the second coefficient of the curve equation corresponding to the peak coordinate point according to the mark value calculation formula; Generate the center point coordinates according to the mark values ​​corresponding to all the peak coordinate points.

5. The alignment method according to claim 4, characterized in that: The center point coordinates are generated in the following way: The first mean value between the mark values ​​corresponding to the two peak coordinate points of the first discrete signal is used as the horizontal coordinate of the center point coordinate, and the second mean value between the mark values ​​corresponding to the two peak coordinate points of the second discrete signal is used as the vertical coordinate of the center point coordinate to generate the center point coordinate.

6. The alignment method according to claim 1, characterized in that: Get the image by: Generate a first image acquisition signal and send it to a first image acquisition chip to acquire the first image captured by the first sensor; And generate a second image acquisition signal and send it to the second image acquisition chip to acquire the second image captured by the second sensor.

7. An imaging-based alignment device, characterized in that: include: A response module, used for responding to the start instruction, generating a first position control signal and sending it to the motion stage, so that the target surface of the object to be measured located on the motion stage moves to a first position indicated by the first position control signal; A first generating module is used to obtain a first image of a target surface at a first position after being magnified by a first multiple by an optical system, determine the first position information of the target surface, generate a second position control signal and send it to the motion stage, so that the target surface moves to a second position indicated by the second position control signal, a preset mark is set on the target surface, and the position information of the target surface indicates the center point coordinates of the preset mark, and the center point coordinates of the target surface are determined in the following manner: according to the target area image corresponding to the preset mark in the image, a first discrete signal and a second discrete signal are generated, wherein the first discrete signal represents the sum of the grayscale values ​​of each column of pixel points in the target area image, and the second discrete signal represents the sum of the grayscale values ​​of each row of pixel points in the target area image; for each discrete signal, two peak coordinate points of the discrete signal and a preset number of sample coordinate points corresponding to each peak coordinate point are determined respectively; for each peak coordinate point, based on the preset number of sample coordinate points corresponding to the peak coordinate point, a curve equation corresponding to the peak coordinate point is generated; according to the curve equation corresponding to the peak coordinate point, the center point coordinates are determined; The second generating module is used to obtain a second image of the target surface at a second position after being magnified by the optical system by a second factor, wherein the second factor is greater than the first factor, and determine the second position information of the target surface to generate a third position control signal and send it to the moving stage, so that the imaging of the target surface is aligned with the center of the field of view of the second sensor.

8. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor communicates with the memory via the bus, and the processor executes the machine-readable instructions to perform the steps of the imaging-based alignment method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the imaging-based alignment method according to any one of claims 1 to 6 are executed.

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