An imaging-based positioning method, device, electronic device and storage medium

Abstract

The present application provides an imaging-based positioning method, device, electronic device and storage medium. By responding to a start instruction, a first position control signal is generated and sent to an adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively; according to the determined first image set, a first target stroke value is determined; according to the first target stroke value, a second position control signal is generated and sent to the adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively; according to the determined second image set, a second target stroke value is determined. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets a preset clarity index value, so as to quickly and accurately determine the optimal focal plane position of the objective lens in the adjustable-focus objective lens of the optical system.

Description

Technical Field

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

[0002] In the prior art, it is necessary to adjust the position of the objective lens of an adjustable-focus objective lens. The conventional focusing method is to perform focusing step by step according to a step size. Applying this method to focus the objective lens in an optical system, especially when there are multiple magnified imaging optical paths with different magnification factors in the optical system, this method takes a lot of time and has low accuracy. Summary of the Invention

[0003] In view of this, the purpose of the present application is to provide an imaging-based positioning method, device, electronic device, and storage medium to quickly and accurately determine the optimal focal plane position of the objective lens in an adjustable-focus objective lens in an optical system of an optical imaging optical path.

[0004] In a first aspect, an embodiment of the present application provides an imaging-based positioning method applicable to an optical system. The optical system at least includes an adjustable-focus objective lens and an image sensor. The adjustable-focus objective lens moves the position of the objective lens according to a travel value. The positioning method includes: responding to a start instruction, generating a first position control signal and sending it to the adjustable-focus objective lens to move the objective lens to positions corresponding to a plurality of first predicted travel values indicated by the first position control signal respectively; determining a first target travel value according to the determined first image set, where the first image set is determined by a plurality of first images obtained when the objective lens is at positions corresponding to the plurality of first predicted travel values, and the first image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system; generating a second position control signal according to the first target travel value and sending it to the adjustable-focus objective lens to move the objective lens to positions corresponding to a plurality of second predicted travel values indicated by the second position control signal respectively; determining a second target travel value according to the determined second image set, where the second image set is determined by a plurality of second images obtained when the objective lens is at positions corresponding to the plurality of second predicted travel values, and the second image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system by a second magnification factor. When the objective lens is at the position corresponding to the second target travel value, the imaging clarity index value of the optical system satisfies a preset clarity index value.

[0005] Preferably, a preset mark is provided on the target surface. For each image set, the target travel value is determined in the following manner: determining the target region image corresponding to the preset mark on each image in the image set; for each target region image, calculating the clarity index value of the target region image; generating a preset fitting curve corresponding to the image set according to the clarity index value of each target region image and the predicted travel value corresponding to the target region image, where the preset fitting curve is used to represent the relationship between the clarity index value and the travel value; and determining the corresponding target travel value according to the preset fitting curve corresponding to the image set.

[0006] Preferably, the step of calculating the clarity index value of each target region image specifically includes: determining the gray value corresponding to each pixel point in the target region image, and determining the maximum gray value and the minimum gray value; and calculating the clarity index value of the target region image based on the maximum gray value and the minimum gray value according to the clarity index value calculation formula.

[0007] Preferably, the step of determining the corresponding target travel value according to the preset fitting curve corresponding to the image set specifically includes: using the travel value corresponding to the maximum clarity index value in the preset fitting curve corresponding to the image set as the corresponding target travel value.

[0008] Preferably, the multiple first predicted travel values indicated by the first position control signal are determined in the following manner: obtaining an initial travel value, and respectively determining four first predicted travel values that are at a first travel interval value and a second travel interval value away from the initial travel value; and using the initial travel value and the four first predicted travel values as the multiple first predicted travel values indicated by the first position control signal; where the first travel interval value is less than the second travel interval value.

[0009] Preferably, the multiple second predicted travel values indicated by the second position control signal are determined in the following manner: respectively determining four second predicted travel values that are at a third travel interval value and a fourth travel interval value away from the first target travel value; and using the first predicted focal plane position and the four second predicted travel values as the multiple second target travel values indicated by the second position control signal; where the third travel interval value is less than the fourth travel interval value, and the fourth travel interval value is less than the first travel interval value.

[0010] Preferably, before the step of calculating the clarity index value of each target region image, the method further includes: performing image noise reduction processing on each target region image.

[0011] In a second aspect, an imaging-based positioning device provided by an embodiment of the present application is applicable to an optical system. The optical system at least includes an adjustable-focus objective lens and an image sensor. The adjustable-focus objective lens moves the position of the objective lens according to a travel value. The positioning device includes:

[0012] A response module, configured to respond to a start instruction, generate a first position control signal and send it to the adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively;

[0013] A first prediction module, configured to determine a first target stroke value according to the determined first image set, wherein the first image set is determined by a plurality of first images obtained when the objective lens is at positions corresponding to a plurality of first predicted stroke values, and the first image is an image of the target surface of the object to be measured captured by an image sensor and magnified by an optical system;

[0014] A generation module, configured to generate a second position control signal according to the first target stroke value and send it to the adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively;

[0015] A second prediction module, configured to determine a second target stroke value according to the determined second image set, wherein the second image set is determined by a plurality of second images obtained when the objective lens is at positions corresponding to a plurality of second predicted stroke values, and the second image is an image of the target surface of the object to be measured captured by an image sensor and magnified by an optical system. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets a preset clarity index value.

[0016] In a third aspect, an embodiment of the present application further provides an electronic device, including: a processor, a memory, and a bus. The memory stores machine-readable instructions executable by the processor. When the electronic device runs, the processor communicates with the memory through the bus, and the processor executes the machine-readable instructions to perform the steps of the above imaging-based positioning method.

[0017] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is run by a processor, it performs the steps of the above imaging-based positioning method.

[0018] An imaging-based positioning method, device, electronic device, and storage medium provided by an embodiment of the present application are applicable to an optical system including an adjustable-focus objective lens and an image sensor. By responding to a start instruction, a first position control signal is generated and sent to the adjustable-focus objective lens, causing the objective lens to move to positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively, so as to obtain first images of the object to be measured magnified and imaged by the first magnification imaging optical path in the optical system at positions corresponding to each first predicted stroke value. According to the determined first image set, a first target stroke value is determined. According to the first target stroke value, a second position control signal is generated and sent to the adjustable-focus objective lens, causing the objective lens to move to positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively, so as to obtain second images of the object to be measured magnified and imaged by the second magnification imaging optical path in the optical system at positions corresponding to each second predicted stroke value. According to the determined second image set, a second target stroke value is determined. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets a preset clarity index value, thereby quickly and accurately determining the optimal focal plane position of the objective lens in the adjustable-focus objective lens in the optical system.

[0019] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specifically gives preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required in the embodiments. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0021] Figure 1 A schematic diagram of the imaging process of an optical system provided by an embodiment of the present application;

[0022] Figure 2 A flowchart of an imaging-based positioning method provided by an embodiment of the present application;

[0023] Figure 3 A flowchart of an image-based stroke value calculation method provided by an embodiment of the present application;

[0024] Figure 4 A schematic diagram of a target area image provided by an embodiment of the present application;

[0025] Figure 5 A schematic diagram of another target area image provided by an embodiment of the present application;

[0026] Figure 6 A schematic structural diagram of a positioning device based on imaging provided by an embodiment of the present application;

[0027] Figure 7 A schematic structural diagram of an electronic device provided by an embodiment of the present application. Detailed implementation manners

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It should be understood that the accompanying drawings in the present application are only for the purposes of illustration and description, and are not used to limit the protection scope of the present application. In addition, it should be understood that the schematic drawings are not drawn to actual scale. The flowcharts used in the present application illustrate operations implemented according to some embodiments of the present application. It should be understood that the operations in the flowchart may not be implemented in sequence, and steps without logical context relationships may be reversed in order or implemented simultaneously. In addition, those skilled in the art may add one or more other operations to the flowchart or remove one or more operations from the flowchart under the guidance of the content of the present application.

[0029] In addition, the described embodiments are only some embodiments of the present application, rather than all embodiments. The components of the embodiments of the present application usually described and illustrated in the accompanying drawings here may be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts fall within the protection scope of the present application.

[0030] In the prior art, it is necessary to adjust the position of the objective lens of an adjustable-focus objective lens. The conventional focusing method is to perform focusing step by step according to a step size. Applying this method to focus the objective lens in an optical system, especially when there are multiple magnified imaging optical paths with different magnification factors in the optical system, this method takes a lot of time and has low accuracy.

[0031] In view of the above problems, the embodiments of the present application provide an imaging-based positioning method, device, electronic device, and storage medium, which will be described below through embodiments.

[0032] To facilitate the understanding of the present application, the technical solutions provided by the present application will be described in detail below with reference to specific embodiments.

[0033] Please refer to Figure 1, which is a schematic diagram of the imaging process of an optical system provided by an embodiment of the present application. The optical system is used to magnify and image the target surface of a test object placed on a moving stage. 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 mirror 3 and an objective lens 4, and the second optical component includes a periscope lens 5, a first beam splitter prism 6, a second beam splitter prism 8, a tube lens 7, a magnifying lens 9, an illumination component 2, a first image sensor 10, and a second image sensor 11. The test object can be placed on the stage 1. The first optical component is respectively fixed at a preset position on the first mounting plate, the second optical component is respectively fixed at a preset position on 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 position corresponding to each optical device and the positional relationship between the optical devices are designed in advance, and only need to be installed according to the rules. The optical system can form two magnifying optical paths with different magnifications.

[0034] Among them, the stage 1 here can specifically be a position-controllable moving stage for placing the test object. The moving 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 moving stage to move in the horizontal plane according to the position control signal sent by the data processor. It should be noted that the relative distance between the moving stage and the plane mirror 3 remains unchanged in the vertical plane.

[0035] The test object here can be an optical workpiece with measurement marks. A preset mark is provided on one target surface of the optical workpiece. The preset mark here can be formed by a chrome plating process. The shape of the preset mark here can be a rectangular border or an irregularly shaped graphic, and is set at the center position on the target surface of the optical workpiece. It should be noted that part of the preset mark is opaque.

[0036] Specifically, the optical system here is a periscope system, where the magnification of the tube lens 7 is five times and the magnification of the magnifying lens 9 is ten times. The illumination component 2 is used to provide a light source and illuminate the test object.

[0037] The test object can reflect the light generated by the light source 2. The light passes through the adjustable-focus objective lens 4, the tube lens 7, or the tube lens 7 and the magnifying lens 9, and other optical devices, and finally forms an image on the first image sensor 10 or the second image sensor 11. The data processing system receives the images collected by the sensor, evaluates the imaging clarity, and thus determines the best focal plane of the objective lens 4.

[0038] Refer to Figure 1, the optical system can adopt an infinite conjugate microscope structure, mainly consisting of two parts: an objective lens and a tube lens. The light between the objective lens 4, the tube lens 7, and the magnifying lens 9 is approximately parallel light, and it is less sensitive to distance. Therefore, the objective lens group can be fixed as a whole on the mounting base. The adjustable focus objective lens that determines the clarity of the image is adjusted by a cam mechanism and a guiding mechanism.

[0039] Among them, the cam mechanism is used to convert rotational motion into linear motion. The guiding mechanism is used to move the objective lens axially. The objective lens and the mounting base are fixed on the micro guide rail to ensure the coaxiality of the optical axis. The objective lens controller can drive the motor to control the movement of the cam mechanism according to the determined stroke value, and control the objective lens to move axially to drive the objective lens to the optimal focal plane position.

[0040] The first image sensor 10 and the second image sensor 11 are used to obtain the images of the object to be measured reflected by the optical system. Taking an optical workpiece as an example, in the image obtained by the first image sensor 10, it is the image of the target surface of the optical workpiece magnified five times by the optical system. In the image obtained by the second image sensor 11, it is the image of the target surface of the optical workpiece magnified fifty times by the optical system. Specifically, the image sensor here can be a CCD camera.

[0041] The objective lens 4 here refers to the objective lens in the adjustable focus objective lens. The adjustable focus objective lens can drive the mounting base of the objective lens through a motor to control the position of the objective lens. Specifically, the adjustable focus objective lens can be connected to a data processor in a data processing system. The data processor can send a position control signal to the objective lens controller of the adjustable focus objective lens, and the objective lens controller drives the motor according to the position control signal to adjust the position of the objective lens in the specified axial direction, thereby changing the position of the focus of the objective lens. The vertical plane where the focus is located is the focal plane. The optimal focal plane position here refers to the position where the imaging clarity in the imaging optical paths with different magnification multiples of the optical system is the highest when the focal plane of the objective lens is at this position.

[0042] Figure 1 The label 12 in it indicates an electronic device equipped with a data processing system. This electronic device can be a computer and is used to execute the imaging-based positioning method of this application.

[0043] Please refer to Figure 2 , a kind of imaging-based positioning method provided by an embodiment of this application, which is applicable to an optical system. The optical system at least includes an adjustable focus objective lens and an image sensor. The adjustable focus objective lens moves the position of the objective lens according to the stroke value. The positioning method includes:

[0044] S101. In response to the start instruction, generate a first position control signal and send it to the adjustable focus objective lens, so that the objective lens moves to the positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively.

[0045] Here, a data processor can respond to a start instruction. The start instruction here is used to generate a first position control signal. The data processor determines a plurality of first predicted travel values according to a preset initial travel value Z0, and generates a first position control signal to move the adjustable focusing objective lens to positions corresponding to the plurality of first predicted travel values respectively. At the same time, the lighting component 2 should also be turned on.

[0046] The travel value here can indicate the position of the objective lens within a pre-calibrated travel range, that is, it can be the actual distance value between the objective lens and a certain point within the travel range, or a value obtained by converting the actual distance value according to a pre-calibrated conversion relationship. For example, when the travel value is 8, the actual distance may be 16mm or 8um.

[0047] Specifically, the number of the first predicted travel values can be five. Here, the following method can be used to determine the plurality of first predicted travel values indicated by the first position control signal:

[0048] Obtain the initial travel value, and respectively determine four first predicted travel values that are at a first travel interval value and a second travel interval value away from the initial travel value. Take the initial travel value and the four first predicted travel values as the plurality of first predicted travel values indicated by the first position control signal. Among them, the first travel interval value is less than the second travel interval value.

[0049] Exemplarily, first set the initial travel value Z0 to zero, and then, with the first travel interval value being 25um and the second travel interval value being 50um, within the range of Z0±50um, the five first predicted travel values are -25um, -50um, 0um, 25um, and 50um respectively.

[0050] S102. Determine a first target travel value according to the determined first image set, where the first image set is determined from a plurality of first images obtained when the objective lens is at positions corresponding to the plurality of first predicted travel values, and the first image is an image of the target surface of the object to be measured magnified by the optical system captured by the image sensor.

[0051] When the objective lens is at each position corresponding to a different first predicted travel value, a different first image is obtained. After the objective lens is respectively moved to positions corresponding to the five first predicted travel values, five images of the target surface of the object to be measured magnified by the optical system can be obtained first through the image sensor. Take these five images as the first image set.

[0052] Specifically, a first target stroke value can be determined according to the first image set through a preset image-based stroke value calculation method. The first target stroke value here indicates the stroke value that maximizes the clarity index value determined based on the clarity index of the images acquired by the image sensor. That is, when the objective lens is at this position, the imaging effect in the image sensor can be clearer.

[0053] S103. Generate a second position control signal according to the first target stroke value and send it to the adjustable focusing objective lens, so that the objective lens moves to the positions corresponding to multiple second predicted stroke values indicated by the second position control signal respectively.

[0054] Here, it is similar to the generation step of the first position control signal. First, multiple second predicted stroke values are determined according to the first target value Z1, and a second position control signal is generated, so that the adjustable focusing objective lens moves to the positions corresponding to the multiple second predicted stroke values respectively.

[0055] Specifically, the number of second predicted stroke values can be five. Here, the multiple second predicted stroke values indicated by the second position control signal can be determined in the following way:

[0056] Four second predicted stroke values at a distance of a third stroke interval value and a fourth stroke interval value from the first target stroke value are determined respectively. The first predicted focal plane position and the four second predicted stroke values are used as the multiple second target stroke values indicated by the second position control signal. Among them, the third stroke interval value is less than the fourth stroke interval value, and the fourth stroke interval value is less than the first stroke interval value.

[0057] Exemplarily, first determine the first target stroke value Z1, and then the third stroke interval value is 4um and the fourth stroke interval value is 8um. When Z1 is 10, within the range of Z1±8um, the five second predicted stroke values are determined to be 2um, 6um, 10um, 14um, and 18um respectively.

[0058] S104. Determine the second target stroke value according to the determined second image set. The second image set is determined from multiple second images obtained when the objective lens is at the positions corresponding to multiple second predicted stroke values. The second image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets the preset clarity index value.

[0059] When the objective lens is at the position corresponding to each different second predicted stroke value, a different second image is acquired. After the objective lens moves to the positions corresponding to the five second predicted stroke values respectively, five second images of the target surface of the object to be measured magnified by the optical system can be acquired first through the image sensor. These five different second images are used as the second image set.

[0060] Specifically, a second target travel value can be determined based on a preset image-based travel value calculation method according to the second image set. The second target travel value here indicates the travel value that maximizes the clarity index value determined based on the clarity index of the images acquired by the image sensor. That is, when the objective lens is moved to this position, the imaging effect in the image sensor can be kept clear at the same time.

[0061] Preferably, the second target travel value determined in the previous round can also be used as the initial travel value in the next round to iteratively execute the above steps S101 to S105, thereby improving the accuracy of positioning the position of the objective lens. For an Figure 1 optical system as shown, first, the above steps S101 to S105 are executed by the first image sensor 10 to complete the rough adjustment of the adjustable focus objective lens of the optical system, and then the above steps S101 to S105 are executed by the second image sensor 11 to complete the fine adjustment of the adjustable focus objective lens of the optical system. Compared with the existing technology, the technical solution of the present application can quickly and accurately adjust the focal length even when there are multiple optical paths with different magnification factors.

[0062] A positioning method based on imaging provided by an embodiment of the present application, by responding to a start instruction, generating a first position control signal and sending it to an adjustable focus objective lens, moving the objective lens to the positions corresponding to a plurality of first predicted travel values indicated by the first position control signal respectively, to obtain the first images of the magnified image of the object to be measured by the magnifying imaging optical path in the optical system at the positions corresponding to each first predicted travel value, determining a first target travel value according to the determined first image set, generating a second position control signal according to the first target travel value and sending it to the adjustable focus objective lens, moving the objective lens to the positions corresponding to a plurality of second predicted travel values indicated by the second position control signal respectively, to obtain the second images of the magnified image of the object to be measured by the magnifying imaging optical path in the optical system at the positions corresponding to each second predicted travel value, determining a second target travel value according to the determined second image set, when the objective lens is at the position corresponding to the second target travel value, the imaging clarity index value of the optical system meets a preset clarity index value, thereby determining the optimal focal plane position of the objective lens, so that the magnified image of the object to be measured by the magnifying imaging optical path in the optical system can be clearly obtained.

[0063] In an embodiment of the present application, an image-based travel value calculation method is proposed for determining a corresponding target travel value according to an image set. Please refer to Figure 3 , which is a flowchart of an image-based travel value calculation method provided by an embodiment of the present application. The method includes:

[0064] S201. Determine the target region image corresponding to the preset marker on each image in the image set.

[0065] As Figure 4 shown, it is a schematic diagram of a target region image provided by an embodiment of the present application. The target region image here refers to the part of the image captured by the sensor corresponding to the imaging of the preset marker on the object to be measured. Among them, Figure 4 the white part in is the imaging corresponding to the shape of the preset marker.

[0066] Preferably, Figure 5 it is another schematic diagram of a target region image provided by an embodiment of the present application. The target region image can be the target region image corresponding to the central region of the preset marker, that is, Figure 3 a part of the image region in. This can reduce the operation burden of the data processing system and thus improve the adjustment speed.

[0067] S202. For each target region image, calculate the clarity index value of the target region image.

[0068] Specifically, before the step of calculating the clarity index value of each target region image for each target region image, it further includes: for each target region image, performing image noise reduction processing on the target region image.

[0069] The noise reduction processing here can include resampling average processing and filtering processing, or other forms of denoising image processing. Calculating the clarity index value based on the denoised image can improve the accuracy of the clarity index value.

[0070] Specifically, the step of calculating the clarity index value of each target region image for each target region image specifically includes:

[0071] Determine the gray value corresponding to each pixel point in the target region image, and determine the maximum gray value and the minimum gray value. According to the clarity index value calculation formula, calculate the clarity index value of the target region image based on the maximum gray value and the minimum gray value.

[0072] In this step, a corresponding clarity index value can be calculated for each target region image. The clarity index value S here is used to evaluate the clarity of the image obtained by the sensor. The clarity index value is mainly calculated according to the maximum gray value and the minimum gray value of the target region image. The gray value range of each pixel point is 0-255. The clarity index value S calculation formula here is:

[0073]

[0074] Among them, gray max is the maximum gray value, graymin is the minimum gray value.

[0075] S203. Generate a preset fitting curve corresponding to the image set according to the clarity index value of each target region image and the predicted travel value corresponding to the target region image, where the preset fitting curve is used to represent the relationship between the clarity index value and the travel value.

[0076] Generate a preset fitting curve for the clarity index values of multiple target region images corresponding to each image set and the predicted travel value corresponding to the position where the objective lens is located when capturing the image. Among them, the abscissa of the preset fitting curve indicates the travel value corresponding to the objective lens, and the ordinate indicates the clarity evaluation value of the image captured by the current sensor at the position corresponding to the travel value of the objective lens.

[0077] It can be understood that the first image set and the second image set respectively correspond to different preset fitting curves.

[0078] S204. Determine the corresponding target travel value according to the preset fitting curve corresponding to the image set.

[0079] The step of determining the corresponding target travel value according to the preset fitting curve corresponding to the image set specifically includes:

[0080] Take the travel value corresponding to the maximum clarity index value in the preset fitting curve corresponding to the image set as the corresponding target travel value.

[0081] It can be understood that based on the mapping relationship between the travel value and the clarity evaluation value in the preset fitting curve, the travel value corresponding to the maximum clarity index value is selected as the target travel value. Thus, it can be determined what the travel value of the objective lens should be when the image captured by the current sensor has the best clarity. Furthermore, it can control the adjustable focus objective lens to move the objective lens to the position corresponding to the target travel value, so that after the object to be measured is magnified and imaged by the magnifying imaging optical path with different magnification multiples of the optical system, the imaging is clear.

[0082] Based on the same inventive concept, an imaging-based positioning device corresponding to the imaging-based positioning method is further provided in the embodiments of the present application. Since the principle of solving problems by the imaging-based positioning device in the embodiments of the present application is similar to that of the above imaging-based positioning method in the embodiments of the present application, the implementation of the device can refer to the implementation of the method, and the repeated parts will not be elaborated.

[0083] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of an imaging-based positioning device provided by an embodiment of the present application. As Figure 6As shown in [figure reference], the imaging-based positioning device 600 is applicable to an optical system, which at least includes a focusing objective lens and an image sensor. The focusing objective lens moves the position of the objective lens according to the stroke value. The positioning device 600 includes:

[0084] A response module 610, configured to respond to a start instruction, generate a first position control signal and send it to the focusing objective lens, so that the objective lens moves to the positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively;

[0085] A first prediction module 620, configured to determine a first target stroke value according to the determined first image set. The first image set is determined by a plurality of first images obtained when the objective lens is at the positions corresponding to a plurality of first predicted stroke values. The first image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system;

[0086] A generation module 630, configured to generate a second position control signal according to the first target stroke value and send it to the focusing objective lens, so that the objective lens moves to the positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively;

[0087] A second prediction module 640, configured to determine a second target stroke value according to the determined second image set. The second image set is determined by a plurality of second images obtained when the objective lens is at the positions corresponding to a plurality of second predicted stroke values. The second image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets the preset clarity index value.

[0088] In a preferred embodiment, a preset mark is set on the target surface. The first prediction module 620 or the second prediction module 640 is further configured to: determine the target region image corresponding to the preset mark on each image in the image set; for each target region image, calculate the clarity index value of the target region image; generate a preset fitting curve corresponding to the image set according to the clarity index value of each target region image and the predicted stroke value corresponding to the target region image. The preset fitting curve is used to represent the relationship between the clarity index value and the stroke value; determine the corresponding target stroke value according to the preset fitting curve corresponding to the image set.

[0089] In a preferred embodiment, the first prediction module 620 or the second prediction module 640 is specifically configured to: determine the gray value corresponding to each pixel point in the target region image, and determine the maximum gray value and the minimum gray value; calculate the clarity index value of the target region image based on the maximum gray value and the minimum gray value according to the clarity index value calculation formula.

[0090] In a preferred embodiment, the first prediction module 620 or the second prediction module 640 is specifically configured to: use the travel value corresponding to the maximum sharpness index value in the preset fitting curve corresponding to the image set as the corresponding target travel value.

[0091] In a preferred embodiment, the first prediction module 620 determines a plurality of first predicted travel values indicated by the first position control signal in the following manner: obtain an initial travel value, and respectively determine four first predicted travel values that are at a first travel interval value and a second travel interval value from the initial travel value; use the initial travel value and the four first predicted travel values as the plurality of first predicted travel values indicated by the first position control signal; wherein, the first travel interval value is less than the second travel interval value.

[0092] In a preferred embodiment, the second prediction module 640 determines a plurality of second predicted travel values indicated by the second position control signal in the following manner: respectively determine four second predicted travel values that are at a third travel interval value and a fourth travel interval value from the first target travel value; use the first predicted focal plane position and the four second predicted travel values as the plurality of second target travel values indicated by the second position control signal; wherein, the third travel interval value is less than the fourth travel interval value, and the fourth travel interval value is less than the first travel interval value.

[0093] In a preferred embodiment, before the step of calculating the sharpness index value of each target region image, the first prediction module 620 or the second prediction module 640 is further configured to: perform image denoising processing on each target region image.

[0094] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of an electronic device provided by an embodiment of the present application. As Figure 7 shown in, the electronic device 700 includes a processor 710, a memory 720, and a bus 730.

[0095] The memory 720 stores machine-readable instructions executable by the processor 710. When the electronic device 700 runs, the processor 710 communicates with the memory 720 through the bus 730. When the machine-readable instructions are executed by the processor 710, the steps of the imaging-based positioning method as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here.

[0096] An embodiment of the present application further provides a computer-readable storage medium. A computer program is stored on the storage medium. When the computer program is run by a processor, the steps of the imaging-based positioning method as described above can be executed. The specific implementation manner can refer to the method embodiment and will not be elaborated here.

[0097] 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 foregoing method embodiments and will not be elaborated herein.

[0098] In 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 illustrative. For example, the division of units is only a logical function division, and there may be other division methods in actual implementation. For another 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 displayed or discussed couplings or direct couplings or communication connections to each other can be through some communication interfaces, and the indirect couplings or communication connections of devices or units can be in electrical, mechanical, or other forms.

[0099] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, in each embodiment of the present application, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0101] 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 executable by a processor. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a memory and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods in each embodiment of the present application. The foregoing memory includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs that can store program codes.

[0102] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present application, used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions recorded in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; 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 all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An imaging-based positioning method, characterized in that, Applicable to an optical system, the optical system at least includes a focus-adjustable objective lens and an image sensor, the focus-adjustable objective lens moves the position of the objective lens according to a stroke value, and the positioning method includes: In response to a start instruction, generate a first position control signal and send it to the focus-adjustable objective lens, so that the objective lens moves to the positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively; According to the determined first image set, determine a first target stroke value, wherein the first image set is determined by a plurality of first images obtained when the objective lens is at the positions corresponding to a plurality of first predicted stroke values, and the first image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system; According to the first target stroke value, generate a second position control signal and send it to the focus-adjustable objective lens, so that the objective lens moves to the positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively; According to the determined second image set, determine a second target stroke value, wherein the second image set is determined by a plurality of second images obtained when the objective lens is at the positions corresponding to a plurality of second predicted stroke values, and the second image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system meets the preset clarity index value; A preset mark is set on the target surface. For each image set, the target stroke value is determined by the following method: Determine the target region image corresponding to the preset mark on each image in the image set; For each target region image, calculate the clarity index value of the target region image; According to the clarity index value of each target region image and the predicted stroke value corresponding to the target region image, generate a preset fitting curve corresponding to the image set, and the preset fitting curve is used to represent the relationship between the clarity index value and the stroke value; According to the preset fitting curve corresponding to the image set, determine the corresponding target stroke value.

2. The method according to claim 1, wherein The step of calculating the clarity index value of each target region image specifically includes: Determine the gray value corresponding to each pixel point in the target region image, and determine the maximum gray value and the minimum gray value; According to the clarity index value calculation formula, calculate the clarity index value of the target region image based on the maximum gray value and the minimum gray value.

3. The method according to claim 1, wherein The step of determining the corresponding target stroke value according to the preset fitting curve corresponding to the image set specifically includes: Take the stroke value corresponding to the maximum clarity index value in the preset fitting curve corresponding to the image set as the corresponding target stroke value.

4. The method according to claim 1, characterized in that, The multiple first predicted stroke values indicated by the first position control signal are determined by the following method: Obtain an initial stroke value, and respectively determine four first predicted stroke values at a first stroke interval value and a second stroke interval value away from the initial stroke value; Take the initial stroke value and the four first predicted stroke values as the multiple first predicted stroke values indicated by the first position control signal; Wherein, the first stroke interval value is less than the second stroke interval value.

5. The method according to claim 4, characterized in that, Determine a plurality of second predicted stroke values indicated by a second position control signal in the following manner: Respectively determine four second predicted stroke values that are at a third stroke interval value and a fourth stroke interval value from a first target stroke value; Use the first predicted focal plane position and the four second predicted stroke values as a plurality of second target stroke values indicated by the second position control signal; Wherein, the third stroke interval value is less than the fourth stroke interval value, and the fourth stroke interval value is less than the first stroke interval value.

6. The method according to claim 2, wherein Before calculating the clarity index value of each target region image for each target region image, further include: Perform image noise reduction processing on each target region image for each target region image.

7. An imaging-based positioning device, characterized in that, Applicable to an optical system, the optical system at least includes an adjustable-focus objective lens and an image sensor, the adjustable-focus objective lens moves the position of the objective lens according to a stroke value, and the positioning device includes: A response module, configured to respond to a start instruction, generate a first position control signal and send it to the adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of first predicted stroke values indicated by the first position control signal respectively; A first prediction module, configured to determine a first target stroke value according to the determined first image set, wherein the first image set is determined from a plurality of first images obtained when the objective lens is at positions corresponding to a plurality of first predicted stroke values, and the first image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system; A generation module, configured to generate a second position control signal according to the first target stroke value and send it to the adjustable-focus objective lens, so that the objective lens moves to positions corresponding to a plurality of second predicted stroke values indicated by the second position control signal respectively; A second prediction module, configured to determine a second target stroke value according to the determined second image set, wherein the second image set is determined from a plurality of second images obtained when the objective lens is at positions corresponding to a plurality of second predicted stroke values, and the second image is an image of the target surface of the object to be measured captured by the image sensor and magnified by the optical system. When the objective lens is at the position corresponding to the second target stroke value, the imaging clarity index value of the optical system satisfies a preset clarity index value; A preset mark is provided on the target surface. For each image set, the first prediction module and the second prediction module determine the target stroke value in the following manner: Determine the target region image corresponding to the preset mark on each image in the image set; For each target region image, calculate the clarity index value of the target region image; Generate a preset fitting curve corresponding to the image set according to the clarity index value of each target region image and the predicted stroke value corresponding to the target region image, and the preset fitting curve is used to represent the relationship between the clarity index value and the stroke value; Determine the corresponding target stroke value according to the preset fitting curve corresponding to the image set.

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 positioning method according to any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, A computer program is stored on the storage medium, and when the computer program is run by a processor, it performs the steps of the imaging-based positioning method according to any one of claims 1 to 6.

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