CN115661483A

CN115661483A - Method, device, storage medium and electronic equipment for identifying Kelvin probe center

Info

Publication number: CN115661483A
Application number: CN202211417479.XA
Authority: CN
Inventors: 蔡超鹏; 陈思乡; 杨奉利; 梁思文; 戴啟辉
Original assignee: Hangzhou Changchuan Technology Co Ltd
Current assignee: Hangzhou Changchuan Technology Co Ltd
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2023-01-31
Anticipated expiration: 2042-11-14
Also published as: CN115661483B

Abstract

The application discloses a method, a device, a storage medium and an electronic device for identifying Kelvin probe centers. Wherein, the method comprises the following steps: determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image; screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set; and constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line. The application solves the technical problem that the center of the double needle is difficult to locate by identifying the needle point due to the fact that the luminous needle point becomes small or disappears as the needle point is easy to wear, oxidize or can accumulate dirt under the condition of long-time use of the Kelvin needle.

Description

Method, device, storage medium and electronic equipment for identifying Kelvin probe center

Technical Field

The present application relates to the field of visual images, and in particular, to a method, an apparatus, a storage medium, and an electronic device for identifying a kelvin probe center.

Background

With the increasing demands of modern electronic devices on miniaturization, light weight, high performance, multiple functions, low power consumption and low cost, the feature size of IC chips is continuously reduced, the integration scale is rapidly enlarged, the chip packaging technology is also continuously improved, bump process flow (Bump wafer) is also developed, bump wafer testing is increasingly popular, and Bump wafer testing requires special probes for needle punching testing, wherein kelvin probes are also commonly used Bump test probes. In the testing process, the probe needs to be aligned, the position of the probe is determined, and in the aligning process, the coordinate position of the bump is determined on one hand, and the coordinate position of the probe is determined on the other hand.

The Kelvin double needle consists of two needles, the conventional Kelvin double needle point is obviously shiny, but under the condition that the Kelvin probe is used for a long time, the needle point is easily abraded, oxidized or dirt is accumulated, so that the shiny needle point is reduced or disappeared. Therefore, the needle point is difficult to determine the center of the double needle by positioning, and the related art does not have an algorithm for Kelvin double needle identification of needle point abrasion, oxidation or dirt accumulation.

In view of the above problems, no effective solution has been proposed.

Disclosure of Invention

The embodiment of the application provides a method, a device, a storage medium and an electronic device for identifying a Kelvin probe center, so as to at least solve the technical problem that under the condition that a Kelvin probe is used for a long time, a needle point is easy to wear, oxidize or dirt is accumulated, a luminous needle point becomes small or disappears, and the double-needle center is difficult to locate by identifying the needle point.

According to an aspect of the embodiments of the present application, there is provided a method of identifying a kelvin probe center, including: determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image; screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set; and constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line.

Optionally, the first contour point constructs a first straight line, and the second contour point constructs a second straight line, including: respectively taking the first contour point and the second contour point as reference, and determining and screening out a third contour point which is away from the end part of the second probe by a third distance in the first contour point set and a fourth contour point which is away from the end part of the first probe by a fourth distance in the second contour point set, wherein the first distance is smaller than the third distance, and the second distance is smaller than the fourth distance; obtaining a first straight line according to the first contour point and the third contour point; and obtaining a second straight line according to the second contour point and the fourth contour point.

Optionally, determining a center point of the kelvin probe based on the first straight line and the second straight line comprises: moving the first straight line for a preset distance along the first probe to obtain a third straight line intersecting with two sides of the first probe; moving the second straight line for a preset distance along the second probe to obtain a fourth straight line intersecting with two sides of the second probe; and determining the central point of the Kelvin probe based on the third straight line and the fourth straight line.

Optionally, determining the center point of the kelvin probe based on the third line and the fourth line comprises: respectively acquiring a first central point corresponding to the third straight line and a second central point corresponding to the fourth straight line; and determining the central point of a connecting line between the first central point and the second central point as the central point of the Kelvin probe.

Optionally, determining the first probe and the second probe in the kelvin probe image comprises: acquiring the central position of a Kelvin probe image; identifying a connected domain in the Kelvin probe image, and determining the connected domain closest to the center position as a first probe; and determining the connected domain closest to the first probe as the second probe.

Optionally, before identifying the connected component in the kelvin probe image, the method further includes: and carrying out graying processing on the Kelvin probe image to obtain a grayscale image corresponding to the Kelvin probe image, and detecting whether the grayscale image meets the preset brightness requirement.

Optionally, identifying connected components in the kelvin probe image comprises: local adaptive threshold segmentation is carried out on the gray level image by using an adaptive threshold algorithm to obtain a target binary image; and calling a depth-first algorithm to determine a connected domain corresponding to the Kelvin probe image in the target binary image.

Optionally, detecting whether the gray-scale map meets a preset brightness requirement includes: determining a white part in the target binary image as a background picture in a gray scale image; and counting the area of the first image pixel corresponding to the pixel value of the background picture larger than the preset value, acquiring the area of the second image pixel corresponding to the binary image, calculating the ratio of the area of the first image pixel to the area of the second image pixel, and determining whether the gray-scale image meets the preset brightness requirement or not according to the ratio.

Optionally, determining whether the gray scale map meets the preset brightness requirement according to the ratio includes: determining that the gray scale image meets the preset brightness requirement under the condition that the ratio is greater than the preset ratio; and under the condition that the ratio is smaller than the preset ratio, determining that the gray scale map does not meet the preset brightness requirement.

According to another aspect of the embodiments of the present application, there is also provided an apparatus for identifying a kelvin probe center, including: the identification module is used for determining a first probe and a second probe in the Kelvin probe image, determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image; the screening module is used for screening out first contour points which are in a first distance with the end part of the second probe in the first contour point set and second contour points which are in a second distance with the end part of the first probe in the second contour point set; and the determining module is used for constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line.

According to another aspect of embodiments of the present application, there is also provided a nonvolatile storage medium including: the storage medium includes a stored program, wherein the apparatus on which the storage medium is located is controlled to perform any one of the methods of identifying a kelvin probe center when the program is run.

According to another aspect of the embodiments of the present application, there is also provided an electronic device, including: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute the instructions to implement any of the methods of identifying a kelvin probe center.

In the embodiment of the application, a needle body contour positioning mode is adopted, and a first contour point set corresponding to a first probe in an image and a second contour point set corresponding to a second probe in the image are determined by determining the first probe and the second probe in a Kelvin probe image; screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set; the center point of the Kelvin probe is determined based on the first straight line and the second straight line, and the purpose of accurately positioning the center of the Kelvin probe based on the outline of the needle body is achieved, so that the technical effect of avoiding the defect of the edge of the needle point from influencing the outline precision is achieved, and the technical problem that the center of a double needle of the Kelvin probe is difficult to position by identifying the needle point due to the fact that the needle point is easy to wear, oxidize or accumulate dirt under the condition that the Kelvin probe is used for a long time, the luminous needle point is reduced or disappears and the double-needle center is difficult to position by identifying the needle point is solved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic flow chart of a method of identifying Kelvin probe centers in accordance with an embodiment of the present application;

FIG. 2 is a schematic flow chart illustrating the construction of a first line from first contour points and a second line from second contour points according to some embodiments of the present disclosure;

FIG. 3 is a schematic flow chart of the determination of the center point of the Kelvin probe based on the first line and the second line in some alternative embodiments of the present application;

FIG. 4 is a schematic flow chart of an alternative method for determining the first probe and the second probe in the Kelvin probe image in the present application;

FIG. 5 is a schematic flow chart illustrating the identification of connected components in Kelvin probe images in an exemplary embodiment of the present application;

FIG. 6 is a flow chart of implementing Kelvin two-pin identification according to an embodiment of the application;

FIG. 7 is a gray scale view of a Kelvin probe according to an embodiment of the present application;

FIGS. 8a and 8b are background binary graphs of a Kelvin probe according to an embodiment of the present disclosure;

FIG. 9 is a first Kelvin probe edge profile according to an embodiment of the present application;

FIG. 10 is a second Kelvin probe edge profile according to an embodiment of the present application;

FIG. 11 is a graph of the first pair of edge point calculations for the Kelvin twin needle in accordance with an embodiment of the present application;

FIG. 12 is a diagram of the results of the Kelvin bi-pin second pair of edge point calculations according to an embodiment of the present application;

FIG. 13 is a schematic view of a distribution of a first line and a second line in an exemplary embodiment of the present application;

FIG. 14 is a diagram illustrating a distribution of a third line, a fourth line, a center point corresponding to the third line, and a center point corresponding to the fourth line in an exemplary embodiment of the present application;

FIG. 15 is a schematic view of the location of the center of a Kelvin probe in an exemplary embodiment of the present application;

FIG. 16 is a schematic diagram of an apparatus for identifying Kelvin probe centers according to an embodiment of the present application;

FIG. 17 shows a schematic block diagram of an example electronic device 170 that may be used to implement embodiments of the present application.

Detailed Description

In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein. Moreover, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

For the convenience of better understanding of the embodiments related to the present application, technical terms or partial terms that may be referred to in the present application are now explained:

the wafer test is to perform a probe test on each die on the chip, and a probe made of gold wire is mounted on the test head to contact with the contact on the die to test the electrical characteristics, and the unqualified die is marked with a mark. During testing, the wafer is held on a vacuum chuck and aligned with a thin probe electrical tester while the probe contacts each bond pad of the die. An electrical tester tests the circuit under the drive of the power supply and records the results. The number, sequence and type of tests are controlled by a computer program.

The kelvin probe is a non-contact nondestructive gas phase environment metal Surface Potential measuring technology based on vibration capacitance, and is used for measuring the Work Function (Work Function) or Surface Potential (Surface Potential) of a material. The method can be used for detecting the tiny change of the surface potential of the material caused by factors such as temperature, humidity, surface chemistry, electricity, mechanics, crystals, adsorption, film formation and the like in a gas phase environment, is a high-sensitivity surface electrochemical analysis technology, and is the only method capable of measuring the surface potential of the corrosion electrode in the gas phase environment. The Kelvin probe is divided into nine components of a vibration probe module, a sample electrode module, a sample environment module, a scanning movement control module, a signal acquisition and analysis module, a mechanical support module, a measurement control software module, a data analysis software module, a computer and the like.

Binary images refer to the situation that each pixel in an image has only two possible values or gray scale states, and people often represent binary images by black and white, B & W, and monochrome images. The binary image is that in the image, the gray levels are only two, and the gray value of any pixel point in the image is 0 or 255, which respectively represents black and white.

The self-adaptive threshold method calculates the local threshold value according to the brightness distribution of different areas of the image instead of the threshold value of the global image, so that different threshold values can be self-adaptively calculated for different areas of the image.

DFS is one of graph algorithms, and is a traversal algorithm for graphs and trees. The depth-first search is a classic algorithm in the graph theory, a corresponding topology sorting table of the target graph can be generated by using the depth-first search algorithm, and a plurality of related graph theory problems such as the maximum path problem and the like can be conveniently solved by using the topology sorting table. The DFS algorithm is typically implemented with a heap or stack to assist. The process is briefly that each possible branch path is deep until the branch path can not be deep any more, if dead routes are encountered, the branch path is retreated, if unexplored branch paths are encountered in the retreating process, the branch path is entered to continue deep, and each node can only visit once.

A connected domain, an area G on the complex plane, is called a single connected domain if a simple closed curve is made in any of the connected domain and the inside of the closed curve always belongs to G. A region is referred to as a multiply connected region if it is not a singly connected region.

The most common convex hull algorithm for convex hulls is the Graham scan method, and the idea of the Graham scan algorithm is based on the properties of the convex hull: solving a point p with the minimum y value in the N points; sorting the rest N-1 points according to the polar angle value of the point p; and traversing the sorted N-1 points, and only keeping the points which rotate anticlockwise.

In accordance with an embodiment of the present application, there is provided an embodiment of a method for identifying Kelvin probe centers, it is noted that the steps illustrated in the flowchart of the figure may be performed in a computer system such as a set of computer executable instructions and that while a logical order is illustrated in the flowchart, in some cases the steps illustrated or described may be performed in an order different than that presented herein.

Fig. 1 is a method for identifying a kelvin probe center according to an embodiment of the present application, as shown in fig. 1, the method including the steps of:

step S102, determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image;

it is to be understood that wherein the first set of contour points refers to a set of needle contour points of the first probe and the second set of contour points refers to a set of needle contour points of the second probe; the determination method of the needle body contour point includes but is not limited to: the convex hull algorithm is used for extracting the contour of the Kelvin probe, and the influence of the edge defect of the needle tip on the contour precision can be effectively avoided.

Step S104, screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set;

it should be noted that, the first contour point is a point in the first contour point set closest to the needle tip of the second probe, and similarly, the second contour point is a point in the second contour point set closest to the needle tip of the first probe, and it should be further noted that, in the screening process, the selectable distance calculation methods include, but are not limited to: euclidean distance, manhattan distance, chebyshev distance, etc.

Step S106, constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line;

it will be appreciated that a first line constructed from a first contour point is a line passing through the first contour point, and similarly, a second line constructed from a second contour point is a line passing through the second contour point.

In the method for identifying the center of the Kelvin probe, a first contour point set corresponding to the first probe in an image and a second contour point set corresponding to the second probe in the image are determined by determining the first probe and the second probe in an image of the Kelvin probe; screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set; the method comprises the steps of constructing a first straight line according to a first contour point, constructing a second straight line according to a second contour point, and determining the center point of the Kelvin probe based on the first straight line and the second straight line, so that the aim of accurately positioning the center of the Kelvin probe based on the contour of a needle body is achieved, the technical effect of avoiding the influence of the defect of the edge of the needle body on the precision of the contour is achieved, and the technical problem that the center of a double needle of the Kelvin probe is difficult to position by identifying the needle point due to the fact that the needle point is easy to wear, oxidize or can accumulate dirt under the condition that the Kelvin probe is used for a long time is solved.

Fig. 2 is a schematic flow chart of constructing a first straight line according to a first contour point and a second straight line according to a second contour point in some embodiments of the present application, as shown in fig. 2, the flow chart mainly includes the following steps:

s202, respectively taking the first contour point and the second contour point as reference, and determining a third contour point which is in the first contour point set and is at a third distance from the end part of the second probe, and a fourth contour point which is in the second contour point set and is at a fourth distance from the end part of the first probe, wherein the first distance is smaller than the third distance, and the second distance is smaller than the fourth distance;

s204, obtaining a first straight line according to the first contour point and the third contour point;

and S206, obtaining a second straight line according to the second contour point and the fourth contour point.

Optionally, the third contour point screened out with the first contour point as a center of circle, all contour points screened out within a preset radius range from the first contour point set with a preset radius as a search range, and then a point closest to the end (needle tip) of the second probe is determined as the third contour point from all contour points, and similarly, the fourth contour point screened out with the second contour point as a center of circle, all contour points screened out within a preset radius range from the second contour point set with a preset radius as a search range, and then a point closest to the end (needle tip) of the first probe is determined as the fourth contour point from all contour points.

It is easy to note that a unique first straight line may be determined based on the first contour point and the third contour point, and a unique second straight line may be determined based on the second contour point and the fourth contour point.

Fig. 3 is a schematic flow chart of determining the center point of the kelvin probe based on the first straight line and the second straight line in some alternative embodiments of the present application, and as shown in fig. 3, the process may be implemented by the following steps:

s302, the first straight line can be moved for a preset distance along the first probe to obtain a third straight line intersecting with two sides of the first probe;

s304, moving the second straight line for a preset distance along the second probe to obtain a fourth straight line intersecting with two sides of the second probe;

and S306, determining the central point of the Kelvin probe based on the third straight line and the fourth straight line.

It is easy to notice that after the first straight line is moved along the first probe by a preset distance, the first straight line intersects with two side edges of the probe body of the first probe to form two intersection points, and the third straight line is a straight line segment determined by the two intersection points. Similarly, the fourth straight line is a straight line segment determined by the two intersection points, and after the second straight line moves a preset distance along the second probe, the second straight line intersects with the two side edges of the second probe body to form the two intersection points.

Specifically, the determination of the center point of the kelvin probe based on the third straight line and the fourth straight line can be implemented as follows: the first central point corresponding to the third straight line and the second central point corresponding to the fourth straight line can be respectively obtained, then the central point of a connecting line between the first central point and the second central point is determined to be the central point of the Kelvin probe, it is easy to notice that the central point of the probe is identified in a contour positioning mode, the influence of the defect of the edge of the needle point on the contour precision is avoided, and further the technical problem that the shiny needle point becomes small or disappears and the double-needle center is difficult to position by identifying the needle point due to the fact that the needle point is easy to wear, oxidize or can accumulate dirt under the condition that the Kelvin probe is used for a long time is solved.

As another optional implementation manner, the central point of the kelvin probe is determined based on the third straight line and the fourth straight line, which may also be implemented in a manner that, specifically, a first central point corresponding to the third straight line and a second central point corresponding to the fourth straight line are obtained, and then the central positions of the first central line and the second central point are determined to be the centers of the kelvin probes.

As an alternative embodiment, fig. 4 is a schematic flowchart of a process for optionally determining a first probe and a second probe in a kelvin probe image in the present application, and as shown in fig. 4, the process may be implemented by the following steps, specifically:

s402, acquiring the central position of the Kelvin probe image;

s404, identifying a connected domain in the Kelvin probe image, and determining the connected domain closest to the center position as a first probe;

s406, determining the connected domain closest to the first probe as a second probe.

The connected component may be calculated by using a DFS algorithm, and the calculation method for measuring the distance between the center position and the connected component may be an euclidean distance, a manhattan distance, or a chebyshev distance, for example, the connected component closest to the center position may be calculated by using the euclidean distance.

It can be understood that, because the distance calculation methods of different dimensions may have different final results, in an embodiment of the present application, a plurality of distance calculation methods may be used to determine the connected domain closest to the center position, and then, the calculation methods under various distance calculation methods are combined to obtain the final connected domain closest to the center position.

In an optional embodiment, before identifying the connected component in the kelvin probe image, the method further includes: and carrying out graying processing on the Kelvin probe image to obtain a gray map corresponding to the Kelvin probe image, and detecting whether the gray map meets the preset brightness requirement.

Fig. 5 is a schematic flowchart of a process for identifying connected components in a kelvin probe image according to an exemplary embodiment of the present application, and as shown in fig. 5, the process may include the following steps:

s502, calling an adaptive threshold algorithm to perform local adaptive threshold segmentation on the gray level image to obtain a target binary image;

s504, calling a depth-first algorithm to determine a connected domain corresponding to the Kelvin probe image in the target binary image.

It should be noted that, the adaptive threshold segmentation is to adaptively calculate different thresholds according to the brightness distribution of different areas of the grayscale image, and the method is suitable for processing the image with uneven illumination. The threshold corresponding to a local area may be generally determined by calculating a mean, a median, and a gaussian weighted average of pixel points in a certain local area, where the threshold may be set according to an actual situation, and is not specifically limited in related embodiments of the present application.

In some embodiments of the present application, alternative adaptive threshold segmentation methods include, but are not limited to: local adaptive threshold segmentation (preferred), maximum entropy threshold segmentation, iterative threshold segmentation, otsu; the depth first algorithm includes, but is not limited to, the DFS algorithm.

Optionally, in order to effectively separate the needle body from the background picture and improve the accuracy of the recognition result, before the connected domain in the kelvin probe image is recognized, the kelvin probe image may be grayed to obtain a grayscale corresponding to the kelvin probe image, and whether the grayscale meets the preset brightness requirement is detected, and then other operations are performed after the preset brightness requirement is met.

Specifically, detecting whether the gray-scale image meets the preset brightness requirement can be realized by the following steps: determining a white part in the target binary image as a background picture in a gray scale image; counting the area of a first image pixel corresponding to the pixel value of the background picture larger than the preset value, obtaining the area of a second image pixel corresponding to the binary image, calculating the ratio of the area of the first image pixel to the area of the second image pixel, and determining whether the gray-scale image meets the preset brightness requirement according to the ratio.

In some embodiments of the present application, determining whether the gray scale map meets the preset brightness requirement according to the ratio includes: when the ratio is greater than the preset ratio, it is determined that the gray scale map meets the preset brightness requirement, and it is easy to notice that when the ratio is less than the preset ratio, it is determined that the gray scale map does not meet the preset brightness requirement.

For example, assuming that the predetermined value is 110, the area of the first image pixel of the background image larger than the predetermined value 110 is 10, and the area of the second image pixel is 60, because the ratio of the area of the background image to the area of the binary image is smaller than 1/5, it is determined that the background brightness is too dark, an early warning prompt is performed to remind to adjust the brightness, and when the needle body contour is adjusted to have a significant difference from the background, image recognition is performed again; if it is assumed that the predetermined value is still 110 at this time, the pixel value of the background picture is adjusted by the light, the area of the first image pixel of the background picture larger than the predetermined value 110 becomes 20, and the area ratio of the background picture to the binary image is larger than 1/5 at this time, it can be determined that the background brightness is normal, and the next segmentation operation is performed.

The above-described manner of adjusting the background luminance includes: manually adjusting the light source controller, calling an algorithm to automatically adjust the brightness and the like.

It is easy to notice that, in the above technical solution, a manner of fitting the contour of the needle body may be adopted, a straight line of the end portion of the double needle is constructed by the contour points of the end portion of the needle body, the straight line of the end portion of the needle body is deviated towards the inside of the needle body to obtain a straight line constructed by the side points of the needle body inside the needle body, a straight line connecting the double needles is constructed by the central point of the straight line after deviation, the central point of the straight line connecting the double needles is the central point of the double needles, compared with a manner of positioning the needle point, the method is more stable, and the centers of the kelvin double needles can be positioned regardless of whether the needle point is worn or not.

To facilitate better understanding of the technical solutions of the present application, a description will now be given with reference to a specific embodiment.

Fig. 6 is a schematic view of a flowchart of a method for identifying a kelvin probe center according to an embodiment of the present application, where the flowchart mainly includes the following steps as shown in fig. 6:

(1) And acquiring a focused Kelvin probe picture, and performing graying processing on the Kelvin probe picture to obtain a grayscale image as shown in FIG. 7.

(2) According to whether the background evaluation picture is too dark, segmenting a background binary image (namely, determining that a white part in the binary image is a background picture in a gray scale image), as shown in fig. 8a and 8b, positioning the background by using the white part of the binary image, calculating the number of pixels of which the statistical background pixel value exceeds a set value (optionally, the set value can be 110), if the number of pixels meets an image area which is greater than 1/5 (namely, a preset ratio), judging that the background brightness is normal (namely, counting that the pixel value of the background picture is greater than a first image pixel area corresponding to a preset value, acquiring a second image pixel area corresponding to the binary image, solving a ratio of the first image pixel area to the second image pixel area, and determining that the gray scale image meets the preset brightness requirement under the condition that the ratio is greater than the preset ratio), and entering step S3; if the number of the pixels does not meet the image area which is larger than 1/5 (the preset proportion), the gray-scale image is determined not to meet the preset brightness requirement, an alarm can be given, and then the brightness is adjusted until the number of the pixels which exceed the set value meets the condition that the number of the pixels exceeds 1/5.

It should be noted that the manner of adjusting the brightness when the background is too dark includes, but is not limited to: the light source controller is manually adjusted, for example, prompt information is sent to a user, the user is enabled to participate in adjustment or call a brightness adjustment algorithm, optionally, in the process of adjusting the brightness based on the brightness adjustment algorithm, the brightness value of the light source may be sequentially increased according to a predetermined step length (optionally, the step length may be 10), until the number of pixels exceeding a set value satisfies an image area greater than 1/5 (a preset ratio).

(3) And performing self-adaptive threshold segmentation on the obtained gray level image to obtain a connected domain of the dark needle body, and obtaining a needle body binary image.

Alternative adaptive threshold segmentation methods include, but are not limited to: local adaptive threshold segmentation, maximum entropy threshold segmentation, iterative threshold segmentation, and Otsu's method.

(4) And calling a depth-first DFS algorithm to determine a connected domain corresponding to the Kelvin probe image in the target binary image.

(5) And screening the needle body connected domain of the first probe closest to the central picture.

It should be noted that, the optional distance calculation methods include, but are not limited to: euclidean distance, manhattan distance, chebyshev distance.

(6) And screening the needle body communication domain of the second probe closest to the center of the needle body communication domain screened previously. In this process, alternative distance calculation methods include, but are not limited to: euclidean distance, manhattan distance, chebyshev distance.

(7) The contour of the two probe bodies can be extracted by the convex hull algorithm, and the contour of the probe bodies of the first probe and the second probe is extracted, as shown in fig. 9 and fig. 10, which are the contour map of the edge of the probe body of the first probe and the contour map of the edge of the probe body of the second probe respectively.

(8) A first contour point having a first distance from the end of the second probe in the first contour point set and a second contour point having a second distance from the end of the first probe in the second contour point set are screened out, and a first pair of edge points (which may also be referred to as a first edge point pair) is formed from the first contour point and the second contour point, as shown in fig. 11, which is a schematic diagram of the first pair of edge points. It should be noted that, in the process of determining the distance, the selectable distance calculation methods include, but are not limited to: euclidean distance, manhattan distance, chebyshev distance.

(9) Screening out a first contour point which is closest to the end part of the second probe in the first contour point set and a second contour point which is closest to the end part of the first probe in the second contour point set; then, with the first contour point and the second contour point as references, a third contour point closest to the end of the second probe except the first contour point in the first contour point set and a fourth contour point closest to the end of the first probe except the second contour point in the second contour point set are screened out, and a second pair of edge points (which may also be referred to as a second edge point pair) is formed according to the third contour point and the fourth contour point, as shown in fig. 12, which is a schematic diagram of the second pair of edge points.

Similarly, the distance calculation method used in the distance calculation process includes, but is not limited to: euclidean distance, manhattan distance, chebyshev distance.

(10) A first straight line is obtained according to the first contour point and the third contour point, a second straight line is obtained according to the second contour point and the fourth contour point, and fig. 13 is a distribution schematic diagram of the first straight line and the second straight line.

(11) Moving the first straight line for a preset distance along the first probe to obtain a third straight line intersecting with two sides of the first probe; moving the second straight line for a preset distance along the second probe to obtain a fourth straight line intersecting with two sides of the second probe; and respectively determining the center points of the third straight line and the fourth straight line, as shown in fig. 14, which are a distribution diagram of the third straight line, the fourth straight line, the center point corresponding to the third straight line, and the center point corresponding to the fourth straight line.

(12) Connecting the center points of the third straight line and the fourth straight line to obtain a straight line, calculating the center point of the straight line to be the center point of the Kelvin probe, and as shown in FIG. 15, the center of the Kelvin probe is the center point of a connecting line formed by connecting the center point of the third straight line and the center point of the fourth straight line, wherein FIG. 15 is a schematic diagram of the distribution position of the centers of the Kelvin probes.

Fig. 16 is a device for identifying a kelvin probe center according to an embodiment of the present application, as shown in fig. 16, the device including:

the recognition module 160 is configured to determine a first probe and a second probe in the kelvin probe image, determine a first contour point set corresponding to the first probe in the image, and determine a second contour point set corresponding to the second probe in the image;

the screening module 162 is configured to screen out a first contour point in the first contour point set, which is a first distance from the end of the second probe, and a second contour point in the second contour point set, which is a second distance from the end of the first probe;

and the determining module 164 is configured to construct a first straight line according to the first contour point, construct a second straight line according to the second contour point, and determine the center point of the kelvin probe based on the first straight line and the second straight line.

In the device, the identification module 160 is configured to determine a first probe and a second probe in a kelvin probe image, determine a first contour point set corresponding to the first probe in the image, and determine a second contour point set corresponding to the second probe in the image; the screening module 162 is configured to screen out a first contour point in the first contour point set, which is a first distance away from the end of the second probe, and a second contour point in the second contour point set, which is a second distance away from the end of the first probe; the determining module 164 is configured to construct a first straight line according to the first contour point, construct a second straight line according to the second contour point, and determine a center point of the kelvin probe based on the first straight line and the second straight line, so as to achieve the purpose of accurate positioning, thereby achieving the technical effect of avoiding the influence of the defect of the edge of the needle body on the contour precision, and further solving the technical problem that the center of the double needle is difficult to determine by positioning the needle tip because the needle tip is easily worn, oxidized or dirt is accumulated, so that the shiny needle tip becomes small or disappears.

According to another aspect of the embodiments of the present application, there is also provided a non-volatile storage medium including a stored program, wherein the apparatus in which the non-volatile storage medium is controlled when the program is running performs any one of the methods for identifying a kelvin probe center.

Specifically, the storage medium is used for storing program instructions of the following functions, and the following functions are realized:

determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image; screening out first contour points which are in a first distance from the end part of the second probe in the first contour point set and second contour points which are in a second distance from the end part of the first probe in the second contour point set; and constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line.

Alternatively, in the present embodiment, the storage medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the aforementioned storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the aforementioned.

An embodiment according to the present application provides an electronic device including: at least one processor; and a memory communicatively coupled to the at least one processor; wherein the memory stores instructions executable by the at least one processor to cause the at least one processor to perform any one of the above methods of identifying a kelvin probe center.

Optionally, the electronic device may further include a transmission device and an input/output device, wherein the transmission device is connected to the processor, and the input/output device is connected to the processor.

FIG. 17 shows a schematic block diagram of an example electronic device 170 that may be used to implement embodiments of the present application. Electronic devices are intended to represent various forms of digital computers, such as laptops, desktops, workstations, personal digital assistants, servers, blade servers, mainframes, and other appropriate computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions, are meant to be exemplary only, and are not meant to limit implementations of the applications described and/or claimed herein.

As shown in fig. 17, the apparatus 170 includes a computing unit 171, which can perform various appropriate actions and processes according to a computer program stored in a Read Only Memory (ROM) 172 or a computer program loaded from a storage unit 178 into a Random Access Memory (RAM) 173. In the RAM 173, various programs and data required for the operation of the device 170 may also be stored. The calculation unit 171, the ROM 172, and the RAM 173 are connected to each other by a bus 174. An input/output (I/O) interface 175 is also connected to bus 174.

Various components in device 170 are connected to I/O interface 175, including: an input unit 176 such as a keyboard, a mouse, and the like; an output unit 177 such as various types of displays, speakers, and the like; a storage unit 178 such as a magnetic disk, optical disk, or the like; and a communication unit 179 such as a network card, modem, wireless communication transceiver, and the like. The communication unit 179 allows the device 170 to exchange information/data with other devices via a computer network such as the internet and/or various telecommunication networks.

The computing unit 171 may be a variety of general and/or special purpose processing components having processing and computing capabilities. Some examples of the computing unit 171 include, but are not limited to, a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), various dedicated Artificial Intelligence (AI) computing chips, various computing units running machine learning model algorithms, a Digital Signal Processor (DSP), and any suitable processor, controller, microcontroller, and so forth. The calculation unit 171 performs the respective methods and processes described above. For example, in some embodiments, the method of identifying Kelvin probe centers may be implemented as a computer software program tangibly embodied in a machine-readable medium, such as storage unit 178. In some embodiments, some or all of the computer program may be loaded and/or installed onto the device 170 via the ROM 172 and/or the communication unit 179. When the computer program is loaded into RAM 173 and executed by computing unit 171, one or more steps of the method of identifying a kelvin probe center described above may be performed. Alternatively, in other embodiments, the computing unit 171 may be configured to perform the method of identifying the kelvin probe centers by any other suitable means (e.g., by means of firmware).

Various implementations of the systems and techniques described here above may be implemented in digital electronic circuitry, integrated circuitry, field Programmable Gate Arrays (FPGAs), application Specific Integrated Circuits (ASICs), application Specific Standard Products (ASSPs), system on a chip (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and/or combinations thereof. These various embodiments may include: implemented in one or more computer programs that are executable and/or interpretable on a programmable system including at least one programmable processor, which may be special or general purpose, receiving data and instructions from, and transmitting data and instructions to, a storage system, at least one input device, and at least one output device.

Program code for implementing the methods of the present application may be written in any combination of one or more programming languages. These program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, causes the functions/acts specified in the flowchart and/or block diagram to be performed. The program code may execute entirely on the machine, partly on the machine, as a stand-alone software package partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of this application, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

In the above embodiments of the present application, the descriptions of the respective embodiments have respective emphasis, and for parts that are not described in detail in a certain embodiment, reference may be made to related descriptions of other embodiments.

In the embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. The above-described embodiments of the apparatus are merely illustrative, and for example, the division of the units may be a logical division, and in actual implementation, there may be another division, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed coupling or direct coupling or communication connection between each other may be an indirect coupling or communication connection through some interfaces, units or modules, and may be electrical or in other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in the form of hardware, or may also be implemented in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a removable hard disk, a magnetic or optical disk, and other various media capable of storing program codes.

The foregoing is only a preferred embodiment of the present application and it should be noted that, as will be apparent to those skilled in the art, numerous modifications and adaptations can be made without departing from the principles of the present application and such modifications and adaptations are intended to be considered within the scope of the present application.

Claims

1. A method of identifying a kelvin probe center, comprising:

determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image;

screening out first contour points, which are in a first distance from the end part of the second probe, in the first contour point set and second contour points, which are in a second distance from the end part of the first probe, in the second contour point set;

and constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line.

2. The method of claim 1, wherein constructing a first line from the first contour points and a second line from the second contour points comprises:

respectively taking the first contour point and the second contour point as reference, and determining a third contour point which is in the first contour point set and is at a third distance from the end part of the second probe, and a fourth contour point which is in the second contour point set and is at a fourth distance from the end part of the first probe, wherein the first distance is smaller than the third distance, and the second distance is smaller than the fourth distance;

obtaining a first straight line according to the first contour point and the third contour point;

and obtaining a second straight line according to the second contour point and the fourth contour point.

3. The method of claim 2, wherein determining the center point of the kelvin probe based on the first line and the second line comprises:

moving the first straight line along the first probe for a preset distance to obtain a third straight line intersecting with two sides of the first probe;

moving the second straight line along the second probe by the preset distance to obtain a fourth straight line intersecting with two sides of the second probe;

determining a center point of the Kelvin probe based on the third straight line and the fourth straight line.

4. The method of claim 3, wherein determining the center point of the Kelvin probe based on the third line and the fourth line comprises:

respectively acquiring a first central point corresponding to the third straight line and a second central point corresponding to the fourth straight line;

and determining a central point of a connecting line between the first central point and the second central point as a central point of the Kelvin probe.

5. The method of claim 1, wherein determining the first probe and the second probe in the kelvin probe image comprises:

acquiring the central position of the Kelvin probe image;

identifying connected domains in the Kelvin probe image, and determining the connected domain closest to the center position as the first probe;

determining the nearest connected domain to the first probe as the second probe.

6. The method of claim 5, wherein prior to identifying connected components in the Kelvin probe image, the method further comprises:

and carrying out graying processing on the Kelvin probe image to obtain a grayscale image corresponding to the Kelvin probe image, and detecting whether the grayscale image meets a preset brightness requirement.

7. The method of claim 6, wherein identifying connected components in the Kelvin probe image comprises:

local adaptive threshold segmentation is carried out on the gray level image by calling an adaptive threshold algorithm to obtain a target binary image;

and calling a depth-first algorithm to determine a connected domain corresponding to the Kelvin probe image in the target binary image.

8. The method of claim 7, wherein detecting whether the gray scale map meets a predetermined brightness requirement comprises:

determining a white part in the target binary image as a background picture in the gray-scale image;

and counting a first image pixel area corresponding to the pixel value of the background picture larger than a preset value, acquiring a second image pixel area corresponding to the binary image, solving a ratio of the first image pixel area to the second image pixel area, and determining whether the gray-scale image meets a preset brightness requirement according to the ratio.

9. The method of claim 8, wherein determining whether the gray scale map meets a predetermined brightness requirement according to the ratio comprises:

determining that the gray scale image meets the preset brightness requirement under the condition that the ratio is greater than a preset ratio;

and under the condition that the ratio is smaller than the preset ratio, determining that the gray scale map does not meet the preset brightness requirement.

10. An apparatus for identifying a kelvin probe center, comprising:

the identification module is used for determining a first probe and a second probe in a Kelvin probe image, and determining a first contour point set corresponding to the first probe in the image and a second contour point set corresponding to the second probe in the image;

the screening module is used for screening out a first contour point which is away from the end part of the first probe by a first distance in the first contour point set and a second contour point which is away from the end part of the second probe by a second distance in the second contour point set;

and the determining module is used for constructing a first straight line according to the first contour point, constructing a second straight line according to the second contour point, and determining the central point of the Kelvin probe based on the first straight line and the second straight line.

11. A non-volatile storage medium, comprising a stored program, wherein the program, when executed, controls an apparatus in which the storage medium is located to perform the method for identifying a kelvin probe center according to any one of claims 1 to 9.

12. An electronic device, comprising:

a processor;

a memory for storing the processor-executable instructions;

wherein the processor is configured to execute the instructions to implement the method of identifying Kelvin probe centers as claimed in any of claims 1 to 9.