CN111652091A

CN111652091A - Method for detecting lamination compliance of cooling fins

Info

Publication number: CN111652091A
Application number: CN202010423895.5A
Authority: CN
Inventors: 杨振; 任宁; 蒋贵勤; 曹惠
Original assignee: Shanghai Heng Yi Intelligent Technology Co ltd
Current assignee: Shanghai Heng Yi Intelligent Technology Co ltd
Priority date: 2020-05-19
Filing date: 2020-05-19
Publication date: 2020-09-11
Anticipated expiration: 2040-05-19
Also published as: CN111652091B

Abstract

The method for detecting the lamination compliance of the cooling fins, provided by the invention, comprises the following steps: s1, setting the view finding direction of the image acquisition device, acquiring the side images of the stacked cooling fin group, performing binarization pretreatment to select characteristic areas on the side surfaces of the cooling fin group, intercepting the characteristic areas as template images, and inputting the template images into image recognition software; s2 positioning datum lines above and below the cooling fin group, and positioning the axis datum of the cooling fin group through matching of the axis positioning templates; s3 determining the deviation of the first feature in the image through the matching of the first feature module according to the reference line positioned in S2; presetting offset according to the reference line positioned in S2, selecting a quantity detection area, and counting the number of connected domains meeting the conditions according to a first operation rule; s4 sequences the connected domains identified in S3, determines the feature layer according to the number of layers of the cooling fin group where the first feature is preset, establishes a first feature matching area through preset offset so as to match with the first feature template, and obtains a key bit matching result.

Description

Method for detecting lamination compliance of cooling fins

Technical Field

The invention relates to the field of visual image processing, in particular to a method for detecting the lamination compliance of cooling fins with a specific lamination structure.

Background

The traditional Chiller (refrigeration system) relates to a press fitting process of cooling fins in the assembly production process, for example, the cooling fins are assembled according to the preset number of the cooling fins and the shapes of the cooling fins in a certain sequence.

However, such cooling fins usually have slight individual shape difference, so that errors are easily generated when the cooling fins are manually discharged in the machining process, and the defective rate is increased.

However, the existing visual image recognition technology is not common in the field of stacked cooling fin detection, and because the cooling fins are arranged closely in the stacking process and the characteristic points are fine, the accuracy rate of detecting the stacking compliance of the cooling fins by directly adopting the prior art is not high, and therefore the accuracy rate of detecting by waiting for a scheme in the field is improved.

Disclosure of Invention

The invention mainly aims to provide a method for detecting the lamination compliance of cooling fins, so as to improve the accuracy of the visual image processing technology on the lamination compliance detection of the cooling fins.

In order to achieve the above object, the present invention provides a method for detecting the lamination compliance of cooling fins, comprising the steps of:

s1 setting the view finding direction of the image acquisition device, obtaining the side image of the cooling fin group after the stack processing, and carrying out binarization preprocessing to select a characteristic region on the side of the cooling fin group, and intercepting the characteristic region as a template image to input image recognition software, wherein the template image comprises: an axis positioning template, a first characteristic template;

s2, acquiring a side image of the cooling fin group to be detected, performing binarization processing, positioning reference lines above and below the cooling fin group, and positioning the axis reference of the cooling fin group through axis positioning template matching;

s3, detecting the side images of the detected cooling fin group, and determining the left and right deviation of the first feature in the images through the matching of the first feature module according to the reference line positioned in the step S2; performing preset offset according to the datum line positioned in the step S2, selecting a number detection area, counting the number of connected domains meeting the conditions according to a first operation rule, and identifying the number of cooling plate groups;

wherein the first operation rule comprises: carrying out image binarization processing on the quantity detection area, and carrying out opening operation and closing operation in morphological analysis, wherein the steps comprise: opening the quantity detection areas by using a circular mask with a parameter radius of 1.5 pixels, then closing the obtained result by using a rectangular mask with 5 x 5 pixels, opening the result by using a rectangular mask with 30 x 3 pixels to divide the quantity detection areas to form a plurality of connected areas, and then screening the connected areas according to a preset size;

s4, sorting the connected domains identified in the step S3, determining feature layers according to the number of layers of the cooling fin group where the first feature is preset, establishing a first feature matching area through preset offset so as to match with the first feature template, and obtaining a key bit matching result.

Optionally, the steps further comprise:

s5, determining a verification region in the side image of the cooling fin group to be detected through preset deviation according to the axis reference of the cooling fin group and the reference lines above and below the cooling fin group, carrying out binarization processing, carrying out opening operation by using a circular mask with a parameter radius of 3.5 pixels, separating a connected region of a processing result into independent regions, screening the connected regions according to a preset size, and counting the number of the connected regions meeting the requirements for comparison and judgment with the preset number.

Optionally, the step of positioning the cooling fin group lower reference line comprises:

s2.1, coarse positioning, manually selecting a bottom positioning detection area of the cooling fin group, and performing binarization processing on the bottom positioning detection area;

s2.2, performing opening operation on the bottom positioning detection area by using a circular mask with a parameter radius of 1.5 pixels, and removing burrs/bulges;

and S2.3, separating the bottom positioning detection area processed in the step S2.2 into independent communication areas, performing characteristic screening according to a preset size, and then sequencing to select the independent communication area close to the upper part of the cooling fin group and set the independent communication area as a reference line below the cooling fin group.

Optionally, the step of positioning the upper datum line of the cooling fin group comprises:

s2.4, coarse positioning, manually selecting a top positioning detection area of the cooling fin group, and carrying out binarization processing on the top positioning detection area;

s2.5, the top positioning detection area is divided into different communication areas, the largest communication area is selected for opening operation, then an external rectangle of the communication area is selected, and the edge of the lowest position of the external rectangle is used as an upper datum line of the cooling fin group.

Preferably, step S4 further includes: and when the matching of the first characteristic template fails, shifting the preset pixel position again to obtain a second small detection area, and if the white area of the area is judged to be a connected domain larger than the preset pixel value, confirming that the matching is successful.

The method for detecting the lamination compliance of the cooling fins can effectively detect the lamination compliance of the cooling fins and further ensure the accuracy, greatly saves the detection time and labor cost compared with manual detection, integrally improves the detection efficiency, prevents the problem that the lamination is directly scrapped to cause waste because the error press-mounting semi-finished product continuously flows into the next process, effectively saves the cost, has the advantages of high accuracy, good stability, no fatigue after long-time work and the like in visual detection, and can greatly improve the productivity of a production line.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic flow chart illustrating the steps of fabricating a mold plate in the method for testing the lamination compliance of cooling fins according to the present invention;

FIG. 2 is a flowchart illustrating the overall steps of the method for detecting the lamination compliance of cooling fins according to the present invention;

FIG. 3 is a schematic view of a template image in the method for detecting the lamination compliance of cooling fins according to the present invention;

FIG. 4 is a schematic view of a datum line positioning process below a cooling plate stack;

FIG. 5 is a schematic view of a cooling fin set axis datum locating process;

FIG. 6 is a schematic view of a datum line locating process over a cooling plate stack;

FIG. 7 is a schematic view of a process for identifying the number of cooling fin groups;

FIG. 8 is a schematic view of a process for identifying the number of cooling fin groups;

FIG. 9 is a schematic view of a process for identifying the number of cooling fin groups;

FIG. 10 is a schematic view of a process for identifying the number of cooling fin groups;

FIG. 11 is a schematic diagram of a first feature template matching identification process;

fig. 12 is a schematic view of the number verification and identification of cooling fin assembly laminations.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

In order to make those skilled in the art better understand the technical solution of the present invention, the technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, shall fall within the scope of the present invention.

It should be noted that the terms "first", "second", "S1", "S2", and the like in the description and claims of the present invention and the above-described drawings are used for distinguishing similar objects 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 invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions.

In the present embodiment, the method for detecting the lamination compliance of cooling fins of the present invention is preferably described by taking the cooling fins with round-mouth and/or triangular-mouth feature points on the side as an example, but it should be understood by those skilled in the art that the foregoing feature points do not limit any implementation of the present invention, and those skilled in the art can implement the same implementation with the embodiments of the present invention according to different structures of the feature points on the cooling fins to be actually detected, so that any implementation manner that can be implemented under the same conditions by combining the detection schemes of the present invention to detect the side feature points of the cooling fins is within the disclosure and protection scope of the present invention.

Furthermore, the prior art Halcon algorithm library/software is preferred as the visual image processing technology used in the embodiments of the present invention, but it should be understood by those skilled in the art that the foregoing prior art visual image processing software is not limited to any implementation possibility of the present invention, and those skilled in the art can implement the embodiments of the present invention equally according to any possible or disclosed visual image processing technology/software, and therefore any equivalent implementation manner that can be implemented by using the prior art visual image processing technology and combining the embodiments of the present invention under the equal condition is within the disclosure and protection scope of the present invention.

Referring to fig. 1 to 12, the method for detecting the lamination compliance of cooling fins provided by the present invention includes the steps of:

in this embodiment, as shown in fig. 3, two triangular opening and round opening features exist on the qualified product of the cooling fin set, so the triangular opening feature is selected and established as the first feature template, and as shown in the figure, the cooling fin set has one more round opening feature at the lower part of the right side, so the axis positioning template is established by taking the 4 round opening features as references.

In this embodiment, the image recognition software is preferably Halcon software, so that after the parameters are initialized, the determined axis positioning template and the first characteristic template are input, and thus the template manufacturing is completed.

S2, acquiring a side image of the cooling fin group to be detected, performing binarization processing, positioning reference lines above and below the cooling fin group, and positioning the axis reference of the cooling fin group through axis positioning template matching; it should be noted that the positioning of the axis datum is mainly used for the positioning reference of the subsequent features, and therefore, as shown in fig. 5, in this embodiment, it is preferable that a row of a plurality of round mouth features with round notches on the last cooling fin at the bottom be used as the identification template, so that the axis datum of the cooling fin group is positioned here, and the offset calculation is convenient to perform subsequently.

Because the product position of the cooling fin group on the production line is relatively fixed, the error is slightly small, the detection region is scribed, binaryzation is carried out on the detection region, blob analysis is carried out, and the reference line below the cooling fin group can be obtained and positioned through gray scale, area and width characteristic detection, so that the step shown in fig. 4 comprises the following steps:

s2.1, coarse positioning, preferably manually selecting a bottom positioning detection area of the cooling fin group, and performing binarization processing on the bottom positioning detection area;

s2.3 separating the bottom positioning detection area processed in step S2.2 into independent connected areas, and sorting the independent connected areas after feature screening according to a preset size, so as to select the independent connected area close to the upper side of the cooling fin group and set the independent connected area as a reference line below the cooling fin group, wherein in this embodiment, the preset size of the screening is preferably: the width is greater than 300 pixels and the height is in the area between 5 and 30 pixels.

Because the positions of the cooling fin groups on the production line are relatively fixed and the error is slightly small, when the upper reference line of the cooling fin groups is positioned, the detection area can be actively drawn manually, so that blob analysis is performed, the detection area is detected through characteristics of gray scale, area and width, the area is subjected to morphological operation and calculation, fine bulges on the edge are removed, then a circumscribed rectangle is obtained for the processed area, namely the row number of the uppermost, lowermost, leftmost and rightmost rows of the area is obtained, and the row number of the lowermost point of the circumscribed rectangle is the obtained positioning upper reference position, so that the step shown in fig. 6 comprises the following steps:

And then, carrying out feature detection of a designated region on the side image of the cooling fin group, wherein the step is as follows:

s3 detecting the side image of the cooling fin group to be detected, and determining the first characteristic, namely the left and right deviation of the triangular opening in the image through the matching of the first characteristic module according to the reference line positioned in the step S2, so that on one hand, the front and back sides of the cooling fin group can be known, and the detection method can also be used for detecting whether the arrangement of the cooling fins is wrong; then, performing preset offset according to the datum line positioned in the step S2 to select a number detection area, counting the number of connected domains meeting the conditions according to a first operation rule, and identifying the number of cooling plate groups;

it should be noted that, as shown in fig. 7 to fig. 10, the first operation rule includes: carrying out image binarization processing on the quantity detection area, and carrying out opening operation and closing operation in morphological analysis, wherein the steps comprise: opening the quantity detection area by using a circular mask with the parameter radius of 1.5 pixels, and then closing the obtained result by using a rectangular mask with 5 multiplied by 5 pixels, wherein the step is to prevent the selected quantity detection area from being divided into two halves although the quantity detection area is at the same height due to the fact that some products are slightly bright;

then, performing opening operation on the result by using a rectangular mask with 30 multiplied by 3 pixels to cut off the links among different areas, dividing a number of detection areas to form a plurality of connected domains, and screening the connected domains according to a preset size; in the preferred embodiment, the connected component is divided into independent areas, and the connected component is screened by setting the width of the connected component to be more than 50 pixels, the height of the connected component to be more than 4 pixels and the area characteristic to be more than 400 pixels, so as to count the number of the connected components which finally meet the condition. Therefore, the number of the lamination sheets of the cooling sheet group can be counted, and whether the number of the cooling sheets is correct or not can be identified.

In order to further determine whether the key feature point in the cooling fin group exists, if the cooling fin group is 32 fins in the embodiment, and the key feature point may be located at the 19 th fin from last, the determining step includes:

s4 sequences each connected domain identified in step S3, and determines the feature layer according to the number of layers where the cooling fin group located is preset according to the first feature, for example, when the number of layers is 19, the position of the 19 th layer can be located according to the calculation result in step S3, and at the same time, a first feature matching region is established by presetting the offset, and the key bit matching result is obtained by matching with the first feature template.

As shown in fig. 11, for example, to determine whether there is a triangle feature in a specific position of the 19 th layer, it is first required to arrange the connected domains in S3 to determine the position of the layer number, so as to position the layer number according to the preset layer number, such as 19 layers, and then obtain the detection region of the inverted triangle by shifting, for example, the detection region is shifted by 522 pixels to the left according to the axis reference of the cooling plate group, draw a rectangle of 60 × 100 pixels, and perform the matching of the first feature template on the region, if the matching is successful, it is proved that the key feature point of the cooling plate group meets the requirement, if the matching fails, a second small detection region can be obtained by shifting the preset pixel position again, if the white area of the region is determined, there is a connected domain with an area greater than 80 pixels, it is considered that the inverted triangle exists, the matching is successful, if there is not, it is determined that the inverted triangle matching fails, thereby recognizing that the product is a defective product.

In order to further detect whether the cooling fin assembly lamination is correct, it is preferable in this embodiment to detect whether the lamination layer number meets the requirement, as shown in fig. 12, where the steps further include: s5, determining a verification region in a side image of the cooling fin group to be detected through preset deviation according to the axis datum and upper and lower datum lines of the cooling fin group, carrying out binarization processing, carrying out opening operation by using a circular mask with a parameter radius of 3.5 pixels, separating a connected region of a processing result into independent regions, screening the connected region according to a preset size, and counting the number of the connected regions meeting the requirement if the number of the connected regions is the same as the number of layers of a set value, wherein the number of the connected regions is correct if the number of the layers is not the same as the number of the layers of the set value, and the stacking is wrong if the number of the layers is not the same as the number of the layers of the set value.

In addition, the detection and judgment processes described in the above embodiments may be combined or individually made as a basis for judging whether the product is qualified according to actual requirements, and it can be seen that the above disclosed preferred embodiments of the present invention are only used to help illustrate the present invention. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and the full scope and equivalents thereof, and any modification, equivalent replacement, or improvement made within the spirit and principle of the invention should be included in the protection scope of the invention.

It will be appreciated by those skilled in the art that, in addition to implementing the system, apparatus and various modules thereof provided by the present invention in the form of pure computer readable program code, the same procedures may be implemented entirely by logically programming method steps such that the system, apparatus and various modules thereof provided by the present invention are implemented in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system, the device and the modules thereof provided by the present invention can be considered as a hardware component, and the modules included in the system, the device and the modules thereof for implementing various programs can also be considered as structures in the hardware component; modules for performing various functions may also be considered to be both software programs for performing the methods and structures within hardware components.

In addition, all or part of the steps of the method according to the above embodiments may be implemented by a program instructing related hardware, where the program is stored in a storage medium and includes several instructions to enable a single chip, a chip, or a processor (processor) 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: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

In addition, any combination of various different implementation manners of the embodiments of the present invention is also possible, and the embodiments of the present invention should be considered as disclosed in the embodiments of the present invention as long as the combination does not depart from the spirit of the embodiments of the present invention.

Claims

1. A method for testing the lamination compliance of cooling fins, comprising the steps of:

2. The method of detecting cooling fin stacking compliance of claim 1, wherein the steps further comprise:

3. The method of detecting cooling fin stacking compliance of claim 1, wherein the step of locating a datum line below the set of cooling fins comprises:

4. The method of detecting cooling fin stack-up compliance of claim 1, wherein the step of locating a datum line above the set of cooling fins includes:

5. The method for detecting the lamination compliance of cooling fins according to claim 1, wherein step S4 further comprises: and when the matching of the first characteristic template fails, shifting the preset pixel position again to obtain a second small detection area, and if the white area of the area is judged to be a connected domain larger than the preset pixel value, confirming that the matching is successful.