CN111855671A - Surface defect detection method, device and system - Google Patents
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- 230000007547 defect Effects 0.000 title claims abstract description 132
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- 238000010191 image analysis Methods 0.000 claims description 4
- 229910052744 lithium Inorganic materials 0.000 abstract description 20
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 abstract description 19
- 210000004027 cell Anatomy 0.000 description 6
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- 238000005516 engineering process Methods 0.000 description 3
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- 239000007773 negative electrode material Substances 0.000 description 1
- 239000011255 nonaqueous electrolyte Substances 0.000 description 1
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- 239000007774 positive electrode material Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
- G01N21/88—Investigating the presence of flaws or contamination
- G01N21/8851—Scan or image signal processing specially adapted therefor, e.g. for scan signal adjustment, for detecting different kinds of defects, for compensating for structures, markings, edges
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Abstract
The application relates to a surface defect detection method, a device and a system, wherein the reflection of a light path can form spaced stripes on a mirror surface, and the stripes emitted by a stripe light source are firstly reflected by a first reflecting plate and a second reflecting plate and finally projected to a surface to be detected of an object to be detected, and the stripes are formed on the surface to be detected. And then, acquiring a stripe image of the surface to be detected for analysis, and indirectly obtaining a detection result of whether the surface to be detected has defects according to the judgment of whether the stripe formed on the surface to be detected is bent. Through the scheme, the automatic detection of whether the concave-convex defect exists on the cylindrical surface or the surface to be detected in other shapes can be effectively carried out, the missing rate is extremely low, manual detection can be replaced, and the detection efficiency is higher. When the scheme is adopted for detecting the surface defects of the lithium battery, the advantage of high detection reliability is achieved.
Description
Technical Field
The present disclosure relates to the field of inspection technologies, and in particular, to a method, an apparatus, and a system for inspecting surface defects.
Background
The lithium battery is a battery which uses lithium metal or lithium alloy as a positive/negative electrode material and uses a non-aqueous electrolyte solution, and is widely applied to daily production and life due to the advantages of high energy, long service life, light weight, low self-discharge rate, environmental protection and the like. In the production process of the lithium battery, a plurality of procedures such as raw material processing, battery production, finished product detection and the like need to be carried out to ensure that the finally obtained lithium battery has better working reliability.
Traditional lithium cell surface defect detects adopts the mode that the camera combines artifical the measuring, nevertheless because the surface of cylindrical lithium cell is the curved surface, leads to the light source effect unstable, and pit, the convex closure on lithium cell surface are difficult obviously to distinguish for traditional lithium cell surface defect detecting method's detection efficiency is low, and appears easily lou examining and excessive measuring scheduling problem. Therefore, the traditional method for detecting the surface defects of the lithium battery has the defect of poor detection reliability.
Disclosure of Invention
Therefore, it is necessary to provide a method, an apparatus and a system for detecting surface defects, aiming at the problem of poor detection reliability of the conventional method for detecting surface defects of lithium batteries.
A surface defect detection method, comprising: acquiring a stripe image; the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector; analyzing whether the stripes are bent or not according to the stripe images; and outputting a detection result of the defect of the surface to be detected when the stripe is bent.
In one embodiment, after the step of analyzing whether the stripe is curved according to the stripe image, the method further includes: and outputting a detection result of the detected surface without defects when the stripes are not bent.
In one embodiment, the step of acquiring the fringe image includes: and when the rotating device controls the object to be detected to rotate by a preset angle, acquiring a stripe image until all positions of the surface to be detected are detected.
In one embodiment, the step of analyzing whether the stripe is curved according to the stripe image includes: carrying out gray level processing according to the stripe image to obtain a stripe gray level image; extracting features according to the stripe gray level image to obtain corresponding stripe information in the stripe image; and analyzing whether the stripes are bent or not according to the stripe information.
A surface defect detection apparatus comprising: the image acquisition module is used for acquiring a stripe image; the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector; the image analysis module is used for analyzing whether the stripes are bent or not according to the stripe images; and the defect analysis module is used for outputting the detection result of the defect of the surface to be detected when the stripe is bent.
A surface defect detection system comprises a strip light source, a first reflector, a second reflector, an image acquisition device and a control device, wherein the first reflector and the second reflector are oppositely arranged at a preset included angle, a reflection channel is formed between the first reflector and the second reflector, the strip light source and the image acquisition device are arranged at a first end of the reflection channel, an object to be detected is arranged at a second end opposite to the first end, and the image acquisition device is connected with the control device; the strip light source is used for emitting strip light, and after the strip light is reflected by the first reflecting plate and the second reflecting plate, stripes are formed on the surface to be detected of the object to be detected; the image acquisition device is used for acquiring a stripe image of the surface to be detected of the object to be detected and sending the stripe image to the control device; the control device is used for defect detection according to the method of any one of claims 1-4.
In one embodiment, the predetermined included angle is 30 to 60 degrees.
In one embodiment, the surface defect detection system further comprises an information prompting device, and the information prompting device is connected with the control device.
In one embodiment, the surface defect detecting system further includes a rotating device, the object to be detected is disposed on the rotating device, and the rotating device is configured to drive the object to be detected to rotate, so as to detect the surface defects of the object to be detected at different positions.
In one embodiment, the surface to be detected is a circumferential surface of a cylindrical battery.
According to the surface defect detection method, device and system, as the reflection of the light path can form spaced stripes on the mirror surface, the stripe light emitted by the stripe light source is firstly reflected by the first reflecting plate and the second reflecting plate, and finally projected to the surface to be detected of the object to be detected, and the stripes are formed on the surface to be detected. And then, acquiring a stripe image of the surface to be detected for analysis, and indirectly obtaining a detection result of whether the surface to be detected has defects according to the judgment of whether the stripe formed on the surface to be detected is bent. Through the scheme, the automatic detection of whether the concave-convex defect exists on the cylindrical surface or the surface to be detected in other shapes can be effectively carried out, the missing rate is extremely low, manual detection can be replaced, and the detection efficiency is higher. When the scheme is adopted for detecting the surface defects of the lithium battery, the advantage of high detection reliability is achieved.
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In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic flow chart illustrating a method for detecting surface defects according to an embodiment;
FIG. 2 is a schematic diagram of a stripe light profile in one embodiment;
FIG. 3 is a side view of an exemplary surface defect inspection system;
FIG. 4 is a schematic flow chart illustrating a surface defect detection method according to another embodiment;
FIG. 5 is a schematic flow chart illustrating a method for detecting surface defects in an exemplary embodiment;
FIG. 6 is a schematic flow chart illustrating a surface defect detection method according to yet another embodiment;
FIG. 7 is a schematic view of a surface defect inspection apparatus according to an embodiment;
FIG. 8 is a schematic diagram illustrating the critical dimension of incident light in one embodiment;
FIG. 9 is a schematic diagram illustrating an exemplary positioning of a reflector;
FIG. 10 is a schematic view illustrating a position of a reflector in another embodiment;
FIG. 11 is a schematic view of a defect-free surface of an object to be inspected according to an embodiment;
FIG. 12 is a schematic view of an embodiment of a surface defect of an object to be inspected.
Detailed Description
To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are illustrated in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
Referring to fig. 1, a surface defect detecting method includes steps S100, S200 and S300.
Step S100, a fringe image is acquired.
Specifically, the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector. This example utilizes a light source that emits a line of light (i.e., a stripe of light) that is rectangular in shape when viewed from the side, as shown in conjunction with fig. 2. And then, after a series of mirror reflection of the reflector, the formed spaced stripe light is projected to the surface to be detected of the object to be detected. At the moment, the defect detection operation of the surface to be detected can be realized only by acquiring a stripe image formed after the stripe light is projected to the surface to be detected for analysis.
It can be understood that the stripe image is not obtained in a unique manner, in one embodiment, the surface defect detection system for implementing the surface defect detection method in the present embodiment further includes an image acquisition device, and in an actual operation process, when a user only needs to start the image acquisition device to realize corresponding stripe image acquisition, the image acquisition device automatically further sends the acquired stripe image to the control device for analysis and processing, so as to obtain a surface defect detection result. Further, in an embodiment, the image capturing device is a camera, and when the user needs to perform the surface defect detection, the camera is directly controlled to be turned on to take a picture, so that the corresponding stripe image can be obtained.
And step S200, analyzing whether the stripes are bent or not according to the stripe images.
Specifically, if the surface of an object is smooth, the light rays projected thereon will also be straight, and conversely, if the surface of the object has grooves or protrusions, the light rays projected thereon will be bent at the grooves or protrusions. The embodiment utilizes the principle to project strip light to the surface to be detected to form stripes, and analyzes whether the stripes are bent or not by collecting stripe images to obtain the detection result whether the surface to be detected is provided with grooves or bulges (namely whether the surface to be detected is provided with defects or not).
It should be noted that the detection mode of whether the stripe is bent by the control device is not unique, and the image acquisition device may directly photograph the surface to be detected with the stripe, and then send the obtained photograph (i.e. stripe image) to the control device, and the control device performs gray scale processing on the received photograph to obtain a corresponding gray scale image, and then identifies the stripe in the gray scale image by using an algorithm, and further analyzes whether the stripe is bent by using an image processing algorithm.
It can be understood that, in an embodiment, the number of the stripes formed on the surface to be detected corresponding to each stripe image is not unique, and when the control device analyzes whether the stripes formed on the surface to be detected are bent, the control device analyzes whether each stripe is bent, and as long as any one of the stripes is bent, that is, indicates that the stripes formed on the surface to be detected are bent, step S300 is performed to output a detection result that the surface to be detected has a defect. Correspondingly, the stripes can be judged to be not bent only if all the stripes in the stripe image are not bent.
And step S300, outputting a defect detection result of the surface to be detected when the stripe is bent.
Specifically, when the control device performs the gray scale processing according to the acquired fringe image to calculate and identify the operation, the situation that the fringe of the surface to be detected is bent may occur, at this time, it indicates that the corresponding position of the bent portion has a groove or a protrusion, that is, the object to be detected has a defect, and at this time, the control device outputs the detection result that the surface to be detected has the defect to inform the user. It can be understood that the mode of the control device outputting the detection result that the surface to be detected has the defect is not unique, and the detection result that the surface to be detected has the defect can be output in the forms of sound, light and the like, as long as the detection result can be known by a user in time.
Further, in an embodiment, the surface defect detecting system further includes an information prompting device, the information prompting device is connected to the control device, when the control device analyzes the stripe image to obtain that the surface to be detected has the defect, the information prompting device can send a prompting message to the information prompting device, and the information prompting device informs a user of a detection result that the surface to be detected has the defect in the forms of sound, light, display, or the like, so as to complete the surface defect detecting operation of the object to be detected.
It should be noted that the structure of the surface defect detecting system is not exclusive, and in an embodiment, please refer to fig. 3 in combination, the surface defect detecting system includes the strip light source 10, the first reflector 20, the second reflector 30, the image capturing device 40 and the control device 60, the first reflector 20 and the second reflector 30 are disposed opposite to each other at a predetermined included angle, a reflective passage is formed between the first reflector 20 and the second reflector 30, the strip light source 10 and the image capturing device 40 are disposed at a first end of the reflective passage, a second end disposed opposite to the first end is disposed with the object 50 to be detected, and the image capturing device 40 is connected to the control device; the strip light source 10 is used for emitting strip light, and after the strip light is reflected by the first reflector 20 and the second reflector 30, stripes are formed on the surface to be detected of the object to be detected 50; the image acquisition device 40 is used for acquiring a stripe image of the surface to be detected of the object to be detected 50 and sending the stripe image to the control device 60; the control device 60 is used for surface defect detection according to the method of the present embodiment.
Referring to fig. 4, in an embodiment, after step S200, the method further includes step S400.
And step S400, outputting a detection result of the defect-free surface to be detected when the stripe is not bent.
Specifically, when the control device analyzes according to the stripe image and determines whether the stripe formed on the surface to be detected is bent, the stripe may not be bent. At this moment, it means that the surface to be detected does not have a groove or a protrusion, and the surface to be detected does not have a defect, and correspondingly, the control device outputs the detection result that the surface to be detected does not have a defect so as to inform the user. Similarly, the mode of outputting the detection result that the surface to be detected has no defect by the control device is not unique, and specifically, the detection result that the surface to be detected has no defect can be output in the forms of sound, light and the like as long as the detection result can be timely known by a user.
Referring to fig. 5, in one embodiment, step S100 includes step S110.
And step S110, when the rotating device controls the object to be detected to rotate by a preset angle, acquiring a stripe image once until all positions of the surface to be detected are detected.
Specifically, in this embodiment, the surface defect detecting system further includes a rotating device, the object to be detected is disposed on the rotating device, and the rotating device rotates to drive the object to be detected, so that the image capturing device can capture the stripe images of different positions of the object to be detected for analysis, and further the surface defect detecting operation of different positions of the object to be detected is realized. In this embodiment, the rotating device is independent of the control device, and the rotation of the rotating device is not affected by the control device, and can be a constant speed rotation all the time, or a preset angle rotation at certain intervals.
In another embodiment, the control device may be connected to the rotating device, and the rotating device rotates under the action of the control device to drive the object to be detected to rotate, so as to detect defects at different positions of the object to be detected. Through the scheme of this embodiment, at the in-process that surface defect detected, controlling means can in time control and wait to detect the rotation of object after carrying out the stripe image acquisition to realize the stripe image acquisition of each position, have higher detection efficiency.
Taking the object 50 to be detected as a cylindrical object as an example, the corresponding surface to be detected is the side surface of the cylindrical object. The rotating device fixes the cylindrical object through two circular bottom surfaces of the cylindrical object. When stripe pattern information is acquired, the control device controls the rotating device to drive the cylindrical object to rotate after the image acquisition device acquires stripe images and information once and sends the stripe images and the information to the control device, so that stripes are projected from different positions of the side surface of the cylindrical object, and then the image acquisition device acquires the stripe images again. And (4) acquiring fringe images at all positions of the side surface and the surface until the cylindrical object rotates for a circle.
It should be noted that the size of the preset angle is not unique, as long as it is ensured that the stripe images corresponding to all positions of the surface to be detected can be obtained in the process that the object to be detected rotates at the preset angle. It can be understood that, in order to ensure the measurement accuracy, the preset angle may be set as small as possible, but accordingly, the amount of the stripe image data acquired by the control device may be increased (i.e., the image acquisition device may acquire more pictures). In order to reduce the data processing amount and improve the detection efficiency of the surface defects, the preset angle may be set as large as possible. Therefore, the size of the preset angle can be set differently according to the requirements of a user or the shape of the object to be detected.
For example, in a preferred embodiment, the predetermined angle may be set to 36 degrees for a cylindrical object to be inspected. Namely, every time the rotating device drives the cylindrical object to rotate for 36 degrees, the processing device controls the image acquisition device to perform the acquisition and sending operation of the stripe image. Correspondingly, in this embodiment, when the surface defect analysis is performed on the same cylindrical object, 10 stripe images are acquired, and the processing device performs analysis according to all the stripe images, so that the defect detection operation on the whole to-be-detected surface of the to-be-detected object can be completed.
Referring to fig. 6, in one embodiment, step S200 includes step S210, step S220, and step S230.
Step S210, carrying out gray level processing according to the stripe image to obtain a stripe gray level image; step S220, extracting characteristics according to the stripe gray level image to obtain corresponding stripe information in the stripe image; and step S230, analyzing whether the stripes are bent or not according to the stripe information.
Specifically, when analyzing whether the stripe is curved according to the stripe image, the control device performs gray processing on the obtained stripe image, that is, converts each pixel in the acquired stripe image into a gray value matched with the acquired stripe image, and finally obtains a gray stripe gray image. In the stripe gray-scale image at this moment, a certain gray-scale difference exists between the pixel point corresponding to each stripe and the pixel point on the surface of the object to be detected, at this moment, only the pixel point matched with the gray-scale value of the stripe pixel point needs to be extracted, stripe information can be obtained, and finally, the control device identifies the extracted stripe information according to an algorithm to analyze, so that a judgment result of whether the stripe is bent or not can be directly obtained.
According to the surface defect detection method, as the reflection of the light path can form spaced stripes on the mirror surface, the stripe light emitted by the stripe light source is firstly reflected by the first reflector and the second reflector, and finally projected to the surface to be detected of the object to be detected, and the stripes are formed on the surface to be detected. And then, acquiring a stripe image of the surface to be detected for analysis, and indirectly obtaining a detection result of whether the surface to be detected has defects according to the judgment of whether the stripe formed on the surface to be detected is bent. Through the scheme, the automatic detection of whether the concave-convex defect exists on the cylindrical surface or the surface to be detected in other shapes can be effectively carried out, the missing rate is extremely low, manual detection can be replaced, and the detection efficiency is higher. When the scheme is adopted for detecting the surface defects of the lithium battery, the advantage of high detection reliability is achieved.
Referring to fig. 7, a surface defect detecting apparatus includes an image obtaining module 100, an image analyzing module 200, and a defect analyzing module 300.
The image obtaining module 100 is configured to obtain a stripe image; the image analysis module 200 is configured to analyze whether the stripe is curved according to the stripe image; the defect analysis module 300 is configured to output a result of detecting that a defect exists on the surface to be detected when the stripe is bent.
Specifically, the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector. This example utilizes a light source that emits a line of light (i.e., a stripe of light) that is rectangular in shape when viewed from the side, as shown in conjunction with fig. 2. And then, after a series of mirror reflection of the reflector, the formed spaced stripe light is projected to the surface to be detected of the object to be detected. At the moment, the defect detection operation of the surface to be detected can be realized only by acquiring a stripe image formed after the stripe light is projected to the surface to be detected for analysis.
If the surface of an object is smooth, the light rays projected on the object will also be in a straight line, and conversely, if the surface of the object is provided with grooves or protrusions, the light rays projected on the object will be bent at the grooves or the protrusions. The embodiment utilizes the principle to project strip light to the surface to be detected to form stripes, and analyzes whether the stripes are bent or not by collecting stripe images to obtain the detection result whether the surface to be detected is provided with grooves or bulges (namely whether the surface to be detected is provided with defects or not).
It should be noted that the detection mode of whether the stripe is bent by the control device is not unique, and the image acquisition device may directly photograph the surface to be detected with the stripe, and then send the obtained photograph (i.e. stripe image) to the control device, and the control device performs gray scale processing on the received photograph to obtain a corresponding gray scale image, and then identifies the stripe in the gray scale image by using an algorithm, and further analyzes whether the stripe is bent by using an image processing algorithm.
When the control device performs gray scale processing according to the acquired stripe image to calculate and identify, the stripe of the surface to be detected may be bent, at this time, it indicates that a groove or a protrusion exists at a position corresponding to the bent portion, that is, the object to be detected has a defect, and at this time, the control device outputs a detection result of the defect of the surface to be detected to inform a user. It can be understood that the mode of the control device outputting the detection result that the surface to be detected has the defect is not unique, and the detection result that the surface to be detected has the defect can be output in the forms of sound, light and the like, as long as the detection result can be known by a user in time.
In one embodiment, the defect analysis module 300 is further configured to output a detection result that the surface to be detected is free of defects when the stripes are not bent.
In an embodiment, the image obtaining module 100 is further configured to obtain a stripe image each time the rotating device controls the object to be detected to rotate by a preset angle until each position of the surface to be detected is detected.
In one embodiment, the image analysis module 200 is further configured to perform gray processing according to the stripe image to obtain a stripe gray map; extracting features according to the stripe gray level image to obtain corresponding stripe information in the stripe image; and analyzing whether the stripes are bent or not according to the stripe information.
For the specific definition of the surface defect detecting device, reference may be made to the above definition of the surface defect detecting method, which is not described herein again. The modules in the surface defect detecting device can be wholly or partially realized by software, hardware and a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.
According to the surface defect detection device, as the light path is reflected to form the spaced stripes on the mirror surface, the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector at first, is projected to the surface to be detected of the object to be detected and forms the stripes on the surface to be detected. And then, acquiring a stripe image of the surface to be detected for analysis, and indirectly obtaining a detection result of whether the surface to be detected has defects according to the judgment of whether the stripe formed on the surface to be detected is bent. Through the scheme, the automatic detection of whether the concave-convex defect exists on the cylindrical surface or the surface to be detected in other shapes can be effectively carried out, the missing rate is extremely low, manual detection can be replaced, and the detection efficiency is higher. When the scheme is adopted for detecting the surface defects of the lithium battery, the advantage of high detection reliability is achieved.
Referring to fig. 3, a surface defect detecting system includes a strip light source 10, a first reflector 20, a second reflector 30, an image collecting device 40 and a control device 60, wherein the first reflector 20 and the second reflector 30 are oppositely disposed at a preset included angle, a reflective channel is formed between the first reflector 20 and the second reflector 30, the strip light source 10 and the image collecting device 40 are disposed at a first end of the reflective channel, a second end disposed opposite to the first end is provided with an object 50 to be detected, and the image collecting device 40 is connected to the control device 60; the strip light source 10 is used for emitting strip light, and after the strip light is reflected by the first reflector 20 and the second reflector 30, stripes are formed on the surface to be detected of the object to be detected 50; the image acquisition device 40 is used for acquiring a stripe image of the surface to be detected of the object to be detected 50 and sending the stripe image to the control device 60; the control device 60 is used for defect detection according to the method described above.
Specifically, the stripe image is an image formed on the surface to be detected of the object to be detected 50 after the stripe light emitted by the stripe light source 10 is reflected by the first reflector 20 and the second reflector 30. This example utilizes a light bar source 10 that emits a line of light (i.e., a bar of light) that is rectangular in shape when viewed from the side, as shown in fig. 2. And then, after a series of mirror reflection of the reflector, the formed spaced stripe light is projected to the surface to be detected of the object to be detected. At the moment, the defect detection operation of the surface to be detected can be realized only by acquiring a stripe image formed after the stripe light is projected to the surface to be detected for analysis.
In the actual operation process, when a user only needs to start the image acquisition device 40 to acquire a corresponding stripe image, the image acquisition device 40 automatically sends the acquired stripe image to the control device 60 for analysis and processing, so as to obtain a surface defect detection result. Further, in an embodiment, the image capturing device 40 is a camera, and when the user needs to perform the surface defect detection, the camera is directly controlled to be turned on to take a picture, so as to obtain the corresponding stripe image.
If the surface of an object is smooth, the light rays projected on the object will also be in a straight line, and conversely, if the surface of the object is provided with grooves or protrusions, the light rays projected on the object will be bent at the grooves or the protrusions. The embodiment utilizes the principle to project strip light to the surface to be detected to form stripes, and analyzes whether the stripes are bent or not by collecting stripe images to obtain the detection result whether the surface to be detected is provided with grooves or bulges (namely whether the surface to be detected is provided with defects or not).
It should be noted that the detection manner of whether the stripe is bent by the control device 60 is not unique, and the image acquisition device 40 may directly photograph the surface to be detected with the stripe, and then send the obtained photograph (i.e. stripe image) to the control device 60, and the control device 60 performs gray processing on the received photograph to obtain a corresponding gray image, and then identifies the stripe in the gray image by using an algorithm, and further analyzes whether the stripe is bent by using an image processing algorithm.
When the control device 60 performs the gray scale processing to calculate and identify the operation according to the acquired stripe image, the stripe of the surface to be detected may be bent, which means that there is a groove or a protrusion in the corresponding position of the bent portion, that is, the object 50 to be detected has a defect, and at this time, the control device 60 outputs the detection result of the defect of the surface to be detected to inform the user. It can be understood that the manner of outputting the detection result of the defect on the surface to be detected by the control device 60 is not exclusive, and specifically, the detection result of the defect on the surface to be detected may be output in the form of sound, light, and the like, as long as the detection result can be timely known by the user. The surface defect detection system of the embodiment has the advantages of novel structure and low cost.
It should be noted that the predetermined angle between the first reflector 20 and the second reflector 30 is not exclusive, as long as the stripe light is ensured not to reach the critical value when reflected between the first reflector 20 and the second reflector 30, i.e. the incident angle is 0 degree (perpendicular to the reflector) as shown in fig. 8. For example, in one embodiment, the preset included angle may be set to a size of 30 degrees to 60 degrees, and specifically may be 60 degrees as shown in fig. 9, 30 degrees as shown in fig. 10, or any value between 30 degrees and 60 degrees. Further, in one embodiment, the adjustment operation of the number of stripes projected onto the object 50 to be detected can be realized by adjusting the angle between the first reflector 20 and the second reflector 30 and the incident light angle of the stripe light source 10.
Further, in an embodiment, the surface defect detecting system further includes an information prompting device, the information prompting device is connected to the control device 60, when the control device 60 analyzes the stripe image to obtain that the surface to be detected has a defect, a prompting message can be sent to the information prompting device, and the information prompting device informs a user of a detection result that the surface to be detected has the defect in the forms of sound, light, display, or the like, so as to complete the surface defect detecting operation of the object to be detected.
In one embodiment, the number of the bar light sources 10 is two or more.
Specifically, in order to ensure that a sufficient number of stripes are formed on the surface to be detected, two or more stripe light sources 10 are used in the present embodiment to perform stripe light emission, and after multiple reflections by the first reflector 20 and the second reflector 30, respectively, a plurality of stripe lights with small intervals are formed on the surface to be detected. It can be understood that, in an embodiment, only one strip light source 10 may be provided, as long as it is ensured that the strip light emitted by the strip light source 10 can form a plurality of strip lights with small intervals on the surface to be detected, so as to implement defect detection at each position of the surface to be detected.
In one embodiment, the surface defect detecting system further includes a rotating device, and the object 50 to be detected is disposed on the rotating device (not shown), and the rotating device is configured to drive the object 50 to be detected to rotate, so as to detect the surface defects of different positions of the object 50 to be detected.
Specifically, in this embodiment, the object to be detected is disposed on the rotating device, and the object to be detected 50 is driven to rotate by the rotation of the rotating device, so that the image acquisition device 40 can acquire the fringe images of the object to be detected 50 at different positions for analysis, and further the surface defect detection operation of the object to be detected 50 at different positions is realized. In this embodiment, the rotating device is connected to the control device 60, and the rotation of the rotating device is not affected by the control device 60, and may be a constant speed rotation all the time, or a preset angle rotation at certain intervals.
In another embodiment, the control device 60 may be connected to a rotating device, and the rotating device rotates under the action of the control device 60 to drive the object 50 to rotate, so as to implement the defect detection operation on different positions of the object 50 to be detected. Through the scheme of this embodiment, in the process of surface defect detection, after the control device 60 acquires the fringe image, the object 50 to be detected can be timely controlled to rotate, so as to acquire the fringe image at each position, and the detection efficiency is high.
Taking the object 50 to be detected as a cylindrical object as an example, the corresponding surface to be detected is the side surface of the cylindrical object. The rotating device fixes the cylindrical object through two circular bottom surfaces of the cylindrical object. When stripe pattern information is acquired, after the image acquisition device 40 acquires a stripe image and information and sends the stripe image and information to the control device 60, the control device 60 controls the rotating device to drive the cylindrical object to rotate, so that stripes are projected at different positions on the side surface of the cylindrical object, and then the image acquisition device 40 acquires the stripe image again. And (4) acquiring fringe images at all positions of the side surface and the surface until the cylindrical object rotates for a circle.
In one embodiment, the surface to be detected is a circumferential surface of a cylindrical battery.
Specifically, the first reflector 20 and the second reflector 30 are symmetrically installed at two sides of the center of the cylindrical battery, at this time, the number of the stripe light sources 10 is two, and the stripe light sources are symmetrically arranged with the symmetry axes of the first reflector 20 and the second reflector 30, two stripe light symmetric angles irradiate on the reflectors, the reflectors can form spaced stripes on the mirror surface due to the reflection of the light path, and the stripes are finally projected onto the surface of the battery to form a plurality of fine stripes. Although the pitch of the stripes on the reflector is not uniform, the pitch of the stripes appearing on the surface of the cell is almost uniform because the surface of the cell is a circular arc surface. As shown in fig. 11, if the stripes are straight lines on the surface of the cylindrical lithium battery, it indicates that the surface of the cylindrical lithium battery is free of defects; as shown in fig. 12, if the stripes are bent on the surface of the cylindrical lithium battery, it indicates that the surface of the cylindrical lithium battery has defects. The surface defect detection system of the embodiment realizes the defect detection operation of the side surface of the cylindrical lithium battery, can effectively solve the detection misjudgment caused by poor polishing uniformity of the cylinder, can effectively detect the concave-convex defect of the cylindrical surface, and has the omission factor of 0.
According to the surface defect detection system, as the light path is reflected to form the spaced stripes on the mirror surface, the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector at first, is projected to the surface to be detected of the object to be detected and forms the stripes on the surface to be detected. And then, acquiring a stripe image of the surface to be detected for analysis, and indirectly obtaining a detection result of whether the surface to be detected has defects according to the judgment of whether the stripe formed on the surface to be detected is bent. Through the scheme, the automatic detection of whether the concave-convex defect exists on the cylindrical surface or the surface to be detected in other shapes can be effectively carried out, the missing rate is extremely low, manual detection can be replaced, and the detection efficiency is higher. When the scheme is adopted for detecting the surface defects of the lithium battery, the advantage of high detection reliability is achieved.
The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.
The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (10)
1. A method of surface defect detection, comprising:
acquiring a stripe image; the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector;
analyzing whether the stripes are bent or not according to the stripe images;
and outputting a detection result of the defect of the surface to be detected when the stripe is bent.
2. The method of claim 1, wherein the step of analyzing whether the stripes are curved according to the stripe image further comprises:
and outputting a detection result of the detected surface without defects when the stripes are not bent.
3. The method of claim 1, wherein the step of obtaining a fringe image comprises:
and when the rotating device controls the object to be detected to rotate by a preset angle, acquiring a stripe image until all positions of the surface to be detected are detected.
4. The method of claim 1, wherein the step of analyzing whether the stripes are curved or not according to the stripe image comprises:
carrying out gray level processing according to the stripe image to obtain a stripe gray level image;
extracting features according to the stripe gray level image to obtain corresponding stripe information in the stripe image;
and analyzing whether the stripes are bent or not according to the stripe information.
5. A surface defect detecting apparatus, comprising:
the image acquisition module is used for acquiring a stripe image; the stripe image is an image formed on the surface to be detected of the object to be detected after the stripe light emitted by the stripe light source is reflected by the first reflector and the second reflector;
the image analysis module is used for analyzing whether the stripes are bent or not according to the stripe images;
and the defect analysis module is used for outputting the detection result of the defect of the surface to be detected when the stripe is bent.
6. A surface defect detection system is characterized by comprising a strip light source, a first reflector, a second reflector, an image acquisition device and a control device,
the first reflector and the second reflector are oppositely arranged at a preset included angle, a reflecting channel is formed between the first reflector and the second reflector, the strip light source and the image acquisition device are arranged at a first end of the reflecting channel, a second end opposite to the first end is provided with an object to be detected, and the image acquisition device is connected with the control device;
the strip light source is used for emitting strip light, and after the strip light is reflected by the first reflecting plate and the second reflecting plate, stripes are formed on the surface to be detected of the object to be detected; the image acquisition device is used for acquiring a stripe image of the surface to be detected of the object to be detected and sending the stripe image to the control device; the control device is used for defect detection according to the method of any one of claims 1-4.
7. The surface defect detection system of claim 6, wherein the predetermined included angle is 30 to 60 degrees.
8. The surface defect detection system of claim 6, further comprising an information presentation device, wherein the information presentation device is connected to the control device.
9. The surface defect detecting system of claim 6, further comprising a rotating device, wherein the object to be detected is arranged on the rotating device, and the rotating device is used for driving the object to be detected to rotate so as to realize surface defect detection of different positions of the object to be detected.
10. The surface defect detection system of claim 6, wherein the surface to be detected is a circumferential surface of a cylindrical battery.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113884016A (en) * | 2021-06-16 | 2022-01-04 | 成都新锐科技发展有限责任公司 | Battery piece warping degree detection method |
| CN113899755A (en) * | 2021-11-17 | 2022-01-07 | 武汉华星光电半导体显示技术有限公司 | Screen crease degree detection method and visual detection equipment |
| CN114659473A (en) * | 2020-12-22 | 2022-06-24 | 宁波舜宇光电信息有限公司 | Flatness detection device, system and detection method |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105627942A (en) * | 2015-12-25 | 2016-06-01 | 华南理工大学 | Imaging apparatus and method for detecting object surface micro deformation through machine vision |
| CN107703058A (en) * | 2017-09-14 | 2018-02-16 | 深圳市智信精密仪器有限公司 | Appearance detection means and the light-source system that the progress outward appearance detection of grating line is provided |
| CN109557101A (en) * | 2018-12-29 | 2019-04-02 | 桂林电子科技大学 | A kind of defect detecting device and method of nonstandard high reflection curve surface work pieces |
| CN110243831A (en) * | 2019-06-06 | 2019-09-17 | 锐捷网络股份有限公司 | Surface defect acquisition system, detection method of surface flaw, device and storage medium |
-
2020
- 2020-07-29 CN CN202010742116.8A patent/CN111855671A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105627942A (en) * | 2015-12-25 | 2016-06-01 | 华南理工大学 | Imaging apparatus and method for detecting object surface micro deformation through machine vision |
| CN107703058A (en) * | 2017-09-14 | 2018-02-16 | 深圳市智信精密仪器有限公司 | Appearance detection means and the light-source system that the progress outward appearance detection of grating line is provided |
| CN109557101A (en) * | 2018-12-29 | 2019-04-02 | 桂林电子科技大学 | A kind of defect detecting device and method of nonstandard high reflection curve surface work pieces |
| CN110243831A (en) * | 2019-06-06 | 2019-09-17 | 锐捷网络股份有限公司 | Surface defect acquisition system, detection method of surface flaw, device and storage medium |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114659473A (en) * | 2020-12-22 | 2022-06-24 | 宁波舜宇光电信息有限公司 | Flatness detection device, system and detection method |
| CN113884016A (en) * | 2021-06-16 | 2022-01-04 | 成都新锐科技发展有限责任公司 | Battery piece warping degree detection method |
| CN113884016B (en) * | 2021-06-16 | 2024-02-13 | 成都新锐科技发展有限责任公司 | Method for detecting warping degree of battery piece |
| CN113899755A (en) * | 2021-11-17 | 2022-01-07 | 武汉华星光电半导体显示技术有限公司 | Screen crease degree detection method and visual detection equipment |
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Application publication date: 20201030 |