Concrete crack detection device and detection method

Abstract

The present disclosure provides a concrete crack detection device, comprising: a detection component and a display device. The detection component includes: a pipe fitting, which is columnar and is used for inserting into a narrow detection hole of a member to be detected; a camera, which is connected to the pipe fitting and is arranged to face the inner wall of the detection hole, and is used for taking a crack picture of the inner wall of the detection hole and sending it to the display device; the display device displays the actual width of the crack according to the crack picture. The present disclosure also provides a detection method based on the above concrete crack detection device. By using this device and method, the detection of concrete cracks can be realized only by a detection hole with a small aperture, avoiding excessive damage to the wall; and the actual width of the crack can be directly obtained through the display device, and the detection is convenient and efficient.

Description

Technical Field

[0001] The present disclosure relates to the technical field of concrete detection, and in particular to a concrete crack detection device and a detection method. Background Art

[0002] Concrete is a commonly used engineering material in various infrastructure projects (including prefabricated buildings), and concrete cracking is a common problem occurring in concrete structures. Especially for prefabricated buildings, cracks are likely to occur between the precast layer and the cast-in-place layer. If cracking occurs, the degree of corrosion of concrete and steel bars will increase, thereby affecting the bearing capacity and durability of the foundation. By regularly detecting whether the concrete foundation is cracked and the crack width, analyzing the cracking cause and taking appropriate treatment measures in time to avoid the destruction of the reinforced concrete foundation is of great significance for ensuring the quality of prefabricated buildings.

[0003] Therefore, it is necessary for those skilled in the art to develop a detection component capable of detecting the crack width. Summary of the Invention

[0004] To solve at least one of the above technical problems, the present disclosure provides a concrete crack detection device and a detection method.

[0005] According to one aspect of the present disclosure, a concrete crack detection device includes: a detection component and a display device, and the detection component includes:

[0006] A pipe fitting, which is columnar and is used to be inserted into a narrow detection hole of a component to be detected;

[0007] A camera, which is connected to the pipe fitting. The camera includes a first camera. The first camera is used to be disposed opposite to the inner sidewall of the detection hole, capture a crack picture of the inner sidewall of the detection hole, and send it to the display device;

[0008] The display device displays the actual crack width according to the crack picture.

[0009] According to at least one embodiment of the present disclosure, the camera is a fixed-focus camera, or

[0010] The camera is a zoom camera, which is used to automatically focus according to the crack clarity and feed back the current focal length to the display device when a clear image of the crack is captured.

[0011] According to at least one embodiment of the present disclosure, corresponding to the fixed-focus camera, the display device is provided with scales representing the actual crack width, and the scales are set according to the corresponding relationship between the captured width of the crack and the actual crack width calibrated in advance.

[0012] According to at least one embodiment of the present disclosure, the display device includes a calculation module and a display module; the calculation module is configured to calculate the actual width W of the crack according to the focal length f of the first camera, the diameter d of the lens of the first camera, the distance L from the focus of the first camera to the inner wall of the detection hole, the number of pixels D1 of the crack along the crack width direction in the crack picture, and the number of pixels D2 of the crack picture along the crack width direction, and send it to the display module, and the display module is configured to display the actual width W of the crack;

[0013] W, f, d, L, D1, and D2 satisfy the relational expression: W = LdD1 / fD2.

[0014] According to at least one embodiment of the present disclosure, the pipe fitting is configured to form a double-line contact with the inner wall of the detection hole, and the contact line is parallel to the axis of the detection hole.

[0015] According to at least one embodiment of the present disclosure, the cross-section of the pipe fitting is triangular, and the first camera is installed at the apex of the triangle; or,

[0016] the cross-section of the pipe fitting is trapezoidal, and the first camera is installed in the middle of the upper base of the trapezoid; or,

[0017] the cross-section of the pipe fitting is a circular crown shape, and the first camera is installed in the middle of the arc facing the straight edge of the circular crown shape.

[0018] According to at least one embodiment of the present disclosure, an anti-collision portion for preventing the pipe fitting from colliding with the inner wall of the detection hole is provided at the end of the pipe fitting where the camera is installed.

[0019] According to at least one embodiment of the present disclosure, a chamfer is provided at the inner end of the pipe fitting to form the anti-collision portion; or,

[0020] the inner end of the pipe fitting is a spherical crown body or a conical body whose cross-section gradually decreases from the outside to the inside to form the anti-collision portion.

[0021] According to at least one embodiment of the present disclosure, the camera is connected to the pipe fitting through a positioning member, and at least one light source is further provided around the camera; at least a part of the pipe fitting is a transparent pipe body, and the transparent pipe body is provided corresponding to the camera and the light source.

[0022] According to at least one embodiment of the present disclosure, the detection component further includes an anti-reflection structure, and the anti-reflection structure is configured to prevent the reflected light of the pipe fitting from entering the first camera.

[0023] According to at least one embodiment of the present disclosure, the pipe fitting includes a support pipe section, the anti-reflection structure is an extension section disposed outside the support pipe section and extending inward, the extension section is used to correspond to the inner side wall of the detection hole, and the positioning member connecting the first camera is disposed on the extension section.

[0024] According to at least one embodiment of the present disclosure, the anti-reflection structure is a through hole opened in the pipe fitting, the through hole corresponds to the light source, and the diameter of the through hole is not less than the illumination range of the light source.

[0025] According to at least one embodiment of the present disclosure, the camera further includes a second camera, and the second camera is disposed opposite to the inner end wall of the front end of the detection hole.

[0026] A concrete crack detection method includes the following steps:

[0027] Drilling step: drilling a detection hole in the member to be detected;

[0028] Crack finding step: inserting the detection component in the concrete crack detection device according to any one of the claims into the detection hole, moving the detection component to make the camera face the crack directly, and making the crack imaging the clearest;

[0029] Reading step: checking the display device and reading the actual width of the crack.

[0030] According to at least one embodiment of the present disclosure, in the drilling step, the detection hole is a blind hole, and the depth of the detection hole satisfies the following conditions:

[0031] The distance L1 from the inner end surface of the detection hole to the joint surface of the blade plate and the cast-in-place layer is equal to the distance L2 from the end surface of the end of the pipe fitting where the camera is installed to the center of the camera.

[0032] According to at least one embodiment of the present disclosure, the specific process of the crack finding step includes:

[0033] Keeping the first camera facing the inner side wall of the detection hole, rotating the pipe fitting to find the crack;

[0034] Moving the pipe fitting back and forth, observing the imaging of the crack, comparing the positions and clarity of the multiple crack imaging, and finding the image where the crack imaging is located in the middle of the display module and is clear.

[0035] According to at least one embodiment of the present disclosure, the specific process of the reading step is:

[0036] The display device obtains the actual width W of the crack based on the focal length f of the first camera, the diameter d of the first camera lens, the distance L from the focal point of the first camera to the inner wall of the detection hole, the number of pixels D1 of the crack along the crack width direction in the crack image, and the number of pixels D2 of the crack image along the crack width direction; W, f, d, L, D1, and D2 satisfy the relational expression: W = LdD1 / fD2.

[0037] According to at least one embodiment of the present disclosure, a calibration step is further included before the drilling step, and the specific process of the calibration step includes:

[0038] Use the preset detection component to photograph the inner walls of multiple preset detection holes, record the photographed width W_photo of the concrete crack, record the actual width W_real of the concrete crack, and establish a one-to-one correspondence between the photographed width W_photo and the actual width W_real;

[0039] Set a scale on the display device according to the corresponding relationship so that the reading of the display device is the actual width W_real.

[0040] According to at least one embodiment of the present disclosure, the following step is further included:

[0041] Take and store an image: Before or after the reading step, take a crack image and store it. Description of the Drawings

[0042] The drawings illustrate exemplary embodiments of the present disclosure and are used together with the description to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure, and the drawings are included in this specification and form a part of this specification.

[0043] Figure 1 is a schematic diagram of a concrete crack detection device according to an embodiment of the present disclosure.

[0044] Figure 2 is Figure 1 a schematic diagram of the display device in the concrete crack detection device shown.

[0045] Figure 3 and Figure 4 is Figure 1 a schematic diagram of the detection component in the concrete crack detection device shown.

[0046] Figure 5 is Figure 1 a schematic diagram of the first embodiment of the pipe fitting in the concrete crack detection device shown.

[0047] Figure 6 is Figure 1 a schematic diagram of the second embodiment of the pipe fitting in the concrete crack detection device shown.

[0048] Figure 7 Is Figure 1 A schematic diagram of the third embodiment of the pipe fitting in the concrete crack detection device shown

[0049] Figure 8 Is Figure 1 A schematic diagram of the first embodiment of the anti-reflection structure in the concrete crack detection device shown

[0050] Figure 9 And Figure 12 Is Figure 1 A schematic diagram of the second embodiment of the anti-reflection structure in the concrete crack detection device shown

[0051] Figure 10 And Figure 11 Is a schematic diagram when the camera faces the crack directly in the crack finding step of the concrete crack detection method of the present disclosure

[0052] In the figure: 10 - detection component; 11 - pipe fitting; 111 - anti-collision part; 112 - support pipe section; 113 - extension section; 114 - through hole; 115 - shielding part; 12 - first camera; 13 - light source; 14 - positioning part; 15 - second camera; 20 - display device; 21 - calculation module; 22 - display module; 23 - scale; 24 - storage module; 30 - component to be detected; 31 - detection hole; 32 - crack Specific Embodiments

[0053] The following further elaborates on the present disclosure in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the relevant content and do not limit the present disclosure. Additionally, it should be noted that for ease of description, only parts related to the present disclosure are shown in the drawings

[0054] It should be noted that, without conflict, the embodiments in the present disclosure and the features in the embodiments can be combined with each other. The following will elaborate on the present disclosure in detail with reference to the accompanying drawings and embodiments

[0055] It should be noted that the term "front" herein is based on the orientation shown in the attached Figure 8 drawing; the term "inside" refers to the inside of the detection hole

[0056] As Figure 1 And 2 shown, according to the first embodiment of the present disclosure, a concrete crack detection device is provided, which is characterized by including: a detection component 10 and a display device 20, and the detection component 10 includes:

[0057] A pipe fitting 11, in a columnar shape, for inserting into the narrow detection hole 31 of the component 30 to be detected

[0058] A camera, connected to the pipe fitting 11, the camera includes a first camera 12, the first camera 12 is used to be arranged facing the inner wall of the detection hole 31, take pictures of the cracks on the inner wall of the detection hole 31, and send them to the display device 20;

[0059] The display device 20 displays the actual width of the crack according to the crack picture.

[0060] The detection part of the present disclosure is of a columnar structure, which can be applied to narrow detection holes. Only detection holes of 2-8 cm are drilled, greatly reducing the damage to the wall. Secondly, by arranging the first camera facing the inner wall of the detection hole 31, the concrete cracks on the inner wall can be directly photographed. Finally, the crack width can be directly displayed by the display device, or the crack width can be directly read through the scale set on the display device, which is very convenient.

[0061] The camera can have at least two implementation manners:

[0062] The first one: the fixed focal length manner. A positioning component is connected inside the pipe fitting 11, and the camera is installed on the positioning component. The focal length of this camera is fixed, which is convenient for calibration.

[0063] The second one: the variable focal length manner. The camera can automatically focus according to information such as the clarity of the photographed crack 32 to ensure the clarity of the photograph. For this variable focal length camera, after each photograph, the camera inputs the focal length of this photograph to the display device 20 so that the display device 20 can calculate the actual width of the crack 32. The specific calculation method is shown in the subsequent description of calibration through the calculation method.

[0064] There are various ways for the display device 20 to display the actual width of the concrete crack:

[0065] The first way is the calibration method: Set multiple standard test blocks of different sizes. Multiple standard test blocks can be provided with detection holes of multiple preset sizes. Use the detection component of the present disclosure to photograph the inner walls of the detection holes of multiple standard test blocks, and set the distance between the lens of the camera of the present disclosure and the inner walls of multiple detection holes as a preset distance. After detection, the cracks captured are displayed by the display device 20, and record the photographed widths W_photo of the concrete cracks in various combination ways of each standard test block, each detection hole, and the distance from each lens to the inner wall. Since the width of the concrete crack captured for each standard test block can be accurately measured by a measuring tool, record the actual widths W_real of the concrete cracks in various combination ways of each detection hole and the distance from each lens to the inner wall, and then record the one-to-one correspondence between the photographed width W_photo and the actual width W_real in each case, and build the above corresponding relationship into the display device.

[0066] After setting up this correspondence, further calibration is achieved through a calibrated scale or an image scaling device, so that the display device can directly display the actual width of the concrete crack.

[0067] For example, the correspondence between the captured width \(W_{cap}\) and the actual width \(W_{act}\) is 1:5. That is, if the captured width \(W_{cap}\) is 1 mm, after conversion according to the correspondence, the actual width \(W_{act}\) is 5 mm.

[0068] The first method: The calibrated unit scale can be set to 5 times the standard unit scale. That is to say, the display device 20 displays the captured original image, but the scale value is 5 times the original. That is, a crack width of 1 mm in the image is read as 5 mm after calibration of the scale. This method is "image unchanged, scale calibrated".

[0069] The second method: The original image can be enlarged to 5 times the original through an image scaling device, and the scale is displayed as the standard unit scale. In this way, after being read by the display device, 1 mm in the original image is displayed as 5 mm after being read by the display device. This method is "image scaled, scale unchanged".

[0070] It can be seen that when detecting the concrete crack of the composite wall, after the display device obtains the captured width \(W_{cap}\), it obtains the actual width \(W_{act}\) corresponding to the captured width \(W_{cap}\) in the current situation through the built-in calibration relationship, and then directly displays \(W_{act}\) on the display device 20 according to the correspondence relationship in the way of "image unchanged, scale calibrated" or "image scaled, scale unchanged". In this way, the user can directly obtain the actual width of the concrete crack by observing the display device 20.

[0071] Of course, the above display device is not limited to displaying the actual crack width in the way of "image unchanged, scale calibrated" or "image scaled, scale unchanged", and it can also be directly displayed in numbers.

[0072] In another embodiment, the crack width can be calculated in real time by calculation. Specifically, the display device 20 includes a calculation module 21 and a display module 22; the calculation module 21 is used to calculate the actual crack width \(W_{cal}\) according to the focal length \(f\) of the camera, the diameter \(d\) of the camera lens, the distance \(L\) from the focus of the camera to the inner wall of the detection hole 31, the number of pixels \(D1\) of the crack 32 in the crack width direction in the crack picture, and the number of pixels \(D2\) of the crack picture in the crack width direction, and send it to the display module 22, and the display module 22 is used to display the actual crack width \(W_{cal}\). The specific principle of the calculation by the calculation module 21 is:

[0073] According to the proportional relationship, the relationship between the width \(H\) of the crack 32 in the crack picture, the number of pixels \(D1\) of the crack 32 in the crack width direction in the crack picture, the number of pixels \(D2\) of the crack picture in the crack width direction, and the crack width \(W_{cal}\) is:

[0074] W = HD1 / D2 A

[0075] like Figure 3 As shown, the relationship between the focal length f of the camera, the diameter d of the camera lens, the distance L from the focus of the camera to the inner wall of the detection hole 31 and the width H of the crack 32 in the crack picture is:

[0076] H=Ld / f B

[0077] Combining formula A and formula B, we can get:

[0078] W=LdD1 / fD2 C

[0079] The concrete crack width can be calculated by formula C and displayed by the display module 22 .

[0080] On the basis of the above calculation, in order to further reduce the error in the calculation process and improve the accuracy, correction can be made through multiple test fitting. Through the test, a one-to-one correspondence between the calculated crack width and the actual crack width is obtained. For example, there are ten crack images, and the values ​​of the calculated crack width and the actual crack width are shown in the following table:

[0081] Picture Number Calculated Crack Width Wcal (cm) Actual Crack Width Wact (cm) Difference (cm) 1 3.1 3.2 0.1 2 4.2 4.1 -0.1 3 4.3 4.1 -0.2 4 5.2 5.0 -0.2 5 3.5 3.7 0.2 6 4.6 4.3 -0.3 7 5.4 5.2 -0.2 8 4.5 4.3 -0.2 9 3.7 3.8 0.1 10 3.4 3.6 0.2

[0082] The average value of the difference is -0.06 cm, therefore, the calculated crack width W is added with 0.06 cm to obtain the crack correction width W, which can be displayed on the display module 22. This makes the width displayed by the display device closer to the actual width of the crack.

[0083] For cameras with fixed focal length, since the focal length f of the camera is a fixed value, the above calibration method can be used to display the concrete crack width, or the crack width can be displayed by calculation and / or fitting correction. For cameras with variable focal length, it is suitable to display the crack width by calculation and / or fitting correction, and the camera only needs to feed back the focal length f when shooting the image to the calculation module.

[0084] On this basis, no matter whether a fixed-focus camera or a zoom camera is used, the calculation module 21 can send the numerical value of the actual width of the crack to the display module 22, and the numerical value of the actual width of the crack is displayed by the display module 22. When a fixed-focus camera is used and the calibration mode is matched for display, a scale 23 can be set on the display module 22 according to the one-to-one correspondence between the crack width in the aforementioned display device 20 and the actual width of the crack, so that the actual width of the crack can be directly read manually. On this basis, the scale 23 is set in the middle position of the display module 22 to facilitate manual viewing and reading.

[0085] In one embodiment, a positioning member 14 is installed inside the pipe fitting 11, and the camera can be connected to the positioning member 14 by means of fixed connection, clamping, etc.; the first camera 12 directly faces the inner wall of the detection hole 31 to photograph the concrete cracks on the inner wall of the detection hole 31. The pipe fitting 11 can be transparent or opaque. If the pipe fitting 11 is opaque, a through hole can be opened on the inner wall of the pipe fitting 11 opposite to the first camera 12 so that the first camera 12 can photograph the inner wall of the detection hole 31.

[0086] The camera further includes a second camera 15, and the second camera 15 faces the inner end wall of the detection hole 31, so that the crack width of the inner end face of the detection hole 31 can be measured.

[0087] The cross-section of the pipe fitting 11 can be circular, and the circular pipe fitting 11 forms a single-line contact with the detection hole 31. In another embodiment, the pipe fitting 11 forms a double-line contact with the inner wall of the detection hole 31, and the contact line is parallel to the axis of the detection hole 31. In this way, during the detection process, the detection component 10 is more stable. The following lists several specific ways to achieve a double-line contact between the pipe fitting 11 and the inner wall of the detection hole 31:

[0088] The first: as Figure 5 shown, the cross-section of the pipe fitting 11 is triangular, and the first camera 12 is installed at the apex of the triangle;

[0089] The second: as Figure 6 shown, the cross-section of the pipe fitting 11 is trapezoidal, and the first camera 12 is installed in the middle of the upper base of the trapezoid;

[0090] The third: as Figure 7 shown, the cross-section of the pipe fitting 11 is crown-shaped, and the first camera 12 is installed in the middle of the arc opposite to the straight edge of the crown shape.

[0091] The above gives several specific structures of the pipe fitting 11 in the present disclosure. It can be understood that in practice, the specific structure of the pipe fitting 11 in the present disclosure is not limited to the above several, as long as the pipe fitting 11 and the inner wall of the detection hole 31 are in two-line contact.

[0092] Since the detection hole 31 is a long and narrow small hole, after drilling, there may be concrete or stones remaining in the detection hole 31. In order to prevent the pipe fitting 11 of the detection component 10 from being impacted or scratched by the remaining concrete or stones when extending into the detection hole 31, in one embodiment, an anti-collision portion 111 for preventing the pipe fitting 11 from colliding with the inner wall of the detection hole 31 is provided at the end of the pipe fitting 11 where the camera is installed. The following lists several specific ways of the anti-collision portion 111:

[0093] The first: as Figure 1 shown, the inner end of the pipe fitting 11 is provided with a chamfer to form the anti-collision portion 111;

[0094] The second type: As Figure 4 shown, the inner end of the pipe fitting 11 is a spherical crown body or a conical body with a cross-section gradually decreasing from the outside to the inside to form an anti-collision part 111.

[0095] The above gives several specific structures of the anti-collision part 111 in the present disclosure. It can be understood that in practice, the specific structure of the anti-collision part 111 in the present disclosure is not limited to the above several types, as long as the cross-section of the front end of the pipe fitting 11 decreases. The front end of the pipe fitting 11 refers to the end where the camera is installed.

[0096] In one embodiment, the positioning member 14 is further provided with at least one light source 13 around the camera to increase the brightness in the detection hole 31 and facilitate clear imaging. In one embodiment, six light sources 13 are provided.

[0097] To ensure the shooting effect of the camera, at least a part of the pipe fitting 11 of the detection component 10 is set as a transparent pipe body, and the transparent pipe body corresponds to the camera and the light source. In this way, the transparent pipe body can not only play a role in transmitting light, ensuring that the camera and the light source can directly shoot or irradiate the concrete cracks outside the transparent pipe body, but also play a role in protecting the camera and the light source. The pipe bodies at other positions can be set as non-transparent pipe bodies or transparent pipe bodies.

[0098] In another specific embodiment, in some cases, the transparent pipe body will form a reflection under the irradiation of the light source 13, affecting the shooting effect. For this reason, in one embodiment, the detection component 10 further includes an anti-reflection structure, and the anti-reflection structure is used to prevent the reflected light of the pipe fitting 11 from entering the first camera 12.

[0099] In one embodiment, as Figure 8 shown, the pipe fitting 11 includes a support pipe section 112, and the anti-reflection structure is an extension section 113 provided outside the support pipe section 112 and extending inward. The extension section 113 is used to correspond to the inner side wall of the detection hole 31, and the positioning member 14 is provided on the extension section 113. In this way, the camera connected to the extension section 113 can directly shoot the wall, avoiding the reflection phenomenon.

[0100] A shielding member 115 is further provided in front of the extension section 113. The function of the shielding member 115 is to prevent the camera and the light source 13 from being impacted or rubbed by the inner side wall of the detection hole 31. Similarly, the shielding member 115 can also be provided with an anti-collision part structure to avoid collision or scratching.

[0101] In another embodiment, as Figure 9 and 12As shown, the anti-reflection structure is a through hole 114 formed in the pipe fitting 11. The through hole 114 corresponds to the light source 13, and the diameter of the through hole 114 is not less than the illumination range of the light source 13. So that the camera can directly photograph the wall without reflection, ensuring clear imaging.

[0102] The following will describe the concrete crack detection method in detail with specific embodiments. The present disclosure provides a concrete crack detection method, including the following steps:

[0103] Drilling step: Drill a detection hole 31 in the component 30 to be detected;

[0104] Crack finding step: Insert the detection component 10 in the concrete crack detection device described in any one of the above into the detection hole 31, move the detection component 10 so that the camera faces the crack directly and the crack imaging is the clearest;

[0105] Reading step: Check the display device 20 and read the actual width of the crack. When reading, different width values are read at different positions of the crack, and the average value of multiple width values is taken as the final reading.

[0106] The detection hole 31 can be a blind hole or a through hole; in one embodiment, the detection hole 31 is a blind hole, and the depth of the detection hole 31 satisfies the following conditions:

[0107] The distance L1 from the inner end surface of the detection hole 31 to the joint surface of the blade and the cast-in-place layer is equal to the distance L2 from the end surface of the pipe fitting 11 where the camera is installed to the center of the camera.

[0108] The detection object is the composite wall of a prefabricated building. The composite wall includes an inner blade and an outer blade arranged oppositely. The cavity between the two blades is used for cast-in-place concrete. For the composite wall, concrete cracks are likely to occur at the joint of the blade and the cast-in-place layer. Therefore, in order to improve the detection accuracy, the drilling depth needs to be calculated before drilling so that the distance L1 from the inner end surface of the detection hole 31 to the joint surface between the blade and the cast-in-place layer is equal to the distance L2 from the end surface of the pipe fitting 11 where the camera is installed to the center of the camera. This can ensure that the camera is basically aligned with the crack in the vertical direction and it is easier to find the crack.

[0109] In one embodiment, the specific process of the crack finding step includes:

[0110] Keep the first camera 12 facing the inner side wall of the detection hole 31, rotate the pipe fitting 11 to find the crack; move the pipe fitting 11 back and forth, observe the imaging of the crack, compare the positions and clarity of the crack imaging multiple times, and find the image where the crack imaging is located in the middle of the display module and is clear.

[0111] Regarding "the camera 12 faces the inner side wall of the detection hole 31", when the cross-section of the pipe fitting 11 is circular, such asFigure 10 , Figure 11 As shown in Figure 11 , it means that the pipe wall facing the first camera 12 is in single-line contact with the inner wall of the detection hole 31. For pipe bodies with cross-sections such as triangles, trapezoids, or circular crowns that are in double-line contact with the detection hole 31, such as Figure 5 , 6 As shown in 6 and

[0112] , it means to rotate while maintaining the double-line contact state, that is, the state where the two vertices of the bottom edge facing the first camera 12 are in contact with the inner wall of the detection hole 31. This is because the first camera 12 is usually preset at the middle position of the double-line contact. Therefore, the double-line contact can ensure that the first camera 12 faces the inner wall of the detection hole 31. In this way, when a crack is found by rotating the pipe fitting 11, the point O on the pipe wall facing the first camera 12 can be made to face the crack on the inner wall of the detection hole 31. Then, the distance from the focus of the first camera 12 to the inner wall of the detection hole 31 is the distance L from the focus of the first camera 12 to the crack. At this time, the detection result is relatively accurate.

[0112] It should be noted that in this crack-finding step, the order of rotating the pipe fitting 11 and moving the pipe fitting 11 forward and backward is not specifically limited. When the drilling depth of the detection hole is relatively accurate, the pipe fitting 11 can be rotated first and then moved forward and backward to fine-tune the pipe fitting 11; if the drilling depth is inaccurate, the pipe fitting 11 can be moved forward and backward first and then rotated. It is also possible to rotate the pipe fitting 11 while moving it forward and backward until a clear image of the concrete crack is seen.

[0113] In the reading step, the actual width of the concrete crack can be obtained and read in two ways.

[0114] The first method is to calibrate first, then detect and display: During calibration, multiple standard test blocks with different sizes are set. Multiple standard test blocks can be provided with detection holes of multiple preset sizes. The inner walls of the detection holes of multiple standard test blocks are photographed by the detection component 10 of the present disclosure, and the distance from the lens of the first camera 12 of the present disclosure to the inner walls of multiple detection holes is set as a preset distance. After detection, the width of the crack is displayed through a display device, and the photographed width W_photo of the concrete crack in various combination modes of each standard test block, each detection hole, and the distance from each lens to the inner wall is recorded. Since the width of the concrete crack photographed for each standard test block can be accurately measured by a measuring tool, the actual width W_real of the concrete crack in various combination modes of each detection hole and the distance from each lens to the inner wall is recorded. Furthermore, the one-to-one correspondence between the photographed width W_photo and the actual width W_real in each case is recorded, and the above correspondence is built into the display device.

[0115] After setting this correspondence, further calibration is achieved through a calibration scale or an image scaling device, so that the display device can directly display the actual width of the concrete crack.

[0116] For example, the correspondence between the shooting width Wshoot and the actual width Wact is 1:5. That is, if the shooting width Wshoot is 1 mm, after conversion according to the correspondence, the actual width Wact is 5 mm.

[0117] The first method: The calibration unit scale can be set to 5 times the standard unit scale. That is to say, the display device 20 displays the original captured image, but the scale value is 5 times the original. That is, a crack width of 1 mm in the image is read as 5 mm after calibration. This method is "image unchanged, scale calibration".

[0118] The second method: The original image can be magnified to 5 times the original through an image scaling device, and the scale is displayed as the standard unit scale. In this way, after being read by the display device, 1 mm in the original image is displayed as 5 mm after being read by the display device. This method is "image scaling, scale unchanged".

[0119] It can be seen that when detecting the concrete cracks of the laminated wall, after the display device obtains the shooting width Wshoot, it obtains the actual width Wact corresponding to the shooting width Wshoot in the current situation through the built-in calibration relationship, and then directly displays Wact on the display device 20 in the way of "image unchanged, scale calibration" or "image scaling, scale unchanged" according to the correspondence. In this way, the user can directly obtain the actual width of the concrete crack by observing the display device 20.

[0120] Of course, the above display device is not limited to displaying the actual crack width in the way of "image unchanged, scale calibration" or "image scaling, scale unchanged", and can also be directly displayed in numbers.

[0121] The second method can calculate the crack width in real time by calculation. Specifically, the display device 20 includes a calculation module 21 and a display module 22; the calculation module 21 is used to calculate the crack width Wcal according to the focal length f of the first camera 12, the diameter d of the lens of the first camera 12, the distance L from the focus of the first camera 12 to the inner wall of the detection hole 31, the pixel points D1 of the crack 32 in the crack picture along the crack width direction, and the pixel points D2 of the crack picture along the crack width direction, and send it to the display module 22, and the display module 22 is used to display the crack width Wcal. The specific principle of the calculation by the calculation module 21 is:

[0122] The relationship between the width H of the crack 32 in the crack picture, the pixel points D1 of the crack 32 in the crack picture along the crack width direction, the pixel points D2 of the crack picture along the crack width direction, and the crack width Wcal is:

[0123] Wcal = HD1 / D2 A

[0124] Such as Figure 3As shown, the relationship between the focal length f of the camera 12, the diameter d of the lens of the camera 12, the distance L from the focus of the camera 12 to the inner wall of the detection hole 31, and the width H of the crack 32 in the crack picture is:

[0125] H = Ld / f B

[0126] Combining Equation A and Equation B, we can obtain:

[0127] W_calculated = LdD1 / fD2 C

[0128] Through Equation C, the width of the concrete crack can be calculated, and it can be directly read by the user through the display module 22.

[0129] On the basis of the above calculation, in order to further reduce the error in the calculation process and improve the accuracy, it can be corrected by fitting through multiple experiments. Through experiments, a one-to-one correspondence between the calculated crack width and the actual crack width is obtained. For example, there are ten crack pictures, and the values of the calculated crack width and the actual crack width are shown in the following table:

[0130] Picture Number Calculated Crack Width (cm) Actual Crack Width (cm) Difference (cm) 1 3.1 3.2 0.1 2 4.2 4.1 -0.1 3 4.3 4.1 -0.2 4 5.2 5.0 -0.2 5 3.5 3.7 0.2 6 4.6 4.3 -0.3 7 5.4 5.2 -0.2 8 4.5 4.3 -0.2 9 3.7 3.8 0.1 10 3.4 3.6 0.2

[0131] The average value of the differences is -0.06 cm. Therefore, adding 0.06 cm to the calculated crack width gives the corrected crack width W_corrected, and the corrected crack width W_corrected can be displayed through the display module 22. This makes the width displayed by the display device closer to the actual crack width.

[0132] In one embodiment, it further includes the steps of:

[0133] Taking and storing images: Before or after the reading step, take a crack image and store it.

[0134] The display device 20 may be provided with a storage module 24 for storing images for subsequent analysis.

[0135] In the description of this specification, the description with reference to terms such as "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments / ways or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments / ways or examples described in this specification and the features of different embodiments / ways or examples.

[0136] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0137] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present disclosure and are not intended to limit the scope of the present disclosure. For those skilled in the art, other changes or modifications can be made based on the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. Concrete crack detection device, Characterized in that, Comprising: A detection component (10) and a display device (20), the detection component (10) comprising: A pipe fitting (11), which is columnar and is used for inserting into a narrow detection hole (31) of a component (30) to be detected; A camera, connected to the pipe fitting (11), the camera comprising a first camera (12), the first camera (12) being used to be arranged facing the inner wall of the detection hole (31), taking pictures of cracks on the inner wall of the detection hole (31), and sending them to the display device (20); The display device (20) displays the actual width of the crack according to the crack picture; The camera is a fixed-focus camera, or the camera is a zoom camera, which is used to automatically focus according to the clarity of the crack and feed back the current focal length to the display device (20) when a clear image of the crack is captured; Corresponding to the fixed-focus camera, the display device (20) is provided with a scale (23) representing the actual width of the crack, and the scale (23) is set according to the corresponding relationship between the photographed width of the concrete crack calibrated in advance and the actual width of the crack; The display device (20) comprises a calculation module (21) and a display module (22); the calculation module (21) is used to calculate the actual width W of the crack according to the focal length f of the first camera (12), the diameter d of the lens of the first camera (12), the distance L from the focus of the first camera (12) to the inner wall of the detection hole (31), the number of pixel points D1 of the crack along the crack width direction in the crack picture, and the number of pixel points D2 of the crack picture along the crack width direction, and send it to the display module (22), and the display module (22) is used to display the actual width W of the crack; W, f, d, L, D1 and D2 satisfy the relation: W = LdD1 / fD2.

2. The concrete crack detection device according to claim 1, Characterized in that, The pipe fitting (11) is used to form a double-line contact with the inner wall of the detection hole (31), and the contact line is parallel to the axis of the detection hole (31).

3. The concrete crack detection device according to claim 2, Characterized in that, The cross section of the pipe fitting (11) is triangular, and the first camera (12) is installed at the apex of the triangle; or, The cross section of the pipe fitting (11) is trapezoidal, and the first camera (12) is installed in the middle of the upper base of the trapezoid; or, The cross section of the pipe fitting (11) is crown-shaped, and the first camera (12) is installed in the middle of the arc facing the straight edge of the crown shape.

4. The concrete crack detection device according to claim 1, Characterized in that, An anti-collision part (111) for preventing the pipe fitting (11) from colliding with the inner wall of the detection hole (31) is provided at the end of the pipe fitting (11) where the camera is installed.

5. The concrete crack detection device according to claim 4, Characterized in that, A chamfer is provided at the inner end of the pipe fitting (11) to form the anti-collision part (111); or, The inner end of the pipe fitting (11) is a spherical crown or a cone with a cross-section gradually decreasing from outside to inside to form the anti-collision part (111).

6. The concrete crack detection device according to claim 1, characterized in that, the camera is connected to the pipe fitting (11) through a positioning member (14), and at least one light source (13) is further provided around the camera by the positioning member (14); at least a part of the pipe fitting (11) is a transparent pipe body, and the transparent pipe body is arranged corresponding to the camera and the light source (13).

7. The concrete crack detection device according to claim 6, characterized in that, the detection component (10) further includes an anti-reflection structure, and the anti-reflection structure is used to prevent the reflected light of the pipe fitting (11) from entering the first camera (12).

8. The concrete crack detection device according to claim 7, characterized in that, the pipe fitting (11) includes a support pipe section, the anti-reflection structure is an extension section arranged outside the support pipe section and extending inwards, the extension section is used to correspond to the inner side wall of the detection hole (31), and the positioning member (14) connecting the first camera (12) is arranged on the extension section.

9. The concrete crack detection device according to claim 7, characterized in that, the anti-reflection structure is a through hole opened in the pipe fitting (11), the through hole corresponds to the light source (13), and the diameter of the through hole is not less than the illumination range of the light source (13).

10. The concrete crack detection device according to claim 1, characterized in that, the camera further includes a second camera (15), and the second camera (15) is arranged facing the inner end wall at the front end of the detection hole (31).

11. A concrete crack detection method, characterized in that, including the following steps: Drilling step: drilling a detection hole (31) in the component to be detected (30); Crack finding step: inserting the detection component (10) in the concrete crack detection device according to any one of claims 1-10 into the detection hole (31), moving the detection component (10) to make the camera face the crack and the crack imaging is the clearest; Reading step: checking the display device (20) and reading the actual width of the crack.

12. The concrete crack detection method according to claim 11, characterized in that, in the drilling step, the detection hole (31) is a blind hole, and the depth of the detection hole (31) satisfies the following conditions: The distance L1 from the inner end face of the detection hole (31) to the joint surface of the blade and the cast-in-place layer is equal to the distance L2 from the end face of the end of the pipe fitting (11) where the camera is installed to the center of the camera.

13. The concrete crack detection method according to claim 11, characterized in that, the specific process of the crack finding step includes: Keeping the first camera (12) facing the inner side wall of the detection hole (31), rotating the pipe fitting (11) to find the crack; Moving the pipe fitting (11) back and forth, observing the imaging of the crack, comparing the positions and clearness of the crack imaging multiple times, and finding the image where the crack imaging is located in the middle of the display module and is clear.

14. The concrete crack detection method according to claim 11, characterized in that, The specific process of the reading step is as follows: The display device (20) obtains the actual width W of the crack based on the focal length f of the first camera (12), the diameter d of the lens of the first camera (12), the distance L from the focus of the first camera (12) to the inner wall of the detection hole (31), the number of pixels D1 of the crack along the crack width direction in the crack image, and the number of pixels D2 of the crack image along the crack width direction; W, f, d, L, D1, and D2 satisfy the relational expression: W = LdD1 / fD2.

15. The concrete crack detection method according to claim 11, characterized in that, before the drilling step, it further includes a calibration step, and the specific process of the calibration step includes: using the preset detection component to photograph the inner walls of a plurality of preset detection holes, recording the photographed width W_photo of the concrete crack, recording the actual width W_real of the concrete crack, and establishing a one-to-one correspondence between the photographed width W_photo and the actual width W_real; setting a scale on the display device according to the correspondence relationship so that the reading of the display device is the actual width W_real.

16. The concrete crack detection method according to claim 11, characterized in that, it further includes the step of: photographing and storing an image: before or after the reading step, photograph the crack image and store it.

Images