Real-time detection device and control method of concrete appearance based on machine vision

Abstract

The present invention provides a real-time detection device and control method for concrete appearance based on machine vision. The device comprises a transparent template mounted on a template, the transparent template being used to observe the appearance of the concrete; a slide rail is provided on one side of the transparent template, a sliding seat is provided on the slide rail, the sliding seat is connected to one end of a connecting rod, and a camera is provided on the other end of the connecting rod, the camera facing the transparent template for capturing images of the concrete. During use, an image of the concrete range is obtained through the transparent template; the image is binarized and threshold segmented to obtain a bubble image; statistics are collected based on bubble distribution, bubble pixels, bubble size, and bubble morphology; and the above steps enable real-time detection of the concrete appearance. The present invention can detect the appearance quality of concrete in real time and identify bubble images, thereby facilitating the implementation of appropriate measures to remedy defects during the pouring process.

Description

Technical Field

[0001] The present invention relates to the field of concrete pouring construction quality control, and in particular to a real-time concrete appearance detection device and control method based on machine vision. Background Art

[0002] With my country's substantial investment in and construction of transportation infrastructure, concrete is increasingly being used in highways and railways, and the requirements for its appearance are becoming increasingly stringent. The evaluation of concrete's appearance quality is a key indicator for the overall quality assessment of a project, and plays a crucial role in project quality. Bubbles, a major surface quality defect of concrete, are small pits that appear on the concrete surface after pouring. These pits, typically regular or irregular, have a nearly circular outline and severely affect the appearance quality of concrete. Currently, the appearance quality of concrete is primarily tested manually, relying on the subjective judgment of the inspector. This results in low accuracy and high costs, and testing can only be performed after the concrete has been formed. Subsequent processing, however, requires only post-processing modifications. Therefore, accurate, real-time inspection of concrete appearance during the concrete vibration process, along with the provision of timely remedial measures, is crucial for improving the structural and appearance quality of concrete. Chinese patent document CN111060521A records a method for detecting the number and area of ​​bubbles on the surface of precast concrete T-beams, which mentions steps such as image grayscale conversion, binarization processing, bubble contour recognition, and bubble contour drawing. However, this solution is highly dependent on image quality. If unavoidable reflection and reflection defects appear on the surface of the transparent template, the recognition accuracy is greatly reduced. The same problem also exists in CN110146511A, a method for detecting bubbles in plain concrete. Some devices are also recorded in the prior art, such as CN211179562U, a concrete surface bubble detection device, which uses a trolley structure to detect the concrete surface, and CN210742138U, a concrete surface bubble detection device, which uses a frame structure for detection. The above-mentioned devices are all relatively complex in structure and inconvenient to use. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a real-time detection device for concrete appearance based on machine vision, which can detect the appearance of concrete in real time and has a simple structure and is easy to use.

[0004] Another technical problem to be solved by the present invention is to provide a control method for a real-time detection device of concrete appearance based on machine vision, which can count bubble data and take corresponding vibration measures to solve concrete appearance defects during the pouring process.

[0005] To solve the above technical problems, the technical solution of the present invention is: a real-time detection device for concrete appearance based on machine vision, comprising a transparent template set on a template, the transparent template being used to observe the appearance of concrete;

[0006] A slide rail is provided on one side of the transparent template, a slide seat is provided on the slide rail, the slide seat is connected to one end of a connecting rod, and a camera is provided on the other end of the connecting rod. The camera faces the transparent template and is used to collect images of concrete.

[0007] In the preferred solution, the cross-section of the sliding seat is a "C"-shaped structure, and a plurality of pressure wheels are provided on the inner side wall of the sliding seat. The pressure wheels are installed in the slide groove through a rotating shaft. The wheel surface of the pressure wheel is pressed against the side wall of the slide rail. A spring is provided between the rotating shaft and the sliding seat to press the wheel surface against the side wall of the slide rail. When the spring is pressed down, the rotating shaft of the pressure wheel slides in the slide groove, and the wheel surface leaves the side wall of the slide rail.

[0008] In a preferred solution, a motor is further provided on the seat body, the output shaft of the motor is connected to the travel wheel, the outer edge of the travel wheel is provided with teeth, a toothed belt is provided on the side wall of the slide rail, and the travel wheel is meshed with the toothed belt.

[0009] In a preferred solution, a control board and a battery are further provided in the sliding seat. The control board is electrically connected to the camera, and the control board is also electrically connected to the motor.

[0010] A control method using the above-mentioned machine vision-based real-time concrete appearance detection device includes the following steps:

[0011] S1. Set a transparent template in the template;

[0012] S2, using a camera to collect images of the concrete surface;

[0013] S3, obtaining a concrete range image;

[0014] S4, performing binarization processing on the image and performing threshold segmentation to obtain a bubble image;

[0015] S5, performing edge detection on the bubbles in the bubble image to obtain a closed edge image of each bubble;

[0016] S6. Counting the bubble distribution, bubble pixels, bubble size, and bubble morphology;

[0017] The above steps can realize real-time detection of concrete appearance.

[0018] In a preferred solution, in step S4, the concrete range image is first preprocessed. The preprocessing method is to copy the concrete range image as the bottom image, invert the bottom image, and reduce the transparency of the bottom image by 10% to 40%. The upper concrete range image and the bottom image are subjected to brightness calculation along each pixel: X×Y / 255; where X is the current pixel brightness value of the original image; Y is the current pixel brightness value of the preprocessed bottom image.

[0019] In a preferred solution, for concrete surfaces with a relatively large bubble area, a vibrating device with an exhaust function is used for vibration.

[0020] In a preferred solution, bubbles on the concrete surface at or near the horizontal plane are vibrated by a vibrating device with adjustable specific gravity.

[0021] In the preferred solution, the structure of the vibrating device is as follows: a rotating shaft is provided in the cylinder, the rotating shaft is connected to the eccentric vibrating block, the outer wall of the cylinder is a grid structure, an air-permeable and water-blocking layer is provided outside the grid structure, and the cylinder is connected to the exhaust device through an exhaust pipe.

[0022] In a preferred embodiment, the structure of the vibrating device is as follows: a rotating shaft is provided in the cylinder, the rotating shaft is connected to a plurality of eccentric vibrating blocks, a specific gravity adjustment capsule is provided in the cylinder, the specific gravity adjustment capsule is connected to an inlet pipe and an outlet pipe, and the inlet pipe and the outlet pipe are used to fill the specific gravity adjustment capsule with media of different specific gravities;

[0023] The vibrating device is configured to respectively make the overall specific gravity greater than, equal to, and less than the specific gravity of concrete by inputting media with different specific gravities.

[0024] The present invention provides a real-time detection device and control method for concrete appearance based on machine vision, which can detect the appearance quality of concrete in real time, and can complete the collection of concrete appearance images by using a structure that travels along a monorail. The structure is very simple, and it is very convenient to use and operate, and it is highly adaptable to templates of various structures. In the method of the present invention, the influence of reflections and inversions on bubble recognition can be overcome, and the recognition accuracy and efficiency are high. The present invention adopts vibration measures, which can help concrete exhaust through auxiliary exhaust functions, thereby reducing bubbles. By adopting a specific gravity adjustment function, the vibration device can reach positions where vibration is unfavorable, such as the upper surfaces of the two wings at the bottom of the T-beam, thereby improving the appearance quality of concrete at these positions. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and examples:

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0027] Figure 2 It is a structural schematic diagram of the sliding seat in the present invention.

[0028] Figure 3 For the present invention Figure 2 AA cross-sectional view of .

[0029] Figure 4 This is a concrete surface map collected on-site in the present invention.

[0030] Figure 5 This is a flowchart of the image processing of the present invention.

[0031] Figure 6 This is an interface diagram of the bubble statistics software of the present invention.

[0032] Figure 7 It is a structural schematic diagram of the vibration device of the present invention.

[0033] Figure 8 for Figure 7 BB cross-sectional diagram.

[0034] In the figure: transparent formwork 1, concrete 2, sliding seat 3, seat body 31, spring 32, pressure wheel 33, walking wheel 34, control panel 35, battery 36, rotating shaft 37, slide 38, motor 39, contact switch 30, connecting rod 4, camera 5, slide rail 6, toothed belt 61, vibrating device 7, exhaust pipe 71, inlet pipe 72, discharge pipe 73, rotating shaft 74, eccentric vibrating block 75, specific gravity adjustment capsule 76, cylinder 77, air-permeable and water-blocking coating 78, bubble 8. DETAILED DESCRIPTION

[0035] Example 1:

[0036] like Figures 1-3 In the present invention, a real-time detection device for concrete appearance based on machine vision includes a transparent template 1 set on the template, and the transparent template 1 is used to observe the appearance of concrete 2; preferably, the transparent template 1 is made of PC or acrylic material.

[0037] like Figure 1 In the figure, a slide rail 6 is provided on one side of the transparent template 1, a slide seat 3 is provided on the slide rail 6, the slide seat 3 is connected to one end of a connecting rod 4, and a camera 5 is provided at the other end of the connecting rod 4. The camera 5 faces the transparent template 1 and is used to collect images of the concrete 2.

[0038] The preferred solution is Figure 3The cross section of the sliding seat 3 is C-shaped. Multiple pressure rollers 33 are provided on the inner sidewall of the sliding seat 3. These pressure rollers 33 are mounted within slots 38 via rotating shafts 37. The rollers 33 press against the sidewalls of the slide rail 6. A spring 32 is provided between the rotating shaft 37 and the sliding seat 3 to press the rollers against the sidewalls of the slide rail 6. When the spring 32 is depressed, the rotating shaft 37 of the pressure rollers 33 slides within the slots 38, freeing the rollers from the sidewalls of the slide rail 6. These pressure rollers 33 serve as guides and limiters, making installation and removal very convenient.

[0039] The preferred solution is Figure 2 、 3 In the figure, a motor 39 is also provided on the base 31, and the output shaft of the motor 39 is connected to the travel wheel 34. The outer edge of the travel wheel 34 is provided with teeth, and a toothed belt 61 is provided on the side wall of the slide rail 6. The travel wheel 34 is meshed and connected with the toothed belt 61.

[0040] The preferred solution is Figure 2 In the embodiment, a control board 35 and a battery 36 are also located within the sliding base 3. The control board 35 is electrically connected to the camera 5 and the motor 39. The main control CPU of the control board 35 uses an STM32F series chip, and the image acquisition chip uses a USB bus-based video decoder chip SAA7113H and a USB control chip CY7C68013. The main control CPU also controls the movement of the motor 39 by outputting pulse signals. Preferably, contact switches 30 are also located at both ends of the sliding base 3. The contact switches 30 are in contact with the main control CPU and serve as switching signals.

[0041] When in use, fix the slide rail 6 to the side of the transparent template 1 that needs to be inspected, install the sliding seat 3 on the slide rail 6 and start working. Remote control can be achieved through the added wireless communication chip, such as WiFi, Bluetooth, LoRa or radio frequency chip. The image collected by the camera 5 is decoded by the video decoding chip SAA7113H and stored in the memory.

[0042] Example 2:

[0043] like Figure 4 、 5 A control method for the above-mentioned device for real-time detection of concrete appearance based on machine vision comprises the following steps:

[0044] S1. Set a transparent template 1 in the template. The transparent template 1 can be arranged globally or in sections. In particular, the transparent template 1 needs to be arranged on the upper surface of a horizontal position, where bubbles are likely to accumulate.

[0045] S2, using a camera to collect images of the surface of concrete 2; collecting images of the surface of concrete by remote control or automatic control. Figure 4As shown in .

[0046] S3, obtain the concrete range image; Figure 5 As shown in , an edge detection algorithm, such as the halcon detection operator, can be used to obtain the concrete range image.

[0047] S4, performing binarization processing on the image and performing threshold segmentation to obtain a bubble image;

[0048] The preferred solution is Figure 5 In the preprocessing method, the concrete range image is first preprocessed. The preprocessing method is to copy the concrete range image as the bottom image, invert the bottom image, and reduce the transparency of the bottom image by 10% to 40%. The brightness calculation of each pixel of the upper concrete range image and the bottom image is performed: X×Y / 255; where X is the brightness value of the current pixel in the original image; Y is the brightness value of the current pixel in the preprocessed bottom image.

[0049] S5, performing edge detection on the bubbles in the bubble image to obtain a closed edge image of each bubble;

[0050] S6. Counting the bubble distribution, bubble pixels, bubble size, and bubble morphology;

[0051] The above steps can realize real-time detection of concrete appearance.

[0052] In a preferred solution, for concrete with a relatively large bubble area on the surface, a vibrating device 7 with an exhaust function is used for vibration.

[0053] In a preferred solution, bubbles on the concrete surface at or near the horizontal plane are vibrated by a vibrating device with adjustable specific gravity.

[0054] The preferred solution is Figure 7 、 8 In the figure, the vibrating device 7 is constructed as follows: a rotating shaft 74 is mounted within a cylindrical body 77, connected to an eccentric vibrating block 75. The outer wall of the cylindrical body 77 comprises a lattice structure, with an air-permeable and water-blocking layer 78 positioned outside the lattice structure. The cylindrical body 77 is connected to the exhaust device via an exhaust pipe 71. The air-permeable and water-blocking layer 78 is made of Oxford cloth and is typically replaced after 5-10 uses. Continuous air extraction maintains a negative pressure within the cylindrical body 77, allowing bubbles in the concrete to be easily expelled from the cylindrical body 77.

[0055] The preferred solution is Figure 7 、 8In the figure, the structure of the vibrating device 7 is as follows: a rotating shaft 74 is provided in the cylinder 77, the rotating shaft 74 is connected to a plurality of eccentric vibrating blocks 75, a specific gravity adjusting capsule 76 is provided in the cylinder 77, the specific gravity adjusting capsule 76 is connected to the inlet pipe 72 and the outlet pipe 73, the inlet pipe 72 and the outlet pipe 73 are used to fill the specific gravity adjusting capsule 76 with media of different specific gravities; the media in this example are water and air.

[0056] Vibrating device 7 is configured to adjust the overall specific gravity to greater than, equal to, or less than that of concrete 2 by injecting media of varying specific gravities. The cylinder 77 and eccentric mass are constructed of aluminum alloy. When water is injected into the specific gravity-adjusting bladder 76, the specific gravity of vibrating device 7 is 2.6. When air is injected, the specific gravity of vibrating device 7 is between 1.5 and 2.0. This ensures that vibrating device 7 floats on the surface of the concrete, allowing accumulated bubbles to be easily expelled or displaced through negative pressure.

[0057] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The embodiments and features in the embodiments of this application may be arbitrarily combined with each other unless they conflict. The scope of protection of the present invention shall be the technical solutions described in the claims, including equivalent alternatives to the technical features of the technical solutions described in the claims. Equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A real-time detection device for concrete appearance based on machine vision, characterized by: It comprises a transparent template (1) arranged on the template, and the transparent template (1) is used to observe the appearance of concrete (2); A slide rail (6) is provided on one side of the transparent template (1), a slide seat (3) is provided on the slide rail (6), the slide seat (3) is connected to one end of a connecting rod (4), and a camera (5) is provided at the other end of the connecting rod (4), and the camera (5) faces the transparent template (1) and is used to collect images of the concrete (2); For bubbles on the concrete surface at or near the horizontal plane, use a vibrating device with adjustable specific gravity to vibrate; The structure of the vibrating device (7) is as follows: a rotating shaft (74) is provided in a cylinder (77), the rotating shaft (74) is connected to a plurality of eccentric vibrating blocks (75), a specific gravity adjusting capsule (76) is provided in the cylinder (77), the specific gravity adjusting capsule (76) is connected to an inlet pipe (72) and an outlet pipe (73), and the inlet pipe (72) and the outlet pipe (73) are used to fill the specific gravity adjusting capsule (76) with media of different specific gravities; The vibrating device (7) is configured to respectively make the overall specific gravity greater than, equal to, and less than the specific gravity of the concrete (2) by inputting media with different specific gravities.

2. The device for real-time detection of concrete appearance based on machine vision according to claim 1 is characterized in that: The cross section of the sliding seat (3) is a "C"-shaped structure. A plurality of pressure wheels (33) are provided on the inner side wall of the sliding seat (3). The pressure wheels (33) are installed in the slide groove (38) through the rotating shaft (37). The wheel surface of the pressure wheel (33) is pressed against the side wall of the slide rail (6). A spring (32) is provided between the rotating shaft (37) and the sliding seat (3) to press the wheel surface against the side wall of the slide rail (6). When the spring (32) is pressed down, the rotating shaft (37) of the pressure wheel (33) slides in the slide groove (38), and the wheel surface leaves the side wall of the slide rail (6).

3. The device for real-time detection of concrete appearance based on machine vision according to claim 2 is characterized in that: A motor (39) is also provided on the seat body (31), and an output shaft of the motor (39) is connected to a travel wheel (34). The outer edge of the travel wheel (34) is provided with teeth. A toothed belt (61) is provided on the side wall of the slide rail (6), and the travel wheel (34) is meshedly connected with the toothed belt (61).

4. The device for real-time detection of concrete appearance based on machine vision according to claim 3 is characterized by: A control board (35) and a battery (36) are also provided in the sliding seat (3). The control board (35) is electrically connected to the camera (5). The control board (35) is also electrically connected to the motor (39).

5. A control method for a real-time detection device for concrete appearance based on machine vision according to any one of claims 1 to 4, characterized in that The following steps are involved: S1. Set a transparent template in the template (1); S2, using a camera to collect images of the surface of the concrete (2); S3, obtaining a concrete range image; S4, performing binarization processing on the image and performing threshold segmentation to obtain a bubble image; S5, performing edge detection on the bubbles in the bubble image to obtain a closed edge image of each bubble; S6. Counting the bubble distribution, bubble pixels, bubble size, and bubble morphology; The above steps can realize real-time detection of concrete appearance.

6. The control method of the device for real-time detection of concrete appearance based on machine vision according to claim 5 is characterized in that: In step S4, the concrete range image is preprocessed by copying the concrete range image as the underlying image, inverting the underlying image, and reducing its transparency by 10% to 40%. The upper layer concrete range image and the underlying image are then subjected to a brightness calculation along each pixel: X × Y / 255, where X is the brightness value of the current pixel in the original image, and Y is the brightness value of the current pixel in the preprocessed underlying image.

7. The control method of the device for real-time detection of concrete appearance using machine vision according to claim 5 is characterized by: For concrete with a relatively large bubble area on the surface, a vibrating device (7) with an exhaust function is used for vibration.

8. The control method of the device for real-time detection of concrete appearance using machine vision according to claim 7 is characterized by: The outer wall of the cylinder (77) is a grid structure, and a breathable and water-blocking cladding (78) is provided outside the grid structure. The cylinder (77) is connected to the exhaust device via an exhaust pipe (71).

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