Wood surface quality detection method and system
By employing upper, middle, and lower optical machinery and AI algorithms in the wood surface quality inspection system, simultaneous inspection of multiple wood surfaces is achieved, solving the problems of low efficiency and poor accuracy in existing technologies. It features high precision, high efficiency, and dustproof capabilities, making it suitable for automated inspection in wood processing enterprises.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN PRIMAX ELECTRONIC & TEKLECOM PROD LTD
- Filing Date
- 2025-12-05
- Publication Date
- 2026-05-12
AI Technical Summary
Existing wood surface quality testing devices are inefficient and inaccurate, making it difficult to simultaneously test multiple wood surfaces, and they are easily affected by high dust environments.
The system employs three optical engines (top, middle, and bottom) to simultaneously inspect the upper, side, and lower surfaces of the wood. By combining grayscale sensors, encoders, AI systems, and image preprocessing technology, it achieves automated and intelligent defect identification and classification.
It significantly improves detection efficiency and accuracy, with a defect detection rate of up to 98%, and has IP6 dustproof capability, making it suitable for high dust environments.
Smart Images
Figure CN122016795A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of product surface inspection technology, and specifically to a method and system for inspecting the surface quality of wood. Background Technology
[0002] Wood appearance inspection is mainly used to assess the surface quality and overall appearance characteristics of wood to ensure that it meets usage standards. Wood surface defects refer to physical or visual defects that appear on the surface of wood due to factors such as the growth environment or production processes during the growth or processing of the wood. Common wood surface defects include knots, discoloration, decay, insect damage, cracks, scars (damage), wood processing defects, and deformation.
[0003] Currently, the timber industry places great emphasis on the inspection process for timber surface quality. Most timber manufacturers on the market basically use manual visual inspection, which is not only inefficient and inaccurate, but also results in inconsistent opinions on defects among individuals, which is very detrimental to the standardization and automation of enterprises.
[0004] Currently available visual inspection devices place the camera at the top of a lightbox. For example, Chinese utility model patent application CN219496131U discloses a visual inspection device for wood surfaces, which includes: a lightbox with a first and second inclined side inside, and a diffuse reflector plate on the inclined side; a camera located at the top of the lightbox, with the camera lens inside the lightbox to capture a field of view (FOV) image of the wood surface within the inspection area; a first and second vertical side inside the lightbox, with a first light source at the bottom of the first vertical side and a second light source at the bottom of the second vertical side, distributed on both sides of the inspection area; the emitting surfaces of the first and second light sources are parallel to the diffuse reflector plates on the second and first inclined sides, respectively. The diffuse reflector plate provides diffuse reflection for the light emitted by the light source, reducing the directionality of the light and improving the uniformity of illumination within the lightbox, thereby obtaining a uniform and stable diffused light illumination area. Under this diffused light illumination area, the FOV image of the wood surface captured by the camera more realistically reproduces the wood surface, which is beneficial for the inspection of the FOV image of the wood surface.
[0005] The existing visual inspection device for wood surfaces uses a diffuser plate to provide diffuse reflection of the light emitted by the light source, making the lighting inside the lightbox uniform. However, the camera is located at the top of the lightbox and the wood is located at the bottom. When shooting downwards, only one side of the wood can be detected at a time. After shooting one side, the wood needs to be flipped over to continue the inspection. Furthermore, it is difficult to detect the sides of the wood, resulting in very limited detection efficiency. In addition, its dust resistance is poor. In high-dust environments such as wood processing plants, it is very easy for dust to adhere to the wood, causing blurry photos and rendering the system unable to operate.
[0006] In view of the above, the inventors propose the following technical solution. Summary of the Invention
[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method and system for detecting the surface quality of wood.
[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for detecting the surface quality of wood, comprising the following steps: Step 1: Use an encoder to sense the speed of the wood movement; Step 2: Collect color data information of the wood using a grayscale sensor; Step 3: Transmit the color data information collected by the grayscale sensor to the industrial computer; Step 4: The industrial computer analyzes the color data using an AI system and converts it into parameters; Step 5: Transfer the converted parameters to the visual inspection mechanism and the light source; Step 6: The visual inspection agency automatically adjusts the exposure value, gain, and number of scans based on the parameters, uses image preprocessing technology to enhance the texture features of the wood, and controls the brightness of the light source to correspond to the different colors and textures of the wood boards, thus achieving high-speed automatic inspection.
[0009] According to another aspect of the present invention, a wood surface quality inspection system includes a housing and a visual inspection mechanism disposed within the housing for photographing and inspecting wood panels. It further includes: an encoding device disposed on the housing for sensing the movement speed of the wood; a grayscale sensing device disposed on the housing for collecting wood color data; a recessed detection position on one side of the housing for allowing the wood panel to pass through; and the visual inspection mechanism includes an upper varnishing machine for photographing and scanning the upper surface of the wood panel, a lower varnishing machine for photographing and scanning the lower surface of the wood panel, and an intermediate varnishing machine for photographing and scanning the sides of the wood panel.
[0010] Furthermore, in the above technical solution, the detection position is provided with an upper transparent part for the upper line scanning camera to take pictures and scan; the detection position is provided with a lower transparent part for the lower line scanning camera to take pictures and scan; and the detection position is provided with a middle transparent part for the middle line scanning camera to take pictures and scan.
[0011] Furthermore, in the above technical solution, the housing is provided with a first cavity and a second cavity, the upper line scanning camera is disposed in the first cavity, and the lower line scanning camera and the middle line scanning camera are disposed in the second cavity.
[0012] Furthermore, in the above technical solution, the box is equipped with a light source for illuminating the wood to achieve supplemental lighting.
[0013] Furthermore, in the above technical solution, the encoding device includes an encoding bracket installed on the box, an encoder set on the encoding bracket for sensing the speed of wood movement, and a first support set on the box for supporting the wooden board.
[0014] Furthermore, in the above technical solution, the grayscale sensing device includes a sensor bracket mounted on the box, a second support part mounted on the sensor bracket for supporting the wooden board, and a grayscale sensing sensor mounted on the sensor bracket for collecting color data of the wooden board.
[0015] Furthermore, in the above technical solution, an adjustment mechanism for moving the box body is provided below the box body. The adjustment mechanism includes a first base plate, a first slide rail disposed on the first base plate, a first slider slidably disposed on the first slide rail, a first lifting frame mounted on the first slider and slidable therewith, an adjustment switch disposed on the first base plate and used to limit the movement of the first lifting frame, a first connecting plate fixed to the lower end of the box body, a first lifting slide rail disposed on the first connecting plate, and a first lifting cylinder disposed on the first lifting frame and connected to the first slide rail for lifting.
[0016] Furthermore, in the above technical solution, a shock-absorbing mechanism for reducing external vibration is provided above the housing. The shock-absorbing mechanism includes a second buffer frame disposed at the upper end of the housing and used to connect with the outside for shock absorption and buffering, and a second mounting frame slidably disposed on the second buffer frame. The second buffer frame is provided with a second slider, and the second mounting frame is provided with a second slide rail corresponding to the second slider.
[0017] Furthermore, in the above technical solution, the upper light-gathering machine includes an upper linear scanning camera, an upper focusing geared motor tractably mounted on the upper linear scanning camera and used to drive the upper linear scanning camera to perform automatic focusing, and an upper light-gathering sleeve mounted on the upper linear scanning camera. An upper flat lens is disposed within the upper light-gathering sleeve to refract external light into the upper light-gathering sleeve. The lower light-gathering machine includes a lower linear scanning camera, a lower focusing geared motor tractably mounted on the lower linear scanning camera and used to drive the lower linear scanning camera to perform automatic focusing, and a lower light-gathering sleeve mounted on the lower linear scanning camera. A lower flat lens is disposed within the lower light-gathering sleeve to refract external light into the lower light-gathering sleeve. The middle light-gathering machine includes a middle linear scanning camera, a middle focusing geared motor tractably mounted on the middle linear scanning camera and used to drive the middle linear scanning camera to perform automatic focusing, and a middle light-gathering sleeve mounted on the middle linear scanning camera.
[0018] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art: This invention addresses the low efficiency and large errors of traditional manual inspection of wood surfaces by employing three optical machines (top, middle, and bottom) to simultaneously inspect the upper, sides, and lower surfaces of the wood, significantly improving inspection efficiency. The invention acquires images of the wood surface through a visual inspection mechanism and utilizes image preprocessing technology to enhance texture features. Combined with AI algorithms, it rapidly identifies and classifies defects such as stains, scars, cracks, and wormholes on the wood surface, achieving precise defect location. This invention boasts a detection rate of over 98% for common wood surface defects. Compared to existing structures, this invention offers advantages such as high precision, high efficiency, and strong real-time performance. It effectively meets the automated quality inspection needs of wood processing enterprises, providing technical support for enterprises to achieve automation, intelligent standardization, and more. Furthermore, the visual inspection mechanism of this invention has IP6 dustproof capability, ensuring image quality is not affected even in high-dust environments, making it suitable for use in high-dust environments in wood processing plants. Attached Figure Description
[0019] Figure 1 This is a three-dimensional structural schematic diagram of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the visual inspection mechanism in this invention; Figure 4 This is a cross-sectional schematic diagram of the optics machine in this invention. Detailed Implementation
[0020] The present invention will be further described below with reference to specific embodiments and accompanying drawings.
[0021] See Figures 1 to 4 The diagram illustrates a method for inspecting the surface quality of wood, comprising the following steps: Step 1: An encoder 32 senses the moving speed of the wood; Step 2: A grayscale sensor 43 collects color data of the wood; Step 3: The color data collected by the grayscale sensor 43 is transmitted to an industrial computer; Step 4: The industrial computer analyzes the color data using an AI system and converts it into parameters; Step 5: The converted parameters are transmitted to a vision inspection mechanism 2 and a light source 5; Step 6: The vision inspection mechanism 2 automatically adjusts the exposure value, gain, and number of scans based on the parameters, enhances the texture features of the wood using image preprocessing techniques, and controls the brightness of the light source to correspond to different colors and textures of the wood, achieving high-speed automatic inspection. The image preprocessing techniques highlight key features in the image by adjusting contrast and brightness or using histogram equalization.
[0022] A wood surface quality inspection system includes a housing 1 and a visual inspection mechanism 2 disposed within the housing 1 for photographing and inspecting wood boards. It also includes: an encoding device 3 disposed on the housing 1 for sensing the movement speed of the wood; a grayscale sensing device 4 disposed on the housing 1 for collecting wood color data; a recessed detection position 11 on one side of the housing 1 for allowing the wood board to pass through; and a visual inspection mechanism 2 including an upper surface scanner 21 for photographing and scanning the upper surface of the wood board, a lower surface scanner 23 for photographing and scanning the lower surface of the wood board, and a middle surface scanner 22 for photographing and scanning the sides of the wood board.
[0023] This invention addresses the low efficiency and large errors of traditional manual inspection of wood surfaces by employing three optical engines (top, middle, and bottom) to simultaneously inspect the upper, sides, and lower surfaces of the wood, significantly improving inspection efficiency. The invention uses a visual inspection mechanism 2 to acquire images of the wood surface and utilizes image preprocessing techniques to enhance texture features. Combined with AI algorithms, it rapidly identifies and classifies defects such as stains, scars, cracks, and wormholes on the wood surface, achieving precise defect location. This invention achieves a detection rate of over 98% for common wood surface defects. Compared to existing structures, this invention offers advantages such as high precision, high efficiency, and strong real-time performance. It effectively meets the automated quality inspection needs of wood processing enterprises, providing technical support for enterprises to achieve automation, intelligent standardization, and more. Furthermore, the visual inspection mechanism 2 of this invention has IP6 dustproof capability, ensuring image quality even in high-dust environments, making it suitable for use in high-dust environments such as wood processing plants. The image preprocessing techniques highlight key features in the image by adjusting contrast and brightness or using histogram equalization.
[0024] The detection position 11 is provided with an upper transparent part 111 for the upper optical machine 21 to perform photographic scanning; the detection position 11 is provided with a lower transparent part 113 for the lower optical machine 23 to perform photographic scanning; and the detection position 11 is provided with a middle transparent part 112 for the intermediate optical machine 22 to perform photographic scanning. Here, the upper transparent part 111 is located below the upper plano lens 214 of the upper optical machine 21, which facilitates imaging by the upper plano lens 214 and can prevent dust from entering the housing 1; the middle transparent part 112 is directly opposite the intermediate optical machine 22, which facilitates photographic detection by the intermediate optical machine 22 and can prevent dust from entering the housing 1; the lower transparent part 113 is directly opposite the lower plano lens 234 of the lower optical machine 23, which facilitates imaging by the lower plano lens 234 and can prevent dust from entering the housing 1.
[0025] The housing 1 contains a first cavity 101 and a second cavity 102. The upper optical unit 21 is located in the first cavity 101, while the lower optical unit 23 and the intermediate optical unit 22 are located in the second cavity 102. Here, the upper optical unit 21 is separated from the lower and intermediate optical units 23 and 22, respectively housed in the first and second cavities 101 and 102. This effectively prevents external stray light from scattering and affecting imaging, thus ensuring image quality. Furthermore, the first cavity 101 is covered by a first cover plate 1011, and the second cavity is covered by a second cover plate 1021.
[0026] The housing 1 is equipped with a light source 5 for illuminating the wood to provide supplemental lighting. The brightness of the light source 5 can be adaptively adjusted to suit different colors and textures of wood, highlighting the wood's detailed features and effectively improving the quality of the inspection.
[0027] The encoding device 3 includes an encoding bracket 31 mounted on the housing 1, an encoder 32 mounted on the encoding bracket 31 for sensing the speed of the wood movement, and a first support part 33 mounted on the housing 1 for supporting the wooden board. Here, the encoding device 3 is located at the detection position 11 of the housing 1. When the wood passes the detection position 11, the encoder 32 mounted on the encoding bracket 31 can collect the speed of the wood movement and transmit the speed information to an external industrial computer to control the vision inspection mechanism 2 to perform automatic adjustment and achieve high-speed automatic inspection.
[0028] The grayscale sensing device 4 includes a sensor bracket 41 mounted on the housing 1, a second support 42 mounted on the sensor bracket 41 for supporting the wooden board, and a grayscale sensor 43 mounted on the sensor bracket 41 for acquiring color data of the wooden board. Here, the grayscale sensing device 4 is also located at the detection position 11 of the housing 1. When the wood passes through the detection position 11, the grayscale sensor 43 will acquire the color information of the wood and transmit the color information to an external industrial computer to control the vision inspection mechanism 2 to enhance the texture features using image preprocessing technology to achieve high-speed automatic detection.
[0029] Below the housing 1 is an adjustment mechanism 6 for moving the housing 1. The adjustment mechanism 6 includes a first base plate 61, a first slide rail 62 mounted on the first base plate 61, a first slider 63 slidably mounted on the first slide rail 62, a first lifting frame 64 mounted on the first slider 63 and slidable therewith, an adjustment switch 65 mounted on the first base plate 61 for limiting the first lifting frame 64, a first connecting plate 66 fixed to the lower end of the housing 1, a first lifting slide rail 67 mounted on the first connecting plate 66, and a first lifting cylinder 68 mounted on the first lifting frame 64 and connected to the first slide rail 62 for lifting. Here, the first connecting plate 66 is raised and lowered by the first lifting slide rail 67 to adjust the height of the housing 1, and the horizontal position of the housing 1 is adjusted by the adjustment switch 65, so that the operator can easily and quickly adjust the position of the housing 1.
[0030] A shock-absorbing mechanism 7 for mitigating external vibrations is provided on the upper part of the housing 1. The shock-absorbing mechanism 7 includes a second buffer frame 73 disposed on the upper end of the housing 1 and used for connecting to the outside for shock absorption, and a second mounting frame 74 slidably disposed on the second buffer frame 73. The second buffer frame 73 is provided with a second slider 72, and the second mounting frame 74 is provided with a second slide rail 71 corresponding to the second slider 72. Here, the shock-absorbing mechanism 7 is provided with a shock-absorbing pad 75 for shock absorption, thereby reducing external vibrations and effectively preventing external vibrations from affecting the imaging of the visual inspection mechanism 2.
[0031] Combination Figure 4As shown, the upper optical machine 21 includes an upper linear scanning camera 211, an upper focusing reduction motor 212 tractably mounted on the upper linear scanning camera 211 and used to drive the upper linear scanning camera 211 to perform automatic focusing, and an upper light-gathering sleeve 213 mounted on the upper linear scanning camera 211. An upper flat lens 214 is disposed inside the upper light-gathering sleeve 213 for refracting external light into the upper light-gathering sleeve 213. The lower optical machine 23 includes a lower linear scanning camera 231, tractably mounted on the lower linear scanning camera 231 and used to drive the lower linear scanning camera... The camera 231 includes a lower focusing reduction motor 232 for automatic focusing and a lower light-entry sleeve 233 mounted on the lower scanning camera 231. The lower light-entry sleeve 233 contains a lower flat lens 234 for refracting external light into the upper light-entry sleeve 233. The intermediate light-generating machine 22 includes a intermediate scanning camera 221, a middle focusing reduction motor 222 tractably mounted on the intermediate scanning camera 221 for automatic focusing, and a middle light-entry sleeve 223 mounted on the intermediate scanning camera 221. Preferably, the upper flat lens 214 in the upper light-generating machine 21 is angled at 45°. When the wood passes the detection position 11, the upper flat lens 214 refracts the upper surface of the wood through the upper transparent part 111, facilitating photographic detection by the upper scanning camera 211. The principle of the lower light-generating machine 23 is roughly the same as that of the upper light-generating machine 21, and will not be described further here.
[0032] In summary, this invention addresses the low efficiency and large errors of traditional manual inspection of wood surfaces by employing three optical machines (top, middle, and bottom) to simultaneously inspect the upper, sides, and lower surfaces of the wood, significantly improving inspection efficiency. This invention uses a visual inspection mechanism 2 to acquire images of the wood surface and utilizes image preprocessing technology to enhance texture features. Combined with AI algorithms, it rapidly identifies and classifies defects such as stains, scars, cracks, and wormholes on the wood surface, achieving precise defect location. This invention achieves a detection rate of over 98% for common wood surface defects. Compared to existing structures, this invention offers advantages such as high precision, high efficiency, and strong real-time performance. It effectively meets the automated quality inspection needs of wood processing enterprises, providing technical support for enterprises to achieve automation, intelligent standardization, and more. Furthermore, the visual inspection mechanism 2 of this invention has IP6 dustproof capability, ensuring image quality is not affected in high-dust environments, making it suitable for use in high-dust environments in wood processing plants.
[0033] Of course, the above description is only a specific embodiment of the present invention and is not intended to limit the scope of the present invention. All equivalent changes or modifications made to the structure, features and principles described in the claims of the present invention should be included in the scope of the claims of the present invention.
Claims
1. A method for testing the surface quality of wood, comprising the following steps: Step 1: Use an encoder (32) to sense the speed of the wood movement; Step 2: Use a grayscale sensor (43) to collect color data information of the wood; Step 3: Transmit the color data information collected by the grayscale sensor (43) to the industrial computer; Step 4: The industrial computer analyzes the color data using an AI system and converts it into parameters; Step 5: Transmit the converted parameters to the visual inspection mechanism (2) and the light source (5); Step 6: The visual inspection agency (2) automatically adjusts the exposure value, gain and number of photo scans according to the parameters, uses image preprocessing technology to enhance the texture features of the wood, and controls the brightness of the light source to correspond to the wood boards of different colors and textures, so as to achieve high-speed automatic inspection.
2. A wood surface quality inspection system, employing the wood surface quality inspection method as described in claim 1, comprising a housing (1) and a visual inspection mechanism (2) disposed within the housing (1) for photographing and inspecting the wood panels, characterized in that, Also includes: Encoding device (3), which is set on the box (1) and used to sense the speed of the wood movement; A grayscale sensing device (4) is installed on the box (1) and used to collect wood color data information; The box (1) has an inwardly recessed detection position (11) on one side for the wooden board to pass through. The visual inspection mechanism (2) includes an upper glazing machine (21) for taking pictures and scanning the upper surface of the wooden board, a lower glazing machine (23) for taking pictures and scanning the lower surface of the wooden board, and an intermediate glazing machine (22) for taking pictures and scanning the side of the wooden board.
3. The wood surface quality inspection system according to claim 2, characterized in that: The detection position (11) is provided with an upper transparent part (111) for the upper light machine (21) to take pictures and scan; the detection position (11) is provided with a lower transparent part (113) for the lower light machine (23) to take pictures and scan; the detection position (11) is provided with a middle transparent part (112) for the middle light machine (22) to take pictures and scan.
4. The wood surface quality inspection system according to claim 1, characterized in that: The housing (1) is provided with a first cavity (101) and a second cavity (102). The upper optical machine (21) is located in the first cavity (101), and the lower optical machine (23) and the middle optical machine (22) are located in the second cavity (102).
5. The wood surface quality inspection system according to claim 1, characterized in that: The box (1) is equipped with a light source (5) for illuminating the wood to achieve supplemental lighting.
6. The wood surface quality inspection system according to claim 1, characterized in that: The encoding device (3) includes an encoding bracket (31) mounted on the box (1), an encoder (32) mounted on the encoding bracket (31) for sensing the speed of wood movement, and a first support part (33) mounted on the box (1) for supporting the wooden board.
7. The wood surface quality inspection system according to claim 1, characterized in that: The grayscale sensing device (4) includes a sensor bracket (41) mounted on the housing (1), a second support part (42) mounted on the sensor bracket (41) and used to support the wooden board, and a grayscale sensing sensor (43) mounted on the sensor bracket (41) and used to collect color data of the wooden board.
8. A wood surface quality inspection system according to claim 1, characterized in that: The box (1) is provided with an adjustment mechanism (6) for moving the box (1) by adjustment. The adjustment mechanism (6) includes a first base plate (61), a first slide rail (62) on the first base plate (61), a first slider (63) slidably disposed on the first slide rail (62), a first lifting frame (64) mounted on the first slider (63) and slidable therewith, an adjustment switch (65) on the first base plate (61) for limiting the first lifting frame (64), a first connecting plate (66) fixed to the lower end of the box (1), a first lifting slide rail (67) on the first connecting plate (66), and a first lifting cylinder (68) on the first lifting frame (64) and connected to the first slide rail (62) for lifting.
9. A wood surface quality inspection system according to claim 1, characterized in that: The box (1) is provided with a shock-absorbing mechanism (7) for reducing external vibration. The shock-absorbing mechanism (7) includes a second buffer frame (73) provided on the upper end of the box (1) and used to connect with the outside for shock absorption and buffering, and a second mounting frame (74) slidably provided on the second buffer frame (73). The second buffer frame (73) is provided with a second slider (72), and the second mounting frame (74) is provided with a second slide rail (71) corresponding to the second slider (72).
10. A wood surface quality inspection system according to claim 1, characterized in that: The upper light machine (21) includes an upper line scanning camera (211), an upper focusing reduction motor (212) which is transmissively mounted on the upper line scanning camera (211) and used to drive the upper line scanning camera (211) to perform automatic focusing, and an upper light-advancing sleeve (213) mounted on the upper line scanning camera (211). An upper flat lens (214) is provided inside the upper light-advancing sleeve (213) for refracting external light into the upper light-advancing sleeve (213). The lower light machine (23) includes a lower linear scanning camera (231), a lower focusing reduction motor (232) that is tractably mounted on the lower linear scanning camera (231) and used to drive the lower linear scanning camera (231) to perform automatic focusing, and a lower light-entry sleeve (233) mounted on the lower linear scanning camera (231). The lower light-entry sleeve (233) is provided with a lower flat lens (234) for refracting external light into the lower light-entry sleeve (233). The central light machine (22) includes a central scanning camera (221), a central focusing geared motor (222) which is transmissively mounted on the central scanning camera (221) and used to drive the central scanning camera (221) to perform automatic focusing, and a central light-advancing sleeve (223) mounted on the central scanning camera (221).