Multi-station collaborative machine vision table tennis whole peripheral surface defect detection equipment

Abstract

The invention relates to the field of machine vision and industrial automation detection, and particularly discloses a multi-station collaborative machine vision table tennis ball full circumferential surface defect detection device which comprises a rack, a ball box is fixedly connected to the top of the rack, and an operation state displayer is fixedly installed on the outer surface of one side of the ball box. The bottom of the other side of the ball box communicates with a hose. According to the multi-station cooperative machine vision table tennis ball full-circumferential-surface defect detection equipment, through multi-station cooperative work, a complex turnover mechanism and a rotary disc structure are abandoned, a ball does not depend on a turnover device, full-circumferential-surface image collection is achieved through combination of natural rolling of the ball and active rotation driven by a motor, and through the design, the structure is simplified, and the working efficiency is improved. The number of moving parts is reduced, the maintenance cost of equipment is greatly reduced, and the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of machine vision and industrial automation detection, in particular to a multi-station coordinated machine vision table tennis full-surface defect detection equipment. BACKGROUND

[0002] Table tennis is prone to surface defects such as cracks, depressions, stains, and uneven mold lines during production. These defects can affect the bounce performance and appearance quality of table tennis. Therefore, automated, full-surface, and high-stability machine vision detection on the production line has become an industry trend.

[0003] In existing public technologies, the public document CN119861084A "A table tennis quality inspection equipment" proposes an automatic detection system based on a quality inspection turntable mechanism. The system uses a feeding assembly, a quality inspection assembly, and a discharging assembly. The quality inspection assembly includes a quality inspection turntable, a turnover mechanism, a top orientation and side orientation detection camera mechanism, and a supporting illumination structure. The ball changes its posture during the quality inspection process by relying on the turnover mechanism, and the surface image is obtained by cameras from different directions. This type of system realizes multi-view detection through a centralized turntable structure, but its overall structure is relatively complex, the number of moving parts of the turnover mechanism is large, and the equipment maintenance cost is high. At the same time, the centralized single-station detection mode is difficult to further improve the tempo on a high-speed production line.

[0004] Another public document CN120259245A "Table tennis defect detection system and electronic device" discloses a table tennis surface detection scheme based on side light source illumination and camera parallel acquisition. This scheme mainly focuses on the imaging method and image processing flow. It improves processing efficiency through parallel acquisition and identifies defects in combination with a deep learning algorithm. This type of technology focuses on the optimization of image recognition algorithm and illumination imaging model, but does not involve ball conveying structure, posture control method, or multi-station coordinated detection process. The overall system structure is still suitable for the process of detecting the surface of multiple table tennis balls, and it is difficult to directly solve the demand for high-speed continuous detection and full-surface coverage.

[0005] In summary, the prior art generally has the following limitations: the existing scheme usually adopts the method of detecting multiple balls at a time, and multiple balls are photographed and processed at the same time in a single detection process. The main problem of this method is that it can only take a one-time photograph of multiple balls within a limited time, resulting in incomplete coverage of each ball detection, and it cannot guarantee that every detail of each ball is fully checked. Therefore, the existing scheme usually needs to rely on a turnover mechanism to change the posture of the ball. The detection-turnover-re-detection process greatly wastes time, resulting in slow overall detection speed and inability to achieve efficient pipeline continuous detection. At the same time, the existing equipment generally relies on a turntable and a turnover mechanism to change the posture of the ball. These structures require multiple moving parts, resulting in a complex device structure and high maintenance costs. Secondly, in a single photograph, the depth of field limitation of the camera causes the surface of the ball outside the focal length to be blurred, making it impossible to clearly capture the defects on the surface of the ball, resulting in reduced detection accuracy. The existing scheme combines multi-angle shooting, which is limited in flexibility and cannot adjust the shooting range flexibly according to the requirements of the actual production detection process. It can only shoot balls at fixed angles, which may result in missed defects. Finally, the existing equipment takes a single multi-angle photograph, but this method cannot fully utilize the pixel resources of the camera, resulting in insufficient resolution of the image and inability to achieve high-quality collection of the details on the surface of the ball. SUMMARY

[0006] (I) Technical problems solved The present application provides a multi-station coordinated machine vision table tennis ball full-surface defect detection device, which solves the problems mentioned in the background art.

[0007] (II) Technical solutions In order to achieve the above object, the present application is implemented by the following technical scheme: A multi-station coordinated machine vision ping pong ball full-surface defect detection equipment, comprising a rack, a ball box is fixedly connected to the top of the rack, a running state display is fixedly installed on the outer surface of one side of the ball box, a hose is communicated with the bottom of the other side of the ball box, and the equipment further comprises: a detection mechanism body, which is fixedly installed at the bottom of the rack and is inclined, wherein the inclination angle is 5°-15°, preferably 8°-12°; a ball beat control mechanism, which is fixedly installed on the upper surface of the bottom plate; wherein the detection mechanism body comprises a bottom plate, an image processing module and an electrical control module are fixedly installed on the upper surfaces of the two sides of the bottom plate, wherein the electrical control module and the image processing module are configured to: perform spherical coordinate calibration and mapping on the local images collected by each detection station, then perform overlapping splicing on the local images of multiple stations under the spherical coordinate system, so that the adjacent local images have a predetermined overlap degree in the spherical area distribution, so that there are at least two or more local images at the same spherical position, and the suspected defects are confirmed and filtered based on the pixel consistency of the overlapping area, so as to improve the robustness and reliability of defect identification, a single ball release mechanism is fixedly connected to the upper surface of the middle part of the bottom plate, the input end of the single ball release mechanism is fixedly connected to the bottom of the hose, the output end of the single ball release mechanism is fixedly connected to a first detection station, the output end of the first detection station is fixedly connected to a second detection station, and the output end of the second detection station is fixedly connected to a third detection station, wherein the first detection station, the second detection station and the third detection station are arranged in the same structure, and the output end of the third detection station is fixedly connected to a ball separating assembly.

[0008] According to one embodiment of the present application, the single ball release mechanism comprises a single ball release support, a cam top rod is elastically connected to the top outer surface of the single ball release support, a ball releasing and blocking mechanism is elastically rotationally connected to the outer surface of the side close to the cam top rod, wherein the ball releasing and blocking mechanism is arranged below the cam top rod, and a ball body conveying channel is further arranged in the single ball release support.

[0009] According to one embodiment of the present application, the first detection station comprises a detection support fixedly connected with the single ball release support, a camera is fixedly installed on the side surface of the detection support, a light source is arranged on the side of the detection support away from the camera, the light source is a transmission type projection light source for the imaging area of the table tennis ball, the light is received by the camera after passing through the table tennis ball, the camera receives the transmission light intensity changes caused by the profile of the table tennis ball, the surface thickness changes, the pits and the gaps, etc., thereby significantly improving the contrast of the joint line, the crack, the gap, etc. relative to the lateral reflection type illumination, forming a high-contrast light and dark boundary and highlighting the surface defects such as the joint line, the crack and the stain, and the diffusion plate and the collimating optical element are arranged in front of the transmission type light source for homogenizing or collimating the transmission light, making the transmission light illumination distribution in the imaging area of the table tennis ball more uniform, reducing the brightness gradient caused by the uneven light spot, thereby further improving the detection capability of the image processing algorithm for weak contrast defects, and the transmission type light source is used in cooperation with the camera with small aperture and large depth of field imaging parameters, so that the local imaging area of the table tennis ball is within the depth of field range of the camera in each detection station, and the multiple local images are spliced and expanded, which ensures the coverage of the whole surface of the table tennis ball while avoiding the problems of depth of field blur and insufficient spatial resolution caused by single panoramic shooting. A cam top rod is elastically and slidingly connected to the top outer surface of the detection support, and a ball releasing and blocking mechanism is elastically and rotatably connected to the outer surface of the detection support near the cam top rod. The camera viewing angle and working distance of each detection station are configured as follows: a single image only covers a local area of the surface of the table tennis ball, multiple local images collected during one complete rotation of the table tennis ball in the station collectively cover the corresponding surface ring belt area of the station, and the table tennis ball region in each image occupies a predetermined proportion in the camera pixel array, thereby improving the spatial resolution of the local image, and the table tennis ball only relies on the active rotation around its own axis driven by the motor in each detection station and the natural rolling along the inclined ball conveying channel between the detection stations to change the imaging area during the whole detection process, thereby simplifying the structure and reducing the cost.

[0010] According to one embodiment of the present application, a station motor is fixedly installed in the detection support, a ball conveying channel is arranged in the detection support, and a friction wheel is rotatably connected to the inner surface of the detection support, wherein the friction wheel is driven to rotate by the station motor.

[0011] According to one embodiment of the present application, the ball separating assembly comprises a ball separating channel fixedly connected with the detection support, and an electric ball separating lever is fixedly installed on the inner surface of the ball separating channel.

[0012] According to one embodiment of the application, the ball rhythm control mechanism comprises camshaft supports, the bottom of the camshaft supports is fixedly connected to the upper surface of the bottom plate, wherein the camshaft supports are arranged in parallel, the top of the camshaft supports is rotatably connected with a camshaft body, the top of the camshaft supports is fixedly installed with a camshaft motor, the input end of the camshaft body is rotatably connected to the output end of the camshaft motor, and the ball rhythm control mechanism is configured to drive the ball stopping rod of the ball releasing and stopping mechanism to lift and fall at a predetermined rhythm to realize the single ball passing of table tennis in turn and leave a time window for completing the local imaging of the corresponding detection station between two rolling.

[0013] According to one embodiment of the application, the outer surface of the camshaft body is fixedly sleeved with a cam body, and the cam body is arranged at a fixed distance on the outer surface of the camshaft body, and four cam bodies are arranged above the four cam top rods.

[0014] The application provides a table tennis surface defect detection method, which comprises the following steps: Step M1: loading and rolling: the table tennis to be detected is placed into a ball box, then enters a hose and then enters a single ball releasing mechanism, and then is sent into a ball conveying channel with an inclination, and then rolls to the entrance of a first detection station under the action of gravity and is stopped by a ball rhythm control mechanism; Step M2: active rotation in the station and local image acquisition: the table tennis is released to the detection station, positioned by a ball releasing and stopping mechanism, then rotated around its own axis by a motor through a friction wheel, backlit by a transmission light source, and exposed multiple times by a camera during the rotation of the table tennis to obtain multiple local high-resolution images, and the backlit transmission light source makes the local defects on the surface of the table tennis show obvious gray or contour changes in the collected images, and compared with the single panoramic shooting in the side light reflection mode, the defect detection rate is improved and the misjudgment rate is reduced in the low-contrast defect scenario; Step M3: natural rolling and posture changing between stations: after the local imaging of the current station is completed, the camshaft motor drives the cam body to rotate, drives the ball releasing and stopping mechanism to release the ball, and makes the ball naturally roll to the entrance of the next detection station without the help of an additional overturning mechanism, and the posture and the area to be shot of the table tennis entering the next station are changed by rolling; Step M4: repeated acquisition in multiple stations: steps M2 and M3 are repeated in the subsequent detection stations, so that the multiple local images obtained by each station are complementary in the distribution of the ball area and have a predetermined redundant overlap; Step M5: image stitching and unfolding: the local images acquired by multiple stations and multiple angles are geometrically corrected, coordinate-mapped and stitched and unfolded to generate an unfolded image covering the basic circumferential surface of the table tennis; Step M6: Defect identification and judgment performs image processing and deep learning algorithm on the developed image to identify surface defects such as mold line abnormality, cracks, depressions, stains, etc., and outputs the pass / fail judgment result of each ping pong ball: Step M7: Sorting of pass and fail products The ball sorting assembly works according to the outputted pass / fail judgment result of each ping pong ball, when the detection result is a pass product, the ball sorting assembly drives the electric ball sorting lever to rotate to the first direction to guide the ball into the pass product channel; when the detection result is a fail product, the electric ball sorting lever rotates to the opposite direction to guide the ball into the fail product channel.

[0015] The ping pong balls are preloaded in the ball box, the balls enter the inside of the detection mechanism main body from the ball box through the hose under the action of gravity, and are sequentially transported through each detection station and the ball sorting assembly along the ball body conveying channel arranged obliquely relative to the horizontal plane on the rack, to complete the conveying, detection and sorting of the ball bodies, when the ball body enters the ball body conveying channel through the hose, it will be temporarily stored in the single ball release mechanism, at this time, the camshaft motor and the station motor in the ball beat control mechanism are started respectively, after the camshaft motor is started, it will drive the camshaft body to rotate, that is, the rotation of the camshaft body drives the rotation of the cam body, and the three cam bodies corresponding to the first detection station, the second detection station and the third detection station on the camshaft body are arranged at different angles, wherein the cam bodies corresponding to the single ball release mechanism and the first detection station are arranged at the same angle, that is, with the rotation of the camshaft body, the ball temporarily stored in the single ball release mechanism will first enter the first detection station, and the ball in the hose continues to enter the single ball release mechanism for filling, and the balls are always in a single and orderly state in the three detection stations through the cam bodies arranged at different angles, to realize beat detection, when the ball stays in a certain detection station, the station motor is controlled to work by the electrical control module, the station motor drives the friction wheel to rotate, so that the ball rotates around its own axis in the station, the image processing module is electrically connected with the camera corresponding to each detection station, at this time, the cooperation of the camera and the light source can complete the photographing of the ball and upload it to the image processing module, the image processing module pre-processes, extracts features, splices local images and identifies defects from multiple images from the camera to obtain the full-surface detection result of the current ball, and converts the result into "pass / fail" control information, when the ball detection is qualified, the electric ball sorting lever of the ball sorting assembly is driven to rotate to the first direction to guide the ball into the pass product channel; when the detection result is a fail product, the electric ball sorting lever rotates to the opposite direction to guide the ball into the fail product channel.

[0016] (Three) Beneficial effects The present application provides a multi-station coordinated machine vision ping pong full-surface defect detection equipment. (I) The multi-station coordinated machine vision ping pong ball full surface defect detection equipment, through multi-station coordinated work, discards the complex turnover mechanism and the turntable structure, the ball body does not rely on turnover device, but through the natural rolling of the ball body and the active rotation of the motor drive, realizes the full surface image acquisition, this design not only simplifies the structure, reduces the number of moving parts, but also greatly reduces the maintenance cost of the equipment, improves the detection efficiency.

[0017] (II) The multi-station coordinated machine vision ping pong ball full surface defect detection equipment, through multi-station distributed working mode, each station independently completes the image acquisition of local area, realizes the coordinated detection of multiple stations, which is different from the single-station centralized detection in the prior art, the whole ball full surface detection process is divided into different station coordinated local detection, after the ball passes through all stations for detection, the full surface detection of the ball is naturally realized, which greatly improves the overall detection efficiency and adaptability, and realizes the detection mode of assembly line.

[0018] (III) The multi-station coordinated machine vision ping pong ball full surface defect detection equipment adopts multi-station local area segmented shooting and coordinated combination mode, the resolution of each local image can be fully utilized, and the final synthesized image pixel has higher resolution than panoramic image in the case of using the same camera, so that the tiny defects can be clearly identified, and the detection precision is greatly improved.

[0019] (IV) The multi-station coordinated machine vision ping pong ball full surface defect detection equipment adopts multi-station local area segmented shooting and coordinated combination mode, each station is responsible for image acquisition and identification task of different area, and can perform image identification through parallel processing, further improving the overall detection efficiency of the system, compared with single-station centralized detection, the multi-station coordinated mode of the application can better allocate the detection task, and avoid the performance bottleneck caused by centralized processing.

[0020] (V) The multi-station coordinated machine vision ping pong ball full surface defect detection equipment avoids the blur problem of out-of-focus area caused by single global shooting due to depth of field through multiple shooting of different local areas. Since the ball itself is arc-shaped, it is difficult to ensure that all surface details of the ball are within the focus during single-station multi-angle shooting. The local image shot by each station can be clearly imaged within the focus, thereby avoiding the defect omission caused by the blur of some areas on the surface of the ball, and significantly improving the stability and accuracy of image processing and defect identification.

[0021] (Six), the multi-station coordinated machine vision table tennis full surface defect detection equipment adopts the mode of multi-station coordinated work, can flexibly configure detection device according to the demand of actual production line, each independent station can independently set the number, angle and resolution of shooting local area of ball body, so as to realize higher precision image acquisition. Through this way, the redundancy of image can be increased between different stations, that is, a single surface detail can appear in multiple images, so as to help improve the integrity and detail definition of image in subsequent image synthesis and analysis process, in addition, since each station works independently, the flexibility of detection line configuration is greatly enhanced. According to the specific production requirements and the demand of detection precision, the shooting angle, position, focal length and other parameters of each station can be adjusted to adapt to different detection tasks, this design not only improves the adaptability of detection system, but also avoids unnecessary mechanical complexity while ensuring high precision, so that the equipment can quickly adapt to the beat and configuration requirements of different production lines.

[0022] (Seven), the multi-station coordinated machine vision table tennis full surface defect detection equipment, by utilizing the natural rolling of the ball and the active rotation of the motor driven, not completely relying on the active driving component, but utilizing the rolling characteristics of the ball itself to realize the change of the ball posture, the cooperative work of rotation and rolling makes the posture updating process more stable and higher precision, reduces the posture deviation caused by the reversing mechanism, improves the consistency and reliability of the detection process. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 It is the structure schematic diagram of the whole application; Figure 2 It is the side view of the application; Figure 3 It is the structure schematic diagram of the detection mechanism of the application; Figure 4 It is the structure schematic diagram of the single ball release mechanism of the application; Figure 5 It is the structure schematic diagram of the detection station of the application; Figure 6 It is the structure schematic diagram of the ball separation assembly of the application; Figure 7 It is the structure schematic diagram of the ball beat control mechanism of the application; Figure 8 It is the control flow schematic diagram of the whole application.

[0024] In the diagram: 1. Frame; 2. Ball box; 3. Operating status display; 4. Hoses; 5. Main body of the detection mechanism; 51. Base plate; 52. Image processing module; 53. Electrical control module; 54. Single ball release mechanism; 55. Detection station 1; 56. Detection station 2; 57. Detection station 3; 58. Ball separating assembly; 59. Single ball release bracket; 510. Cam push rod; 511. Ball release and blocking mechanism; 512. Ball conveying channel; 513. Detection bracket; 514. Camera; 515. Light source; 516. Station motor; 517. Friction wheel; 518. Ball separating channel; 519. Electric ball separating lever; 6. Ball rhythm control mechanism; 61. Camshaft bracket; 62. Camshaft body; 63. Camshaft motor; 64. Cam body. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] First embodiment: as follows Figures 1 to 8 As shown, the present invention provides a technical solution: a multi-station collaborative machine vision ping-pong ball full-circumference defect detection device, including a frame 1, a ball box 2 fixedly connected to the top of the frame 1, a running status display 3 fixedly installed on one outer surface of the ball box 2, and a flexible tube 4 connected to the bottom of the other side of the ball box 2, and further including: The main body of the testing mechanism 5 is fixedly installed at the bottom of the frame 1, and the main body of the testing mechanism 5 is inclined, wherein the inclination angle is 5° to 15°, preferably 8° to 12°; The ball beat control mechanism 6 is fixedly installed on the upper surface of the base plate 51; The detection mechanism body 5 comprises a bottom plate 51, the upper surfaces of the two sides of the bottom plate 51 are respectively fixedly provided with an image processing module 52 and an electrical control module 53, the electrical control module 53 and the image processing module 52 are configured to: perform spherical coordinate calibration and mapping on the local images collected by each detection station, then perform overlapping splicing on the local images of multiple stations under the spherical coordinate system, so that the adjacent local images have a predetermined overlap in the spherical area distribution, so that there are at least two or more local images in the same spherical position, and the suspected defects are confirmed and filtered based on the pixel consistency of the overlapping area, so as to improve the robustness and reliability of defect identification, the upper surface of the middle part of the bottom plate 51 is fixedly connected with a single ball releasing mechanism 54, the input end of the single ball releasing mechanism 54 is fixedly connected with the bottom of the hose 4, the output end of the single ball releasing mechanism 54 is fixedly connected with a first detection station 55, the output end of the first detection station 55 is fixedly connected with a second detection station 56, and the output end of the second detection station 56 is fixedly connected with a third detection station 57, wherein the first detection station 55, the second detection station 56 and the third detection station 57 are provided in the same structure, and the output end of the third detection station 57 is fixedly connected with a ball separating assembly 58.

[0027] The single ball releasing mechanism 54 comprises a single ball releasing support 59, a cam lifting rod 510 is elastically and slidably connected to the top outer surface of the single ball releasing support 59, a ball releasing and blocking mechanism 511 is elastically and rotatably connected to the outer surface of the side of the single ball releasing mechanism 54 close to the cam lifting rod 510, wherein the ball releasing and blocking mechanism 511 is arranged below the cam lifting rod 510, and the single ball releasing support 59 is further provided with a ball body conveying passage 512.

[0028] The first detection station 55 comprises a detection support 513 fixedly connected with the single ball release support 59, a camera 514 is fixedly installed on the side surface of the detection support 513, a light source 515 is arranged on the side of the detection support 513 away from the camera 514, the light source 515 is a transmission type projection light source 515 for the ping pong ball imaging area, the light is received by the camera 514 after passing through the ping pong ball, so that the camera 514 receives the transmission light intensity change caused by the ping pong ball profile, surface thickness change, pits and gaps and the like, thereby significantly improving the contrast of the joint line, crack, gap and other defects relative to the side reflection type illumination, to form a high-contrast light and dark boundary and highlight the surface defects such as joint line, crack, stain and the like, and a diffusion plate and a collimating optical element are arranged in front of the transmission type light source 515, for homogenizing or collimating the transmission light, so that the transmission light illumination distribution in the ping pong ball imaging area is more uniform, reducing the brightness gradient caused by uneven light spots, thereby further improving the detection capability of the image processing algorithm for weak contrast defects, and the transmission type light source 515 is used in cooperation with the camera to use small aperture and large depth of field imaging parameters, so that the local imaging area of the ping pong ball is within the depth of field range of the camera at each detection station, and the multiple local images are spliced and expanded, which avoids the problems of depth of field blur and insufficient spatial resolution caused by single panoramic shooting while ensuring the coverage of the whole surface of the ping pong ball, and a cam top rod 510 is also elastically and slidingly connected to the top outer surface of the detection support 513, and a ball releasing and blocking mechanism 511 is also elastically and rotatably connected to the outer surface of the detection support 513 close to the cam top rod 510, wherein the camera 514 of each detection station is configured to have a view angle and a working distance, and a single image only covers a local area of the ping pong ball surface, so that multiple local images collected during one complete rotation of the ping pong ball in the station collectively cover the corresponding surface ring belt area of the station, and the ping pong ball region in each image occupies a predetermined proportion in the camera pixel array, so as to improve the spatial resolution of the local image, and at the same time, the ping pong ball only relies on the active rotation around its own axis generated by the motor drive in each detection station and the natural rolling generated along the inclined ball conveying channel 512 between the detection stations to change the imaging area during the whole detection process, thereby simplifying the structure and reducing the cost.

[0029] A station motor 516 is fixedly installed in the inside of the detection support 513, and a ball conveying channel 512 is also arranged in the inside of the detection support 513, and a friction wheel 517 is rotatably connected to the inner surface of the detection support 513, wherein the friction wheel 517 is driven to rotate by the station motor 516.

[0030] The ball separating assembly 58 comprises a ball separating channel 518 fixedly connected with the detection support 513, and a motor-driven ball separating lever 519 is fixedly installed on the inner surface of the ball separating channel 518.

[0031] Second embodiment: as Figures 1 to 8As shown, the ball rhythm control mechanism 6 includes camshaft supports 61 fixedly connected at the top surface of the bottom plate 51, wherein two camshaft supports 61 are arranged in parallel, camshaft bodies 62 are rotatably connected at the top of the camshaft supports 61, camshaft motors 63 are fixedly installed at the top of the camshaft supports 61, and the input ends of the camshaft bodies 62 are rotatably connected to the output ends of the camshaft motors 63, wherein the ball rhythm control mechanism 6 is configured to drive the ball stopping rod of the ball releasing and stopping mechanism 511 to lift and fall at a predetermined rhythm to realize the single ping-pong ball passing in turn and leave a time window for completing local imaging of the corresponding detection station between two rolling.

[0032] The outer surface of the camshaft body 62 is fixedly sleeved with cam bodies 64 fixedly arranged at a distance on the outer surface of the camshaft body 62, wherein four cam bodies 64 are arranged above the four cam top rods 510.

[0033] A ping-pong ball surface defect detection method, comprising the following steps: Step M1: feeding and rolling The ping-pong ball to be detected is placed into the ball box 2, enters the hose 4, and then enters the single ball releasing mechanism 54, and the single ping-pong ball is sent into the ball conveying channel 512 with an inclination angle, rolls to the entrance of the first detection station under the action of gravity, and is stopped by the ball rhythm control mechanism 6; Step M2: active rotation in the station and local image acquisition The ping-pong ball is released to the detection station, positioned by the ball releasing and stopping mechanism 511, then the motor drives the friction wheel 517 to drive the ping-pong ball to rotate around its axis, at the same time, the transmission light source 515 is used for backlight illumination, and the camera 514 is controlled to expose multiple times during the rotation of the ping-pong ball to obtain multiple local high-resolution images, the transmission light source 515 is used for backlight illumination to make the local defects on the surface of the ping-pong ball appear as obvious gray scale or contour changes in the collected images, and compared with the single panoramic shooting in the side light reflection mode, the defect detection rate is improved and the false positive rate is reduced in the low contrast defect scenario; Step M3: natural rolling and posture changing between stations After completing the local imaging of the current station, the camshaft motor 63 drives the cam body 64 to rotate, drives the ball releasing and stopping mechanism 511 to release the ball, and makes the ball naturally roll to the entrance of the next detection station without the help of an additional overturning mechanism, so as to change the posture and the area to be shot when the ping-pong ball enters the next station through rolling; Step M4: multiple station repeated acquisition The steps M2 and M3 are repeated in the subsequent detection stations, so that the multiple local images obtained by each station are complementary in the distribution of the ball area and have a predetermined redundant overlap; Step M5: Image stitching and unwrapping The partial images collected by multiple stations and multiple angles are geometrically corrected, coordinate-mapped, and stitched and unwrapped to generate an unwrapped image covering the basic surface of the ping pong ball. Step M6: Defect identification and determination Image processing and deep learning algorithms are performed on the unwrapped image to identify surface defects such as mold line abnormalities, cracks, depressions, and stains, and to output the pass / fail determination results for each ping pong ball.

[0034] Step M7: Sorting of qualified and unqualified products The ball sorting assembly 58 operates according to the output of the pass / fail determination results for each ping pong ball. When the detection result is a qualified product, the ball sorting assembly 58 drives the electric ball sorting lever 519 to rotate to the first direction, guiding the ball into the qualified product channel. When the detection result is an unqualified product, the electric ball sorting lever 519 rotates to the opposite direction, guiding the ball into the unqualified product channel.

[0035] When working, table tennis balls are pre-stored in the ball box 2, and the balls enter the detection mechanism main body 5 from the ball box 2 through the hose 4 under the action of gravity, and are sequentially transported through each detection station and the ball sorting assembly 58 along the ball body conveying channel 512 arranged on the rack 1 obliquely relative to the horizontal plane, so as to complete the transportation, detection and sorting of the ball bodies. When the ball bodies enter the ball body conveying channel 512 through the hose 4, they will be temporarily stored in the single ball releasing mechanism 54. At this time, the camshaft motor 63 and the station motor 516 in the ball beat control mechanism 6 are started respectively. After the camshaft motor 63 is started, it will drive the camshaft body 62 to rotate, that is, the rotation of the camshaft body 62 drives the rotation of the cam body 64. The three cam bodies 64 corresponding to the first detection station 55, the second detection station 56 and the third detection station 57 on the camshaft body 62 are arranged at different angles, wherein the cam body 64 corresponding to the single ball releasing mechanism 54 and the first detection station 55 is arranged at the same angle. That is, with the rotation of the camshaft body 62, the ball temporarily stored in the single ball releasing mechanism 54 will first enter the first detection station 55, and the ball in the hose 4 will continue to enter the single ball releasing mechanism 54 for filling. The balls are always in a single and orderly state in the three detection stations for conveying through the cam bodies 64 arranged at different angles, so as to realize beat detection. When the ball stays in a certain detection station, the station motor 516 is controlled to work by the electrical control module 53. The station motor 516 drives the friction wheel 517 to rotate, so that the ball rotates around its own axis in the station. The image processing module 52 is electrically connected with the camera 514 corresponding to each detection station. At this time, the camera 514 and the light source 515 can be used to complete the photographing of the ball and upload the image to the image processing module 52. The image processing module 52 pre-processes, extracts features, splices local images and identifies defects from multiple images from the camera 514, obtains the detection result of the whole surface of the current ball, and converts the result into "qualified / unqualified" control information. When the ball is qualified, the electric ball sorting lever 519 of the ball sorting assembly 58 is driven to rotate to the first direction, so as to guide the ball into the qualified ball channel. When the detection result is unqualified, the electric ball sorting lever 519 rotates to the opposite direction, so as to guide the ball into the unqualified ball channel.

[0036] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it should be taken in a descriptive sense and not a limiting sense.

[0037] While the embodiments of the application have been shown and described herein, it is to be understood that the application is not limited to these embodiments. Rather, it is to be understood that various modifications, changes, substitutions and alterations can be made to the embodiments of the application without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A multi-station collaborative machine vision ping-pong ball full-circumference defect detection device, comprising a frame (1), characterized in that: The top of the frame (1) is fixedly connected to a ball box (2), and a running status display (3) is fixedly installed on one side of the outer surface of the ball box (2). A flexible hose (4) is connected to the bottom of the other side of the ball box (2). The frame also includes: The main body of the testing mechanism (5) is fixedly installed at the bottom of the frame (1) and the main body of the testing mechanism (5) is inclined. A ball beat control mechanism (6) is fixedly installed on the upper surface of the base plate (51); The main body (5) of the detection mechanism includes a base plate (51). An image processing module (52) and an electrical control module (53) are fixedly installed on the upper surfaces of both sides of the base plate (51). A single ball release mechanism (54) is fixedly connected to the upper surface of the middle part of the base plate (51). The input end of the single ball release mechanism (54) is fixedly connected to the bottom of the hose (4). The output end of the single ball release mechanism (54) is fixedly connected to the first detection station (55). The output end of the first detection station (55) is fixedly connected to the second detection station (56). The output end of the second detection station (56) is fixedly connected to the third detection station (57). The first detection station (55), the second detection station (56), and the third detection station (57) are configured with the same structure. The output end of the third detection station (57) is fixedly connected to the ball-splitting assembly (58).

2. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection equipment according to claim 1, characterized in that: The single ball release mechanism (54) includes a single ball release bracket (59). A cam rod (510) is elastically slidably connected to the top outer surface of the single ball release bracket (59). A ball release and blocking mechanism (511) is elastically rotatably connected to the outer surface of the single ball release mechanism (54) near the cam rod (510). The ball release and blocking mechanism (511) is located below the cam rod (510). A ball conveying channel (512) is also provided inside the single ball release bracket (59).

3. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection equipment according to claim 2, characterized in that: The first detection station (55) includes a detection bracket (513), which is fixedly connected to a single ball release bracket (59). A camera (514) is fixedly installed through the side surface of the detection bracket (513). A light source (515) is provided on the side of the detection bracket (513) away from the camera (514). The light source (515) is a transmissive projection light source (515) for imaging the ping-pong ball. A cam rod (510) is also elastically slidably connected to the top outer surface of the detection bracket (513). A ball release and blocking mechanism (511) is also elastically rotatably connected to the outer surface of the detection bracket (513) near the cam rod (510).

4. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection equipment according to claim 3, characterized in that: The testing bracket (513) is fixedly installed with a station motor (516) inside. The testing bracket (513) is also provided with a ball conveying channel (512). The inner surface of the testing bracket (513) is rotatably connected with a friction wheel (517), which is driven to rotate by the station motor (516).

5. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection device according to claim 4, characterized in that: The ball-splitting assembly (58) includes a ball-splitting channel (518), which is fixedly connected to the detection bracket (513). An electric ball-splitting lever (519) is fixedly installed on the inner surface of the ball-splitting channel (518).

6. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection device according to claim 5, characterized in that: The ball beat control mechanism (6) includes a camshaft bracket (61), the bottom of which is fixedly connected to the upper surface of the base plate (51). There are two camshaft brackets (61) arranged parallel to each other. A camshaft body (62) is rotatably connected through the top of the camshaft bracket (61). A camshaft motor (63) is fixedly installed on the top of the camshaft bracket (61). The input end of the camshaft body (62) is rotatably connected to the output end of the camshaft motor (63).

7. The multi-station collaborative machine vision ping-pong ball full-circumference defect detection device according to claim 6, characterized in that: The outer surface of the camshaft body (62) is fixedly sleeved with a cam body (64). The cam body (64) is provided at a fixed distance on the outer surface of the camshaft body (62), and the four cam bodies (64) are respectively provided above the four cam push rods (510).

8. A method for detecting surface defects on a ping-pong ball, using a multi-station collaborative machine vision ping-pong ball full-circumference defect detection device as described in claim 1, characterized in that: Includes the following steps: Step M1: Loading and Rolling The ping-pong ball to be tested is placed into the ball box (2), and then enters the hose (4) from the ball box (2) and then enters the single ball release mechanism (54). The ping-pong ball is sent into the ball conveying channel (512) with an inclination angle. Under the action of gravity, it rolls to the entrance of the first testing station and is stopped by the ball rhythm control mechanism (6). Step M2: Active rotation and local image acquisition within the workstation The ping-pong ball is released to the detection station, and the ball is positioned by the ball release and blocking mechanism (511). Then, the motor drives the ping-pong ball to rotate around its own axis by driving the friction wheel (517). At the same time, a transmissive light source (515) is used for backlight illumination, and the camera (514) is controlled to expose multiple times during the rotation of the ping-pong ball to obtain multiple local high-resolution images. Step M3: Natural rolling change of posture between workstations After completing the local imaging of the current station, the camshaft motor (63) drives the cam body (64) to rotate, which drives the ball release and blocking mechanism (511) to release the ball, so that it rolls naturally to the entrance of the next detection station without the aid of an additional flipping mechanism. The rolling changes the posture of the ping-pong ball when it enters the next station and the area to be photographed. Step M4: Repeated data acquisition at multiple workstations Steps M2 and M3 are repeated at subsequent detection stations so that the multiple local images acquired at each station complement each other in terms of spherical area distribution and have predetermined redundant overlap. Step M5: Image stitching and unfolding Geometric correction, coordinate mapping, and stitching and unfolding are performed on local images acquired from multiple workstations and angles to generate an unfolded image covering almost the entire circumference of a ping-pong ball; Step M6: Defect Identification and Judgment Image processing and deep learning algorithms are performed on the unfolded image to identify surface defects such as abnormal parting lines, cracks, dents, and stains, and the pass / fail judgment result of each ping-pong ball is output. Step M7: Sorting qualified and unqualified products The ball-splitting assembly (58) operates based on the pass / fail judgment result of each ping-pong ball. When the test result is a pass / fail product, the ball-splitting assembly (58) drives the electric ball-splitting lever (519) to rotate to one side and swing in the first direction, guiding the ball into the pass / fail product lane. When the test result is a fail / fail product, the electric ball-splitting lever (519) swings in the opposite direction, guiding the ball into the fail / fail product lane.

Images