Joint fork product appearance detection method and device

Abstract

The invention relates to a yoke product appearance detection method and device, and relates to the field of product automatic detection, and the method comprises the steps: collecting a product in-place trigger signal at a preset discharge port of a discharge mechanism; when the product in-place trigger signal is 1, a preset pushing mechanism is controlled by a preset fixed pushing force to horizontally push out a product, and a preset product distribution image at the initial position of a discharging plate is collected; identifying a product initial position from the product distribution image; when the initial position of the product is not within the preset predicted drop point position range, the product is defined as an intruded product, and the intruded product is moved out of the discharging plate; and when the initial position of the product is within the range of the predicted drop point position, a preset detection mechanism is controlled to detect the appearance of the product in the process that the product is discharged along the discharging plate. The method has the effect of improving the product detection efficiency and the detection precision.

Description

Technical Field

[0001] This invention relates to the field of automated product inspection, and in particular to a method and apparatus for inspecting the appearance of a forklift product. Background Technology

[0002] Joint-type products are important connecting components in mechanical transmission systems, used to transmit torque and motion; they are mainly used on universal joints or drive shafts, allowing power to be transmitted between two shafts within a certain angular range, while compensating for axial, radial and angular deviations.

[0003] The production of forklift products mainly includes steps such as blanking, medium-frequency heating, die forging, edge trimming, hot precision pressing, temperature-controlled cooling, shot blasting, and appearance inspection. Currently, the industry mainly relies on manual visual inspection for forklift appearance inspection. However, manual inspection is slow and cannot meet the high-speed requirements of modern production lines. Furthermore, it is affected by factors such as personnel fatigue and differences in experience, resulting in a high rate of missed and false inspections. Summary of the Invention

[0004] To improve product testing efficiency and accuracy, this invention provides a method and apparatus for inspecting the appearance of forklift products.

[0005] In a first aspect, the present invention provides a method for inspecting the appearance of a forklift product, employing the following technical solution: A method for inspecting the appearance of a forklift product, comprising: At the discharge port of the preset discharge mechanism, a product arrival trigger signal is collected; When the product arrival trigger signal is 1, the preset push mechanism is controlled by a preset fixed push force to push the product horizontally, and the product distribution image at the preset starting position of the unloading plate is collected. Identify the starting position of the product from the product distribution image; When the starting position of the product is not within the preset expected landing position range, the product is defined as an intruding product and the intruding product is removed from the feed plate; When the product's starting position is within the expected landing position range, a preset detection mechanism is controlled to inspect the product's appearance during the product's feeding process along the feeding plate.

[0006] By adopting the above technical solution, when a product appears at the discharge port, the system can push the product using a pushing device, allowing the product to be discharged from different starting positions on the discharge plate and automatically slide down the plate. During the descent, the detection mechanism can simultaneously photograph and inspect the product on the discharge plate, thus achieving automated product inspection. Compared to manual inspection, this method offers higher inspection efficiency and accuracy. Since the initial discharge position of the product is determined by its own weight, this step allows the system to distinguish whether the currently discharged product is the one requiring inspection by observing its different starting positions, thereby rejecting any intruding products.

[0007] Optionally, the detection method for products located within the expected landing point range includes: Calculate the ejection distance based on the product's starting position and the preset ejection position; When the delivery distance is inconsistent with the preset planning distance, the product is defined as a product with multiple material shortages and is marked for key inspection. The product with multiple material shortages is subjected to key appearance inspection using a preset precision inspection method. When the launch distance is consistent with the planned distance, the product is defined as a relatively complete product, and the detection mechanism is controlled to collect product images of the relatively complete product at fixed points. The product image is compared with a preset image of the stored product to determine whether there are any abnormal offset features; In the presence of the aforementioned anomaly offsetting feature, the relatively complete product is redefined as a product with multiple material shortages.

[0008] Optional, detailed testing methods include: Collect images of products with multiple material shortages; Generate a grayscale distribution image based on the images of the products with multiple material shortages; The grayscale distribution image is compared with a preset product reference grayscale image to determine the grayscale difference features and grayscale difference regions; The gray-level difference regions in the gray-level distribution image are analyzed and the gray-level values ​​of the regions are extracted. When the gray value of the area is less than the preset reference gray value, the gray value difference area is defined as a material shortage area and the material shortage area is marked. When the gray value of the region is greater than the preset reference gray value, the gray value difference region is defined as a multi-material region and the multi-material region is marked.

[0009] Optional, also includes: Extract the minimum and maximum gray values ​​from the gray-scale distribution image; Calculate the grayscale difference between the maximum grayscale value and the minimum grayscale value; When the grayscale difference is less than the preset resolution grayscale, the product outline area is selected according to the image of the product with multiple material shortages. The nozzle preset in the detection mechanism is controlled to spray a brightening liquid onto the outline area of ​​the product. The brightening liquid is formed by mixing a solvent-compatible metallic brightener and a fluorescent agent. Based on the image of the product with multiple material shortages, the gray values ​​of the region are re-extracted, and the regions with material shortages and regions with excess material are marked. After marking is completed, the preset wiping device is controlled to wipe away the gloss-enhancing liquid from the product surface.

[0010] Optional, also includes: The ultraviolet device pre-installed on the detection mechanism is controlled to acquire ultraviolet images of the product. Identify residual fluorescent agent features and locations from product UV images; Fluorescent profiles are identified based on the ultraviolet images of the product and the location of the fluorescent agent. A crack is defined in the product and the location of the fluorescent agent is marked if and only if the fluorescent profile is linear.

[0011] Optionally, the detection mechanism is equipped with multiple cameras arranged in a row, and the method for acquiring images of products with multiple material shortages includes: The product feeding speed on the feeding plate is matched with the oscillation angular velocity of the detection mechanism when it swings above the feeding plate; The detection mechanism is controlled to swing at the swing angular velocity and multiple cameras are controlled to simultaneously take pictures of the product at preset unit shooting intervals to obtain an image set; Compare the identical pixel elements in two adjacent image units in the image set, remove low-brightness pixels, and then merge the two image units; By combining all image units in the image set, an image of a product with multiple material shortages is obtained.

[0012] Secondly, this application provides a forklift product appearance inspection device, which adopts the following technical solution: A forklift product appearance inspection device, which uses a forklift product appearance inspection method for inspection, includes a base, a loading box rotatably mounted on the base, a unloading plate fixedly connected to the base, an inspection mechanism rotatably mounted on the base for performing appearance inspection on the forklift product, and a discharge mechanism mounted on the unloading plate for sorting and discharging the forklift product from the loading box. The feeding box has a filling state and a discharging state. In the filling state, the feeding box is set horizontally, and in the discharging state, the feeding box is tilted downward toward the discharging plate. During the process of the feeding box rotating from the filling state to the discharging state, the side wall of the detection mechanism abuts against the opening of the feeding box and rotates synchronously with the feeding box. In the discharging state, the detection mechanism disengages from the feeding box and rotates above the unloading plate for detection.

[0013] By adopting the above technical solution, the detection mechanism can act as a barrier, abutting against the opening of the feeding box during its upward rotation to prevent products from falling out until the feeding box reaches the discharge state before discharging. When the feeding box is in the discharge state, the detection mechanism can also function as a detection device, inspecting the products being discharged on the unloading plate, resulting in high efficiency.

[0014] Optionally, the feeding box is equipped with a receiving plate and a pressure spring that drives the receiving plate to slide.

[0015] By adopting the above technical solution, in the filling state, the product to be tested is pressed onto the receiving plate, and the weight of the product causes the receiving plate to slide downwards, compressing the pressure spring. In the discharging state, due to the inclined setting of the feeding box, the weight of the product does not act on the receiving plate and the pressure spring. At this time, the pressure spring can overcome the friction of the product and drive the receiving plate to slide towards the outlet direction of the feeding box, thereby pushing the product out of the feeding box and facilitating product discharge.

[0016] Optionally, the discharge mechanism has a feeding chamber for products to enter from the feeding box and a single-layer discharge channel, the single-layer discharge channel being connected to the feeding chamber; a material sorting block is slidably disposed in the feeding chamber, moving towards the feeding box to flatten the product into a single layer, the material sorting block having a material sorting curved surface; both the bottom of the feeding chamber and the single-layer discharge channel are provided with conveyor belts that transport the product away from the feeding box.

[0017] Optionally, the feeding plate is provided with a reversing groove, and a lifting block is provided in the reversing groove to reversing and ejecting the product entering the reversing groove; the lifting block has a reversing surface that is inclined toward the feeding box.

[0018] In summary, this application includes at least one of the following beneficial technical effects: When a product appears at the discharge port, the system can push the product using a pushing device, allowing it to be discharged from different starting positions on the discharge plate and automatically slide down the plate. During the descent, the detection mechanism can simultaneously photograph and inspect the product on the discharge plate, thus achieving automated product inspection. Compared to manual inspection, this method offers higher inspection efficiency and accuracy. Since the initial discharge position of the product is determined by its own weight, this step can distinguish whether the currently discharged product is the one that needs to be inspected by observing its different starting positions, thereby rejecting any intruding products. The detection mechanism acts as a barrier, abutting against the opening of the feeding box as it rotates upwards to prevent products from falling out until the feeding box reaches the discharge state before discharging. When the feeding box is in the discharge state, the detection mechanism can also function as a detection device, inspecting the products being discharged on the unloading plate, which is highly efficient. In the filling state, the product to be tested is pressed onto the receiving plate, and the weight of the product causes the receiving plate to slide downwards, compressing the pressure spring. In the discharging state, due to the tilted design of the feeding box, the weight of the product is not applied to the receiving plate and the pressure spring. At this time, the pressure spring overcomes the friction of the product, driving the receiving plate to slide towards the outlet of the feeding box, thus pushing the product out of the feeding box and facilitating its discharge. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a forklift product appearance inspection device according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the feeding box according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the feeding box in the discharging state according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the feeding box in the filling state according to an embodiment of the present invention; Figure 5 This is a cross-sectional view of the discharge mechanism according to an embodiment of the present invention; Figure 6 This is a cross-sectional view of the feed plate at the reversing groove in an embodiment of the present invention; Figure 7 This is a flowchart of a method for inspecting the appearance of a forklift product according to an embodiment of the present invention.

[0020] The parts referred to by the numbers in the above attached diagrams are as follows: 1. Base; 2. Feeding box; 21. Receiving plate; 22. Pressure spring; 3. Discharging plate; 31. Reversing groove; 32. Lifting block; 4. Detection mechanism; 41. Swing arm; 42. Mounting base; 5. Discharge mechanism; 51. Feeding chamber; 52. Single-layer discharge channel; 53. Conveyor belt; 54. Material sorting block; 55. Material sorting curved surface. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] This application discloses a forklift product appearance inspection device.

[0023] Reference Figure 1 A forklift product appearance inspection device includes a base 1, a loading box 2, a unloading plate 3, an inspection mechanism 4, and a discharge mechanism 5. The loading box 2 is rotatably mounted on the base 1 and driven to rotate by a hydraulic cylinder. The loading box 2 is used to hold the forklift products to be inspected. The unloading plate 3 is fixedly mounted on the base 1, and the products can be tilted and discharged along the unloading plate 3 after being poured out of the loading box 2. The discharge mechanism 5 is located at the end of the unloading plate 3 near the loading box 2. The discharge mechanism 5 is used to organize the products in the loading box 2, ensuring that the products are discharged in a single layer, i.e., the products do not stack. The inspection mechanism 4 is rotatably mounted on the base 1 and can swing above the unloading plate 3. The inspection mechanism 4 is used to inspect the appearance of the products.

[0024] The testing mechanism 4 includes two swing arms 41 and a mounting base 42 connected between the two swing arms 41 and spanning above the feed plate 3. Various testing devices are installed on the mounting base 42, including cameras, lights, sensors, ultraviolet devices, and nozzles.

[0025] Reference Figure 1 and Figure 2 The feeding box 2 is a square box with a sliding support plate 21 inside, which is used to support the products. A pressure spring 22 is provided between the support plate 21 and the bottom surface of the feeding box 2.

[0026] Combination Figures 2 to 4 The feeding box 2, driven by the hydraulic cylinder, has two states: a filling state and a discharging state. In the filling state, the feeding box 2 is horizontally positioned with its opening facing upwards, allowing the product to be tested to be filled into it. During the transition from the filling state to the discharging state, the feeding box 2 rotates upwards, and in the discharging state, the feeding box 2 is tilted downwards, with its opening facing the discharge plate 3, allowing the product inside to be poured out.

[0027] In the filling state, the product to be tested is pressed onto the receiving plate 21. Under the influence of the product's gravity, the receiving plate 21 slides downward, and the pressure spring 22 is compressed. In the discharging state, because the feeding box 2 is tilted, the weight of the product does not act on the receiving plate 21 and the pressure spring 22. At this time, the pressure spring 22 can overcome the friction of the product and drive the receiving plate 21 to slide towards the outlet direction of the feeding box 2, thereby pushing the product out of the feeding box 2.

[0028] When the feeding box 2 is in the filling state, the detection mechanism 4 abuts against the top of the feeding box 2, and when the feeding box 2 rotates upward, the detection mechanism 4 rotates upward synchronously. During this process, the mounting base 42 of the detection mechanism 4 always abuts against the outlet position of the feeding box 2, so that the product inside the feeding box 2 is not easy to fall out during the rotation.

[0029] When the feeding box 2 switches to the discharge state, the detection mechanism 4 separates from the feeding box 2 and swings back and forth above the discharge plate 3 under the drive of the hydraulic cylinder, and begins to detect the products being discharged.

[0030] Reference Figure 1 and Figure 5 The discharge mechanism 5 is a rectangular box that spans the feed plate 3. The discharge mechanism 5 has an infeed chamber 51 and a single-layer discharge channel 52, which are connected. After being poured out of the feed box 2, the product first enters the infeed chamber 51, then passes through the single-layer discharge channel 52, and finally rests on the upper surface of the feed plate 3. In this embodiment, the infeed chamber 51 has a large space, capable of accommodating a large number of products, while the height of the single-layer discharge channel 52 is less than twice the product thickness, allowing only a single product to pass through at a time.

[0031] Furthermore, both the bottom of the feeding chamber 51 and the single-layer discharge channel 52 are equipped with conveyor belts 53, which rotate in a direction away from the loading box 2. Additionally, a material handling block 54 is slidably disposed within the feeding chamber 51. The material handling block 54 has a material handling curved surface 55 and is moved by a cylinder. Under the drive of the cylinder, the material handling block 54 can move towards the loading box 2.

[0032] When a product enters the feeding chamber 51 from the feeding box 2, the bottom of the product can move away from the feeding box 2 under the action of the conveyor belt 53, while the top of the product can be pushed by the material handling block 54, so that a single product can move on the conveyor belt 53 and the rest of the products are pushed by the material handling block 54, thus making it less likely to obstruct the discharge of a single product.

[0033] Reference Figure 1 and Figure 6 Furthermore, to enable the product to be flipped on the feeding plate 3 so that both sides of the product can be inspected, a reversing groove 31 is provided on the feeding plate 3, which is opened along the width direction of the feeding plate 3. A lifting block 32 is installed in the reversing groove 31 and is driven to move up and down by a hydraulic cylinder. The lifting block 32 has a reversing surface that is inclined towards the loading box 2.

[0034] When the product falls into the reversing groove 31, due to the existence of the reversing surface, the top position of the product is tilted away from the feeding box 2. When the lifting block 32 drives the product out of the reversing groove 31, the top position of the product first falls on the feeding plate 3 and slides down on the feeding plate 3, thereby achieving flipping.

[0035] Based on the same inventive concept, embodiments of the present invention provide a method for inspecting the appearance of a forklift product.

[0036] Reference Figure 7 A method for inspecting the appearance of a forklift product includes the following steps: In this embodiment, the discharge port of the discharge mechanism 5 is connected to the single-layer discharge channel 52, and the size of the discharge port is only for discharging a single product. The feeding plate 3 is provided with a pushing mechanism on one side of the discharge port of the discharge mechanism 5. The pushing mechanism can push the product so that the product has a fixed initial horizontal velocity.

[0037] Step S1: Collect the product arrival trigger signal at the discharge port of the preset discharge mechanism 5.

[0038] The product arrival trigger signal refers to the signal triggered when the product to be detected passes through the discharging mechanism 5 and arrives at the discharge port. The discharge port is equipped with a photoelectric sensor, which detects the product's arrival and triggers the signal.

[0039] Step S2: When the product arrival trigger signal is 1, the preset push mechanism is controlled by a preset fixed push force to push the product horizontally, and the product distribution image at the preset starting position of the unloading plate 3 is collected.

[0040] A product arrival trigger signal of 0 indicates that the photoelectric sensor has not detected the product. A product arrival trigger signal of 1 indicates that the photoelectric sensor has detected the product, and the product is located at the discharge port.

[0041] The fixed driving force is the force applied by the pushing mechanism set by the technicians when pushing the product. Under the driving force of the fixed driving force and the action of friction, products of different weights slide horizontally a different distance. Therefore, when the products stop sliding, different products can be located at different starting positions on the feed plate 3.

[0042] The starting position of the feeding plate 3 is connected to the discharge port, which is the position where the product begins to slide downwards on the feeding plate 3. The starting position of the feeding plate 3 is a rectangular area.

[0043] The product distribution image is an image captured by a camera installed on the detection mechanism 4 at the starting position of the feeding plate 3. The product after being pushed by the pushing mechanism can be identified in the product distribution image.

[0044] Step S3: Identify the starting position of the product from the product distribution image.

[0045] The product starting position is the actual position of the product to be tested within the starting position range of the feeding plate 3. The product starting position can be obtained from the product distribution image through image recognition.

[0046] Step S4: When the starting position of the product is not within the preset expected landing position range, the product is defined as an intruding product, and the intruding product is removed from the feed plate 3.

[0047] The expected landing point range is a range set by technicians for a specific product. Each qualified product will land within a fixed range under the push of the pushing mechanism, which will not be elaborated here. The expected landing point range can be changed according to different product models to adapt to the different product feeding situations on the feeding plate 3.

[0048] When the product's initial position, driven by the pushing mechanism, does not fall within the expected landing point range, it indicates a significant difference in quality between the product and the product to be tested, resulting in a situation where the product falls outside the expected landing point range. For such products, the system defines them as intrusive products, i.e., products that accidentally fall into the loading bin 2 and are discharged. The system will control the grippers to pick up and remove the intrusive products from their initial position.

[0049] Step S5: When the product's starting position is within the expected landing position range, the preset detection mechanism 4 is controlled to detect the product's appearance during the product's feeding process along the feeding plate 3.

[0050] If the product's starting position is within the expected landing point range, it indicates that the product's quality meets the weight standard for the product to be tested, and the product is the product to be tested. After being detected as a normal product to be tested, the product can be fed along the feeding plate 3, and the product's appearance is inspected by the testing mechanism 4 during the feeding process.

[0051] The detection method for products located within the expected landing point range includes the following steps: Step S50: Calculate the ejection distance based on the product's starting position and the preset ejection position.

[0052] The ejection position is the position where the pushing mechanism begins to push the product to be tested. This position is a fixed position set by the technicians and is determined by the position of the discharge port, which will not be elaborated here.

[0053] The ejection distance is the distance the product slides under the push of the pushing mechanism. The push distance is the distance between the product's initial position and the ejection position. Once the initial position and the ejection position are determined, the ejection distance can be calculated.

[0054] Step S51: When the delivery distance is inconsistent with the preset planning distance, the product is defined as a product with multiple material shortages and marked for key inspection. The product with multiple material shortages is subjected to key appearance inspection using a preset fine inspection method.

[0055] The planned distance is a distance set by technicians based on the model of the product to be tested. The complete product to be tested can slide along the planned distance under the push of the pushing mechanism, which will not be elaborated here.

[0056] Since the sliding distance of the product is related to its own weight, if the pushing distance is inconsistent with the planned distance, it indicates that the weight of the product differs from the standard product, and that the product surface has excess or insufficient material. For products with excess or insufficient material, the system will mark them for key inspection, and subsequently, when loading and unloading from the feeding plate 3, the system will use a fine inspection method to perform a visual inspection. The fine inspection method will not be elaborated here, but will be described in detail in subsequent embodiments.

[0057] Step S52: When the ejection distance is consistent with the planned distance, the product is defined as a relatively complete product, and the detection mechanism 4 is controlled to collect product images of the relatively complete product at fixed points.

[0058] If the delivery distance matches the planned distance, the system initially identifies the product as relatively complete, and controls the camera of the detection mechanism 4 to be positioned on top of the product to capture an image. Based on this image, a preliminary inspection of the product is then performed.

[0059] Step S53: Compare the product image with the preset stored product images to determine whether there are any abnormal offset features.

[0060] The images of the products in the inventory are images of completed products that have been pre-stored in the system by technicians, and will not be described in detail here.

[0061] Anomaly cancellation features refer to situations where there is both excess and deficiency material on the product surface, making the weight of the tested product the same as a normal product. In this case, the excess and deficiency material can be clearly identified in the image, meaning that the volume of the excess and deficiency material is relatively large compared to the product itself.

[0062] Compare the captured product image with the image of the stock product. If they match, the relatively intact product surface is considered normal. If there are differences in features between the product image and the stock product image, then the product surface has abnormal offsetting features.

[0063] Step S54: In the case of the aforementioned abnormality offsetting feature, the relatively complete product is redefined as a product with multiple material shortages.

[0064] Due to the presence of abnormal offsetting features, the product was mistakenly identified as a relatively complete product during the initial inspection. At this time, the system will re-mark the product as a product with multiple missing materials, and the product will be re-inspected using the fine inspection method in step S51.

[0065] The detailed examination method includes the following steps: Step S520: Collect images of products with multiple material shortages.

[0066] The image of the product with multiple shortages refers to the image obtained by taking pictures of the marked products with multiple shortages using the camera on the detection mechanism 4. The method of image acquisition by the camera will not be described in detail here, but will be described in detail in subsequent embodiments.

[0067] Step S5200: Generate a grayscale distribution image based on the image of the multi-material-deficient product.

[0068] In product images captured by a camera, each pixel has different brightness levels. The closer the product surface is to the camera, the brighter the pixel; conversely, the farther the product surface is from the camera, the lower the pixel's brightness. These different brightness levels result in different grayscale distributions.

[0069] A grayscale distribution image refers to an image that reflects the grayscale distribution at various points on the surface of a product. A grayscale distribution image can be obtained by performing grayscale image processing on images of products with multiple material shortages. The grayscale image processing methods are existing technologies and will not be elaborated upon here.

[0070] Step S5201: Compare the grayscale distribution image with the preset product reference grayscale image to determine the grayscale difference features and grayscale difference regions.

[0071] A product reference grayscale image refers to an image obtained by processing a fully functional product image captured by a camera into grayscale. The product reference grayscale image can be used as a reference image to distinguish grayscale anomalies in the image. The product reference grayscale image is determined in advance by technicians and will not be elaborated here.

[0072] Gray-scale difference features refer to the locations in a product's gray-scale distribution image where the gray-scale values ​​differ from normal values. Gray-scale difference regions refer to the locations of gray-scale difference features within the gray-scale distribution image.

[0073] By comparing a grayscale distribution image with a product baseline grayscale image, the differences between the two reveal grayscale difference features. Once these grayscale difference features are identified, their corresponding grayscale difference regions within the grayscale distribution image can be located.

[0074] Step S5202: Analyze the gray-level difference regions from the gray-level distribution image and extract the region gray-level values.

[0075] Regional grayscale values ​​refer to the specific grayscale parameters of regions with grayscale differences. Regional grayscale values ​​are obtained by analyzing regions of grayscale difference in a grayscale distribution image.

[0076] Step S5203: When the gray value of the region is less than the preset reference gray value, the gray value difference region is defined as a material shortage region, and the material shortage region is marked.

[0077] The reference grayscale refers to the grayscale value at the location corresponding to the grayscale difference area in the reference grayscale image of the product. This grayscale value is the grayscale value of a normal complete product.

[0078] The grayscale value of a region with grayscale difference must be greater than or less than the base grayscale value.

[0079] If the grayscale value of a region is lower than the baseline grayscale value, it indicates that the brightness at that location is low. This location appears far from the normal product when captured by the camera, potentially indicating a material shortage causing a surface depression. After determining the cause of the grayscale difference, the location is marked and addressed after subsequent product output.

[0080] Step S5204: When the gray value of the region is greater than the preset reference gray value, the gray value difference region is defined as a multi-material region and the multi-material region is marked.

[0081] If the grayscale value of a region is greater than the baseline grayscale value, it indicates that the brightness at that location is relatively high. This location appears close to a normal product when captured by the camera, potentially indicating excess material causing surface bumps or burrs. After determining the cause of the grayscale difference, the location is marked and addressed in subsequent product output.

[0082] Ambient brightness can affect the grayscale difference in images captured by a camera. The following steps can be taken to address this issue: Step S521: Extract the minimum gray value and the maximum gray value based on the gray distribution image.

[0083] The minimum and maximum gray values ​​are the gray values ​​at the minimum and maximum positions in the gray-scale distribution image, respectively. These values ​​can be directly extracted from the gray-scale distribution image.

[0084] Step S5210: Calculate the grayscale difference between the maximum grayscale value and the minimum grayscale value.

[0085] The grayscale difference is the difference between the maximum grayscale value and the minimum grayscale value.

[0086] Step S5211: When the grayscale difference is less than the preset resolution grayscale, select the product outline area according to the multi-material shortage product image.

[0087] The grayscale resolution is the minimum difference in grayscale values ​​between two locations that the system can distinguish, as set by the technicians. If the grayscale difference between the two regions is too small, the system will not be able to distinguish them.

[0088] If the grayscale difference is not less than the distinguishable grayscale, the system can directly analyze the grayscale distribution image to mark areas with excess material and areas with insufficient material.

[0089] If the grayscale difference is less than the distinguishable grayscale, the system cannot directly process the grayscale distribution image and cannot determine the grayscale difference region, so processing is required.

[0090] The product outline area refers to the surface outline of the product to be inspected. After the camera captures an image of the product with multiple material shortages, the product outline area can be selected from the image of the product with multiple material shortages.

[0091] Step S5212: Control the nozzle preset in the detection mechanism 4 to spray a brightening liquid onto the product outline area. The brightening liquid is formed by mixing a solvent-compatible metallic brightener and a fluorescent agent.

[0092] To increase the grayscale difference of the product in the grayscale distribution image, in this embodiment, the detection mechanism 4 is equipped with a nozzle connected to a solution tank containing a brightening agent. The brightening agent is formed by mixing a metallic brightener and a fluorescent agent. Both the metallic brightener and the fluorescent agent are water-based, exhibiting good solvent compatibility and minimizing the likelihood of mutual reaction. The nozzle sprays the brightening agent onto the product's outline area, brightening the product surface and increasing light reflectivity.

[0093] Step S5213: Re-extract the grayscale values ​​of the regions based on the images of products with multiple material shortages, and mark the material shortage regions and material shortage regions.

[0094] After the brightening liquid is sprayed, the grayscale difference on the product surface will increase. At this time, the system will re-photograph the product with multiple material shortages and re-extract the grayscale value of the area, and then operate according to steps S520 to S5204.

[0095] Step S5214: After marking is completed, control the preset wiping device to wipe away the gloss enhancer on the product surface.

[0096] The wiping device is located on one side of the feeding plate 3. After the areas with insufficient material and areas with excess material are marked, the system will use the wiping device to wipe away the excess brightening liquid on the product surface.

[0097] It also includes the following steps: Step S522: Control the ultraviolet device preset on the detection mechanism 4 to collect ultraviolet images of the product.

[0098] A product UV image refers to an image obtained by taking a picture of a product using a UV device. Because the product is coated with a brightening liquid containing fluorescent agents in the previous process, if there are cracks on the product surface, the fluorescent agents will remain in the cracks and can be identified in the product UV image.

[0099] Step S5220: Identify residual fluorescent agent features and locations from the UV image of the product.

[0100] The location of fluorescent agents refers to the actual position of residual fluorescent agents on the product surface. If fluorescent agents remain on the product, their characteristics can be directly identified from the product's ultraviolet (UV) image. Once the fluorescent agent characteristics are identified, their position in the UV image can be determined. Then, based on the image scale captured by the UV device, the fluorescent agent location can be finally obtained.

[0101] Step S5221: Identify the fluorescence profile based on the ultraviolet image of the product and the location of the fluorescent agent.

[0102] Fluorescence profile refers to the outline of the fluorescent agent characteristics at the location of the fluorescent agent. The fluorescence profile can be obtained directly from the analysis of the fluorescent agent characteristics at the location of the fluorescent agent in the ultraviolet image of the product.

[0103] Step S5222: Define the presence of a crack in the product and mark the location of the fluorescent agent if and only if the fluorescent profile is linear.

[0104] The fluorescent agent residue on the product surface may be due to cracks or it may be due to not being wiped clean. The outlines of the fluorescent agent characteristics are different in these two ways. The condition of the product surface, i.e. whether there are cracks, can be judged based on the fluorescent outline.

[0105] Because the cracks on the product surface are linear, the fluorescent agent remaining in the cracks will also appear as linear in the ultraviolet image of the product, whereas the fluorescent agent remaining on the product surface is generally in block form.

[0106] When a linear fluorescent outline is detected, it indicates the presence of a crack on the product surface, which will affect product quality. The location of the fluorescent agent is the location of the crack, and the system will mark the location of the fluorescent agent for subsequent processing of the product.

[0107] The method for acquiring images of products with multiple missing parts using multiple cameras arranged on the testing unit 4 includes the following steps: In this embodiment, the detection mechanism 4 can swing back and forth on the feeding plate 3, and the span of the multiple cameras on the detection mechanism 4 is relatively large compared to the product to be detected. Therefore, the detection mechanism 4 can capture and process a three-dimensional image of the product.

[0108] Step S523: Match the oscillation angular velocity of the detection mechanism 4 when it swings above the feeding plate 3, based on the preset feeding speed of the product on the feeding plate 3.

[0109] The feeding speed is the feeding speed of the product to be tested on the feeding plate 3 set by the technicians, which will not be elaborated here.

[0110] The oscillation angular velocity is the oscillation speed of the detection mechanism 4 when it oscillates above the loading plate to take pictures.

[0111] When the testing agency 4 takes pictures of the product, it needs to be synchronized with the product. The testing agency 4 is always located above the product. Therefore, the swing angular velocity is directly proportional to the feeding speed. The greater the feeding speed, the greater the swing angular velocity.

[0112] Step S5230: Control the detection mechanism 4 to swing at the swing angular velocity and control multiple cameras to simultaneously take pictures of the product at a preset unit shooting interval to obtain an image set.

[0113] The testing agency 4 will continuously take pictures of the product while it is swinging. The unit shooting interval is the time interval between two adjacent pictures when the camera continuously takes pictures of the product, which is set by the technicians. It will not be elaborated here.

[0114] The image set is a collection of images of the product taken by all the cameras.

[0115] Step S5231: Compare the same element pixels in two adjacent image units in the image set, remove low-brightness pixels, and merge the two image units.

[0116] When a camera captures a product from different positions, the positions of shadows and highlights on the product will change. By comparing two adjacent images, the system extracts the pixels that are the same, removes the pixels with lower brightness and keeps the pixels with higher brightness, and then stitches the two image units together. The resulting image has higher overall brightness, making it easier for the system to recognize the content in the image.

[0117] Step S5232: Complete the stitching of all image units in the image set to obtain images of products with multiple material shortages.

[0118] By continuously merging adjacent images in step S5231, all image units are eventually merged into one image, which is the image of the product with multiple material shortages.

[0119] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for inspecting the appearance of a forklift product, characterized in that, include: At the discharge port of the preset discharge mechanism (5), a product arrival trigger signal is collected; When the product arrival trigger signal is 1, the preset push mechanism is controlled by the preset fixed push force to push the product horizontally, and the product distribution image at the preset feeding plate (3) starting position is collected; Identify the starting position of the product from the product distribution image; When the starting position of the product is not within the preset expected landing position range, the product is defined as an intrusive product and the intrusive product is removed from the feed plate (3). When the product's starting position is within the range of the expected landing position, the preset detection mechanism (4) is controlled to detect the product's appearance during the product's feeding process along the feeding plate (3).

2. The method for inspecting the appearance of a forklift product according to claim 1, characterized in that, The detection method for products located within the expected landing point range includes: Calculate the ejection distance based on the product's starting position and the preset ejection position; When the delivery distance is inconsistent with the preset planning distance, the product is defined as a product with multiple material shortages and is marked for key inspection. The product with multiple material shortages is subjected to key appearance inspection using a preset precision inspection method. When the launch distance is consistent with the planned distance, the product is defined as a relatively complete product, and the detection mechanism (4) is controlled to collect product images of the relatively complete product at fixed points. The product image is compared with a preset image of the stored product to determine whether there are any abnormal offset features; In the presence of the aforementioned anomaly offsetting feature, the relatively complete product is redefined as a product with multiple material shortages.

3. The method for inspecting the appearance of a forklift product according to claim 2, characterized in that, Detailed testing methods include: Collect images of products with multiple material shortages; Generate a grayscale distribution image based on the images of the products with multiple material shortages; The grayscale distribution image is compared with a preset product reference grayscale image to determine the grayscale difference features and grayscale difference regions; The gray-level difference regions in the gray-level distribution image are analyzed and the gray-level values ​​of the regions are extracted. When the gray value of the area is less than the preset reference gray value, the gray value difference area is defined as a material shortage area and the material shortage area is marked. When the gray value of the region is greater than the preset reference gray value, the gray value difference region is defined as a multi-material region and the multi-material region is marked.

4. The method for inspecting the appearance of a forklift product according to claim 3, characterized in that, Also includes: Extract the minimum and maximum gray values ​​from the gray-scale distribution image; Calculate the grayscale difference between the maximum grayscale value and the minimum grayscale value; When the grayscale difference is less than the preset resolution grayscale, the product outline area is selected according to the image of the product with multiple material shortages. The nozzle preset in the detection mechanism (4) is controlled to spray a brightening liquid onto the outline area of ​​the product. The brightening liquid is formed by mixing a solvent-compatible metallic brightener and a fluorescent agent. Based on the image of the product with multiple material shortages, the gray values ​​of the region are re-extracted, and the regions with material shortages and regions with excess material are marked. After marking is completed, the preset wiping device is controlled to wipe away the gloss-enhancing liquid from the product surface.

5. The method for inspecting the appearance of a forklift product according to claim 4, characterized in that, Also includes: Control the ultraviolet device preset on the detection mechanism (4) to collect ultraviolet images of the product; Identify residual fluorescent agent features and locations from product UV images; Fluorescent profiles are identified based on the ultraviolet images of the product and the location of the fluorescent agent. A crack is defined in the product and the location of the fluorescent agent is marked if and only if the fluorescent profile is linear.

6. The method for inspecting the appearance of a forklift product according to claim 3, characterized in that, The detection mechanism (4) is equipped with multiple cameras arranged in a row, and the method for acquiring images of products with multiple material shortages includes: The product feeding speed on the feeding plate (3) is matched with the oscillation angular velocity of the detection mechanism (4) when it swings above the feeding plate (3); The detection mechanism (4) is controlled to swing at the swing angular velocity and multiple cameras are controlled to take pictures of the product simultaneously at a preset unit shooting interval to obtain an image set; Compare the identical pixel elements in two adjacent image units in the image set, remove low-brightness pixels, and then merge the two image units; By combining all image units in the image set, an image of a product with multiple material shortages is obtained.

7. A forklift product appearance inspection device, which uses the forklift product appearance inspection method as described in any one of claims 1 to 6 for inspection, characterized in that, It includes a base (1), a loading box (2) rotatably mounted on the base (1), a unloading plate (3) fixedly connected to the base (1), an inspection mechanism (4) rotatably mounted on the base (1) and used for visual inspection of the fork products, and an unloading mechanism (5) mounted on the unloading plate (3) for sorting and unloading the fork products in the loading box (2). The feeding box (2) has a filling state and a discharging state. In the filling state, the feeding box (2) is set horizontally, and in the discharging state, the feeding box (2) is tilted downward toward the discharging plate (3). During the process of the feeding box (2) rotating from the filling state to the discharging state, the side wall of the detection mechanism (4) abuts against the opening of the feeding box (2) and rotates synchronously with the feeding box (2). When in the discharging state, the detection mechanism (4) disengages from the feeding box (2) and rotates above the unloading plate (3) for detection.

8. The forklift product appearance inspection device according to claim 7, characterized in that, The feeding box (2) is equipped with a receiving plate (21) and a pressure spring (22) that drives the receiving plate (21) to slide.

9. The forklift product appearance inspection device according to claim 7, characterized in that, The discharge mechanism (5) has a feeding chamber (51) for products to enter from the feeding box (2) and a single-layer discharge channel (52), the single-layer discharge channel (52) being connected to the feeding chamber (51); a material sorting block (54) is slidably disposed in the feeding chamber (51) and moves toward the feeding box (2) to flatten the product into a single layer, the material sorting block (54) having a material sorting curved surface (55); both the bottom of the feeding chamber (51) and the single-layer discharge channel (52) are provided with conveyor belts (53) that convey products away from the feeding box (2).

10. The forklift product appearance inspection device according to claim 7, characterized in that, The feed plate (3) is provided with a reversing groove (31), and a lifting block (32) is provided in the reversing groove (31) to reversing and pushing out the product entering the reversing groove (31); the lifting block (32) has a reversing surface that is inclined toward the feed box (2).

Images