Smooth surface appearance detection device

Abstract

The invention discloses a smooth surface appearance detection device which comprises a detection platform, a conveying assembly arranged on the detection platform, a grabbing assembly arranged on the detection platform and used for grabbing products on the conveying assembly, and a visual detection assembly arranged on the detection platform and used for conducting visual detection on the products. The visual detection assembly comprises a stand column arranged on the detection platform, a first cross rod arranged on the stand column, a camera arranged on the first cross rod, a second cross rod arranged on the stand column and a light source arranged on the second cross rod. The light source, the camera, the first cross rod, the second cross rod and the stand column form the visual detection assembly, the detection environment of the camera is guaranteed through the light source, and meanwhile intelligence and continuity of visual detection are achieved through the conveying assembly and the grabbing assembly; the purposes of reducing the influence of environmental factors on the visual mechanism, improving the detection efficiency of visual detection and improving the detection accuracy of the visual mechanism are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of visual inspection production application, and particularly relates to a smooth surface appearance detection device. BACKGROUND

[0002] In the prior art, visual detection is to replace human eyes with machines to measure and judge. Visual detection is to convert a target to be taken into an image signal by a machine vision product (i.e. an image taking device, divided into CMOS and CCD) and transmit the image signal to a dedicated image processing system. The visual mechanism in the traditional process is to detect by using a single camera, and the visual mechanism has deviation when detecting due to external factors (such as light), which affects the visual detection effect.

[0003] How to improve the accuracy of visual mechanism detection is a technical problem that needs to be solved by the technical personnel in the technical field at present.

[0004] The information disclosed in this BACKGROUND section is only intended to enhance the understanding of the general background of the present application, and should not be taken as recognition or suggestion that this information forms the prior art that is already known to those skilled in the art. SUMMARY

[0005] To solve the above technical problems, the present application provides a smooth surface appearance detection device to reduce the influence of environmental factors on the visual mechanism and improve the accuracy of visual mechanism detection.

[0006] To achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A smooth surface appearance detection device comprises a detection platform, a conveying assembly arranged on the detection platform, a grabbing assembly arranged on the detection platform for grabbing products on the conveying assembly, and a visual detection assembly arranged on the detection platform for visual detection of the products.

[0008] The visual detection assembly comprises a stand arranged on the detection platform, a first horizontal rod arranged on the stand, a camera arranged on the first horizontal rod, a second horizontal rod arranged on the stand, and a light source arranged on the second horizontal rod, wherein the light source cooperates with the camera.

[0009] The present application comprises a visual detection assembly by using a light source, a camera, a first horizontal rod, a second horizontal rod and a stand, uses the light source to ensure the detection environment of the camera, and uses the conveying assembly and the grabbing assembly to realize the intelligence and continuity of visual detection, so as to reduce the influence of environmental factors on the visual mechanism, improve the detection efficiency of visual detection and improve the accuracy of visual mechanism detection.

[0010] Further, the visual detection assembly further comprises a hollow shaft sleeve arranged at the bottom of the camera and matched with the camera, a detection box arranged at the bottom of the hollow shaft sleeve, and a third horizontal rod arranged on the side wall of the detection box, wherein the first horizontal rod, the third horizontal rod and the second horizontal rod are arranged on the stand in sequence from top to bottom.

[0011] Further, the end of the first horizontal rod, the second horizontal rod and the third horizontal rod is installed on the stand through an adjustable guide rail unit.

[0012] The adjustable guide rail unit comprises a sliding block, a locking rotating piece arranged on the vertical side wall of the sliding block, and a sliding block locking piece arranged on the other vertical side wall of the sliding block, wherein the vertical side wall of the sliding block is provided with a row of locking holes matched with the sliding block locking piece, and the locking rod of the sliding block locking piece can realize locking or unlocking of the sliding block during the operation.

[0013] The side of the stand facing the sliding block is provided with a guide rail, and the vertical side walls of the two sides of the sliding block are arranged on the guide rail, and the sliding block locking piece and the locking rotating piece are matched to fix the sliding block on the guide rail.

[0014] The adjustable guide rail unit is used to adjust the height of the camera, the detection box and the light source, thereby further improving the effect of visual detection.

[0015] Further, the second horizontal rod is provided with a mounting rod perpendicular to the second horizontal rod, and the mounting rod is perpendicular to the stand and the second horizontal rod.

[0016] The two ends of the mounting rod are provided with L-shaped mounting blocks, and the vertical part of the L-shaped mounting block is connected with the light source.

[0017] Further, the vertical part of the L-shaped mounting block is provided with an adjusting column and a fixing column.

[0018] The end of the outer side wall of the positioning light source is provided with a mounting vertical plate, the mounting vertical plate is provided with an arc-shaped groove, the adjusting column is located in the arc-shaped groove, and the adjusting column is threadedly connected with a locking nut, the center of the mounting vertical plate is further provided with a through hole matched with the fixing column, the fixing column is arranged in the through hole, the vertical plate can rotate around the fixing column, and the rotation angle is limited by the arc-shaped groove. The adjusting column, the fixing column, the mounting vertical plate, the arc-shaped groove and the locking nut can be used to adjust the irradiation angle of the light source, thereby ensuring the detection environment of the camera and improving the precision of visual detection.

[0019] Further worth noting that the conveying assembly includes a product conveying belt for conveying products, a defective product conveying belt for conveying defective products and a qualified placement unit for placing qualified products; the tail ends of the product conveying belt and the defective product conveying belt are provided with material blocking plates.

[0020] Further worth noting that the qualified placement unit includes a placement table and a pair of placement blocks arranged on the placement table, the surface of the placement table is provided with a plurality of placement holes, the two sides of the placement block are provided with blocking edges with mounting grooves, and the placement block is mounted on the placement table through the mounting grooves and screws matched with the placement.

[0021] Further worth noting that the grabbing assembly includes a mechanical arm arranged on the detection platform and a clamping piece arranged at the end of the mechanical arm, the clamping piece obtains products from the product conveying belt, sends the products to the camera detection area for detection, and according to the detection result, the products are conveyed to the qualified placement unit or the defective product conveying belt.

[0022] Further worth noting that the monitoring platform is further provided with a protective cover, the protective cover protects the visual detection assembly and the grabbing assembly, the left and right symmetrical side walls of the protective cover are provided with through grooves, and the head end of the product conveying belt and the tail end of the defective product conveying belt respectively extend out from the through grooves and are placed outside the protective cover. The setting of the protective cover can avoid the damage of the whole equipment and prolong the service life of the equipment.

[0023] Further worth noting that the detection table is further provided with a control terminal, the control terminal is connected with the conveying assembly, the grabbing assembly and the visual detection assembly; the control terminal is further connected with an alarm.

[0024] The present application has the following advantages:

[0025] 1. The present application comprises a visual detection assembly composed of a light source, a camera, a first horizontal rod, a second horizontal rod and a stand, the light source is used to ensure the detection environment of the camera, the conveying assembly and the grabbing assembly are used to realize the intelligence and continuity of visual detection, thereby reducing the influence of environmental factors on the visual mechanism, improving the detection efficiency of visual detection and improving the accuracy of visual mechanism detection.

[0026] 2. The present application adjusts the height of the camera, the detection box and the light source through the adjustable guide rail unit, further improves the effect of visual detection.

[0027] 3. The application can adjust the illumination angle of the light source through the setting of the adjusting column, the fixed column mounting vertical plate, the arc-shaped groove and the locking nut, ensures the detection environment of the camera and improves the precision of visual detection.

[0028] 4. The application realizes the effective distinction of products after detection through the defective product conveying belt and the qualified product placing unit, realizes the centralized processing of products, adjusts the position of the placing table through the placing hole and the flange with the mounting groove, and meets the placing requirements of products with various sizes.

[0029] 5. The application can avoid the damage of the whole equipment through the setting of the protective cover, prolongs the service life of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description.

[0031] Figure 1 A structural schematic view of a smooth surface appearance detection device disclosed by the embodiments of the application;

[0032] Figure 2 An assembly schematic view of a conveying assembly in a smooth surface appearance detection device disclosed by the embodiments of the application;

[0033] Figure 3 A front view schematic view of a visual detection assembly in a smooth surface appearance detection device disclosed by the embodiments of the application;

[0034] Figure 4 A test schematic view of a visual detection assembly in a smooth surface appearance detection device disclosed by the embodiments of the application;

[0035] Figure 5 A Figure 3 enlarged schematic view of A in FIG. 1;

[0036] Figure 6 A Figure 4 enlarged schematic view of B in FIG. 1;

[0037] Figure 7 A Figure 4 enlarged schematic view of C in FIG. 1;

[0038] Figure 8 A function curve of a Gaussian density function;

[0039] Figure 9 A MRF schematic view in a Markov random field;

[0040] Figure 10 An experimental data graph of the application;

[0041] Corresponding component name represented by figure number and letter:

[0042] 1. Detection platform 2. Conveying assembly 21. Feeding conveying belt 22. Unqualified product conveying belt 23. Qualified placement unit 24. Material blocking plate 231. Placement table 232. Placement block 233. Placement hole 234. Installation groove 235. Blocking edge 3. Product grabbing assembly

[0043] 31. Manipulator 32. Gripper 4. Visual detection assembly 41. Column 42. First cross bar 43. Camera 44. Second cross bar

[0044] 44. Light source 46. Hollow shaft sleeve 47. Detection box 48. Third cross bar 491. Slider 492. Locking rotating piece

[0045] 493. Slider locking piece 494. Locking hole 410. Guide rail 411. Installation rod 412. L-shaped installation block 413. Fixed column

[0046] 414. Installation vertical plate 415. Arc-shaped groove 5. Control terminal 6. Alarm 7. Protective cover 71. Through groove. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application.

[0048] The application provides a smooth surface appearance detection device, which works as follows: a visual detection assembly is formed by a light source, a camera, a first cross bar, a second cross bar and a column, the detection environment of the camera is ensured by the light source, the intelligence and continuity of visual detection are realized by a conveying assembly and a grabbing assembly, and the influence of environmental factors on the visual mechanism is reduced, the detection efficiency of visual detection is improved, and the accuracy of visual mechanism detection is improved.

[0049] The application will be further described in detail below in combination with embodiments and specific implementation manners.

[0050] As shown in Figure 1 A smooth surface appearance detection device, which comprises a detection platform 1, a conveying assembly 2 arranged on the detection platform, a grabbing assembly 3 arranged on the detection platform and used for grabbing products on the conveying assembly, a visual detection assembly 4 arranged on the detection platform and used for visually detecting the products, a control terminal 5 arranged on the detection platform, and an alarm 6 arranged on the detection platform. The control terminal is connected with the conveying assembly, the grabbing assembly, the visual detection assembly and the alarm (the control of each device by the control terminal is a relatively mature technical solution in the prior art, and thus will not be described here).

[0051] Among them:

[0052] As Figure 2 shown in the figure, the grabbing component comprises a mechanical arm 31 arranged on the detection platform and a clamping piece 32 arranged at the end of the mechanical arm.

[0053] As Figure 3 and Figure 4 shown in the figure, the visual detection component comprises a stand 41 arranged on the detection platform, a first horizontal rod 42 arranged on the stand, a camera 43 arranged on the first horizontal rod, a second horizontal rod 44 arranged on the stand, and a light source 44 arranged on the second horizontal rod, which cooperates with the camera.

[0054] More specifically, according to the product and environmental factors, a suitable light source is installed in the inner position of the camera to cooperate with the camera to realize the visual detection function. According to the program set by the control terminal, the mechanical arm 31 and the clamping piece 32 cooperate to clamp and move the product on the conveying component 2 to the camera, and the camera 43 takes a photo and compares. The control terminal controls the mechanical arm 31 and the clamping piece 32 to place the product in the designated area according to the comparison result.

[0055] The camera in the application detects based on the image background modeling technology of the mixed Gaussian model and the image difference cutting technology of the Markov random field.

[0056] The detection algorithm needs to use good product pictures to learn and model respectively through the above-mentioned technologies. In the actual detection stage, the algorithm will combine the good product pictures and the actual production pictures for joint analysis, detect the defect area, and perform defect information statistics.

[0057] More specifically:

[0058] The mixed Gaussian model is as follows:

[0059] A random variable X obeys a Gaussian distribution with a mathematical expectation μ and a variance σ, also known as a normal distribution. When μ=0 and σ=1, the normal distribution is a standard normal distribution. The Gaussian distribution probability density function (normal random variable probability density function) is:

[0060]

[0061] Figure 8 The function curve of the Gaussian density function is,

[0062] It is symmetrical on both sides of x=μ:

[0063] The sample number of x between μ-σ and μ+σ accounts for 68.2% of the entire sample number;

[0064] The sample number of x between μ-2σ and μ+2σ accounts for 95.4% of the entire sample number;

[0065] The number of samples between μ-3σ and μ+3σ accounts for 99.6% of the entire number of samples;

[0066] The smooth texture-free workpiece surface image is distributed evenly, and we model the normal defect-free surface as a Gaussian distribution to obtain the Gaussian distribution model of the surface. We take the samples within μ-3σ and μ+3σ as normal sample distribution, and the samples outside as abnormal defect sample distribution.

[0067] The Markov random field is as follows:

[0068] The joint probability distribution of the Markov random field (MRF) can be expressed in the following decomposition form, which can be expressed in the form of a local potential function, or a local factor connected product, as shown in the following formula:

[0069]

[0070] Each node in the Markov random field represents a pixel point, and the nodes are connected by edges, that is, the pixel points are connected by edges.

[0071] As Figure 9 The MRF representation of the image of 16 pixel points can determine whether the point is a local point or an edge point through the probability distribution value of each point.

[0072] The probability distribution value of each point can determine whether the point is a local point or an edge point.

[0073] Graph cut is a binary classification method of image, which essentially assigns labels to pixel points. This method constructs a suitable energy function E(A) according to the properties of the difference map itself, and uses the graph cut method to minimize this energy function, so that when the energy is minimized, each pixel point belongs to the most suitable classification.

[0074] The energy function E(A) is:

[0075] E(A) = λ·R(A) + B(A)

[0076]

[0077] R(A) and B(A) are the cost functions of the region term and the boundary term, respectively.

[0078] Graph cut algorithm based on MRF: This method makes reasonable assumptions about the pixel points and their neighborhood pixel points: if a pixel is marked as a change class or an unchanged class, then the pixels around it are most likely to be the same label.

[0079] According to this assumption, the method uses the line-process method to reserve edge information, combines the EM and MoLC to accurately estimate the probability distribution model parameters of the image, and selects MRF as a tool to continuously optimize the energy function of MRF through graph cut algorithm, and finally effectively distinguishes the unchanged class and the changed class in the difference map.

[0080] In a new embodiment, as shown in Figure 3 、 Figure 5 and Figure 6 , the visual detection assembly further comprises a hollow shaft sleeve 46 arranged at the bottom of the camera and matched with the camera, a detection box 47 arranged at the bottom of the hollow shaft sleeve, and a third cross bar 48 arranged on the side wall of the detection box. The first cross bar, the third cross bar and the second cross bar are arranged on the stand in sequence from top to bottom.

[0081] The end of the first cross bar, the second cross bar and the third cross bar is installed on the stand through an adjustable guide rail unit. The adjustable guide rail unit comprises a sliding block 491, a locking rotating piece 492 arranged on the vertical side wall of the sliding block, and a sliding block locking piece 493 arranged on the other vertical side wall of the sliding block (the structure of the sliding block locking piece is a common locking piece, which is not described here). The vertical side wall of the sliding block is provided with a row of locking holes 494 matched with the sliding block locking piece. The locking rod of the sliding block locking piece can realize locking or unlocking of the sliding block during the operation process.

[0082] The stand is provided with a guide rail 410 on the side facing the sliding block. The vertical side walls on both sides of the sliding block are arranged on the guide rail. The sliding block locking piece and the locking rotating piece cooperate to fix the sliding block on the guide rail. Through the guide rail 411 and the sliding block 491, the height of the camera, the detection box and the light source can be adjusted respectively. The sliding block is fixed through the sliding block locking piece 493 and the locking rotating piece 492, which further ensures the detection effect of visual detection.

[0083] In a new embodiment, as shown in Figure 3 and Figure 7 , the second cross bar is provided with a mounting rod 411 perpendicular to the second cross bar. The mounting rod is perpendicular to the stand and the second cross bar. The two ends of the mounting rod are provided with L-shaped mounting blocks 412. The vertical part of the L-shaped mounting block is connected with the light source.

[0084] The vertical part of the L-shaped mounting block is provided with an adjusting column and a fixing column 413; the end of the outer sidewall of the light source positioning part is provided with a mounting vertical plate 414, the mounting vertical plate is provided with an arc-shaped slot 415, the adjusting column is located in the arc-shaped slot, and a locking nut is threadedly connected to the adjusting column; the center of the mounting vertical plate is also provided with a through hole matched with the fixing column, the fixing column is located in the through hole, the vertical plate can rotate around the fixing column, and the rotating angle is limited by the arc-shaped slot. The angle of the light source can be adjusted through the arc-shaped slot 414 and the adjusting column, and the detection requirements of the camera are further met.

[0085] In a new embodiment, as shown in Figure 2 The conveying assembly 2 comprises a product conveying belt 21 for conveying products, a defective product conveying belt 22 for conveying defective products, and a qualified placement unit 23 for placing qualified products; the tail ends of the product conveying belt and the defective product conveying belt are provided with material blocking plates 24.

[0086] The qualified placement unit comprises a placement table 231 and a pair of placement blocks 232 arranged on the placement table; the surface of the placement table is provided with a plurality of placement holes 233; the two sides of the placement block are provided with a blocking edge 235 with a mounting slot 234; and the placement block is mounted on the placement table through the mounting slot and screws matched with the placement. The qualified product and the defective product are classified and collected through the defective product conveying belt and the qualified placement unit, and the placement holes and the mounting slots are arranged to adjust the position of the placement block to meet the placement requirements of products of various sizes.

[0087] In a new embodiment, as shown in Figure 1 The detection platform is also provided with a protective cover 7 (in order to directly see the structural relationship between the protective cover and the internal structure, the front and rear covers of the protective cover are hidden in the figure, and an operation screen can also be arranged on the protective cover to facilitate direct operation of the staff), the protective cover protects the visual detection assembly and the grabbing assembly, the left and right symmetrical sidewalls of the protective cover are provided with through slots 71, and the head end of the product conveying belt and the tail end of the defective product conveying belt are respectively arranged outside the protective cover from the through slots.

[0088] The experimental data shown in Figure 10 The experimental data shown in

[0089] Through the above mode, the smooth surface appearance detection device provided by the application is composed of a visual detection assembly of a light source, a camera, a first horizontal rod, a second horizontal rod and a stand column, the detection environment of the camera is ensured by using the light source, the intelligence and continuity of visual detection are realized by using the conveying assembly and the grabbing assembly, and the purposes of reducing the influence of environmental factors on the visual mechanism, improving the detection efficiency of visual detection and improving the accuracy of visual mechanism detection are achieved.

[0090] The above only describes the preferred embodiment of the smooth surface appearance detection device disclosed by the application, and it should be noted that, for ordinary skilled persons in the art, without departing from the inventive concept, several modifications and improvements can be made, which all belong to the protection scope of the application.

Claims

1. A smooth surface appearance inspection device, characterized in that: The system comprises a detection platform, a conveying assembly arranged on the detection platform, a grabbing assembly arranged on the detection platform for grabbing products on the conveying assembly, and a visual inspection assembly arranged on the detection platform for performing visual inspection on the products; The visual inspection component includes a column arranged on the inspection platform, a first crossbar arranged on the column, a camera arranged on the first crossbar, a second crossbar arranged on the column, and a light source arranged on the second crossbar, wherein the light source cooperates with the camera.

2. The smooth surface appearance inspection device according to claim 1, characterized in that: The visual detection component also includes a hollow sleeve arranged at the bottom of the camera and cooperating with the camera, a detection box arranged at the bottom of the hollow sleeve and a third cross bar arranged on the side wall of the detection box, and the first cross bar, the third cross bar and the second cross bar are arranged on the column in sequence from top to bottom.

3. The smooth surface appearance inspection device according to claim 2, characterized in that: The ends of the first crossbar, the second crossbar and the third crossbar are all mounted on the upright post via adjustable guide rail units; The adjustable guide rail unit includes a slider, a locking rotating member provided on a vertical side wall of the slider, and a slider locking member provided on another vertical side wall of the slider; the vertical side wall of the slider is provided with a row of locking holes that cooperate with the slider locking member; the locking rod of the slider locking member can lock or release the slider during the toggling process; A guide rail is provided on one side of the column facing the slider, and vertical side walls on both sides of the slider are provided on the guide rail. The slider locking member and the locking rotation member cooperate to fix the slider on the slide rail.

4. The smooth surface appearance inspection device according to claim 2, characterized in that: The second crossbar is provided with a mounting rod perpendicular to the second crossbar, and the mounting rod is in a perpendicular relationship with the column and the second crossbar; L-shaped mounting blocks are provided at both ends of the mounting rod, and the outer wall of the vertical portion of the L-shaped mounting block is connected to the light source.

5. The smooth surface appearance inspection device according to claim 4, characterized in that: The vertical portion of the L-shaped mounting block is provided with an adjusting column and a fixing column; A mounting vertical plate is provided at the end of the outer wall of the positioning light source, an arc-shaped groove is provided on the mounting vertical plate, the adjustment column is located in the arc-shaped groove, and a locking nut is threadedly connected to the adjustment column; a through hole is also provided in the center of the mounting vertical plate to cooperate with the fixing column, the fixing column is provided in the through hole, the vertical plate can rotate around the fixing column, and the rotation angle is limited by the arc-shaped groove.

6. The smooth surface appearance inspection device according to claim 1, characterized in that: The conveying assembly includes a feeding conveyor belt for conveying products, a defective product conveyor belt for conveying defective products, and a qualified product placement unit for placing qualified products; the tail ends of the feeding conveyor belt and the defective product conveyor belt are both provided with a baffle plate.

7. The smooth surface appearance inspection device according to claim 6, characterized in that: The qualified placement unit includes a placement table and a pair of placement blocks arranged on the placement table. Several placement holes are set on the surface of the placement table. Both sides of the placement block are provided with retaining edges with mounting grooves. The placement block is installed on the placement table through the mounting grooves and screws that match the placement.

8. The smooth surface appearance inspection device according to claim 6, characterized in that: The grabbing assembly includes a robotic arm arranged on the inspection platform and a clamping piece arranged at the end of the robotic arm. The clamping piece obtains the product from the feeding conveyor belt, sends the product to the camera inspection area for inspection, and transfers the product to the qualified placement unit or the defective product conveyor belt according to the inspection results.

9. The smooth surface appearance inspection device according to claim 6, characterized in that: A protective cover is also provided on the monitoring platform, which provides protection for the visual detection component and the grasping component. Through grooves are provided on the left and right symmetrical side walls of the protective cover. The head end of the feeding conveyor belt and the tail end of the defective product conveyor belt extend from the through grooves and are placed on the outside of the protective cover.

10. The smooth surface appearance inspection device according to claim 1, characterized in that: The detection platform is also provided with a control terminal, which is connected to the conveying component, the grabbing component and the visual detection component; the control terminal is also connected to an alarm.

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