Curved shell appearance inspection apparatus and method

Abstract

The application provides a curved surface shell appearance detection device and method, and belongs to the technical field of appearance defect detection. The device comprises a plurality of arc surface detection modules distributed along the conveying direction of a conveying module; each arc surface detection module is used for detecting one or several local arc surfaces of the same shape, symmetry or mirror symmetry in the curved surface shell; the first bright field light surface of the arc surface detection module is parallel to the first local arc surface to be detected of the curved surface shell at the corresponding arc surface detection station; the arc surface detection camera vertically photographs the local arc surface to be detected through the first center hole; and the first driving motor unit is used for driving the curved surface shell on the jig to rotate synchronously through rotation, so that the local arc surface to be detected on the curved surface shell is rotated to a to-be-detected position parallel to the first bright field light surface. The application can realize the detection of the global arc surface of the curved surface shell, and can improve the detection efficiency of each local arc surface.

Description

Technical Field

[0001] This application relates to the field of appearance defect detection technology, and in particular to an appearance inspection device and method for curved shells. Background Technology

[0002] In today's rapidly evolving industrial landscape, various shell components with complex curved structures (such as headphone shells, portable speaker shells, and small electronic device shells, hereinafter collectively referred to as "curved shells") have become core appearance components of end products. These components are typically made of plastic, and their surfaces often integrate multi-area composite structures including curved surfaces, sidewalls, top surfaces, and bottom surfaces, and are available in various colors such as black, silver, and blue. Their appearance quality directly determines consumers' purchasing decisions; therefore, rigorous inspection of curved shells for various surface defects such as point-like foreign objects, linear foreign objects, discoloration, dents, and scratches is a crucial aspect of quality control in consumer electronics production lines.

[0003] Traditional visual inspection of consumer electronics plastic casings relies on manual labor, which is increasingly failing to meet quality requirements in terms of efficiency and standards. To overcome the limitations of manual inspection, some companies have introduced machine vision inspection technology. However, existing machine vision inspection technologies typically employ standardized optical modules, and their universal light sources are ill-suited for uniform illumination of irregular curved surfaces. Furthermore, their incomplete field of view can lead to missed defects. Consequently, current machine vision inspection technologies are generally only applicable to casings with simple surfaces, such as those with relatively flat surfaces. Their applicability to complex curved casings, such as those used in headphones, is limited, failing to accurately detect defects across all areas. Moreover, for such complex curved casings, existing equipment struggles to simultaneously handle the imaging needs of different types of defects, including point marks, lines, discoloration, dents, and scratches.

[0004] Therefore, there is an urgent need for a technical solution that is universally adaptable, comprehensively identifies defects, and integrates the detection process to address many pain points in existing technologies and support the dual improvement of product appearance quality control and production efficiency in industries such as consumer electronics. Summary of the Invention

[0005] The purpose of this application is to provide an appearance inspection device and inspection method for curved shells to solve at least one of the above-mentioned technical problems.

[0006] In a first aspect, this application provides an appearance inspection device for curved shells, comprising:

[0007] The system includes a feeding module, a bottom surface detection module, a top surface detection module, a conveying module, a discharging module, a fixture that carries the curved shell to be tested and moves on the conveying module, a central control module, and multiple arc surface detection modules distributed along the conveying direction of the conveying module.

[0008] Each arc surface detection module is used to detect one or more local arc surfaces of the same shape, symmetrical or mirror symmetrical in the curved shell;

[0009] The arc surface detection module includes: a first bright field light surface with a first central hole, a plurality of first dark field light surfaces distributed around the first bright field light surface, an arc surface detection camera disposed behind the first central hole, and a first drive motor unit disposed below the arc surface detection station. The first bright field light surface is parallel to the first local arc surface to be tested on the curved shell located at the corresponding arc surface detection station. The arc surface detection camera vertically photographs the first local arc surface to be tested through the first central hole. The first drive motor unit is used to drive the curved shell on the fixture to rotate synchronously by rotating, thereby rotating the first local arc surface to be tested on the curved shell to a test position parallel to the first bright field light surface.

[0010] The central control module is connected to each module and is used to control the coordinated operation of each module.

[0011] Optionally, the first drive motor unit includes: a first power and reduction assembly, a first lifting assembly connected to the first power and reduction assembly, and a first positioning actuator disposed at the top of the first lifting assembly;

[0012] The first power and deceleration assembly drives the first lifting assembly to move the first positioning actuator up, down and rotate. When the first positioning actuator rises to a first height, it is fixedly connected to the fixture. When it falls to a second height, it separates from the fixture and drives the fixture and the curved shell on the fixture to rotate synchronously at the first height.

[0013] Optionally, the fixture includes a base, a support assembly, and a placement assembly;

[0014] The base has a through hole and is used to support the support assembly;

[0015] The bottom of the support column in the support assembly extends out of the through hole, and the top of the support column is fixed to the placement assembly. When the first positioning actuator rises to the first height, it contacts and is fixed to the bottom of the support column.

[0016] The placement component is used to place and limit the curved shell.

[0017] A second aspect of this application provides a method for inspecting the appearance of curved shells, applied to the curved shell appearance inspection equipment described in any embodiment of this application, comprising:

[0018] Step S10: Transport the curved shell to the bottom surface inspection station and perform bottom surface inspection;

[0019] Step S20: Transfer the curved shell that has completed the bottom surface inspection to the conveying module, and pass through each arc surface inspection station and top surface inspection station in sequence. Perform corresponding local arc surface inspection and top surface inspection at each arc surface inspection station and top surface inspection station. The local arc surface inspection at at least one arc surface inspection station includes: when the curved shell is transported to the corresponding arc surface inspection station, call the first drive motor unit to rotate the curved shell so that the first local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the first local arc surface to be tested. Continue to call the first drive motor unit to rotate the curved shell so that the second local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the second local arc surface to be tested. The first local arc surface to be tested and the second local arc surface to be tested have the same shape, are symmetrical, or are mirror symmetrical.

[0020] Step S30: Transfer the curved shell, which has completed the appearance inspection of all positions, to the unloading module.

[0021] The curved shell appearance inspection equipment and method in this application, by setting up a bottom surface inspection module, a top surface inspection module, and multiple arc surface inspection modules, divides the curved part of the curved shell into multiple local arc surfaces based on the curved shell. Local arc surfaces with the same shape, symmetry, or mirror symmetry are assigned to the same arc surface inspection module for appearance inspection. By combining multiple arc surface inspection modules, global arc surface inspection of the curved shell can be achieved. Furthermore, for each curved surface detection module, the combined design of its first bright field light surface and first dark field light surface can effectively identify various appearance defects such as point-like foreign objects, line-like foreign objects, discoloration, pressure marks, and scratches on the corresponding local curved surface. By arranging the first drive motor unit below the detection station, the first drive motor unit ensures that the local curved surface to be tested is parallel to the first bright field light surface through precise lifting and rotation control. Combined with the synergistic illumination of the dark field light source, shadow interference during complex curved surface imaging is avoided. Moreover, based on the positional relationship between local curved surfaces with the same shape, symmetry, or mirror symmetry, in addition to completing the detection of one local curved surface, other local curved surfaces with the same shape, symmetry, or mirror symmetry can be rotated to the same angle by adaptive rotation of the first drive motor, and then the local curved surface can be detected again. This allows one curved surface detection module to complete the detection of multiple local curved surfaces, improving the detection efficiency of local curved surfaces. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation on the scope of this application.

[0023] Figure 1 This is a schematic diagram of the overall structure of the curved shell in one embodiment;

[0024] Figure 2 This is a top view of the curved shell in one embodiment;

[0025] Figure 3 This is a schematic diagram showing the region division of the sidewall of the curved shell in one embodiment;

[0026] Figure 4 This is a schematic diagram showing the division of the top surface and arc surface of a curved shell in one embodiment;

[0027] Figure 5 This is a schematic diagram of the structure of a curved shell appearance inspection device in one embodiment;

[0028] Figure 6 This is a schematic diagram of the curved shell appearance inspection device in another embodiment;

[0029] Figure 7 This is a partial structural diagram of the sidewall inspection station area in one embodiment;

[0030] Figure 8 This is a schematic diagram of a portion of the structure located in the arc surface detection station area in one embodiment;

[0031] Figure 9 This is a schematic diagram of a portion of the structure in the top surface inspection station area in one embodiment;

[0032] Figure 10 This is a schematic diagram of a portion of the structure in the material feeding module area in one embodiment;

[0033] Figure 11 This is a schematic diagram of the structure of the first handling robot grasping the curved shell in one embodiment. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0035] All terms used in this application (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0036] For example, the terms "first," "second," etc., used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element.

[0037] For example, the terms "comprising" or "including" used in this application indicate the presence of features, steps, operations and / or components, but do not exclude the presence or addition of one or more other features, steps, operations or components.

[0038] This application provides a surface shell appearance inspection device. The surface shell refers to a shell-like structural component that includes at least one continuous curved surface structure (including regular arc surfaces, irregular curved surfaces, or multi-surface combinations), has a closed or semi-closed contour, and is used to support and protect internal components of a product or directly serve as a core component of the product's appearance. Typically, the curved surface is the main appearance or functional surface, and the curved surface contour must meet the requirements of product assembly, human-machine interaction, or aerodynamics / fluid dynamics. The material of the surface shell can be plastic, metal, composite materials, etc.; the size can range from micro (millimeter level) to large (meter level), and because it directly exposes or affects the core performance of the product, it needs to be inspected for defects such as point-like foreign objects, linear foreign objects, discoloration, pressure marks, and scratches.

[0039] Curved housings can be categorized into consumer electronics housings, automotive component housings, industrial equipment housings, and medical device housings. Consumer electronics housings include headphone shells, wireless Bluetooth headset charging case shells, smartwatch shells, portable speaker shells, tablet computer bezel shells, laptop palm rest shells, VR headset shells, and smart speaker shells. Automotive component housings include car door handle shells, car rearview mirror shells, car center console screen bezel shells, car seat adjustment buttons, and new energy vehicle charging port covers. Industrial equipment housings include industrial robot end effectors, small pneumatic components, automated conveyor line rollers, and industrial sensor protective shells. Medical device housings include blood glucose meter shells, portable ultrasound probe shells, medical stethoscope ear hook shells, and rehabilitation device handle shells.

[0040] Based on the surface shape and appearance inspection requirements of the shell, the curved shell can be divided into bottom, top, arc, and side surfaces. Adjacent surfaces are connected or may overlap to ensure no areas are missed during appearance inspection. The bottom, top, arc, and side surfaces can be further subdivided into multiple sub-regions depending on the inspection needs. The number and size of the sub-regions can be determined based on the structural characteristics of the curved shell and the number and capacity of the inspection modules in the testing equipment. Taking a curved shell as an example, such as a headphone shell... Figure 1 As shown, it can be divided into a bottom surface, a top surface, multiple local curved surfaces, and multiple local side surfaces.

[0041] Based on the structural characteristics, surface morphology differences, and comprehensive coverage requirements for appearance defect detection of curved shells, and following the principles of "independent detection of zones, seamless connection between adjacent areas, and coverage without blind spots," curved shells can be divided into four core surface areas: bottom, top, curved surface, and side. Each core surface area is a key functional or aesthetic surface of the shell. Adjacent areas are naturally connected by transition surfaces (virtual boundaries are used when there are no obvious boundaries), and the transition area is included in the detection range of any adjacent core area, ensuring that no area is missed or duplicated in appearance inspection. Furthermore, to adapt to the refined inspection needs of complex curved surfaces, one or more of the core surface areas (bottom, top, curved, side, etc.) can be further divided into multiple sub-regions based on changes in surface curvature, defect-prone locations, and optical imaging adaptability. Each sub-region is equipped with a targeted detection module and imaging parameters to achieve accurate defect capture.

[0042] Taking the curved shell 100 as an example of the headphone shell, as shown in Figure 1 and Figure 2 As shown, its overall structure is composed of a top surface 110, an arc surface 120, a side wall 130, and a bottom surface. Based on this, the top surface 110 and the bottom surface can each be used as a detection area of ​​a detection module, while the arc surface 120 and the side wall 130 can be divided into multiple local detection areas, each detected by a corresponding detection module. For the side wall 130, an exemplary division method is as follows... Figure 3 As shown, the sidewall 130 can be divided into areas A, B, C, and D. Area B can be further divided into areas B1, B2, B3, B4, B5, and B6. Similarly, area D can be divided into areas D1, D2, D3, D4, D5, and D6. Likewise, for the curved surface 120, as... Figure 4 As shown, it can be divided into areas F, G, H, J, L, and M. Figure 4In this diagram, area S is the top surface 110, and the bottom surface is area E. Based on this division, the headphone shell can be divided into areas A, B (B1~B6), C, D (D1~D6), E, ​​F, G, H, J, L, M, and S. Among these, the shapes of the different areas exhibit similarity, symmetry, or mirror symmetry. For example, the shape of the local sidewall area B1 is similar to, symmetrical to, or mirror-symmetrical with areas D1, B6, and D6; the shape of the local sidewall area B2 is similar to, symmetrical to, or mirror-symmetrical with areas D2, B5, and D5; the shape of the local sidewall area B3 is similar to, symmetrical to, or mirror-symmetrical with areas D3, B4, and D4; the shape of the local curved surface area F is similar to, symmetrical to, or mirror-symmetrical with areas G, L, and M; and the shape of the local curved surface area H is similar to, symmetrical to, or mirror-symmetrical with area J. It is understandable that other methods of dividing the curved shell can also be used, which will not be elaborated upon further.

[0043] For curved shell appearance inspection equipment, combined with Figure 5 and Figure 6 , Figure 10 As shown, it includes a feeding module 210, a bottom surface detection module 230, a top surface detection module 260, a conveying module 245, a discharging module 290, a fixture 300 that carries the curved shell 100 to be tested and moves on the conveying module 245, a central control module, and multiple arc surface detection modules 270 distributed along the conveying direction of the conveying module 245. It also includes: multiple side wall detection modules 250, a positioning and guiding module 220 located upstream of the feeding module 210, a dust removal module located upstream of the positioning and guiding module 220, a first handling robot 240 located downstream of the feeding module 210, a second handling robot 280 located downstream of the conveying module 245, and a circuit control cabinet 295. The central control module is connected to each module and is used to control the coordinated operation of each module.

[0044] The conveying module 245 can be any suitable shape, such as a straight line or a ring. The feeding module 210, the positioning and guiding module 220, the bottom surface detection module 230, and the conveying module 245 are connected in sequence. The side wall detection module 250, the top surface detection module 260, and the arc surface detection module 270 are arranged in sequence along the conveying direction on the conveying module 245. The unloading module 290 is connected to the output end of the conveying module 245.

[0045] Specifically, the positioning and guiding module 220 is fixed above the end station of the jig conveyor line of the feeding module 210, and is rigidly connected to the equipment frame through an aluminum alloy bracket. The positioning and guiding module 220 is equipped with a positioning camera to take pictures of the curved shell flowing to the end of the conveyor line. The central control module identifies the position coordinates of the curved shell at the end of the conveyor line and performs preliminary defect detection based on the picture.

[0046] The positioning guidance module 220 includes a positioning camera and an auxiliary light surface. The structure between the auxiliary light surface and the positioning camera is similar to that of the light surface and camera in the top surface detection module 260. The positioning camera can be a 2000W global shutter industrial camera, which can clearly identify the edge contour and positioning reference points of the curved shell on the fixture 300. The auxiliary light surface can include a dark field light surface and a bright field light surface. Both the dark field light surface and the bright field light surface have annular central holes. The dark field light surface is located between the end station and the bright field light surface. The light emitted by the bright field light surface illuminates the upper surface of the product at a perpendicular angle, avoiding reflection interference with the cooperation of the dark field light surface. The positioning camera is located above the bright field light surface and can photograph the upper surface of the curved shell at the end station through the annular central holes of the bright field light surface and the dark field light surface.

[0047] When the curved housing is stationary at the end of the workpiece, the positioning camera can capture multiple frames of images of the upper surface, such as five frames at a frame rate of 30fps. Image acquisition can be completed after the fixture conveyor line has come to a complete stop. The central control module uses image detection algorithms to identify the X and Y axis coordinate offsets and Z axis rotation angle of the product, while simultaneously detecting initial defects on the upper surface of the product (such as obvious scratches or large pieces of discolored foreign objects), providing accurate data support for subsequent handling and inspection.

[0048] The conveyor module 245 adopts a ring-shaped synchronous belt conveyor structure with an overall rectangular layout, which is compatible with the overall dimensions of the equipment, saving installation space while ensuring a reasonable layout of the inspection stations. The conveyor module 245 has drive and positioning components, which use a servo motor and planetary reducer to drive the synchronous belt pulley to rotate, and use an encoder to achieve closed-loop control of the conveying position; the synchronous belt conveyor line has a fixture positioning component at each inspection station of the inspection module. When the fixture 300 arrives at the corresponding inspection station, the positioning component can accurately lock the fixture 300 at the inspection station.

[0049] The various modules of the equipment are sequentially connected in the following order: feeding module 210 → positioning and guiding module 220 → bottom surface detection module 230 → conveying module 245 → side wall detection module 250 → top surface detection module 260 → curved surface detection module 270 → unloading module 290, forming a closed-loop detection process. Understandably, the connection sequence can also be any other suitable method.

[0050] Taking this sequence as an example, when a person places the earphone shell on the fixture 300 of the loading module 210, the fixture conveyor line sends the fixture 300 to the robot gripping station (i.e., the end station of the fixture conveyor line of the loading module 210) and locks it; the positioning and guidance module 220 takes a picture of the product, identifies the coordinates and initial defects, and the first handling robot 240 grips the product according to the coordinate information and transfers it to the bottom surface inspection module 230 to complete the bottom surface inspection; the first handling robot 240 places the product with the bottom surface inspection completed on the input fixture of the conveying module 245, and the circular line drives the fixture 300 to pass through each side wall inspection module 250, top surface inspection module 260 and arc surface inspection module 270 in sequence, and completes the appearance inspection of the corresponding local area at the inspection station of each module.

[0051] The conveyor module 245 delivers products that have completed inspection of all appearance areas to the unloading station at the output end. The second handling robot 280, based on the inspection results, transfers qualified and defective products to the corresponding fixture lines of the unloading module 290, achieving sorting. The locking methods at each inspection / unloading station are similar to the locking and positioning methods at the robot gripping station, and will not be elaborated further. It is understood that other connection sequences are also possible, and are not limited here.

[0052] The central control module communicates with the controllers of each module via network communication or electrical connection to acquire measurement data from each detection module, and coordinates the operation of each module based on this measurement data. Furthermore, the working rhythm of each module is also coordinated under the collaborative control of the central control module to avoid inconsistent detection rhythms among the modules, which could lead to transportation chaos.

[0053] The loading module 210 is used to automate or manually load and initially position the product to be tested. The fixture conveyor line on the loading module 210 can adopt a synchronous belt conveyor structure to support the fixture 300 and the curved shell to be tested.

[0054] like Figure 11 As shown, the first handling robot 240 can be a four-axis / six-axis industrial robot, equipped with a vacuum suction cup gripper 241 at the end. Based on the coordinate information fed back by the central control module, it grabs the product to be tested and smoothly transfers the product to the testing station at the bottom surface testing module 230.

[0055] The fixture 300 is used to carry the product to be tested and moves with the conveyor module 245. Corresponding fixtures 300 are provided on the conveyor lines of the loading module 210, the conveyor module 245, and the unloading module 290. For example... Figure 7 and Figure 8As shown, the fixture 300 includes a base 310, a support assembly, and a placement assembly 330. The placement assembly can be an injection-molded part adapted to the contour of the product to be tested, and its upper surface is provided with a positioning part that fits into the curved shell, which can effectively limit the radial displacement and circumferential rotation of the product during the testing process.

[0056] In this embodiment, each arc surface detection module 270 is used to detect one or more local arc surfaces of the same shape, symmetrical or mirror symmetrical in the curved shell. The arc surface detection module 270 includes: a first bright field light surface with a first central hole, a plurality of first dark field light surfaces distributed around the first bright field light surface, an arc surface detection camera disposed behind the first central hole, and a first drive motor unit disposed below the arc surface detection station. The first bright field light surface is parallel to the first local arc surface to be tested on the curved shell at the corresponding arc surface detection station. The arc surface detection camera vertically photographs the first local arc surface to be tested through the first central hole. The first drive motor unit is used to drive the curved shell on the fixture 300 to rotate synchronously by rotating, thereby rotating the first local arc surface to be tested on the curved shell to a test position parallel to the first bright field light surface.

[0057] like Figure 5 and Figure 6 As shown, the curved surface detection modules 270 are evenly distributed along the conveying direction of the conveying module 245, with a total of 7 groups. It is understood that more or fewer groups can be set, or some curved surface detection modules 270 may be in standby mode, i.e., not participating in the appearance detection of the curved shell. For example, 6 groups may correspond to the detection of 6 local curved surface areas of the earphone shell, namely areas F, G, H, J, L, and M, or only 3 groups may correspond to the detection of these 6 local curved surface areas. Several local curved surfaces with the same shape, symmetry, or mirror symmetry may be detected by the same curved surface detection module.

[0058] Each group of curved surface detection modules 270 has the same structure, such as Figure 8 As shown, it includes a first bright-field light surface 271, a first dark-field light surface 272, a curved surface detection camera 273, and a first drive motor unit 274. The first bright-field light surface 271 is a customized light source with a central aperture to accommodate the lens of the curved surface detection camera 273. It integrates a precision light guide plate and a microstructure diffusion film. Light enters from the side and is scattered by the light guide plate, exiting at a near-vertical angle (e.g., 85°~95°) onto the local curved surface to be measured. Its light-emitting surface uniformity is ≥90%, effectively avoiding hot spots and providing excellent imaging results for point-like foreign objects and discoloration defects. The local curved surface to be measured can be a plane fitted based on this plane, with the light rays being substantially perpendicular to this fitted plane.

[0059] In one embodiment, the first dark field light surface 272 is distributed around the first bright field light surface 271, and the second angle between the light emitted by each first dark field light surface 272 and the first plane is less than 15°.

[0060] The first dark-field light surface 272 can have 2, 3, 4, 5, 6, or any other suitable number of strip LED light sources. Taking 4 strip LED light sources as an example, they are distributed around the first bright-field light surface 271 along the directions of 0°, 90°, 180°, and 270° respectively. The length of each strip light source is 60mm, the spacing between the LEDs is 5mm, and the angle between the light source and the plane of the local curved surface to be measured can be less than 15°, for example, it can be adjusted within the range of 5°-15°, so that the light surface emitted by the first dark-field light surface 272 is almost parallel to the fitting plane of the local curved surface to be measured. The brightness and switching sequence of the first dark-field light surface 272 can be independently controlled in each direction. The light shines at an angle close to parallel to the curved surface to be measured, so that micro-undulation defects such as pressure marks and scratches produce obvious shadows.

[0061] The curved surface inspection camera 273 is specifically a 500w global shutter industrial camera, which is set behind the first central hole of the first bright field light surface 271. The lens axis is perpendicular (or basically perpendicular) to the fitting plane of the first bright field light surface 271. It can vertically photograph the local curved surface to be tested through the first central hole at a preset frame rate to obtain a corresponding number of photos for appearance defect detection of the local curved surface to be tested.

[0062] The curved shell appearance inspection device in this application, by setting up a bottom surface inspection module 230, a top surface inspection module 260, and multiple arc surface inspection modules 270, divides the curved part of the curved shell into multiple local arc surfaces. Local arc surfaces with the same shape, symmetry, or mirror symmetry are assigned to the same arc surface inspection module 270 for appearance inspection. By combining multiple arc surface inspection modules 270, global arc surface inspection of the curved shell can be achieved.

[0063] For each arc surface detection module 270, the combined design of its first bright field light surface 271 and first dark field light surface 272 can effectively identify various appearance defects such as point-like foreign objects, line-like foreign objects, discoloration, pressure marks, and scratches on the corresponding local arc surface. By arranging the first drive motor unit 274 below the detection station, the first drive motor unit 274 ensures that the local arc surface to be tested is parallel to the first bright field light surface 271 through precise lifting and rotation control. Combined with the coordinated illumination of the four-directional dark field light source, shadow interference during complex curved surface imaging is avoided. Furthermore, based on the positional relationship between local arc surfaces with the same shape, symmetry, or mirror symmetry, in addition to completing the detection of one local arc surface, other local arc surfaces with the same shape, symmetry, or mirror symmetry can be rotated to the same angle by adaptive rotation of the first drive motor, and then the local arc surface can be detected again. This allows one arc surface detection module 270 to complete the detection of multiple local arc surfaces, improving the detection efficiency of local arc surfaces.

[0064] It should be noted that this embodiment only uses a headset shell as an example to describe the present invention in detail, and is not intended to limit the scope of protection of the present invention. For other shells with complex curved surface structures (such as smartwatch shells, drone shells, etc.), accurate detection can be achieved simply by adjusting the outline of the fixture placement components, the number and position of the arc surface detection module 270, and the number of local arc surface divisions of the curved shell, all of which fall within the scope of protection of the present invention.

[0065] In one embodiment, the first drive motor unit 274 includes: a first power and deceleration assembly 2741, a first lifting assembly 2742 connected to the first power and deceleration assembly 2741, and a first positioning actuator 2743 disposed at the top of the first lifting assembly 2742; the first power and deceleration assembly 2741 drives the first lifting assembly 2742 to drive the first positioning actuator 2743 to rise, fall and rotate; the first positioning actuator 2743 is fixedly connected to the fixture when it rises to a first height, separates from the fixture when it falls to a second height, and drives the fixture and the curved shell on the fixture to rotate synchronously at the first height.

[0066] In this embodiment, as Figure 8 As shown, the structure of the first drive motor unit 274 is described based on the scenario of detecting the curved surface of a headset shell. The first drive motor unit 274 is fixed in the equipment frame below the curved surface detection station, and is vertically installed, coaxially aligned with the curved surface detection station of the conveying module 245, and located below the corresponding station. Its core components include a first power and deceleration component 2741, a first lifting component 2742, and a first positioning actuator 2743. These components are rigidly connected in sequence to form an integrated drive structure.

[0067] The first power and reduction assembly 2741 provides rotational power and precision control for the first drive motor unit 274. The power motor can be a vertical servo motor, and the reduction assembly can be a planetary reducer, which effectively reduces motor speed, amplifies output torque, and suppresses rotational vibration, ensuring smooth and shock-free rotation of the fixture and product. The motor and reducer are rigidly fixed to the bottom base plate of the first lifting assembly 2742 via a flange. Anti-vibration rubber pads are installed between the flange and the base plate to reduce the impact of motor vibration on detection accuracy.

[0068] The first lifting assembly 2742 is used to drive the first positioning actuator 2743 to move up and down in the vertical direction, realizing the connection / separation with the fixture. The first lifting assembly 2742 can adopt a high-precision lifting scheme of servo motor + ball screw nut pair. The nut and the screw are matched and coaxially connected to the ball screw through a coupling, driving the screw to rotate and driving the nut seat to move up and down.

[0069] The first positioning actuator 2743 is a key component connecting the first lifting assembly 2742 and the fixture 300, and it can be a columnar structure. The upper end face of the first positioning actuator 2743 is provided with a recess / groove. When the first positioning actuator 2743 is raised to the second height, the bottom of the support assembly of the fixture is positioned in the recess / groove, and the fixture rotates synchronously under the rotation of the first positioning actuator 2743.

[0070] The operation of the first drive motor unit 274 is divided into four stages: descent reset, ascent connection, rotation drive, and descent separation. The entire process is controlled in a closed loop by the central control module. The specific process is as follows: In the initial state, the first positioning actuator 2743 is lowered to the lower limit (second height), and the upper end surface is lower than the bottom surface of the fixture support column of the conveying module 245. After the conveying module 245 sends the fixture 300 carrying the earphone shell to the arc surface detection station, the servo motor of the first lifting component 2742 is started, driving the first positioning actuator 2743 to rise vertically along the guide shaft. During the ascent, the bottom surface of the support column of the fixture 300 is inserted into the concave hole / groove on the upper surface of the first positioning actuator 2743 and positioned to achieve precise centering. After the first positioning actuator 2743 continues to rise to the first height, the central control module sends a rotation command to the first power and deceleration assembly 2741 according to the arc surface detection requirements. The first positioning actuator 2743 drives the fixture 300 and the curved shell to rotate synchronously, rotating the curved shell on the fixture 300 to a specified angle so that the corresponding local arc surface to be detected is parallel to the first dark field light surface 272. After the image acquisition of the current local arc surface is completed, the rotation action is repeated to rotate another local arc surface to be detected to be parallel to the first dark field light surface 272 and acquire an image. After all local arc surfaces of the corresponding station are detected, the central control module sends a reset command to drive the first positioning actuator 2743 to descend vertically to the second height, so that the first drive motor unit 274 and the curved shell are aligned, and then the fixture 300 is transported to the next detection station.

[0071] In this embodiment, by controlling the rising, falling and rotating of the positioning actuator, the curved shell on the fixture 300 can be driven to rotate synchronously, and the local arc surface to be inspected can be accurately rotated to a specified angle, so as to reliably perform appearance defect inspection on one or more corresponding local arc surfaces.

[0072] In one embodiment, the fixture includes a base, a support assembly, and a placement assembly; the base has a through hole and is used to support the support assembly; the bottom of a support column in the support assembly extends out of the through hole, the top of the support column is fixed to the placement assembly, and the positioning actuator contacts and is fixed to the bottom of the support column when it rises to a first height; the placement assembly is used to place and limit the curved housing.

[0073] like Figure 7 and Figure 8As shown, the base 310 is the core load-bearing component of the fixture 300, and also provides a positioning reference for the support assembly and the first drive motor unit 274. One or more through holes are provided in the central area of ​​the base 310 or at any suitable location. The support assembly connects the base 310 and the placement assembly 330, and simultaneously transmits rotational power to the first drive motor unit 274. The support assembly includes a support column 322 and a support plate 321. The support plate 321 also has through holes. The support column 322 passes through the through holes in the support plate 321 and the base 310. The support plate 321 is placed on the base 310, which supports the support assembly.

[0074] The bottom structure of the support column 322 is adapted to the structure of the recess / groove on the upper end face of the positioning actuator, so that when the support column is inserted into the recess / groove on the upper end face of the positioning actuator, it can be fixedly connected with the positioning actuator.

[0075] The placement component 330 is fixed to the top of the support column 322 and directly contacts the curved shell. Its structure is adapted to the contour of the bottom surface of the curved shell, ensuring that the curved shell 100 will not shift during transportation or rotation with the fixture 300.

[0076] In one embodiment, the curved shell appearance inspection device further includes multiple sidewall inspection modules 250; each sidewall inspection module 250 is used to inspect one or more local arc surfaces of the curved shell. When the same sidewall inspection module 250 inspects multiple local side surfaces, the multiple local side surfaces have the same shape, are symmetrical, or are mirror symmetrical. The bottom surface inspection module 230, the top surface inspection module 260, the multiple sidewall inspection modules 250, and the multiple arc surface inspection modules 270 together realize the appearance inspection of all surfaces of the curved shell.

[0077] like Figure 7 As shown, the equipment is equipped with a total of 7 side wall detection modules 250, which are evenly arranged along the conveying direction of the conveying module 245 and are all installed inside the equipment frame to ensure that the detection camera and the side wall of the earphone shell are on the same horizontal detection surface, thus avoiding image blurring caused by shooting angle deviation.

[0078] Taking the sidewall of the earphone shell as an example of a ring-shaped vertical structure, the first group of sidewall detection modules detects areas A and C; the second group of sidewall detection modules detects areas B1 and D6; the third group of sidewall detection modules detects areas B2 and D5; the fourth group of sidewall detection modules detects areas B3 and D4; the fifth group of sidewall detection modules detects areas B4 and D3; the sixth group of sidewall detection modules detects areas B5 and D2; and the seventh group of sidewall detection modules detects areas B6 and D1.

[0079] This division of labor mode reduces the number of modules by utilizing the symmetrical features of the sidewalls, while ensuring no omissions in detection. Furthermore, the camera field of view of a single module can completely cover a single sub-region, avoiding duplication or omissions caused by cross-shooting of multiple regions.

[0080] Through the collaboration of the above-mentioned detection modules, the equipment achieves full coverage of the four core surfaces of the curved shell: bottom surface, top surface, side wall, and arc surface, without missing any appearance surfaces or transition parts.

[0081] Similar to the curved surface detection module 270, specifically, the sidewall detection module includes: a second bright-field light surface with a second central hole parallel to the third plane where the first local side of the curved shell to be tested is located at the corresponding sidewall detection station; multiple second dark-field light surfaces with a third angle to the third plane; a sidewall detection camera located behind the second central hole; and a second drive motor unit located below the corresponding curved surface detection station. The sidewall detection camera vertically captures the first local side of the test through the second central hole. The second drive motor unit below the sidewall detection station is used to drive the curved shell on the fixture 300 to rotate synchronously, thereby rotating the first local side of the test on the curved shell to a test position parallel to the second bright-field light surface. The second dark-field light surfaces are distributed around the second bright-field light surface, and the fourth angle between the light emitted by each second dark-field light surface and the third plane is less than 15°.

[0082] The second bright-field light surface 251 can also adopt a customized central hole side-emitting light source, with a second central hole 2511 in the middle to fit the lens of the side wall detection camera. Internally, it integrates a precision light guide plate and a diffusion film to achieve uniform light emission from the emitting surface. Light enters from the side and is scattered by the light guide plate, exiting at an angle perpendicular to the third plane (the plane where the first measured local side is located), avoiding the formation of shadows on the side wall surface by obliquely incident light. The uniform, vertically illuminating light allows for clear contrast between light and dark areas on the side wall surface, making it easier for image detection algorithms to identify minute defects.

[0083] The second dark-field light surface 252 uses four strip LED light sources, distributed around the second bright-field light surface at 0°, 90°, 180°, and 270° directions respectively. The third angle between the light source and the third plane can be adjusted within the range of 0° to 15°, so that the light shines at an angle close to parallel to the side wall surface. The low-angle illumination of the light can produce obvious shadows on the minor scratches and dents on the side wall surface. The four-directional light sources can cover scratches of different directions (horizontal, vertical, and diagonal), avoiding the omission of defects caused by a single-directional light source. The switching sequence and brightness of each light source can be independently controlled to adapt to the reflective characteristics of different colored side walls (e.g., reducing brightness for silver side walls and increasing brightness for blue side walls).

[0084] The sidewall inspection camera 253 is a 500W global shutter industrial camera. The camera vertically captures the first local side to be tested through the second central hole 2511. The working distance between the lens and the sidewall is moderate and fixed to ensure stable imaging magnification. Optionally, five or any other suitable number of images are acquired for each local side to be tested. For example, the five images correspond to a combination mode of bright field illumination alone and four dark field light sources illuminating individually in sequence. By fusing multiple frames, various defects such as point marks, discoloration, scratches, and pressure marks can be captured simultaneously, avoiding missed defects caused by a single illumination mode.

[0085] Similarly, the second drive motor unit 254 can have the same structure as the first drive motor unit 274, and also includes a second power and reduction assembly 2541, a second lifting assembly 2542 connected to the second power and reduction assembly 2541, and a second positioning actuator 2543 disposed at the top of the second lifting assembly 2542, which will not be described in detail here.

[0086] In one embodiment, the top surface detection module 260 includes: a third bright field light surface with a third central hole, which is parallel to the fifth plane containing the top surface of the curved housing at the corresponding top surface detection station; a third dark field light surface located between the third bright field light surface and the top surface detection station; and a top surface detection camera disposed behind the third central hole. The third dark field light surface is parallel to the fifth plane and has a fourth central hole. The top surface detection camera takes a vertical picture of the top surface through the third central hole and the fourth central hole. The fourth central hole contains uniformly arranged ring-shaped LED beads. The light emitted by the ring-shaped LED beads forms a fifth angle with the shooting axis of the top surface detection camera and converges at a specific point on the shooting axis.

[0087] like Figure 9 As shown, the top surface detection module 260 is fixed above the middle of the conveying module 245. The core components also include the third bright field light surface 261, the third dark field light surface 262, and the top surface detection camera 263, which are designed in a coaxial layout of camera-third bright field light surface-third dark field light surface-top surface of product.

[0088] The third bright field light surface 261 also adopts a custom-designed central aperture light source with a third central aperture in the middle. It integrates a precision light guide plate and a microstructure diffusion film. The light is emitted at an angle perpendicular to the fifth plane (the plane where the top surface is located). The vertical and uniform light can eliminate the reflection interference in the flat S-area in the center of the top surface, so that point-like foreign objects and color defects can form clear images, providing high-contrast image data for the algorithm.

[0089] The third dark-field light surface 262 is a ring structure, arranged parallel to the fifth plane, located between the third bright-field light surface and the top surface inspection station. A fourth central hole is located in the center to ensure unobstructed camera field of view. An appropriate number of LED beads are evenly arranged inside the fourth central hole. Angle and convergence design: The light emitted by the ring-shaped LED beads forms a fifth angle with the shooting axis of the top surface inspection camera. This fifth angle can be adjusted within a certain range, such as 5°-15°. All light converges at a specific point on the shooting axis, for example, 5mm above the center of the top surface. This design allows light to uniformly cover the transition arc surface and central area of ​​the top surface at a low angle, producing obvious bright lines or shadows for defects such as scratches and dents, while avoiding glare caused by direct light hitting the lens.

[0090] The top surface inspection camera 263 can also be a 2000w global shutter industrial camera, using a dual exposure mode to acquire a preset number (e.g., 2) of top surface images. The low-exposure image is used to capture defects in bright areas, such as scratches on a silver top surface, while the high-exposure image is used to capture defects in dark areas, such as discoloration on a blue top surface. The camera shoots the top surface vertically through the third and fourth central holes, ensuring that the shooting axis is coaxial with the center of the top surface to avoid image distortion in edge areas.

[0091] The bottom surface inspection module 230 also includes a corresponding bottom surface inspection camera, a bright field light surface, and a dark field light surface. Its structure is similar to that of the top surface inspection module 260. The difference is that the bottom surface inspection module 230 is located below the corresponding inspection station to capture images of the bottom surface of the curved shell. Further details will not be provided here.

[0092] In one embodiment, the curved shell appearance inspection device further includes a dust removal module upstream of the positioning and guiding module 220, a first handling robot 240 downstream of the feeding module 210, and a second handling robot 280 downstream of the conveying module 245.

[0093] like Figure 10 As shown, the dust removal module includes a second ion air knife 211 located above the feeding module 210 and a first ion air knife 212 disposed on the side wall of the feeding module 210. The air surface blown out by the first ion air knife 212 has a sixth included angle with the transmission surface of the feeding module 210.

[0094] In this embodiment, the dust removal module is located in the upstream area of ​​the feeding module 210. Through the dual design of "preliminary dust removal + precise cleaning", it removes dust, hair and other impurities from the product surface and avoids impurities being misjudged as defects.

[0095] The second ion air knife 211 is horizontally fixed above the fixture conveyor line of the feeding module 210 and connected to the equipment frame via an adjustable bracket for easy angle adjustment. The air knife has a suitable length to match the width of the fixture conveyor line, ensuring coverage of the entire conveying area. The first ion air knife 212 can be an inductive ion air knife, with its blowing surface forming a sixth angle (e.g., 45°) with the conveying surface of the feeding module 210 (the surface of the fixture conveyor line), and the wind speed can be adjusted within a suitable range. When the curved housing of the fixture 300 enters the coverage area of ​​the ion air knife, the central control module triggers the first ion air knife 212 to start, and the ion air blown at the sixth angle is evenly swept across the upper surface of the product, which can both blow off floating dust and neutralize the static electricity on the product surface, preventing secondary dust adsorption and achieving preliminary cleaning.

[0096] The first ion air knife 212 is fixed to the side wall of the loading module 210, with its air outlet aligned with the center area of ​​the fixture 300. It is equipped with an infrared gesture sensor to support manual gesture triggering. The air knife outlet diameter is appropriately sized, allowing for adjustment of the airflow direction within a certain angle range. After the curved housing is manually placed on the fixture 300, the first ion air knife can be activated via gesture (such as waving across the sensing area). The air outlet is then directed at the lower surface and edge gaps of the curved housing, areas difficult for the ion air knife to cover, blowing out directional ion air to achieve precise cleaning of the curved housing.

[0097] The positioning and guiding module 220 is used to take a picture of the top surface of the curved shell that is transported downstream of the feeding module 210, and to identify the position coordinates of the curved shell and perform preliminary appearance inspection of the top surface based on the picture.

[0098] The first handling robot 240 is used to grasp the curved shell downstream of the loading module 210 according to the position coordinates, move the grasped curved shell to the bottom surface inspection station where the bottom surface inspection module 230 is located, and after the bottom surface inspection module 230 completes the bottom surface inspection, it grasps the curved shell at the bottom surface inspection station and moves it to the first position of the conveying module 245.

[0099] The positioning and guidance module 220 works in conjunction with the first handling robot 240 to automate the product transfer process from "loading - bottom surface inspection - circular conveyor line," while simultaneously performing product positioning and preliminary top surface inspection. In addition to identifying the product's position coordinates, the positioning and guidance module 220 also performs preliminary top surface appearance inspection. The module includes a 2000W industrial camera with a 50mm FA lens and a custom light source. The camera has a pixel size of 2.4μm, the lens has a field of view (FOV) of 150mm × 100mm, and a single pixel accuracy of 27μm. It captures an image of the top surface of the earphone shell on the fixture. The central control module uses an image detection algorithm to identify the product's X and Y axis coordinate offsets and Z axis rotation angle, and transmits the coordinate data to the first handling robot 240 in real time.

[0100] In addition, the images captured by the camera of the positioning and guidance module 220 are used for preliminary defect screening, focusing on identifying obvious serious defects such as large pieces of foreign objects of different colors and long scratches. If a serious defect is detected, the central control module directly marks the product as a defective product, and the first handling robot 240 then transfers it to the temporary storage area for defective products, without having to enter the subsequent inspection process, thus improving inspection efficiency.

[0101] The first handling robot 240 can be a four-axis / six-axis industrial robot equipped with a vacuum suction cup gripper at its end to grasp the curved shell. Based on the coordinate information fed back by the positioning and guidance module 220, the first handling robot 240 moves to the robot gripping station of the fixture conveyor line. The vacuum suction cup adheres to the top edge of the product, and negative pressure adsorption is activated. After confirming that the adsorption is firm, the product is lifted from the fixture 300 and the curved shell is transferred to the fixed area (such as the positioning groove) of the bottom surface inspection module 230 according to the preset path. Then the suction cup is released and reset, waiting for the bottom surface inspection to be completed.

[0102] After the bottom surface inspection module 230 completes the inspection and sends a signal indicating completion, the first handling robot 240 moves to the bottom surface inspection station again, grabs the product, and transfers it to the first position of the conveying module 245 (the input fixture of the circular line). During placement, it ensures that the product is precisely aligned with the positioning boss of the fixture 300. After the transfer is completed, the robot returns to its initial position and waits for the next grabbing instruction.

[0103] The unloading module 290 includes a first unloading section 291 and a second unloading section 292. The second handling robot 280 moves the curved shell with appearance defects located at the second position of the conveying module 245 to the first unloading section 291, and moves the curved shell with acceptable appearance located at the second position of the conveying module 245 to the second unloading section 292.

[0104] The structure of the second handling robot 280 is basically similar to that of the first handling robot 240, and will not be described in detail here. The second handling robot 280 and the unloading module 290 work together to achieve automatic separation of qualified and defective products.

[0105] The unloading module 290 includes a first unloading section 291 (defective product unloading fixture line) and a second unloading section 292 (qualified product unloading fixture line). Both are arranged on one side of the output end of the conveying module 245 and can be similar to the loading module 210, both adopting a belt conveyor structure.

[0106] After the conveyor module 245 delivers the products that have completed all inspections to the second position (the output fixture of the circular line), the central control module sends the product inspection results (qualified / defective) and current position coordinates to the second handling robot 280. If the product is defective, the second handling robot 280 moves to the second position, picks up the product, and transfers it to the conveyor belt of the first unloading section 291. It releases the suction cup and places the product on the conveyor belt, which then transports the product to the end collection box. If the product is qualified, the robot picks up the product and transfers it to the conveyor belt of the second unloading section 292, precisely placing it in the preset position (matching the positioning requirements of the subsequent packaging production line). The product then enters the packaging process with the conveyor belt.

[0107] The curved shell appearance inspection equipment in this application removes surface dust from curved shells through a dual dust removal design, significantly reducing the false judgment rate of impurities and improving inspection accuracy. The high-precision positioning of the robot and the vacuum suction cup clamp design ensure no displacement or scratches during product transfer, protecting the product's appearance. The entire process, from dust removal, positioning, transfer to unloading and sorting, requires no manual intervention, increasing efficiency by more than three times compared to manual transfer and avoiding errors caused by manual operation. By adjusting the robot's gripping path and fixture positioning structure, it can adapt to curved shells of different sizes and shapes (such as headphone shells, wireless Bluetooth earphone charging cases, and smartwatch cases), demonstrating strong versatility.

[0108] In one embodiment, a method for inspecting the appearance of a curved shell is provided. This method can be applied to the curved shell appearance inspection equipment as described in any embodiment of this application, including:

[0109] Step S10: Transport the curved shell to the bottom surface inspection station and perform bottom surface inspection.

[0110] Step S20: Transfer the curved shell that has completed the bottom surface inspection to the conveying module, and sequentially pass through each arc surface inspection station and top surface inspection station. Perform corresponding local arc surface inspection and top surface inspection at each arc surface inspection station and top surface inspection station. The local arc surface inspection at at least one arc surface inspection station includes: when the curved shell is transported to the corresponding arc surface inspection station, call the first drive motor unit to rotate the curved shell so that the first local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the first local arc surface to be tested. Continue to call the first drive motor unit to rotate the curved shell so that the second local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the second local arc surface to be tested. The first local arc surface to be tested and the second local arc surface to be tested have the same shape, are symmetrical, or are mirror symmetrical.

[0111] Step S30: Transfer the curved shell, which has completed the appearance inspection of all positions, to the unloading module.

[0112] In this embodiment, the first handling robot, based on the coordinate information of the curved shell fed back by the positioning and guidance module, smoothly grasps the product using a vacuum suction cup gripper, with the suction cup adhering to the top surface of the product during grasping. Then, the robot transports the product to a predetermined position in the bottom surface inspection station (such as the positioning slot in the inspection table) according to a preset path. This predetermined position is perfectly matched with the bottom surface of the product, ensuring that the bottom surface is coaxially aligned with the inspection camera lens.

[0113] After placement, the central control module triggers the bottom surface inspection module to start: the bottom surface inspection camera, illuminated by a customized central aperture light source, vertically photographs the bottom surface of the product. Specifically, the light source illuminates the bottom surface at a vertical angle to avoid shadow interference, and the camera uses a single exposure mode to acquire an appropriate number of images, covering the entire bottom surface area. The acquired images are transmitted to the central control module in real time, where an image detection algorithm identifies appearance defects and provides the defect identification results. When defects are found, their location, type, and size are further marked. After inspection is completed, a "inspection complete" signal is sent back to the first handling robot.

[0114] Step S20: Zone detection - full coverage of curved surface and top surface, collaborative detection of symmetrical areas.

[0115] After receiving the bottom surface inspection completion signal, the first handling robot moves back to the bottom surface inspection station, picks up the product, and transfers it to the first position of the conveyor module. This position is the fixture positioning station at the input end of the circular conveyor. When the product is placed, it precisely fits with the positioning boss (placement component) of the fixture to ensure stable conveying. The central control module controls the circular conveyor module to start, driving the fixture and product to move along the conveying direction. During the movement, the encoder realizes closed-loop position control to ensure that the product accurately arrives at each inspection station.

[0116] Curved Surface Inspection: In this embodiment, the inspection equipment is pre-configured with the area of ​​the curved shell to be inspected corresponding to each inspection module. The annular conveyor module drives the product to pass through each curved surface inspection station sequentially. The curved surface inspection module at each station is used to perform appearance inspection on one or more corresponding local curved surfaces. The specific inspection process is as follows:

[0117] After the curved shell reaches the corresponding arc surface detection station, the conveying module stops moving, and the central control module sends a "arc surface detection start" signal. The first drive motor unit is activated, and the lifting assembly drives the positioning actuator to rise to the first height, so that the bottom of the fixture's support column inserts into the recessed hole / groove on the upper surface of the positioning actuator. The power and deceleration assembly drives the positioning actuator to rotate the fixture and the product. The rotation angle is precisely calculated by the central control module, and ultimately, the plane containing the local arc surface of the target to be detected is parallel to the first bright field surface.

[0118] After rotation and positioning, the first bright field light surface and the first dark field light surface are alternately illuminated: when the bright field light surface is illuminated alone, an appropriate number of images (e.g., 2 images) are collected to capture point-like foreign objects and different colors; when multiple dark field light sources are illuminated individually in sequence, an appropriate number of images (e.g., 1 image) are collected for each to capture scratches and pressure marks in different directions.

[0119] After completing the detection of a local curved surface, if the detection module is also configured to detect other local curved surfaces, the central control module sends a "rotation switch" signal. For example, if the first local curved surface is area F and the second local curved surface is area M, based on the positional relationship between the two, the first drive motor unit drives the product to continue rotating 180°, so that the plane where area M is located rotates to a detection position parallel to the first bright field light surface.

[0120] Repeat the above process of lighting the light source and acquiring images to complete the defect detection in area M. After completing the detection of all corresponding local arc surfaces, the first drive motor unit drives the positioning actuator to descend to the second height, separates from the fixture, and the ring conveyor module carries the product into the next set of arc surface detection stations.

[0121] The remaining arc surface detection modules operate in the same manner as described above to achieve full coverage of defects in each arc surface sub-region.

[0122] Top surface inspection: The central control module pre-sets the shooting parameters and gloss parameters according to the color of the curved shell to ensure that the captured image clearly shows the appearance defects. For example, if the top surface of the curved shell is blue or black (high reflectivity), the angle between the ring LED on the third dark field gloss surface and the fifth angle of the shooting axis is adjusted to 15° (high angle); if it is silver-white (low reflectivity), the angle is adjusted to 5° (low angle).

[0123] The top surface inspection camera uses a dual-exposure mode to acquire images: low exposure acquires a preset number of images (e.g., 1 image) to capture defects in bright areas (such as scratches or bright lines); high exposure acquires a preset number of images (e.g., 1 image) to capture defects in dark areas (such as discoloration or minor pressure marks). The acquired images are transmitted to the central control module, where image detection algorithms identify whether defects exist on the top surface.

[0124] Step S30: Material Unloading Module Transfer. After the product has completed inspection of all areas, the conveyor module sends it to the second position (the jig station at the output end of the circular line). The central control module summarizes all inspection data from the bottom, curved, and top surfaces, generating a complete defect inspection report (including defect location, type, and size). Upon receiving the "material unloading transfer" signal, the second handling robot moves to the second position, grabs the product using a vacuum suction cup gripper, and moves it onto the material unloading module.

[0125] The curved shell appearance inspection method in this application configures multiple arc surface inspection modules. Each arc surface inspection module performs appearance inspection on one or more local arc surfaces of the curved shell that have the same shape, are symmetrical or mirror symmetrical. During the local arc surface appearance inspection process, the precise rotation of the first drive motor unit ensures that the arc surface to be tested is parallel to the bright field light surface. Combined with multi-frame image acquisition and multi-light source combination, the accuracy and efficiency of the appearance inspection of the arc surface of the curved shell can be effectively improved.

[0126] In one embodiment, the curved shell appearance inspection method of this application further includes, before step S10:

[0127] Step S01, Dust Removal Pretreatment: Call the first ion air knife to perform first dust removal on the lower surface of the curved shell at the first station of the feeding module, and call the second ion air knife to perform second dust removal on the upper surface of the curved shell at the second station of the feeding module.

[0128] Step S02: Loading and Positioning: Call the positioning guidance module to photograph the curved shell at the third station of the loading module, identify the position coordinates of the curved shell at the third station, and call the first handling robot to transport the curved shell to the bottom inspection station based on the position coordinates of the curved shell at the third station.

[0129] In step S01, a "bottom-to-top" dust removal design can be used to specifically clean the lower and upper surfaces of the curved shell. Specifically, the first station of the loading module is located at the manual loading end, where the fixture conveyor line has a short pause cycle to ensure sufficient cleaning time. The first ion air knife is fixed to the side wall of the fixture conveyor line at this station, with its outlet angled upwards at 45° towards the fixture placement area. After the curved shell is manually placed into the fixture at the first station, the fixture triggers the station sensor, and the central control module automatically activates the first ion air knife. The air blown from the outlet of the first ion air knife is directed towards the lower surface of the product and the gap between the fixture and the product.

[0130] The second station is located downstream of the first station. The second ion air knife is horizontally fixed above the fixture conveyor line. It can be perpendicular to the conveyor surface or at any suitable angle, such as 45°. After the curved housing of the fixture reaches the second station, the central control module synchronously activates the second ion air knife, and the air surface sweeps evenly across the upper surface of the product.

[0131] Step S02: Loading and Positioning. The third station is located downstream of the second station and is the robot gripping station for the loading module. The fixture conveyor line is equipped with a positioning cylinder here to lock the fixture. The central control module calls the positioning guidance module to start and take an image of the top surface of the product.

[0132] After the image is transmitted to the central control module, the edge features of the product are extracted through relevant image detection algorithms, and the X-axis, Y-axis coordinate offset and Z-axis rotation angle are accurately identified. At the same time, the positioning reference point on the top surface of the product is marked. The coordinate data is stored in real time and sent synchronously to the controller of the first handling robot to ensure accurate adaptation of the grasping action.

[0133] After receiving the coordinate data, the first handling robot moves to the third station according to the preset path. The end vacuum suction cup clamp is adjusted to an angle parallel to the top surface of the product, and the suction cup adheres to the top surface of the product, initiating negative pressure suction. The robot then transports the product along the preset path, delivering it to the positioning slot of the bottom surface inspection station. After placement, the robot releases the suction cup and returns to its initial position, awaiting the next gripping command.

[0134] In step S10, the customized central hole surface light source of the bottom surface detection module is activated, and the light shines perpendicularly on the bottom surface to avoid shadow interference; the industrial camera adopts continuous acquisition mode, and the image is transmitted to the central control module in real time; the central control module calls the corresponding image detection algorithm to accurately identify point foreign objects (minimum 0.1mm×0.1mm), dents, discoloration and other appearance defects, and marks the coordinates and size of the defects; after the detection is completed, the central control module generates the bottom surface detection result and sends a "detection completed" signal to the first handling robot to trigger the subsequent transfer action.

[0135] In one embodiment, before step S40, the method further includes: calling the sidewall detection module to perform local sidewall detection on the curved shell at the sidewall detection station.

[0136] In this embodiment, the sidewall inspection process is similar to the curved surface inspection process. After the bottom surface inspection is completed, the curved shell enters the sidewall inspection process. Alternatively, the sidewall inspection process can be entered after the top surface and curved surface inspections are completed.

[0137] When the fixture reaches a certain side wall inspection station, the lifting component of the second drive motor unit drives the positioning actuator to rise to the first height, achieving engagement with the fixture. The power and deceleration components drive the positioning actuator to rotate the fixture and the product, rotating the curved shell to a detection position where the plane of the local side to be tested is parallel to the second bright field surface.

[0138] The second bright-field light surface is activated, illuminating the local side surface to be measured perpendicularly to the third plane. Multiple second dark-field light surfaces are then activated, each forming a certain angle with the third plane, illuminating the local side surface at a low angle, almost parallel to the third plane. The sidewall detection camera is activated, capturing a perpendicular image of the local side surface to be measured through the second central aperture.

[0139] When the second bright field light surface is lit individually, the camera captures a preset number of images (e.g., 2); when multiple second dark field light surfaces are lit individually in sequence, the camera captures a preset number of images (e.g., 1 for each); the captured images are transmitted to the central control module in real time for defect detection.

[0140] After completing the inspection of one local sidewall, if other local sidewalls to be inspected are configured, the central control module sends a "rotation switch" signal. The second drive motor unit drives the product to rotate at an appropriate angle, rotating the plane containing the other local sidewalls to be inspected to a detection position parallel to the second bright field light surface. The above process of light source illumination, image acquisition, and defect recognition is repeated to complete the local sidewall inspection. After all local sidewalls at the corresponding station have been inspected, the positioning actuator of the second drive motor unit descends to the second height and separates from the fixture. The conveyor module then transports the curved shell to the next station.

[0141] In step S40, after the curved shell completes full-area inspection of its bottom, arc, and top surfaces, the annular conveyor module delivers it to the second position of the conveyor module (the output station of the annular line). The central control module sends the final inspection results to the second handling robot (which has the same structure as the first handling robot), and the second handling robot determines the transfer path for the curved shell based on these results.

[0142] If the product is determined to be defective, the robot will transfer it to the first unloading section (defective product unloading fixture line) according to the path, gently place the product on the conveyor belt, and the product will be conveyed to the end defective product collection box by the conveyor belt; if the product is determined to be qualified, the robot will transfer it to the second unloading section (qualified product unloading fixture line), accurately place it at the preset positioning point, and the product will enter the packaging process by the conveyor belt.

[0143] In one embodiment, for a curved shell, the detection sequence is as follows: bottom surface detection → side wall detection → top surface detection → arc surface detection. Understandably, the detection sequence can also be adaptively adjusted by changing the positions of the various detection modules.

[0144] This embodiment employs a dual dust removal design, involving separate workstations and surfaces, to effectively remove impurities from the surface of curved shells, significantly reducing the probability of misidentifying impurities as defects and improving detection accuracy. The high-precision coordinate recognition of the positioning guidance module and the smooth transport by the robot ensure accurate placement of the product at each workstation, providing a stable benchmark for subsequent inspections. Furthermore, this method is adaptable to curved shells of different sizes and materials; only the corresponding parameters need to be adjusted according to adaptability, making it highly versatile.

[0145] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0146] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of this application and form different embodiments. For example, all the embodiments above can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A curved shell appearance inspection device, characterized in that, include: The system includes a feeding module, a bottom surface detection module, a top surface detection module, multiple side wall detection modules, a conveying module, a discharging module, a fixture that carries the curved shell to be tested and moves on the conveying module, a central control module, and multiple arc surface detection modules distributed along the conveying direction of the conveying module. Each arc surface detection module is used to detect one or more local arc surfaces of the same shape, symmetrical or mirror symmetrical in the curved shell; The arc surface detection module includes: a first bright field light surface with a first central hole, a plurality of first dark field light surfaces distributed around the first bright field light surface, an arc surface detection camera disposed behind the first central hole, and a first drive motor unit disposed below the arc surface detection station. The first bright field light surface is parallel to the first local arc surface to be tested on the curved shell located at the corresponding arc surface detection station. The arc surface detection camera vertically photographs the first local arc surface to be tested through the first central hole. The first drive motor unit is used to drive the curved shell on the fixture to rotate synchronously by rotating, thereby rotating the first local arc surface to be tested on the curved shell to a test position parallel to the first bright field light surface. Each sidewall detection module is used to detect one or more local arc surfaces of the curved shell. When the same sidewall detection module detects multiple local side surfaces, the multiple local side surfaces have the same shape, are symmetrical, or are mirror symmetrical. The sidewall detection module includes: a second bright field light surface with a second central hole that is parallel to the third plane where the first local side of the curved shell to be tested is located at the corresponding sidewall detection station; a plurality of second dark field light surfaces with a third angle to the third plane; a sidewall detection camera located behind the second central hole; and a second drive motor unit located below the corresponding arc surface detection station. The top surface inspection module includes: a third bright field light surface with a third central hole that is parallel to the fifth plane where the top surface of the curved shell located at the corresponding top surface inspection station is located; a third dark field light surface located between the third bright field light surface and the top surface inspection station; and a top surface inspection camera located behind the third central hole. The bottom surface detection module, top surface detection module, multiple side wall detection modules, and multiple curved surface detection modules work together to achieve appearance inspection of all surfaces of the curved shell; The central control module is connected to each module and is used to control the coordinated operation of each module.

2. The curved shell appearance inspection device according to claim 1, characterized in that, The first drive motor unit includes: a first power and reduction assembly, a first lifting assembly connected to the first power and reduction assembly, and a first positioning actuator disposed at the top of the first lifting assembly; The first power and deceleration assembly drives the first lifting assembly to move the first positioning actuator up, down and rotate. When the first positioning actuator rises to a first height, it is fixedly connected to the fixture. When it falls to a second height, it separates from the fixture and drives the fixture and the curved shell on the fixture to rotate synchronously at the first height.

3. The curved shell appearance inspection device according to claim 2, characterized in that, The fixture includes a base, a support assembly, and a placement assembly; The base has a through hole and is used to support the support assembly; The bottom of the support column in the support assembly extends out of the through hole, and the top of the support column is fixed to the placement assembly. When the first positioning actuator rises to the first height, it contacts and is fixed to the bottom of the support column. The placement component is used to place and limit the curved shell.

4. The curved shell appearance inspection device according to claim 1, characterized in that, The first dark field light surface is distributed around the first bright field light surface, and the second angle between the light emitted by each first dark field light surface and the first plane is less than 15°.

5. The curved shell appearance inspection device according to claim 1, characterized in that, The sidewall detection camera vertically captures the first local side of the test area through the second central hole. The second drive motor unit below the sidewall detection station is used to drive the curved shell on the fixture to rotate synchronously, thereby rotating the first local side of the test area on the curved shell to the test position parallel to the second bright field light surface. The second dark field light surface is distributed around the second bright field light surface, and the fourth angle between the light emitted from each second dark field light surface and the third plane is less than 15°. The third dark field light surface is parallel to the fifth plane and has a fourth central hole. The top surface detection camera takes a vertical picture of the top surface through the third and fourth central holes. The fourth central hole has a uniformly arranged ring-shaped LED bead inside. The light emitted by the ring-shaped LED bead forms a fifth angle with the shooting axis of the top surface detection camera and converges at a specific point on the shooting axis.

6. The curved shell appearance inspection device according to any one of claims 1 to 5, characterized in that, The curved shell appearance inspection equipment also includes a positioning and guiding module located above and downstream of the feeding module, and the conveying module is annular; The feeding module, positioning and guiding module, bottom surface detection module, and conveying module are connected in sequence. The side wall detection module, top surface detection module, and arc surface detection module are arranged in sequence along the conveying direction on the conveying module. The unloading module is connected to the output end of the conveying module.

7. The curved shell appearance inspection device according to claim 6, characterized in that, It also includes a dust removal module upstream of the positioning and guidance module, a first handling robot downstream of the feeding module, and a second handling robot downstream of the conveying module; The dust removal module includes a second ion air knife located above the feeding module and a first ion air knife disposed on the side wall of the feeding module. The air surface blown out by the first ion air knife has a sixth included angle with the transmission surface of the feeding module. The positioning and guiding module is used to take a picture of the top surface of the curved shell transported downstream of the feeding module, and to identify the position coordinates of the curved shell and perform preliminary appearance inspection of the top surface based on the picture. The first handling robot is used to grasp the curved shell downstream of the loading module according to the position coordinates, move the grasped curved shell to the bottom surface inspection station where the bottom surface inspection module is located, and after the bottom surface inspection module completes the bottom surface inspection, it grasps the curved shell at the bottom surface inspection station and moves it to the first position of the conveying module. The unloading module includes a first unloading section and a second unloading section. The second handling robot will move the curved shell with appearance defects located at the second position of the conveying module to the first unloading section, and move the curved shell with acceptable appearance located at the second position of the conveying module to the second unloading section.

8. A method for inspecting the appearance of a curved shell, characterized in that, The curved shell appearance inspection device as described in any one of claims 1 to 7 comprises: Step S10: Transport the curved shell to the bottom surface inspection station and perform bottom surface inspection; Step S20: Transfer the curved shell that has completed the bottom surface inspection to the conveying module, and pass through each arc surface inspection station and top surface inspection station in sequence. Perform corresponding local arc surface inspection and top surface inspection at each arc surface inspection station and top surface inspection station. The local arc surface inspection at at least one arc surface inspection station includes: when the curved shell is transported to the corresponding arc surface inspection station, call the first drive motor unit to rotate the curved shell so that the first local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the first local arc surface to be tested. Continue to call the first drive motor unit to rotate the curved shell so that the second local arc surface to be tested of the curved shell is parallel to the first bright field light surface. Take an image and perform appearance inspection on the second local arc surface to be tested. The first local arc surface to be tested and the second local arc surface to be tested have the same shape, are symmetrical, or are mirror symmetrical. Step S30: Transfer the curved shell, which has completed the appearance inspection of all positions, to the unloading module.

9. The method for inspecting the appearance of curved shells according to claim 8, characterized in that, Before step S10, the method further includes: Step S01, Dust Removal Pretreatment: Call the first ion air knife to perform first dust removal on the lower surface of the curved shell at the first station of the feeding module, and call the second ion air knife to perform second dust removal on the upper surface of the curved shell at the second station of the feeding module. Step S02: Loading and positioning: Call the positioning guidance module to take a picture of the curved shell at the third station of the loading module, identify the position coordinates of the curved shell at the third station, and call the first handling robot to transport the curved shell to the bottom detection station based on the position coordinates of the curved shell at the third station. Step S10 includes: calling the bottom surface inspection module to perform bottom surface inspection on the curved shell located at the bottom surface inspection station; Before step S40, the method further includes: calling the sidewall detection module to perform local sidewall detection on the curved shell at the sidewall detection station; Step S40 includes: for the curved shell that has completed appearance inspection, calling the second handling robot to move the curved shell with appearance defects located in the second position of the conveying module to the first unloading section, and moving the curved shell with qualified appearance located in the second position of the conveying module to the second unloading section.

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