Workpiece surface coating method and system

Abstract

The invention provides a workpiece surface coating method and system. The system comprises surface detection equipment, control equipment and coating equipment, the surface detection equipment acquires surface coating data of the to-be-detected workpiece coated with the paint and sends the surface coating data to the control equipment; the control equipment determines a supplementary coating parameter aiming at each coating defect existing on the surface of the to-be-detected workpiece according to the surface coating data, generates a supplementary coating control instruction according to the supplementary coating parameter of each coating defect and sends the supplementary coating control instruction to the coating equipment; and the coating equipment performs paint coating on each coating defect existing on the surface of the to-be-detected workpiece according to the supplementary coating control instruction. Therefore, by accurately determining the coating repairing parameter of each coating defect existing on the surface of the workpiece, high-precision detection and accurate paint repairing of the coating defects on the surface of the workpiece are achieved through automatic operation, manual intervention is reduced, the paint repairing efficiency is improved, the paint repairing quality is guaranteed, the production cost is reduced, and the consistency and reliability of the protection performance of the workpiece are guaranteed.

Description

Technical Field

[0001] The present application relates to the field of control technology, and in particular to a workpiece surface coating method and system. Background Art

[0002] Conformal coating is a process of coating the surface of electronic components with protective materials. It is mainly used to improve the waterproof, moisture-proof and corrosion-resistant properties of the product. It is widely used in electronics, electrical appliances, automobiles, aerospace and other fields.

[0003] After the paint is applied to the workpiece surface, the existing technology requires manual inspection and manual re-applying of unsatisfactory areas with a brush. However, this manual re-applying method is labor-intensive and can result in poor coating results, such as inconsistent thickness, which can reduce the protective effect of the workpiece. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide a workpiece surface coating method and system, which can determine the repainting parameters of each coating defect on the workpiece surface, and then realize high-precision detection and precise repainting of coating defects on the workpiece surface through automated operation, reduce manual intervention, improve repainting efficiency, ensure repainting quality, reduce production costs, and ensure the consistency and reliability of workpiece protective performance.

[0005] The present invention provides a method for coating a workpiece surface, which is applied to a workpiece surface coating system. The system includes: a surface detection device, a control device, and a coating device. The method includes:

[0006] The surface detection device acquires surface coating data of the workpiece to be detected that has been coated with paint, and sends the surface coating data to the control device;

[0007] The control device determines, based on the surface coating data, a repainting parameter for each coating defect present on the surface of the workpiece to be inspected, generates a repainting control instruction based on the repainting parameter for each coating defect, and sends the repainting control instruction to the coating device; wherein the repainting parameter includes at least one of the following: coating path, repainting amount, coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time;

[0008] The coating equipment applies paint to each coating defect on the surface of the workpiece to be inspected according to the re-coating control instruction.

[0009] The embodiment of the present application also provides a workpiece surface coating system, the system comprising: a surface detection device, a control device and a coating device;

[0010] The surface detection device is used to obtain surface coating data of the workpiece to be detected that has been coated with paint, and send the surface coating data to the control device;

[0011] The control device is configured to determine, based on the surface coating data, a repainting parameter for each coating defect present on the surface of the workpiece to be inspected, and generate a repainting control instruction based on the repainting parameter for each coating defect and send the repainting control instruction to the coating device; wherein the repainting parameter includes at least one of the following: coating path, repainting amount, coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time;

[0012] The coating equipment is used to apply paint to each coating defect existing on the surface of the workpiece to be inspected according to the re-coating control instruction.

[0013] An embodiment of the present application also provides an electronic device, comprising: a processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor. When the electronic device is running, the processor and the memory communicate through the bus, and when the machine-readable instructions are executed by the processor, the steps of the workpiece surface coating method as described above are performed.

[0014] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the workpiece surface coating method as described above are executed.

[0015] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A flow chart of a workpiece surface coating method provided in an embodiment of the present application is shown;

[0018] Figure 2 A schematic structural diagram of a workpiece surface coating system provided in an embodiment of the present application is shown;

[0019] Figure 3 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for which protection is claimed, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work falls within the scope of protection of the present application.

[0021] Research has found that existing technologies require manual inspection after coating a workpiece surface, with manual refinishing using a brush to correct any unsatisfactory coating. However, this manual refinishing method is labor-intensive and can result in poor coating results, such as inability to maintain a consistent coating thickness, which can reduce the protective effect of the workpiece.

[0022] Based on this, an embodiment of the present application provides a method for coating the surface of a workpiece to determine the repainting parameters of each coating defect on the surface of the workpiece, and then achieve high-precision detection and precise repainting of coating defects on the surface of the workpiece through automated operation, reduce manual intervention, improve repainting efficiency, ensure repainting quality, reduce production costs, and ensure the consistency and reliability of the workpiece protective performance.

[0023] See also Figure 1 , Figure 1 This is a flow chart of a workpiece surface coating method provided in an embodiment of the present application. The method provided in an embodiment of the present application is applied to a workpiece surface coating system, the system comprising: a surface detection device, a control device and a coating device; Figure 1 As shown in , the method includes:

[0024] S101 : The surface detection device acquires surface coating data of a workpiece to be detected that has been coated with paint, and sends the surface coating data to the control device.

[0025] The workpieces to be inspected in the embodiments of the present application include various products that are widely used in the electronics, electrical appliances, automobile, aerospace and other industries and require triple-conformal coating, such as printed circuit boards, electronic components, precision mechanical parts, etc.; by coating triple-conformal coating, the waterproof, moisture-proof and corrosion-resistant properties of the products can be improved.

[0026] Surface inspection equipment can include high-precision laser sensors or optical imaging systems. Surface coating data can include information on paint thickness, surface flatness, and defects such as missing coatings, as well as three-dimensional data of the workpiece being inspected. In practice, surface inspection equipment can achieve micron-level resolution, allowing for customized accuracy standards tailored to the coating requirements of individual products, ensuring accurate identification of even the smallest defects.

[0027] In this step, the surface inspection device can obtain the surface coating data of the workpiece to be inspected that has completed the paint coating work, and send the surface coating data to the control device.

[0028] In a possible implementation, step S101 may include:

[0029] The workpiece surface of the workpiece to be inspected that has been coated with paint is scanned and inspected to obtain surface coating data of the workpiece to be inspected; whether there are coating defects on the workpiece surface of the workpiece to be inspected is identified based on the surface coating data; if there is at least one coating defect, the surface coating data is sent to the control device.

[0030] In this step, the surface inspection equipment can determine whether there are coating defects on the surface of the workpiece to be inspected based on the surface coating data; if there are coating defects, it will be sent to the control device for re-coating operation; if not, the workpiece to be inspected can be determined to be a qualified workpiece and other inspection links can be carried out.

[0031] Alternatively, after acquiring the surface coating data, the surface detection device may directly send the data to the control device, and the control device may determine whether there are coating defects.

[0032] S102. The control device determines a recoating parameter for each coating defect on the surface of the workpiece to be inspected based on the surface coating data, generates a recoating control instruction based on the recoating parameter for each coating defect, and sends the instruction to the coating device.

[0033] The control device, based on an advanced PLC (Programmable Logic Controller) or industrial computer, receives data from the detection module and performs real-time analysis and processing. It also features a human-computer interface, allowing operators to easily set device parameters, monitor operating status, and store and query data.

[0034] In this step, the control device can identify each coating defect existing on the surface of the workpiece to be inspected based on the received surface coating data, and then determine the repainting parameters for each coating defect based on the preset repainting algorithm, and generate repainting control instructions for controlling the coating device based on the repainting parameters for each coating defect.

[0035] The touch-up paint parameters include at least one of the following: coating path, touch-up paint amount, coating speed, coating pressure, coating spacing, coating angle, coating time and paint spraying amount per unit time.

[0036] In a possible implementation, for the coating path, step S102 may include:

[0037] Step a1: determining the defect profile of each coating defect existing on the surface of the workpiece according to the surface coating data corresponding to each point on the surface of the workpiece to be inspected and the preset coating requirements.

[0038] For example, unqualified surface points can be marked based on the paint layer thickness in the surface coating data corresponding to each point on the surface of the workpiece to be inspected and the thickness requirement in the preset coating requirements, thereby forming a defect profile of each coating defect existing on the workpiece surface.

[0039] Step a2: For each coating defect, generate the minimum circumscribed rectangle of the defect outline to obtain the defect coordinate range.

[0040] Here, because the defect shape of each coating defect may be irregular, in order to facilitate the determination of the coating path, it is necessary to generate a minimum bounding rectangle and obtain the defect coordinate range of the minimum bounding rectangle.

[0041] Step a3: planning a coating path for each coating defect according to the defect contour and defect coordinate range of each coating defect.

[0042] In this step, for each coating defect, a cluster of straight lines is generated according to the coating spacing within the corresponding defect coordinate range to obtain the original path shape; the closed shape enclosed by the corresponding defect contour is compared with the original path shape to obtain the path of the overlapping part, and the path of the overlapping part is determined as the coating path for the coating defect.

[0043] If multiple touch-up tracks are used, the spacing between adjacent touch-up tracks needs to be appropriately set. Too much spacing may result in missed touch-ups, while too little spacing may cause excessive overlap, impacting touch-up quality and appearance. In the present embodiment, the coating spacing can be determined based on the effective coating width of the paint during the coating process as determined experimentally; the linear orientation can be adjusted as needed.

[0044] Exemplarily, multiple straight lines are drawn according to the defect coordinate range and the predetermined coating spacing to obtain the original path shape; the corresponding defect shape and the original path shape are compared to obtain the part of the original path shape that falls within the range of the defect shape, that is, the path of the overlapping part; the path of the overlapping part is determined as the coating path for the coating defect at that location.

[0045] More specifically, based on the actual spray or dot coating coverage of the nozzle or coating needle, the effective coverage width w of the paint on the product surface is experimentally determined at a certain coating pressure and speed. To ensure complete coverage of the touch-up area and avoid excessive overlap, the coating interval d is generally set to a certain ratio of the coverage width w, for example, d = 0.7w. This ratio can be adjusted based on the actual touch-up effect and paint liquid characteristics, and is generally between 0.6-0.8 to ensure appropriate overlap between adjacent tracks and ensure uniform touch-up.

[0046] In this way, if there are multiple coating defects on the workpiece surface that need to be repainted, the coating paths can be generated separately.

[0047] In another possible implementation, with respect to the amount of touch-up paint, step S102 may include:

[0048] Step b1: for each coating defect existing on the surface of the workpiece to be inspected, divide the closed shape enclosed by the defect outline into a plurality of voxels, and determine the defect volume of each coating defect.

[0049] The surface coating data may include three-dimensional data, so that the closed shape area surrounded by the defect outline can be divided into multiple tiny voxels (three-dimensional pixels), and the defect volume V_{defect} can be estimated based on the size of the voxels and the number of voxels contained in the defect area.

[0050] Step b2: determining the original touch-up amount of each coating defect based on the density of the paint and the defect volume of each coating defect.

[0051] Here, the density ρ of the paint is known, and the original touch-up paint amount m = ρ × V_{defect} can be determined according to the law of conservation of mass.

[0052] Step b3: Determine the paint compensation coefficient based on the paint loss during the coating process measured experimentally.

[0053] To account for losses in the actual coating process, such as paint mist volatilization and ineffective adhesion of some paint liquid, a paint compensation factor k is introduced. It is generally determined experimentally and has a value range of, for example, 1.1-1.3.

[0054] Step b4: correcting the original touch-up paint amount for each coating defect according to the paint compensation coefficient to obtain the touch-up paint amount for each coating defect.

[0055] Specifically, the actual amount of paint touch-up required for each coating defect is M=k×m.

[0056] In another possible implementation, step S102 further includes determining the coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time by:

[0057] Regarding the coating speed, first, an initial coating speed v0 can be given based on experience and equipment performance. For example, it can be set to a common standard speed value such as 50 mm / s. Then, based on the amount of paint touch-up M, the cross-sectional area S of the nozzle or coating needle (which can be calculated by measuring the inner diameter of the needle or the nozzle orifice size), and the flow rate u of the paint liquid (the flow rate of the paint liquid is related to the coating pressure, the viscosity of the paint liquid, etc., and can be determined experimentally or calculated according to the fluid mechanics formula), according to the flow formula Q = v × S, and Q = u × S, (Q is the amount of paint sprayed per unit time, which is also the paint liquid flow rate per unit time), combined with the touch-up amount M and the required touch-up time t (which can be initially set according to the production rhythm and experience), the adjusted coating speed is calculated. Finally, the initial coating speed v0 and the adjusted coating speed v. If the difference between the two is large, the current speed is corrected in real time according to a certain ratio (such as a proportional coefficient of 0.5) to obtain the final coating speed v = v0 + (v-v0) × 0.5, thereby avoiding the impact of speed mutation on the quality of touch-up paint.

[0058] Regarding the coating pressure, the viscosity η of the conformal coating is first measured using a viscometer. Then, according to Poiseuille's law in fluid mechanics, for a circular pipe (similar to the paint flow channel inside a nozzle or needle), the pressure difference ΔP of the paint flowing in the pipe is related to the viscosity η, flow velocity u, pipe length L, and pipe radius r. The theoretical formula is: The flow rate u here can be calculated based on the previously calculated coating speed and nozzle characteristics. The pipe length L and radius r are the actual dimensions of the nozzle or needle. This allows the theoretical coating pressure P_{theory} to be calculated. A small-scale trial coating can then be performed on the actual equipment. The theoretical pressure can be adjusted based on the test results (e.g., whether the paint sprays smoothly, whether there are any drips or uneven spraying). If the paint spray is not smooth, the pressure can be increased appropriately. If there are drips or the spray is too intense, the pressure can be reduced appropriately to obtain the final coating pressure P_{final}.

[0059] The coating time can be calculated based on the touch-up paint amount M. Specifically, based on the determined touch-up paint amount M and the paint spraying amount per unit time Q (Q = v × S × ρ, where v is the coating speed, S is the cross-sectional area of ​​the nozzle or coating needle, and ρ is the paint liquid density), the theoretical coating time can be calculated. Furthermore, the theoretical coating time can be corrected to account for factors such as the actual touch-up process, which may require slower speeds at the beginning and end to ensure stable starting and stopping of the paint liquid, as well as the acceleration and deceleration time of the equipment movement. For example, a correction time Δt can be added (which can be determined based on the equipment movement characteristics and experience, such as 0.5-1 second), resulting in a final coating time t_{final} = t_{theory} + Δt.

[0060] In another possible implementation, with respect to the coating angle, step S102 may include:

[0061] Step c1: using a three-dimensional scanning technology to establish a three-dimensional model of the workpiece to be inspected, and dividing each coating defect in the three-dimensional model into a plurality of sub-areas.

[0062] Step c2: Calculate the surface normal direction of each sub-region and determine it as the coating angle of the sub-region.

[0063] Here, the surface data collected using 3D scanning technology (such as high-precision laser sensors or optical imaging systems) can be used to create an accurate 3D model of the workpiece to be inspected, and the position and shape of the coating defects that need to be repainted can be clearly determined in the model.

[0064] Each coating defect requiring touch-up is divided into several tiny sub-areas. Using mathematical algorithms (such as normal calculation methods based on a triangular mesh model), the surface normal direction (i.e., the direction perpendicular to the surface of that tiny area) can be calculated. The optimal coating direction should be as consistent as possible with the surface normal direction at that point to ensure vertical adhesion of the paint solution for optimal adhesion. In other words, the surface normal direction is determined as the coating angle for that sub-area.

[0065] Afterwards, based on the calculated coating angle (normal direction), combined with the mechanical structure and motion control capabilities of the equipment, the angle that the nozzle or coating needle needs to be adjusted is calculated, and a re-coating control instruction is generated; precise adjustments are made through the equipment's angle adjustment mechanism to ensure that the coating angle meets the requirements.

[0066] In another possible implementation, with respect to the paint spraying amount per unit time and the coating angle, step S102 may include:

[0067] Step d1 : controlling the surface inspection device to rescan each coating defect existing on the surface of the workpiece, and using an image processing algorithm to determine the precise outline of each coating defect.

[0068] In this step, the surface inspection equipment is controlled to perform a second high-precision scan of each coating defect area to obtain detailed contour data of the defect edge. Using image processing algorithms (such as the Canny edge detection algorithm), the identified edge contours are refined, redundant pixels are removed, and the precise pixel-level outline of each coating defect is accurately identified, facilitating more accurate calculation of recoating parameters.

[0069] Step d2: Extend along the precise outline of the coating defect toward the normal paint layer to obtain an edge buffer zone of a predetermined width.

[0070] In this step, a buffer zone with a predetermined width, d, is set outside the defect edge, i.e., along the precise contour of the coating defect toward the normal paint layer. (Where d is determined based on actual conditions, such as paint fluidity and product surface roughness, and is generally within the range of 0.5-2 mm.) This transition zone is designed to create a natural transition between the touch-up area and the normal paint layer.

[0071] Step d3: Divide the predetermined width into multiple sub-edge buffer zones into which the edge buffer zone is divided.

[0072] In this step, the cutting width can be set in equal intervals or unequal intervals. For example, if a coating defect is circular, the generated multiple sub-edge buffer zones are multiple concentric rings.

[0073] Step d4: Determine the paint spraying amount per unit time of each sub-edge buffer zone based on the ratio between the distance between each sub-edge buffer zone and the precise outline of the coating defect and the predetermined width and the maximum paint spraying amount per unit time to form a gradient paint spraying.

[0074] In the transition area of ​​the edge buffer zone, the paint volume per unit time is gradually changed. From the defect edge to the normal paint layer, the paint volume per unit time decreases linearly from the maximum paint volume per unit time to zero. By establishing a linear function relationship between the touch-up paint volume and the distance, such as Where Q(x) is the amount of paint sprayed per unit time corresponding to the sub-edge buffer zone at a distance x from the exact contour of the coating defect, and Q_{max} is the amount of paint sprayed per unit time at the center of the coating defect.

[0075] Step d5: Determine a coating angle perpendicular to the tangential direction according to the tangential direction of the precise contour of the coating defect.

[0076] In this step, the spray nozzle's coating angle can be dynamically adjusted based on the direction of the defect edge contour, keeping the nozzle perpendicular to the contour's tangent. This helps ensure that the paint is evenly sprayed on the edge, improving the quality of the touch-up paint at the edge.

[0077] In addition, the coating speed can be appropriately reduced at the edge of the defect, for example, to 70%-80% of the normal speed. This will give the paint more time to adhere to the edge and avoid insufficient coverage or loss of paint due to excessive speed.

[0078] In another possible implementation manner, for a special defect location that is not a planar location, step S102 further includes:

[0079] Step e1: determining defect geometric features of the coating defect based on the surface coating data.

[0080] In this step, the geometric shape of the workpiece is first modeled. When the workpiece is fully scanned using a 3D laser scanner, the 3D point cloud data of the workpiece included in the surface coating data is obtained; through the point cloud processing algorithm, the point cloud data is converted into a polygonal mesh model to accurately reconstruct the geometric shape of the workpiece.

[0081] Step e2: When the defect geometric feature of the coating defect is determined to be a raised defect based on the surface coating data, the paint spraying amount per unit time is corrected according to the raised height compensation coefficient corresponding to the raised height of the raised portion to increase the amount of touch-up paint at the raised portion; and the coating path at the raised portion is determined to be a circular path centered on the highest point; wherein the raised compensation coefficient is calibrated through experiments.

[0082] Treatment of raised positions: Since the paint liquid at the raised positions is more likely to be lost, the amount of touch-up paint can be appropriately increased according to the geometric parameters of the raised positions (such as height and slope). For example, for a raised position with a height of h, the amount of touch-up paint is increased by ΔQ = k × h. Among them, k is the raised position compensation coefficient determined according to the experiment, and the value range is 0.1-0.5. Adjust the coating path. When planning the touch-up path, adopt a circular coating path for the raised position. For example, with the highest point of the raised position as the center, touch-up paint is applied in a spiral or concentric circle manner to ensure that all sides of the raised position are fully covered.

[0083] Step e3: When the defect geometric feature of the coating defect is determined to be a concave defect based on the surface coating data, the amount of paint sprayed per unit time is corrected according to the concave compensation coefficient corresponding to the concave depth of the concave to reduce the amount of paint touch-up at the concave; and the coating angle is adjusted according to the position of the concave so that the paint is sprayed to the bottom of the concave; wherein the concave compensation coefficient is calibrated through experiments.

[0084] Treatment of concave positions: Since paint liquid easily accumulates in concave positions, the amount of touch-up paint can be appropriately reduced based on the geometric parameters of the concave position (such as depth and area). For example, for a concave position with a depth of d, the amount of touch-up paint can be reduced by ΔQ. ′ =k ′ ×d. Among them, k ′ The sag compensation coefficient is determined experimentally and ranges from 0.1 to 0.3. Furthermore, the coating angle is adjusted and the nozzle posture is optimized. In concave areas, the nozzle posture is adjusted to tilt at a certain angle so that the paint can be sprayed to the bottom of the concave at a suitable coating angle to avoid excessive accumulation of paint at the edge of the concave.

[0085] Step e4: When the defect geometric feature of the coating defect is determined to be a slope defect based on the surface coating data, the coating path is projected onto the slope coordinate system through a coordinate change algorithm based on the slope inclination angle so that the direction of the coating path is consistent with the slope inclination direction; and the coating pressure is increased and the coating speed is reduced based on the slope inclination angle.

[0086] Processing of the inclined surface: Adjust the coating parameters according to the inclined surface angle and measure the angle θ of the inclined surface. Adjust the coating speed and coating pressure according to the angle. For example, when θ is greater than a certain threshold (such as 30°), appropriately reduce the coating speed and increase the coating pressure to ensure that the paint can adhere to the inclined surface. Adjust the direction of the paint touch-up path. The direction of the paint touch-up path should be consistent with the direction of the inclined surface to avoid the paint flowing or uneven accumulation on the inclined surface. Specifically, the coordinate transformation algorithm can be used to project the paint touch-up path into the local coordinate system of the inclined surface for planning.

[0087] S103 , the coating equipment applies paint to each coating defect on the surface of the workpiece according to the re-coating control instruction.

[0088] The coating equipment in the embodiments of this application is equipped with a high-precision micro-spray nozzle or coating needle, which can accurately spray or spot-apply conformal coating to the areas requiring touch-up according to the control device's instructions. The coating pressure and flow rate can be precisely adjusted to ensure uniform and consistent touch-up. Furthermore, the coating module features an automatic cleaning function to prevent nozzle clogging and ensure consistent touch-up quality.

[0089] Furthermore, the method further comprises:

[0090] S104, the surface inspection device reacquires updated surface coating data of the workpiece to be inspected;

[0091] S105, identifying whether coating defects still exist on the surface of the workpiece to be inspected according to the updated surface coating data;

[0092] S106. If at least one coating defect still exists, the updated surface coating data is resent to the control device to perform defect re-coating, or the updated surface coating data is submitted to relevant personnel.

[0093] Regarding steps S104 to S106, after the touch-up is complete, the workpiece undergoes a second inspection by the surface inspection equipment to ensure that the paint layer meets the quality requirements. Qualified workpieces can be sent to the next step. Unqualified workpieces can be automatically repainted again using the above method or submitted to relevant personnel for manual intervention.

[0094] Furthermore, the system further comprises: a transmission and positioning device; and the method further comprises:

[0095] The conveying and positioning device fixes the workpiece to be inspected and, according to the conveying instruction sent by the control device, conveys the workpiece to be inspected to the defect detection work area corresponding to the surface inspection device and the coating work area corresponding to the coating device.

[0096] The conveying and positioning equipment in the embodiments of the present application uses a conveyor belt or robotic arm to automatically transport the products to be repainted to the defect inspection and coating work areas. During the inspection and repainting process, a precise positioning fixture or visual positioning system ensures that the product is positioned accurately and securely, ensuring the accuracy of inspection and repainting.

[0097] In one possible embodiment, the workpiece surface coating system's workflow includes the following: First, the workpiece to be inspected is transported to a defect inspection area via a conveying and positioning device. The surface inspection device performs a comprehensive scan of the conformal coating on the workpiece surface, acquires surface coating data, and transmits it to a control device. The control device then analyzes the surface coating data to determine whether the product requires touch-up, including the specific location, area, amount of paint required, and path for touch-up. If touch-up is required, the workpiece to be inspected is automatically transported to the coating area via the conveying and positioning device. The coating device then precisely touches up the workpiece according to the touch-up control instructions from the control device. Finally, after touch-up, the workpiece to be inspected is transported back to the defect inspection area for a second inspection to ensure that the paint layer meets quality requirements. Acceptable workpieces are transported to the next process step; unacceptable workpieces undergo re-touch-up or undergo manual intervention.

[0098] A workpiece surface coating method provided in an embodiment of the present application is applied to a workpiece surface coating system, the system comprising: a surface detection device, a control device and a coating device; the method comprising: the surface detection device acquiring surface coating data of the workpiece to be inspected that has been coated with paint, and sending the surface coating data to the control device; the control device determining, based on the surface coating data, re-coating parameters for each coating defect existing on the surface of the workpiece to be inspected, generating a re-coating control instruction based on the re-coating parameters for each coating defect and sending the instruction to the coating device; the coating device coating each coating defect existing on the surface of the workpiece to be inspected with paint according to the re-coating control instruction.

[0099] The embodiments of the present application have the following beneficial effects:

[0100] 1. Improve the efficiency of paint touch-up: Automated operation can greatly shorten the time of paint touch-up. Compared with traditional manual paint touch-up, the efficiency can be increased by several times or even dozens of times, which is suitable for large-scale production needs.

[0101] 2. Ensure the quality of touch-up paint: Accurate touch-up paint can be achieved through the touch-up algorithm of the control equipment and high-precision detection and coating equipment, avoiding the errors and unevenness that may occur in manual touch-up paint, and ensuring the consistency and reliability of the product's protective performance.

[0102] 3. Reduce production costs: Reduce manual intervention, reduce labor costs and product scrap rates caused by paint touch-up quality problems, while improving production efficiency and indirectly reducing production costs.

[0103] 4. Improve production flexibility: The equipment can be quickly adjusted and switched according to the size, shape and coating requirements of different products to adapt to diverse production needs and improve the flexibility and adaptability of the production line.

[0104] 5. It can be widely used in various products requiring conformal coating in the electronics, electrical appliances, automotive, aerospace and other industries, such as printed circuit boards, electronic components, and precision mechanical parts. It is suitable for quality control during the product production process and local repainting during after-sales maintenance, effectively improving product quality and service life, and enhancing product stability and reliability in harsh environments.

[0105] Determining appropriate touch-up parameters is crucial for ensuring touch-up quality. First, pre-determining the touch-up amount ensures uniform coverage of the conformal coating in the touch-up area, avoiding excess paint (dripping and accumulation) and insufficient paint (poor performance), ensuring uniform application. Second, determining the appropriate touch-up amount based on product requirements and test results ensures that the paint layer thickness meets standard requirements after touch-up, controlling the paint layer thickness and ensuring product protection. Third, specifying the touch-up amount allows coating equipment to operate precisely, eliminating repeated touch-ups and over-applying, saving time and materials and improving overall touch-up efficiency. Fourth, by combining the touch-up amount and the touch-up path, the control system can more effectively plan the speed and dwell time of the nozzle or applicator, ensuring an efficient and orderly touch-up process. Fifth, ensuring an appropriate touch-up amount reduces the burden and wear on the coating equipment caused by excessive or insufficient paint, such as nozzle clogging or excessive wear, thereby extending equipment life and reducing maintenance costs. Sixth, in addition to the touch-up amount, the application pressure and speed also play a role in the touch-up parameters. For example, the coating pressure affects the atomization effect and adhesion strength of the three-proof paint. Only when the pressure is appropriate can the paint be evenly and firmly adhered to the product surface; the coating speed, the amount of paint to be touched up, and the coating pressure cooperate with each other. Too fast speed may result in insufficient paint, and too slow speed may cause paint accumulation. Only when the three are reasonably matched can high-quality and efficient touch-up operations be achieved.

[0106] In summary, the embodiments of the present application accurately determine the repainting parameters of each coating defect on the surface of the workpiece, and then achieve high-precision detection and precise repainting of coating defects on the surface of the workpiece through automated operations, which can reduce manual intervention, improve repainting efficiency, ensure repainting quality, reduce production costs, and ensure the consistency and reliability of the workpiece's protective performance.

[0107] See also Figure 2 , Figure 2 This is a schematic diagram of the structure of a workpiece surface coating system provided in an embodiment of the present application. The workpiece surface coating system 200 includes: a surface detection device 210, a control device 220 and a coating device 230;

[0108] The surface detection device 210 is used to obtain surface coating data of the workpiece to be detected that has been coated with paint, and send the surface coating data to the control device 220;

[0109] The control device 220 is configured to determine, based on the surface coating data, a recoating parameter for each coating defect present on the surface of the workpiece to be inspected, generate a recoating control instruction based on the recoating parameter for each coating defect, and send the recoating control instruction to the coating device 230; wherein the recoating parameter includes at least one of the following: coating path, recoating amount, coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time;

[0110] The coating device 230 is used to apply paint to each coating defect on the surface of the workpiece to be inspected according to the re-coating control instruction.

[0111] Furthermore, with respect to the coating path, when the control device 220 is used to determine the recoating parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is used to:

[0112] Determining the defect profile of each coating defect existing on the surface of the workpiece according to the surface coating data corresponding to each point on the surface of the workpiece to be inspected and the preset coating requirements;

[0113] For each coating defect, generate the minimum circumscribed rectangle of the defect outline and obtain the defect coordinate range;

[0114] The coating path for each coating defect is planned according to the defect contour and defect coordinate range of each coating defect.

[0115] Furthermore, when the control device 220 is used to plan a coating path for each coating defect according to the defect profile and defect coordinate range of each coating defect, the control device 220 is used to:

[0116] For each coating defect, a cluster of straight lines is generated within the corresponding defect coordinate range according to the coating spacing to obtain an original path shape; wherein the coating spacing is determined based on the effective coverage width of the paint during the coating process measured experimentally;

[0117] The closed shape enclosed by the corresponding defect outline is compared with the original path shape to obtain the path of the overlapping portion, and the path of the overlapping portion is determined as the coating path for the coating defect at that location.

[0118] Furthermore, with respect to the touch-up amount, when the control device 220 is used to determine the touch-up parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is further used to:

[0119] For each coating defect existing on the surface of the workpiece to be inspected, dividing the closed shape enclosed by the defect outline into a plurality of voxels, and determining the defect volume of each coating defect;

[0120] Determine the original touch-up amount for each coating defect based on the density of the paint and the defect volume of each coating defect;

[0121] Determine the paint compensation factor by experimentally measuring the paint loss during the coating process;

[0122] The original touch-up paint amount of each coating defect is corrected according to the paint compensation coefficient to obtain the touch-up paint amount of each coating defect.

[0123] Furthermore, with respect to the coating angle, when the control device 220 is used to determine the recoating parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is further used to:

[0124] Furthermore, with respect to the touch-up amount, when the control device 220 is used to determine the touch-up parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is used to:

[0125] Using three-dimensional scanning technology to establish a three-dimensional model of the workpiece to be inspected, and dividing each coating defect in the three-dimensional model into a plurality of sub-areas;

[0126] The surface normal direction of each sub-region is calculated and determined as the coating angle of the sub-region.

[0127] Furthermore, with respect to the touch-up amount, when the control device 220 is used to determine the touch-up parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is further used to:

[0128] Controlling the surface inspection device 210 to rescan each coating defect existing on the surface of the workpiece to be inspected, and using an image processing algorithm to determine the precise outline of each coating defect;

[0129] Expand along the precise contour of the coating defect toward the normal paint layer to obtain an edge buffer zone of predetermined width;

[0130] Dividing the predetermined width into multiple sub-edge buffer zones into which the edge buffer zone is divided;

[0131] Determine the paint spraying amount per unit time of each sub-edge buffer zone according to the ratio between the distance between each sub-edge buffer zone and the precise outline of the coating defect and the predetermined width and the maximum paint spraying amount per unit time, so as to form a gradient paint spraying;

[0132] According to the tangent direction of the precise contour of the coating defect, the coating angle perpendicular to the tangent direction is determined.

[0133] Furthermore, when the control device 220 is used to determine the recoating parameters for each coating defect existing on the surface of the workpiece to be inspected based on the surface coating data, the control device 220 is also used to:

[0134] When the defect geometric feature of the coating defect is determined to be a convex defect according to the surface coating data, the paint spraying amount per unit time is corrected according to the convexity compensation coefficient corresponding to the convexity geometric parameters of the convexity to increase the amount of touch-up paint at the convexity; and the coating path at the convexity is determined to be a circular path with the highest point as the center; wherein the convexity compensation coefficient is calibrated through experiments;

[0135] When the defect geometric feature of the coating defect is determined to be a concave defect based on the surface coating data, the amount of paint sprayed per unit time is corrected based on the concave compensation coefficient corresponding to the concave geometric parameters of the concave portion to reduce the amount of paint touch-up at the concave portion; and the coating angle is adjusted based on the position of the concave portion so that the paint is sprayed to the bottom of the concave portion; wherein the concave compensation coefficient is calibrated through experiments;

[0136] When the defect geometric feature of the coating defect is determined to be a slope defect based on the surface coating data, the coating path is projected onto the slope coordinate system through a coordinate change algorithm according to the slope inclination angle so that the direction of the coating path is consistent with the slope inclination direction; and the coating pressure is increased and the coating speed is reduced according to the slope inclination angle.

[0137] Furthermore, the surface detection device 210 is also used to:

[0138] Reacquiring updated surface coating data of the workpiece to be inspected;

[0139] identifying whether coating defects still exist on the surface of the workpiece to be inspected according to the updated surface coating data;

[0140] If at least one coating defect still exists, the updated surface coating data is sent to the control device 220 again to perform defect re-coating, or the updated surface coating data is submitted to relevant personnel.

[0141] Furthermore, the workpiece surface coating system 200 also includes: a conveying and positioning device 240; the conveying and positioning device 240 is used to fix the workpiece to be inspected, and according to the conveying instruction sent by the control device 220, convey the workpiece to be inspected to the defect detection working area corresponding to the surface detection device 210 and the coating working area corresponding to the coating device 230.

[0142] See also Figure 3 , Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 3 As shown in FIG, the electronic device 300 includes a processor 310 , a memory 320 and a bus 330 .

[0143] The memory 320 stores machine-readable instructions executable by the processor 310. When the electronic device 300 is running, the processor 310 communicates with the memory 320 via the bus 330. When the machine-readable instructions are executed by the processor 310, the above-mentioned Figure 1 The specific implementation of the steps of the workpiece surface coating method in the method embodiment shown can be found in the method embodiment, and will not be repeated here.

[0144] The embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the computer program can execute the above-mentioned Figure 1 The specific implementation of the steps of the workpiece surface coating method in the method embodiment shown can be found in the method embodiment, and will not be repeated here.

[0145] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0146] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. There may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some communication interface, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0147] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0148] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0149] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0150] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The scope of protection of the present application is not limited thereto. Although the present application has been described in detail with reference to the above-mentioned embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-mentioned embodiments within the technical scope disclosed in the present application, or perform equivalent replacements for some of the technical features thereof. These modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for coating a workpiece surface, characterized in that: Applied to a workpiece surface coating system, the system includes: a surface detection device, a control device and a coating device; the method includes: The surface detection device acquires surface coating data of the workpiece to be detected that has been coated with paint, and sends the surface coating data to the control device; The control device determines, based on the surface coating data, a repainting parameter for each coating defect present on the surface of the workpiece to be inspected, generates a repainting control instruction based on the repainting parameter for each coating defect, and sends the repainting control instruction to the coating device; wherein the repainting parameter includes at least one of the following: coating path, repainting amount, coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time; The coating equipment applies paint to each coating defect on the surface of the workpiece to be inspected according to the re-coating control instruction.

2. The method according to claim 1, characterized in that For the coating path, the control device determines, based on the surface coating data, a recoating parameter for each coating defect on the surface of the workpiece to be inspected, including: Determining the defect profile of each coating defect existing on the surface of the workpiece according to the surface coating data corresponding to each point on the surface of the workpiece to be inspected and the preset coating requirements; For each coating defect, generate the minimum circumscribed rectangle of the defect outline and obtain the defect coordinate range; The coating path for each coating defect is planned according to the defect contour and defect coordinate range of each coating defect.

3. The method according to claim 2, characterized in that Planning the coating path for each coating defect based on the defect profile and defect coordinate range of each coating defect, including: For each coating defect, a cluster of straight lines is generated within the corresponding defect coordinate range according to the coating spacing to obtain an original path shape; wherein the coating spacing is determined based on the effective coverage width of the paint during the coating process measured experimentally; The closed shape enclosed by the corresponding defect outline is compared with the original path shape to obtain the path of the overlapping portion, and the path of the overlapping portion is determined as the coating path for the coating defect at that location.

4. The method according to claim 2, characterized in that With respect to the touch-up amount, the control device determines, based on the surface coating data, touch-up parameters for each coating defect on the surface of the workpiece to be inspected, and further includes: For each coating defect existing on the surface of the workpiece to be inspected, dividing the closed shape enclosed by the defect outline into a plurality of voxels, and determining the defect volume of each coating defect; Determine the original touch-up amount for each coating defect based on the density of the paint and the defect volume of each coating defect; Determine the paint compensation factor by experimentally measuring the paint loss during the coating process; The original touch-up paint amount of each coating defect is corrected according to the paint compensation coefficient to obtain the touch-up paint amount of each coating defect.

5. The method according to claim 1, characterized in that With respect to the coating angle, the control device determines, based on the surface coating data, a recoating parameter for each coating defect existing on the surface of the workpiece to be inspected, including: Using three-dimensional scanning technology to establish a three-dimensional model of the workpiece to be inspected, and dividing each coating defect in the three-dimensional model into a plurality of sub-areas; The surface normal direction of each sub-region is calculated and determined as the coating angle of the sub-region.

6. The method according to claim 4, characterized in that The control device determines, based on the surface coating data, a repainting parameter for each coating defect on the surface of the workpiece to be inspected, with respect to the paint spraying amount per unit time and the coating angle, and further includes: Controlling the surface inspection device to rescan each coating defect present on the surface of the workpiece to be inspected, and using an image processing algorithm to determine the precise outline of each coating defect; Expand along the precise contour of the coating defect toward the normal paint layer to obtain an edge buffer zone of predetermined width; Dividing the predetermined width into multiple sub-edge buffer zones into which the edge buffer zone is divided; Determine the paint spraying amount per unit time of each sub-edge buffer zone according to the ratio between the distance between each sub-edge buffer zone and the precise outline of the coating defect and the predetermined width and the maximum paint spraying amount per unit time, so as to form a gradient paint spraying; According to the tangent direction of the precise contour of the coating defect, the coating angle perpendicular to the tangent direction is determined.

7. The method according to claim 4, characterized in that The control device determines, based on the surface coating data, a recoating parameter for each coating defect existing on the surface of the workpiece to be inspected, and further includes: When the defect geometric feature of the coating defect is determined to be a convex defect according to the surface coating data, the paint spraying amount per unit time is corrected according to the convexity compensation coefficient corresponding to the convexity geometric parameters of the convexity to increase the amount of touch-up paint at the convexity; and the coating path at the convexity is determined to be a circular path with the highest point as the center; wherein the convexity compensation coefficient is calibrated through experiments; When the defect geometric feature of the coating defect is determined to be a concave defect based on the surface coating data, the amount of paint sprayed per unit time is corrected based on the concave compensation coefficient corresponding to the concave geometric parameters of the concave portion to reduce the amount of paint touch-up at the concave portion; and the coating angle is adjusted based on the position of the concave portion so that the paint is sprayed to the bottom of the concave portion; wherein the concave compensation coefficient is calibrated through experiments; When the defect geometric feature of the coating defect is determined to be a slope defect based on the surface coating data, the coating path is projected onto the slope coordinate system through a coordinate change algorithm according to the slope inclination angle so that the direction of the coating path is consistent with the slope inclination direction; and the coating pressure is increased and the coating speed is reduced according to the slope inclination angle.

8. The method according to claim 1, characterized in that After the coating equipment coats each coating defect on the surface of the workpiece to be inspected according to the re-coating control instruction, the method further includes: The surface inspection device reacquires updated surface coating data of the workpiece to be inspected; identifying whether coating defects still exist on the surface of the workpiece to be inspected according to the updated surface coating data; If at least one coating defect still exists, the updated surface coating data is resent to the control device to perform defect re-coating, or the updated surface coating data is submitted to relevant personnel.

9. A workpiece surface coating system, characterized in that: The system includes: surface detection equipment, control equipment and coating equipment; The surface detection device is used to obtain surface coating data of the workpiece to be detected that has been coated with paint, and send the surface coating data to the control device; The control device is configured to determine, based on the surface coating data, a repainting parameter for each coating defect present on the surface of the workpiece to be inspected, and generate a repainting control instruction based on the repainting parameter for each coating defect and send the repainting control instruction to the coating device; wherein the repainting parameter includes at least one of the following: coating path, repainting amount, coating speed, coating pressure, coating spacing, coating angle, coating time, and paint spraying amount per unit time; The coating equipment is used to apply paint to each coating defect existing on the surface of the workpiece to be inspected according to the re-coating control instruction.

10. An electronic device, characterized in that: include: A processor, a memory and a bus, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the processor and the memory communicate through the bus, and the machine-readable instructions are executed by the processor to execute the steps of the workpiece surface coating method as described in any one of claims 1 to 8.

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