Automobile multi-station continuous spraying color difference online closed-loop management process

Abstract

The application discloses a color difference online closed-loop management and control process for multi-station continuous spraying of an automobile, comprising a management and control system and a management and control method, wherein the management and control system comprises a detection system, a feeding station, multiple processing stations and multiple detection stations, a conveying system comprises a main path, a branch path and a transmission manipulator, the transmission manipulator is used for conveying workpieces along the main path to pass through each processing station and the corresponding detection station in a preset process sequence, or the transmission manipulator is used for conveying workpieces along the branch path to reciprocate in each detection station and a rechecking station, the transmission manipulator is provided with an electronic tag, and the electronic tag is used for associating and marking workpiece information and process parameters of workpieces to be processed, the process realizes the closed-loop control of one sequence and one detection through the whole-process tracking of the workpieces by the electronic tag, the workpiece processing information is synchronized in real time, timely detection can be realized after each processing process, problems can be found and treated in time, and problem workpieces can be prevented from flowing into the next process.

Description

Technical Field

[0001] This invention belongs to the field of automotive painting inspection technology, and more specifically, relates to an online closed-loop control process for color difference in multi-station continuous painting of automobiles. Background Technology

[0002] Currently, multi-station continuous painting production lines for automotive bodies have achieved automated continuous operation. The production line is sequentially set up with processing stations such as pretreatment, intermediate coat spraying, intermediate coat drying, base coat spraying, clear coat spraying, and final drying, enabling large-scale completion of automotive body painting operations. However, existing continuous painting production lines still have many significant shortcomings in terms of color difference control and process quality control. Most existing spray painting production lines only conduct color difference sampling inspections after the finished products come off the line. They lack a synchronous online detection mechanism for each process. Problems such as uneven grayness of the intermediate coating, color difference deviation of the base color layer, and deviation of the spray coating film thickness cannot be detected in time during the process. Defective workpieces continue to flow into subsequent work stations and are not detected until the finished product stage. This not only causes a lot of waste of paint, energy and time, but also easily leads to batch color difference defects, which greatly increases the cost of rework and repair.

[0003] The existing process lacks a precise binding mechanism between workpiece and painting process parameters. The painting parameters and color difference acceptance standards differ for different car models and different colors. The production line cannot quickly match the corresponding control standards, which easily leads to the mixing of common parameters. This exacerbates the color difference between different areas of the car body and different batches of workpieces, resulting in low accuracy in color difference control.

[0004] In summary, the existing multi-station continuous painting production mode for automobiles has problems such as lagging process inspection, simple conveying and diversion structure, chaotic parameter matching, and insufficient color difference detection accuracy. It cannot achieve precise online color difference control throughout the entire process, and it is difficult to meet the production and use requirements of high uniformity color difference and high yield rate for high-end automobile body painting. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing an online closed-loop control process for color difference in continuous multi-station automotive painting, thereby solving the problem of untimely post-painting workpiece inspection.

[0006] To achieve the above objectives, the present invention provides an online closed-loop control process for color difference in multi-station continuous spraying of automobiles, including a control system and a control method, wherein the control system includes: Material loading station, multiple processing stations, and multiple inspection stations; The multiple processing stations are sequentially configured along the workpiece conveying direction as a pretreatment station, an intermediate coating spraying station, an intermediate coating drying station, a base coat spraying station, a clear coat spraying station, and a final drying station; The inspection station includes a re-inspection station and a process inspection station corresponding to each of the processing stations. The process inspection station is used to detect the processing effect of the corresponding processing station in real time. The process inspection station includes a pretreatment inspection station, an intermediate coating spraying inspection station, an intermediate coating drying inspection station, a base coat spraying inspection station, a clear coat spraying inspection station, and a final drying inspection station. The conveying system includes a main path, branch paths, and multiple conveying robots. The conveying robots are used to transport workpieces along the main path through each processing station and the corresponding inspection station in a preset process sequence, or the conveying robots are used to transport workpieces along the branch paths back and forth between each inspection station and the re-inspection station. The conveying robots are equipped with electronic tags, which are used to associate and mark the workpiece information and process parameters of the workpiece to be processed. The detection system includes: a storage module, a processing module, and electronic tag readers installed at each processing station and process detection station, as well as detection probes corresponding to each station. The processing module pre-stores judgment thresholds and spraying process parameters corresponding to each detection station. The detection probes include a surface finish detection probe, a thickness detection probe, a color difference detection probe, and a supplementary lighting module. The loading station is equipped with an input system for associating and binding the electronic tag of the transfer robot with the workpiece information and process parameters of the workpiece it is holding. The input system is electrically connected to the detection system, enabling the detection system to retrieve the spraying process parameters and judgment threshold of the corresponding workpiece based on the electronic tag.

[0007] Optionally, the control method includes: S1. The conveying system begins to transport the workpiece: The conveying robot grabs the workpiece at the loading position and associates and binds the workpiece information and process parameters with the electronic tag; S2. The conveyor system transports the workpieces sequentially through each processing station and process inspection station: S3. Based on the test results, determine whether to proceed to the next processing station or send it to the re-inspection station; S4. If the workpiece fails inspection continuously, the production line shall be stopped for manual repair.

[0008] Optionally, the conveying system transports the workpiece sequentially through various processing stations and process inspection stations, including: S21. When the workpiece enters the processing station, the detection system confirms the workpiece information and process parameters according to the electronic tag, and performs processing according to the corresponding process parameters; S22. When a workpiece enters the corresponding inspection station from the processing station, the inspection system confirms the workpiece information and process parameters based on the electronic tag, and checks whether the processing at the corresponding processing station is qualified.

[0009] Optionally, the step of determining whether to proceed to the next processing station or send the sample to the re-inspection station based on the detection results includes: S31. If qualified, the transfer robot will transport the workpiece to the next processing station. S32. If the workpiece is not qualified, the transfer robot will transport the workpiece to the re-inspection position.

[0010] Optionally, stopping the production line for manual repair if the workpiece fails continuous inspection includes three consecutive failures at any of the aforementioned process inspection stations, or three consecutive cumulative failures at any two adjacent process inspection stations.

[0011] Optionally, the pretreatment inspection station is equipped with the surface finish detection probe, which is used to detect the surface cleanliness, roughness, and oil particle defects of the workpiece.

[0012] Optionally, the intermediate coating spraying inspection station and the intermediate coating drying inspection station are equipped with the thickness detection probe and the color difference detection probe, which are used to detect the thickness of the intermediate coating dry film, surface smoothness and gray uniformity, and collect gray color difference data.

[0013] Optionally, the base color spraying inspection station is equipped with the thickness detection probe, the color difference detection probe, and the supplementary lighting module, which are used to comprehensively collect workpiece film thickness data and color parameters, and to determine the spraying hue, brightness, saturation, and overall color difference.

[0014] Optionally, the varnish spraying inspection station is equipped with a thickness detection probe for detecting the varnish film thickness, surface gloss, and orange peel appearance quality.

[0015] Optionally, the final drying and inspection station is equipped with a color difference detection probe and a supplementary lighting module for the final comprehensive inspection and judgment of the workpiece's color difference and appearance.

[0016] This invention provides an online closed-loop control process for color difference in continuous multi-station automotive painting, the advantages of which are: This multi-station continuous painting process for automobiles uses an online closed-loop control technology for color difference. As the workpiece enters the production line from the loading station, it is tracked throughout the entire process via electronic tags, synchronizing workpiece processing information in real time. Compared to fixing electronic tags to the workpiece, this method has less impact on the workpiece, does not hinder grinding and painting, and reduces the number of electronic tags required, saving costs. This achieves full-process tracking of the workpiece. Simultaneously, this tracking enables closed-loop control with one-inspection-per-sequence, allowing for timely inspection after each processing step, identifying and addressing problems promptly, and preventing defective workpieces from flowing to the next process.

[0017] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0019] Figure 1 A schematic diagram of an online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to an embodiment of the present invention is shown.

[0020] Explanation of reference numerals in the attached figures: 1. Processing station; 2. Inspection station; 3. Re-inspection station; 4. Loading station; 5. Conveying system; 6. Electronic tag; 11. Pretreatment station; 12. Intermediate coat spraying station; 13. Intermediate coat drying station; 14. Base coat spraying station; 15. Clear coat spraying station; 16. Final drying station; 21. Pretreatment inspection station; 22. Intermediate coat spraying inspection station; 23. Intermediate coat drying inspection station; 24. Base coat spraying inspection station; 25. Clear coat spraying inspection station; 26. Final drying inspection station. Detailed Implementation

[0021] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0022] like Figure 1 As shown, the online closed-loop control process for color difference in multi-station continuous spraying of automobiles includes a control system and a control method. The control system includes: 4 material loading stations, 1 multiple processing stations, and 2 multiple inspection stations; Multiple processing stations 1 are sequentially set along the workpiece conveying direction as pretreatment station 11, intermediate coating spraying station 12, intermediate coating drying station 13, base coat spraying station 14, clear coat spraying station 15, and final drying station 16. Inspection station 2 includes re-inspection station 3 and process inspection stations corresponding to each processing station 1. The process inspection stations are used to detect the processing effect of the corresponding processing station 1 in real time. The process inspection stations include pretreatment inspection station 21, intermediate coating spraying inspection station 22, intermediate coating drying inspection station 23, base coat spraying inspection station 24, clear coat spraying inspection station 25, and final drying inspection station 26. The conveying system 5 includes a main path, branch paths, and multiple conveying robots. The conveying robots are used to transport workpieces along the main path through each processing station 1 and the corresponding inspection station 2 in a preset process sequence, or the conveying robots are used to transport workpieces along the branch paths back and forth between each inspection station 2 and the re-inspection station 3. The conveying robots are equipped with electronic tags 6, which are used to associate and mark the workpiece information and process parameters of the workpiece to be processed. The detection system includes: a storage module, a processing module, and electronic tag readers installed at each processing station 1 and process detection station, as well as detection probes corresponding to each station. The processing module pre-stores the judgment thresholds and spraying process parameters corresponding to each detection station 2. The detection probes include a surface finish detection probe, a thickness detection probe, a color difference detection probe, and a supplementary lighting module. The loading station 4 is equipped with an input system for associating and binding the electronic tag 6 of the transfer robot with the workpiece information and process parameters of the workpiece it holds. The input system is electrically connected to the detection system, enabling the detection system to retrieve the spraying process parameters and judgment threshold of the corresponding workpiece based on the electronic tag 6.

[0023] Specifically, when workpieces enter the production line for spraying from loading station 4, each workpiece is tracked and marked using electronic tags 6. This allows for full-process tracking of the workpieces, real-time synchronization of processing information, minimal impact on the workpieces, no obstruction of grinding and spraying, and reduced requirement for the number of electronic tags 6, saving costs and achieving full-process tracking of workpiece processing. Simultaneously, this tracking enables closed-loop control with one-inspection-per-sequence, allowing for timely inspection after each processing step, identifying and addressing problems promptly, and preventing defective workpieces from flowing into the next process.

[0024] Furthermore, the electronic tag 6 is fixedly installed on the transfer robot rather than the workpiece itself. When the robot picks up a workpiece at the loading station 4, the input system writes the corresponding process parameters and inspection standards of the current workpiece into the information database of the electronic tag 6, forming an independent production process file for each workpiece, thus achieving one-to-one binding between the robot and the gripped workpiece. After all the workpieces have been sprayed and removed from the line, before the robot returns to the loading station 4 to pick up a new workpiece, the system automatically clears the original stored data in the electronic tag 6 and inputs the workpiece information and process parameters, completing the tag data reset. The entire data read, write, and reset mechanism ensures that parameters do not cross-reference after workpiece replacement, and that workpiece gaps on the production line will not affect the normal operation of each station. Because the workpiece information and corresponding process parameters are linked and bound through the electronic tag 6, the process parameters of each processing station 1 can be pre-set when linking workpiece information, and the workpiece information can be updated in a timely manner after processing station 1 and inspection station 2.

[0025] In this embodiment, the control method includes: S1. Conveying system 5 starts conveying workpieces: The conveying robot grabs the workpiece at the loading position 4 and associates and binds the workpiece information and process parameters with the electronic tag 6. S2, Conveying system 5 transports workpieces sequentially through each processing station 1 and the process inspection station: S3. Based on the test results, determine whether to proceed to the next processing station 1 or send to the re-inspection station 3; S4. If the workpiece fails inspection continuously, the production line shall be stopped for manual repair.

[0026] Specifically, the electronic tag 6 is used to associate the workpiece information and process parameters, which makes it easier for each processing station 1 and inspection station 2 to process according to their respective preset parameters and inspect according to their respective thresholds.

[0027] Furthermore, to adapt to small-batch production of various workpieces, electronic tags 6 can be used to update workpiece information and process parameters in a timely manner. Compared to image recognition, which requires a large amount of data for different workpieces, this method is more convenient and cost-effective.

[0028] Furthermore, the threshold values ​​for different processes are different. For example, the gray level of the intermediate coating is ΔE≤1.0, the base color station is ΔE≤1.2, and the finished product is ΔE≤1.5, with each level tightening the threshold.

[0029] In this embodiment, the conveying system 5 transports the workpiece sequentially through each processing station 1 and the process inspection station, including: S21. When the workpiece enters the processing station 1, the detection system confirms the workpiece information and process parameters according to the electronic tag 6, and processes it according to the corresponding process parameters; S22. When the workpiece enters the corresponding inspection station 2 from the processing station 1, the inspection system confirms the workpiece information and process parameters according to the electronic tag 6, and checks whether the processing of the corresponding processing station 1 is qualified.

[0030] Specifically, each step is inspected to prevent defective workpieces from entering the next process, thus avoiding waste of materials and time.

[0031] In this embodiment, determining whether to proceed to the next processing station 1 or to the re-inspection station 3 based on the detection results includes: S31. If qualified, the transfer robot will transport the workpiece to the next processing station 1. S32. If the workpiece is not qualified, the transfer robot will transport the workpiece to the re-inspection station 3.

[0032] Specifically, after the transfer robot leaves processing station 1 or inspection station 2 and enters re-inspection station 3, subsequent processing station 1 waits for the next transfer robot to carry the workpiece. Because of the electronic tag 6, the transfer robot independently records the workpiece's process information, ensuring continuous production even if there is a workpiece supply shortage on the production line. Re-inspection station 3 performs manual inspection and repair. After successful repair, the robot can re-enter loading station 4 or directly return to inspection station 2 where the problem was found. After passing inspection, processing continues.

[0033] In this embodiment, if the workpiece fails continuous inspection, the production line is stopped for manual repair, including if any process inspection station fails three consecutive inspections, or if any two adjacent process inspection stations fail a total of three consecutive inspections.

[0034] Specifically, consecutive failures indicate a problem at the corresponding processing station 1 or inspection station 2. Furthermore, if two adjacent inspection stations fail consecutively, it suggests a significant accumulation of errors at these two processing stations, requiring maintenance. Additionally, because the remaining workpieces on the production line are bound to the transfer robot and electronic tags 6, their processing progress is preserved, preventing loss of progress due to system power outages, debugging, or updates.

[0035] In this embodiment, the pretreatment inspection station 21 is equipped with a surface finish inspection probe, which is used to detect the surface cleanliness, roughness, and oil particle defects of the workpiece.

[0036] In this embodiment, the intermediate coating spraying inspection station 22 and the intermediate coating drying inspection station 23 are equipped with a thickness detection probe and a color difference detection probe, which are used to detect the thickness of the intermediate coating dry film, surface smoothness and gray uniformity, and collect gray color difference data.

[0037] In this embodiment, the base color spraying inspection station 24 is equipped with a thickness detection probe, a color difference detection probe, and a supplementary lighting module, which are used to comprehensively collect workpiece film thickness data and color parameters, and to determine the spraying hue, brightness, saturation, and overall color difference.

[0038] Specifically, the internationally recognized uniform color space parameter Lab* is adopted, where L represents the brightness of the color, a represents the red-green color bias, and b represents the yellow-blue color bias. Through these three sets of parameters, the color difference of the painted workpiece can be accurately quantified, and the hue, brightness, saturation and overall color difference can be quantitatively detected and judged.

[0039] In this embodiment, the varnish spraying inspection station 25 is equipped with a thickness detection probe for detecting the varnish film thickness, surface gloss, and orange peel appearance quality.

[0040] In this embodiment, the final drying and inspection station 26 is equipped with a color difference detection probe and a supplementary lighting module for the final color difference and appearance comprehensive inspection and judgment of the workpiece.

[0041] In this embodiment, the online closed-loop control process for color difference in multi-station continuous automotive painting is used, taking vehicle body painting as an example: After the production line starts operating, the workpiece information binding is first completed at loading station 4. The transfer robot is equipped with an industrial electronic tag 6 (UHF ultra-high frequency passive anti-metal high temperature resistant RFID carrier). After the transfer robot grabs the car body to be painted, the system records the car model's exclusive standard painting process parameters, appearance and color difference judgment thresholds for each process, and color system reference L* / a* / b* color values, and uniquely associates them with the electronic tag 6 to establish an independent production process file for each workpiece.

[0042] After the workpiece is bound, the conveyor robot moves the car body along the main conveyor path to each processing station 1 to complete the spraying operation. During the operation of each spraying station, the electronic tag reader reads the tag data in real time and automatically calls the exclusive process parameters of the corresponding station. Under normal production conditions, the dry film thickness of the intermediate coating spraying station 12 is strictly controlled to be 35~50μm, and the film thickness of the base color spraying station 14 is 15~25μm. The production line temperature is maintained at 20~26℃ and the ambient humidity is 50%~65%. Core parameters such as spraying atomization pressure, spray gun distance, and fan width are unified to solidify the consistency of basic spraying conditions.

[0043] After each coating process is completed, the workpiece immediately enters the corresponding inspection station. The inspection system activates the supplementary lighting module to create a standard inspection environment free from external light interference. Data is collected through various inspection probes, and preset judgment thresholds are retrieved to automatically complete the quality judgment. Among them, the pretreatment station 11 focuses on screening for surface oil stains, particles, and roughness defects; the intermediate coating station strictly controls film thickness and gray uniformity; the base coat spraying station 14 is the core color difference control node, accurately collecting three-color coordinate parameters; the clear coat spraying station 15 controls film thickness and appearance gloss orange peel defects; and the final drying station 16 completes the final color difference and appearance comprehensive acceptance of the finished product.

[0044] When the online inspection of the process determines that the workpiece is unqualified, the system automatically issues a diversion command, and the transmission robot is disconnected from the main road and switched to the rework branch road. The workpiece is transferred to the re-inspection station 3 for manual targeted repair and debugging. After the repair is completed, it is re-inspected. After it meets the standard, it is reconnected to the main production line to complete the subsequent spraying process. All qualified workpieces are continuously transferred along the main road for production without delaying the overall production rhythm of the production line.

[0045] If a single workstation fails to meet standards three times consecutively, or if two adjacent workstations fail to meet standards a total of three times, the system will automatically lock the production line and issue an early warning signal. Staff will then immediately carry out equipment maintenance, spraying parameter adjustment, and raw material inspection to eliminate systemic production abnormalities.

[0046] Through actual mass production application verification, after adopting this process, color difference abnormalities in the entire process of automotive body painting can be detected online, defective workpieces can be isolated for rework and compliant return, completely eliminating batch color difference defects, significantly improving the color difference qualification rate of the whole vehicle painting finished product, reducing production loss costs, and significantly improving the overall production economic benefits.

[0047] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A closed-loop online color difference control process for multi-station continuous spraying in automobiles, characterized in that, It includes a control system and a control method, wherein the control system includes: Material loading station, multiple processing stations, and multiple inspection stations; The multiple processing stations are sequentially configured along the workpiece conveying direction as a pretreatment station, an intermediate coating spraying station, an intermediate coating drying station, a base coat spraying station, a clear coat spraying station, and a final drying station; The inspection station includes a re-inspection station and a process inspection station corresponding to each of the processing stations. The process inspection station is used to detect the processing effect of the corresponding processing station in real time. The process inspection station includes a pretreatment inspection station, an intermediate coating spraying inspection station, an intermediate coating drying inspection station, a base coat spraying inspection station, a clear coat spraying inspection station, and a final drying inspection station. The conveying system includes a main path, branch paths, and multiple conveying robots. The conveying robots are used to transport workpieces along the main path through each processing station and the corresponding inspection station in a preset process sequence, or the conveying robots are used to transport workpieces along the branch paths back and forth between each inspection station and the re-inspection station. The conveying robots are equipped with electronic tags, which are used to associate and mark the workpiece information and process parameters of the workpiece to be processed. The detection system includes: a storage module, a processing module, and electronic tag readers installed at each processing station and process detection station, as well as detection probes corresponding to each station. The processing module pre-stores judgment thresholds and spraying process parameters corresponding to each detection station. The detection probes include a surface finish detection probe, a thickness detection probe, a color difference detection probe, and a supplementary lighting module. The loading station is equipped with an input system for associating and binding the electronic tag of the transfer robot with the workpiece information and process parameters of the workpiece it is holding. The input system is electrically connected to the detection system, enabling the detection system to retrieve the spraying process parameters and judgment threshold of the corresponding workpiece based on the electronic tag.

2. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The control methods include: S1. The conveying system begins to transport the workpiece: The conveying robot grabs the workpiece at the loading position and associates and binds the workpiece information and process parameters with the electronic tag; S2. The conveyor system transports the workpieces sequentially through each processing station and process inspection station: S3. Based on the test results, determine whether to proceed to the next processing station or send it to the re-inspection station; S4. If the workpiece fails inspection continuously, the production line shall be stopped for manual repair.

3. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 2, characterized in that, The conveying system transports workpieces sequentially through various processing stations and process inspection stations, including: S21. When the workpiece enters the processing station, the detection system confirms the workpiece information and process parameters according to the electronic tag, and performs processing according to the corresponding process parameters; S22. When a workpiece enters the corresponding inspection station from the processing station, the inspection system confirms the workpiece information and process parameters based on the electronic tag, and checks whether the processing at the corresponding processing station is qualified.

4. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 3, characterized in that, The step of determining whether to proceed to the next processing station or send the sample to the re-inspection station based on the test results includes: S31. If qualified, the transfer robot will transport the workpiece to the next processing station. S32. If the workpiece is not qualified, the transfer robot will transport the workpiece to the re-inspection position.

5. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 2, characterized in that, The statement that if a workpiece fails continuous inspection, the production line shall be stopped for manual repair includes any of the aforementioned process inspection stations failing three consecutive inspections, or any two adjacent process inspection stations accumulating three consecutive inspection failures.

6. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The pretreatment and inspection station is equipped with the surface finish detection probe, which is used to detect the surface cleanliness, roughness, and oil particle defects of the workpiece.

7. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The intermediate coating spraying inspection station and the intermediate coating drying inspection station are equipped with the thickness detection probe and the color difference detection probe, which are used to detect the thickness of the intermediate coating dry film, surface smoothness and gray uniformity, and collect gray color difference data.

8. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The base color spraying inspection station is equipped with the thickness detection probe, the color difference detection probe, and the supplementary lighting module, which are used to comprehensively collect workpiece film thickness data and color parameters, and to determine the spraying hue, brightness, saturation, and overall color difference.

9. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The varnish spraying inspection station is equipped with a thickness detection probe to detect the varnish film thickness, surface gloss, and orange peel appearance quality.

10. The online closed-loop control process for color difference in multi-station continuous spraying of automobiles according to claim 1, characterized in that, The final drying and inspection station is equipped with a color difference detection probe and a supplementary lighting module for the final comprehensive inspection and judgment of the workpiece's color difference and appearance.

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