Intelligent paint color customization system based on digital twinning and plc linkage

Abstract

The present application relates to a smart paint color customization system based on digital twinning and PLC linkage, relates to the field of automatic control technology, and comprises a parameter acquisition device for collecting paint color customization parameters; the present application is provided with a double-tab structure of a sample selection interface containing hundreds of color cards and a self-defined color mixing interaction interface through online interaction, so that the user can quickly select hundreds of color cards verified by entity spraying calibration, and independently mix and match any multiple proportions of pigments provided by the merchant, realize the unification of standardized color selection and personalized color mixing, perform legality verification, threshold verification and format verification on the paint color customization parameters, realize the standardized circulation of data from user submission to production execution, establish a standardized virtual-real two-way linkage mechanism, so that the optimized process parameters can be directly applied to entity production without manual secondary input and debugging, and after spraying is completed, the camera deployed at the connection display station can be used to real-time view the surface presentation effect of the sample plate under the current lighting conditions.

Description

Technical Field

[0001] This invention relates to the field of automation control technology, and in particular to an intelligent paint color customization system based on digital twin and PLC linkage. Background Technology

[0002] Currently, in the field of industrial paint customization and spraying, certified spraying technicians rely on their professional experience to complete the entire process of paint color matching, sample making, and workpiece spraying. Users can only select colors through hundreds of physical color cards and cannot preview the spraying effect of the paint on the target workpiece in advance. There is no digital control link in the entire process. Some large manufacturing enterprises have introduced digital tools for a single link, including separate online color selection APPs and mini-programs that only realize color card display and basic color selection functions; independent production line PLC control systems that only realize local drive and trajectory control of physical spraying equipment; and single digital twin simulation software that only realizes 3D visualization of the production line and offline programming. These three types of tools are independent of each other, without a unified data interaction standard, and cannot realize cross-link data interoperability, forming information silos that are common in the industry. In summary, existing intelligent paint color customization methods have the following shortcomings in practical applications: Existing intelligent paint color customization only provides a single online color selection function and cannot achieve end-to-end data communication from customization parameters to production execution. The digital twin system is only used for production line visualization, and the PLC control system is only responsible for driving the local physical equipment. There is no standardized two-way linkage mechanism between the two. The process parameters optimized by virtual simulation cannot be directly sent to the physical PLC controller for execution, requiring manual secondary transcription and debugging. The front-end online customization needs are completely disconnected from the back-end offline production process. The customization parameters submitted by users need to be manually converted into production control parameters, which is prone to human error. Furthermore, there is no standardized remote color monitoring closed loop, resulting in frequent batch color difference disputes. To address the aforementioned technical shortcomings, a solution is proposed. Summary of the Invention

[0003] This invention adopts the following technical solution: an intelligent paint color customization system based on digital twin and PLC linkage, comprising: The online interactive customization module, serving as the user's front-end interaction entry point, features a dual-tab architecture with a selection interface containing hundreds of color cards and a custom color matching interactive interface, used to collect and encrypt paint color customization parameters. The cloud service module is used to exchange and parse data on paint color customization parameters, convert them into simulation-identifiable process parameters, transform equipment operation data into front-end renderable and visual data, and provide full-process data storage services by building a relational database. The digital twin simulation module, based on the Unity 3D engine, constructs a three-dimensional simulation scene that is proportionally replicated to the physical spraying production line. It is used to receive paint color process parameters sent by the cloud service module and complete the spraying in the virtual scene, iteratively optimizing the spraying process and equipment operating parameters. The PLC main control module is used to receive the optimized spraying process and equipment operating parameters, control the sample loading and unloading, display stand placement, color matching and spraying in real time, generate timing control instructions and send them out for execution. The automated execution module is used to receive timing control commands and perform sample delivery, workstation positioning, spraying and transfer operations. The remote visual monitoring module is used to collect multi-angle image data of the sprayed sample and provide the actual color value to the customer for selection.

[0004] Furthermore, as the user's front-end interaction entry point, it features a dual-tab architecture with a selection interface containing hundreds of color cards and a custom color matching interaction interface. This is used to collect and encrypt custom paint color parameters, and the specific process is as follows: The online interactive customization module is built on the HBuilder X development framework and has dual-platform adaptation capabilities for PC and mobile devices. Multi-terminal display adaptation is achieved through a PC mode switch indicator at the top of the interface. The online interactive customization module adopts a dual-tab interactive architecture, with two main function entry points: sample selection and customization. The sample selection tab corresponds to a selection interface with hundreds of color cards. The interface uses a matrix layout of 3 rows × 8 columns to display hundreds of color cards. The hundreds of color cards are divided into three major color gradients: red gradient, green gradient, and blue gradient. Within each color gradient, the cards are arranged in descending order from 255 to 32 with a step size of 32. Each color swatch has an independent checkbox, a color swatch number identifier, and a text description of the color parameters. The bottom of the interface has a real-time selection count display area and a confirmation / submission button to form a standard set of selection parameters. The customization tab corresponds to a custom color mixing interface, which includes a customer identification input unit, a four-channel pigment ratio input unit, a data verification prompt unit, and a mixing submission unit. The four-channel pigment ratio input unit has four sets of numeric input boxes for red pigment ratio, green pigment ratio, blue pigment ratio and black pigment ratio. The number of channels can be increased or decreased according to the amount of pigment that the merchant can provide. Each set of input boxes is marked with a % unit label and supports integer ratio values ​​in the range of 0 to 100. After the user clicks the submit button, the system collects the customer's identifier and the four-channel pigment ratio values ​​to form a custom color matching parameter set. The collected standard sample parameter set and the custom color matching parameter set are then associated and packaged with the current user's operation timestamp and terminal device identifier to obtain the paint color customization parameters. The packaged data is then uploaded to the backend interface of the service module using an encryption protocol.

[0005] Furthermore, data exchange and parsing are used to analyze and interpret paint color customization parameters, transforming them into simulation-recognizable process parameters. Equipment operation data is converted into front-end renderable and visualized data, and a relational database is built for end-to-end data storage services. The specific process is as follows: The system receives uploaded paint color customization parameters, including the proportion parameters of each pigment channel, customer identifier, and order timestamp. It parses the received parameters and extracts the values ​​of each field. It performs a validity check on each field value, including whether the customer identifier meets the preset format rules and whether the order timestamp is in a valid time format. If any field fails the check, it returns a parameter error message to the online interactive customization module and blocks the subsequent process. After verification, the front-end color value parameters are converted into simulation-recognizable process parameters according to the preset color value process mapping rule library. The simulation-recognizable process parameters include four-channel pigment ratio parameters, and the simulation-recognizable process parameters are sent to the digital twin simulation module. According to the preset rendering data encoding rules, the device operating status data is converted into front-end renderable visual data, and the converted visual data is pushed to the online interactive customization module for real-time display. The generated simulation-identifiable process parameters, virtual simulation results data, and equipment operating status data are associated and archived in a relational database according to timestamps and order identifiers to complete the full-process data storage service.

[0006] Furthermore, the cloud service module also includes a basic paint color data table and a customer-customized order data table, as detailed below: The system adopts a business-driven structured design, which is divided into two core data table clusters based on business scenarios: basic paint color data storage and customer customized order data storage. The data tables are linked through standardized fields to achieve data linkage. The paint color basic data table is used to store standardized paint color formulas and storage location information. It includes a number field, which is a primary key auto-incrementing index for quick location and related queries of paint color records. The name field stores the standard color code identifier for the paint. The proportions of pigment in the red channel, green channel, blue channel, and black channel are directly used as the feeding control parameters of the PLC spraying equipment. The shelf number field, the layer number field, and the sequence number field together constitute a three-dimensional warehouse positioning coding system, which is used for the precise positioning of paint raw materials in physical warehouses. The paint color basic data table is used to store standardized paint color formulas and warehouse location information. It includes a number field, which is a primary key auto-incrementing index for quick location and related queries of paint color records.

[0007] Furthermore, a 3D simulation scene, proportionally replicated from the physical painting production line, is constructed using the Unity 3D engine. This 3D simulation scene, with the same equipment configuration, layout structure, and kinematic parameters, is directly deployed and run on the physical painting production line. The specific process is as follows: A three-dimensional virtual simulation scene, which is replicated to the same scale as the physical spraying production line, is built using a four-layer structured architecture consisting of a physical layer, a model layer, a logic layer, and an interaction layer. The physics layer is used to construct the physical space boundaries of the production line, collision detection bodies, and gravity simulation parameters, providing physics engine support for the entire scenario; The model layer contains complete 3D models of the painting robot unit, vision inspection unit, workpiece storage and positioning station, material transfer unit, automatic painting reciprocating machine unit, painting execution unit, paint supply and pressure control unit, and production line transmission structure. The geometric topology and kinematic parameters of each 3D model correspond to the physical equipment. The painting robot unit is a 4-DOF industrial robotic arm model, which includes a complete kinematic chain structure of base, rotary joint, upper arm, forearm and wrist joint, and a painting pipeline interface at the end of the robotic arm. The material transfer unit is an integrated model of AGV automatic guided vehicle and lifting mechanism. The AGV is equipped with a magneto-optical sensor simulation module, and the lifting mechanism includes lifting guide rails and fork tooth structure. The paint supply and pressure control unit includes models of paint containers for four basic colors: red, green, blue, and black, as well as models of matching nitrogen tanks and pressure vessels. The logic layer incorporates a device kinematics model, a spraying process simulation algorithm, and timing scheduling logic to simulate the behavior of virtual devices. The interaction layer provides a data communication interface to enable bidirectional data interaction with the cloud service module and the PLC main control module.

[0008] Furthermore, the system receives paint color process parameters from the cloud service module and completes the spraying in a virtual scene, iteratively optimizing the spraying process and equipment operating parameters. The specific process is as follows: The simulation-identifiable process parameters are received through the interaction layer. These parameters include at least four-channel pigment ratio parameters, spray gun spraying speed parameters, spraying distance parameters, and paint output parameters. Spraying is started in a 3D virtual simulation scene. The full-process simulation pre-run includes AGV material transfer simulation, lifting machine material loading and unloading simulation, reciprocating machine spraying simulation and robotic arm assisted operation simulation, to verify the collaborative logic between each workstation and the equipment movement trajectory. During the full-process simulation and pre-playing of spraying, the logic layer performs equipment kinematics simulation and iterative optimization of spraying process parameters. The equipment kinematics simulation simulates the motion trajectory and speed curve of each executing device according to the process parameters. The iterative optimization of spraying process parameters adjusts the spray gun moving speed, spraying distance and spraying overlap rate parameters according to the feedback of virtual spraying effect, and approaches the optimal parameter combination in a multi-round iterative manner. During the simulation and pre-run of the entire spraying process, the position and angle of the virtual device are continuously corrected by receiving sensor signals from the PLC main control module in real time, so as to realize that the virtual simulation process completely maps the real operation process and is synchronized in real time.

[0009] Furthermore, multi-angle image data of the completed sprayed sample is collected, and the actual color values ​​are provided to the customer for selection. The specific process is as follows: After the sample is sprayed and enters the testing station, image acquisition is performed according to the user's current operating mode: if the user is in color comparison mode, the sample board is viewed remotely via a high-definition camera at preset angles. The preset angle sequence includes a front view, a left oblique view, and a right oblique view. If the user is in custom color matching mode, the same sample plate handling process will be performed on the newly sprayed sample after color matching, and the actual color value of the new sample will be provided to the customer for selection. During image acquisition, the lighting parameters of the detection station are adjusted according to user instructions. The lighting parameters include light type and light intensity. The light type includes fluorescent lamps, warm light lamps and cool light lamps. The light intensity is continuously adjustable within a preset range. Sample images are acquired under different lighting parameters to present the actual performance of sample color under different lighting environments.

[0010] Furthermore, it also includes a sample board storage and display module, used to retrieve designated sample boards from the shelf, place them in sequence on the display stand, and return them to their original positions after the display is completed. The specific process is as follows: The shelving has a 5-column, 9-layer three-dimensional structure, storing hundreds of sample boards. Each sample board corresponds to a unique storage location code. Color codes and storage location codes are linked and stored in the database and updated in real time. Two AGV carts are deployed on the track in front of the shelving for horizontal handling of sample boards. The elevator is located next to the shelf and uses retractable forks to perform vertical picking and placing of sample boards. The four-axis robot is located next to the display stand and has a picking and placing actuator at the end for transferring sample boards between the AGV and the display stand. Once the user selects a batch of sample boards and confirms the display order, the system generates a retrieval task sequence, which sequentially dispatches AGV carts, elevators, and four-axis robots to work together to retrieve the selected sample boards from the shelves and place them on the display stand in order. After the demonstration, the system generates a return task sequence to collect the sample panels and return them to their original storage locations, while simultaneously updating the location status of the corresponding sample panels in the database.

[0011] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: This intelligent paint color customization system, based on digital twin and PLC linkage, features a dual-tab architecture with an online interactive interface containing hundreds of color cards for selection and a custom color mixing interface. This allows users to quickly select from hundreds of color cards verified through physical spraying calibration and independently mix any proportion of pigments provided by the vendor, achieving a unified approach to standardized color selection and personalized color mixing. The system performs legality, threshold, and format checks on paint color customization parameters, intercepting invalid and dirty data and converting it into simulation-recognizable process parameters. It also transforms equipment operation data into front-end renderable and visual data, achieving standardized data flow from user submission to production execution. Before physical production, the system allows for simulation preview to confirm the paint color effect, enabling early detection and mitigation of equipment production risks through virtual pre-production, avoiding material waste and time losses caused by physical trial and error. A standardized virtual-physical two-way linkage mechanism is established, allowing optimized process parameters to be directly implemented in physical production without manual secondary input and debugging. After spraying, the system automatically collects multi-angle high-definition images of the sample. After image preprocessing by the cloud service module, the system calculates the color difference between the actual color value and the customized color value based on a standard color difference algorithm, achieving digital and traceable quality acceptance. Attached Figure Description

[0012] Figure 1 A schematic diagram of the overall system flow structure of the present invention is shown; Figure 2 A schematic diagram of the PLC control flow structure of the present invention is shown; Figure 3 A schematic diagram of the automated execution and visual monitoring process structure of the present invention is shown. Detailed Implementation

[0013] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0014] Example: like Figure 1-3 As shown, the intelligent paint color customization system based on digital twin and PLC linkage of the present invention adopts a lightweight architecture design, using only ordinary laptops as the development and operation carrier, without an additional list of dedicated hardware devices, and can meet the system development and operation requirements with commercial laptops that support mainstream configurations.

[0015] The tools that software development and operation rely on include: HBuilder X: Used for developing and building online interactive custom modules, supporting multi-platform adaptation including Android, iOS, and WeChat Mini Programs; TIA Portal: Used for the development, debugging, and downloading of control programs for PLC main control modules, enabling standardized programming of industrial automation control logic; Navicat Premium: Used for visual management and operation of database units, supporting structured design, data backup and daily operation and maintenance of MySQL databases; MySQL database: As the core relational database of the cloud service module, it stores structured data such as basic paint color data of the entire system, customer customized order data, and equipment operation status data; Unity 3D: Used for the development of 3D simulation scenes for digital twin simulation modules, enabling the construction of 1:1 scale production line models, virtual spraying simulation pre-visualization, and iterative optimization of process parameters; SolidWorks: Used for modeling and designing 3D models of workpieces and production line structures; 3ds Max: Used for rendering and lightweight processing of production line models; Proteus, an electronic design automation software, is used for circuit simulation and functional verification of embedded microcontroller control subunits in automated execution modules.

[0016] This embodiment uses a regular laptop computer as the sole operating platform to verify the entire process of personalized paint color customization of the present invention in a simulation environment without physical spray painting production line hardware: (a) Online customization by users Users launch the interactive terminal developed based on HBuilder X, select PC mode via the PC mode switch icon at the top of the interface, and enter the paint color customization interface.

[0017] Users can submit their customization requests using one of the following two methods: Method 1: Selection of hundreds of color cards: Users click the "Select Sample" tab to enter the selection interface of hundreds of color cards. The interface displays hundreds of color cards in a 3-row × 8-column matrix layout. Users select the custom color with color card number 24 from the hundreds of color cards and check the checkbox below the color card. The selected X count area at the bottom of the interface is updated synchronously. Users click the "Confirm Selection Submit" button to complete the selection. Method 2: Custom Color Matching: Users click the "Customize" tab to enter the custom color matching interface. They enter the customer name in the "Customer Identification" input field and enter 50, 10, 30, and 10 respectively in the "Red, Green, Blue, and Black" pigment ratio input fields in the "Four-Channel Pigment Ratio Input Field". The interface's built-in real-time ratio summation and verification logic automatically calculates that the sum of the four ratios is 100%. After the verification is successful, the "Submit" button changes from disabled to enabled. Users click the "Submit" button to complete the customization.

[0018] (ii) Cloud-based data verification, parsing, and storage After receiving the data submitted by the user, the backend interface of the cloud service module performs the following operations: First, the received parameters are validated to confirm that the sum of the pigment ratios of 50, 10, 30, and 10 is 100%, which meets the preset constraints. After the validation is passed, the parsing process begins. Based on the preset color value process mapping rule library, the pigment ratio parameters input by the user are converted into simulation-recognizable process parameters that can be recognized by the digital twin simulation module. The simulation-recognizable process parameters include at least: four-channel pigment ratios, 50% red, 10% green, 30% blue, 10% black, spray gun spraying speed parameters, spraying distance parameters, and paint output parameters. Finally, the order information and simulation-identifiable process parameters are written into the paint color basic data table and the customer customized order data table in the MySQL database and archived. The newly added order data records can be viewed synchronously through the Navicat Premium tool.

[0019] (III) Digital Twin Simulation and Parameter Optimization The digital twin simulation module receives simulation-identifiable process parameters from the cloud service module, and uses the Unity 3D engine to build a 1:1 scale replica of the physical spraying production line, thus initiating a full-process simulation pre-play of the spraying process.

[0020] The entire spraying process simulation pre-runs the following simulation steps sequentially in a Unity virtual scene: AGV material transfer simulation: AGV automatic guided vehicles pick up materials from the shelf along a preset track and transport them to the spraying station to verify the feasibility and timeliness of the transfer path; Lifting machine loading and unloading simulation: The lifting mechanism performs workpiece loading and unloading operations to verify the accuracy of the lifting action and fork tooth positioning; Reciprocating spraying simulation: The reciprocating machine drives the spray gun to move along a preset trajectory to simulate the paint mist coverage effect under different spraying speeds and spraying distances; Simulation of robotic arm assisted operation: A 4-DOF industrial robotic arm performs assisted actions to verify the coordination of the kinematic chains of each joint and obstacle avoidance safety. The built-in device kinematics model in the logic layer simulates the motion trajectory and speed curve of each execution device based on the process parameters identified in the simulation. The spraying process parameter iterative optimization unit automatically adjusts the spray gun moving speed, spraying distance and spraying overlap rate parameters based on the feedback of the virtual spraying effect, and approaches the optimal parameter combination in a multi-round iterative manner. The physical layer calculates the spatial distance between moving parts in real time, performs equipment collision detection, marks the collision position and outputs warning information when a collision risk is detected. After the simulation is completed, the optimal process parameters generated through iterative optimization are sent to the PLC main control module via the OPC UA protocol. Simultaneously, the virtual spraying effect is rendered in real-time to generate a simulation preview image, which is then sent back to the online interactive customization module for user confirmation. Once the user confirms that the spraying effect matches their customization requirements, they submit a simulation confirmation command.

[0021] (iv) PLC control logic simulation and virtual-real linkage verification In TIA Portal software, the control program of the PLC main control module is run in simulation mode to achieve linkage verification with the digital twin simulation module; Based on the simulation environment of the S7-1511-1 PN controller, load the core function block programs of the painting process function block, vehicle release process function block, and robot process function block of the PLC main control module. A communication link is established with the Kepware server via the OPC UA protocol. The paint color ratio parameters in the optimal process parameters are converted into the corresponding input variables in the PLC process image area through a linear mapping algorithm: red pigment dosage is written to %IW4, green pigment dosage is written to %IW16, blue pigment dosage is written to %IW18, and black pigment dosage is written to %IW24. After receiving the process parameters from the simulation, the PLC main control module automatically executes the following verification process: Virtual workstation positioning: The raw material outbound and material grabbing control logic is executed through the picking process function block to verify the correctness of the parameter transmission in the background data block of the picking process function block; Pigment ratio logic verification: The painting process function block reads the pigment ratio parameters in the input variables %IW4, %IW16, %IW18, and %IW24, executes the conditional jump logic, and verifies the ratio control accuracy under different pigment ratios. Spraying sequence control: The GRAPH sequence function chart program of the painting process function block is executed sequentially to verify the triggering logic of each step transition condition and the correctness of the timing of step execution; During the execution of each functional block, the PLC main control module transmits the program running status and step execution results back to the digital twin simulation module in real time through the communication link, driving the corresponding device model in the virtual scene to update its status synchronously, and completing the complete closed-loop verification of virtual and real two-way linkage.

[0022] (v) Remote visual monitoring and order closed loop After completing the virtual spraying process, the digital twin simulation module generates a virtual finished product image and color difference comparison data. The intelligent color difference comparison unit of the remote visual monitoring module calculates the color difference between the virtual finished product color value and the customized color value based on the standard color difference algorithm, and generates a standardized color difference detection report. The color difference detection report includes sample identification, color difference values ​​from various angles, and comprehensive color difference judgment results. The color difference detection report is pushed to the user terminal of the online interactive customization module via HTTPS encryption protocol. After the user confirms that the virtual spraying effect is consistent with the customization requirements, the user submits the order to complete the confirmation instruction.

[0023] After receiving the order completion confirmation instruction, the cloud service module updates the order status to "completed". All data throughout the process is archived in a unified MySQL database. The complete order records and simulation logs can be queried through the database management Navicat Premium tool, forming a complete digital record from online customization to order closure.

[0024] This embodiment fully verifies the end-to-end data interoperability, virtual-physical linkage, and order process of the present invention in a simulation environment without physical hardware devices. It realizes the full-process digital verification from online user customization to PLC control logic simulation. The verification results show that the system can stably realize the virtual simulation and control logic linkage of personalized paint color customization, with a verification cycle of no more than 30 minutes. It is suitable for simulation verification and teaching training scenarios of lightweight customization for small and micro enterprises.

[0025] The size of the interval and threshold is set to facilitate comparison. The size of the threshold depends on the amount of sample data and the number of bases set by those skilled in the art for each set of sample data; as long as it does not affect the ratio between the parameter and the quantized value.

[0026] The above formulas are all dimensionless calculations. The formulas are derived from software simulations based on a large amount of collected data to obtain the most recent real-world results. The preset parameters in the formulas are set by those skilled in the art according to the actual situation. In the embodiments provided in this application, it should be understood that the disclosed system can be implemented in other ways; for example, the system embodiments described above are merely illustrative, for example, the division of modules is merely a logical functional division, and there may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed; another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be indirect coupling or communication connection through some interfaces, devices or modules, and can be electrical, mechanical or other forms; The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An intelligent paint color customization system based on digital twin and PLC linkage, characterized in that, include: The online interactive customization module, serving as the user's front-end interaction entry point, features a dual-tab architecture with a selection interface containing hundreds of color cards and a custom color matching interactive interface, used to collect and encrypt paint color customization parameters. The cloud service module is used to exchange and parse data on paint color customization parameters, convert them into simulation-identifiable process parameters, transform equipment operation data into front-end renderable and visualized data, and provide full-process data storage services by building a relational database, storing the color ratio information and location information of the sample in the database and updating it in real time. The digital twin simulation module, based on the Unity 3D engine, constructs a three-dimensional simulation scene that is proportionally replicated to the physical spraying production line. It is used to receive paint color process parameters sent by the cloud service module and complete the spraying in the virtual scene, iteratively optimizing the spraying process and equipment operating parameters. The PLC main control module is used to receive the optimized spraying process and equipment operating parameters, control the sample loading and unloading, display stand placement, color matching and spraying in real time, generate timing control instructions and send them out for execution. The automated execution module is used to receive timing control commands and perform sample delivery, workstation positioning, spraying and transfer operations. The remote visual monitoring module is used to collect multi-angle image data of the sprayed sample and provide the actual color value to the customer for selection.

2. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, As the user's front-end interaction entry point, it features a dual-tab architecture with a selection interface containing hundreds of color cards and a custom color matching interface. This is used to collect and encrypt paint color customization parameters, and the specific process is as follows: The online interactive customization module is built on the HBuilder X development framework and has dual-platform adaptation capabilities for PC and mobile devices. Multi-terminal display adaptation is achieved through a PC mode switch indicator at the top of the interface. The online interactive customization module adopts a dual-tab interactive architecture, with two main function entry points: sample selection and customization. The "Select Samples" tab corresponds to a selection interface with hundreds of color cards, which are displayed in a matrix layout of 3 rows × n columns. Each color swatch has an independent checkbox, a color swatch number identifier, and a text description of the color parameters. The bottom of the interface has a real-time selection count display area and a confirmation / submission button to form a standard set of selection parameters. The customization tab corresponds to the custom color mixing interface, which includes a customer identification input unit, a four-channel pigment ratio input unit, a data verification prompt unit, and a mixing submission unit. The four-channel pigment ratio input unit has four sets of numeric input boxes for red pigment ratio, green pigment ratio, blue pigment ratio and black pigment ratio. The number of channels can be increased or decreased according to the amount of pigment that the merchant can provide. Each set of input boxes is marked with a % unit label and supports integer ratio values ​​in the range of 0 to 100. After the user clicks the submit button, the system collects the customer's identifier and the four-channel pigment ratio values ​​to form a custom color matching parameter set. The collected standard sample parameter set and the custom color matching parameter set are then associated and packaged with the current user's operation timestamp and terminal device identifier to obtain the paint color customization parameters. The packaged data is then uploaded to the backend interface of the service module using an encryption protocol.

3. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, This is used for data exchange and parsing of customized paint color parameters, transforming them into simulation-recognizable process parameters, converting equipment operation data into front-end renderable and visual data, and providing end-to-end data storage services through the construction of a relational database. The specific process is as follows: The system receives uploaded paint color customization parameters, including the proportion parameters of each pigment channel, customer identifier, and order timestamp. It parses the received parameters and extracts the values ​​of each field. It performs a validity check on each field value, including whether the customer identifier meets the preset format rules and whether the order timestamp is in a valid time format. If any field fails the check, it returns a parameter error message to the online interactive customization module and blocks the subsequent process. After the verification is passed, the pigment dosage corresponding to each pigment channel is calculated according to the preset color value process mapping rule library and the proportional parameters of each pigment channel. The pigment dosage is obtained by multiplying the preset total amount of paint by the proportional parameters of each channel. Then, according to the pigment dosage corresponding to each pigment channel and the preset hydraulic pump unit time flow parameters, each pigment dosage is converted into the hydraulic pump running time parameters corresponding to each pigment channel. According to the preset rendering data encoding rules, the device operating status data is converted into front-end renderable visual data, and the converted visual data is pushed to the online interactive customization module for real-time display. The generated simulation-identifiable process parameters, virtual simulation results data, and equipment operating status data are associated and archived in a relational database according to timestamps and order identifiers to complete the full-process data storage service.

4. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, The cloud service module also includes a basic paint color data table and a customer-customized order data table, as detailed below: The system adopts a business-driven structured design, which is divided into two core data table clusters based on business scenarios: basic paint color data storage and customer customized order data storage. The data tables are linked through standardized fields to achieve data linkage. The paint color basic data table is used to store standardized paint color formulas and warehouse location information. It includes a number field, which is a primary key auto-incrementing index for quick location and related queries of paint color records. The name field stores the standard color code identifier for the paint. The proportions of pigment in the red channel, green channel, blue channel, and black channel are directly used as the feeding control parameters of the PLC spraying equipment. The shelf number field, the layer number field, and the sequence number field together constitute a three-dimensional warehouse positioning coding system, which is used for the precise positioning of paint raw materials in physical warehouses. The paint color basic data table is used to store standardized paint color formulas and warehouse location information. It includes a number field, which is a primary key auto-incrementing index for quick location and related queries of paint color records.

5. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, A 3D simulation scene, built using the Unity 3D engine and scaled up to the actual paint spraying production line, is directly deployed and run on the production line with the same equipment configuration, layout structure, and kinematic parameters. The specific process is as follows: A three-dimensional virtual simulation scene, which is replicated to the same scale as the physical spraying production line, is built using a four-layer structured architecture consisting of a physical layer, a model layer, a logic layer, and an interaction layer. The physics layer is used to construct the physical space boundaries of the production line, collision detection bodies, and gravity simulation parameters, providing physics engine support for the entire scenario; The model layer contains complete 3D models of the painting robot unit, vision inspection unit, workpiece storage and positioning station, material transfer unit, automatic painting reciprocating machine unit, painting execution unit, paint supply and pressure control unit, and production line transmission structure. The geometric topology and kinematic parameters of each 3D model correspond to the physical equipment. The painting robot unit is a 4-DOF industrial robotic arm model, which includes a complete kinematic chain structure of base, rotary joint, upper arm, forearm and wrist joint, and a painting pipeline interface at the end of the robotic arm. The material transfer unit is an integrated model of AGV automatic guided vehicle and lifting mechanism. The AGV is equipped with a magneto-optical sensor simulation module, and the lifting mechanism includes lifting guide rails and fork tooth structure. The paint supply and pressure control unit includes models of paint containers for four basic colors: red, green, blue, and black, as well as models of matching nitrogen tanks and pressure vessels. The logic layer incorporates a device kinematics model, a spraying process simulation algorithm, and timing scheduling logic to simulate the behavior of virtual devices. The interaction layer provides a data communication interface to enable bidirectional data interaction with the cloud service module and the PLC main control module.

6. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, The system is used to receive paint color process parameters issued by the cloud service module and complete the spraying in a virtual scene, iteratively optimizing the spraying process and equipment operating parameters. The specific process is as follows: The simulation-identifiable process parameters are received through the interaction layer. These parameters include at least four-channel pigment ratio parameters, spray gun spraying speed parameters, spraying distance parameters, and paint output parameters. Spraying is started in a 3D virtual simulation scene. The full-process simulation pre-run includes AGV material transfer simulation, lifting machine material loading and unloading simulation, reciprocating machine spraying simulation and robotic arm assisted operation simulation, to verify the collaborative logic between each workstation and the equipment movement trajectory. During the full-process simulation and pre-playing of spraying, the logic layer performs equipment kinematics simulation and iterative optimization of spraying process parameters. The equipment kinematics simulation simulates the motion trajectory and speed curve of each executing device according to the process parameters. The iterative optimization of spraying process parameters adjusts the spray gun moving speed, spraying distance and spraying overlap rate parameters according to the feedback of virtual spraying effect, and approaches the optimal parameter combination in a multi-round iterative manner. During the full-process simulation of spraying, the position and angle of the virtual device are continuously corrected by receiving sensor signals from the PLC main control module in real time, so as to realize that the virtual simulation process completely maps the real operation process and is synchronized in real time.

7. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, This process involves acquiring multi-angle image data of the sprayed sample and providing the actual color values ​​to the customer for selection. The specific process is as follows: After the sample is sprayed and enters the testing station, image acquisition is performed according to the user's current operating mode: if the user is in color comparison mode, the sample board is viewed remotely via a high-definition camera at preset angles. The preset angle sequence includes a front view, a left oblique view, and a right oblique view. If the user is in custom color matching mode, the same sample plate handling process will be performed on the newly sprayed sample after color matching, and the actual color value of the new sample will be provided to the customer for selection. During image acquisition, the lighting parameters of the detection station are adjusted according to user instructions. The lighting parameters include light type and light intensity. The light type includes fluorescent lamps, warm light lamps and cool light lamps. The light intensity is continuously adjustable within a preset range. Sample images are acquired under different lighting parameters to present the actual performance of sample color under different lighting environments.

8. The intelligent paint color customization system based on digital twin and PLC linkage according to claim 1, characterized in that, It also includes a sample board storage and display module, used to retrieve designated sample boards from the shelf, place them in sequence on the display stand, and return them to their original positions after the display is completed. The specific process is as follows: The shelving has a 5-column, 9-layer three-dimensional structure, storing hundreds of sample boards. Each sample board corresponds to a unique storage location code. Color codes and storage location codes are linked and stored in a database and updated in real time. Two AGV carts are deployed on the track in front of the shelving for horizontal handling of the sample boards. The elevator is located next to the shelf and uses retractable forks to perform vertical picking and placing of sample boards. The four-axis robot is located next to the display stand and has a picking and placing actuator at the end for transferring sample boards between the AGV and the display stand. Once the user selects a batch of sample boards and confirms the display order, the system generates a retrieval task sequence, which sequentially dispatches AGV carts, elevators, and four-axis robots to work together to retrieve the selected sample boards from the shelves and place them on the display stand in order. After the demonstration, the system generates a return task sequence to collect the sample panels and return them to their original storage locations, while simultaneously updating the location status of the corresponding sample panels in the database.

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