A virtual assembly method for printing press based on virtual simulation technology

Abstract

The present invention provides a printing press virtual assembly method based on virtual simulation technology, comprising: constructing a PZ1740E offset printing press model through 3Ds MAX software, importing the constructed PZ1740E offset printing press model into Blender for paper feeding animation design, and importing the model and the animation into Unity for function realization. The printing press virtual assembly method based on virtual simulation technology provided by the present invention meets people's demand for developing a virtual simulation system for printing process flow by combining a fault simulation function with a virtual assembly system, provides a solution for the virtual simulation realization of the cause of printing image faults, and helps to promote the expansion and development of the content of the virtual assembly system.

Description

Technical Field

[0001] The invention relates to the technical field of virtual simulation, and in particular to a printing press virtual assembly method based on virtual simulation technology. Background Art

[0002] Nowadays, with the progress of the times and the rapid development of science and technology, virtual assembly technology has developed into a high-tech technology, which is widely used in simulated assembly processes in virtual environments and has become a vital component of virtual manufacturing. It perfectly combines the advantages of virtual reality technology and 3D modeling technology, simulates a virtual assembly environment, verifies the correctness of the design ideas and operation processes of the assembly, and facilitates the early discovery of problems in the assembly, and then modifies the model, and finally realizes the visualization of the assembly process. Among them, collision detection technology is an indispensable key technology in the virtual assembly process. It can improve the authenticity of the virtual assembly process and play a very important role in enhancing the immersion of the virtual assembly system. Many foreign universities and laboratories have begun to devote themselves to the research and development of virtual assembly systems and have achieved certain research achievements. Major universities in my country have also begun to introduce virtual assembly technology into education and teaching, and related research topics have continued to increase, and certain research results have been achieved.

[0003] Printing engineering is an engineering major with strong professionalism and high practical and skill requirements. Practitioners need to have an in-depth understanding of process principles, processes and equipment structures. Therefore, under the teaching arrangement of the actual course, skill training and experimental operation courses should be added to further combine theoretical knowledge with production practice. At present, due to the large area occupied by printing experimental equipment, complex operation, serious consumables and insufficient funds, most of the practical operations cannot be performed, and the course content is still mainly theoretical teaching. Under this teaching mode, students often have vague or unclear understanding, no accurate cognition, and difficulty in teaching, resulting in general teaching effects and formalized and proceduralized practical operations. In the actual operation process, printing machinery occupies a large area and is generally semi-open or closed machinery, so it is impossible to observe the actual machine operation process, internal mechanical structure and fault problems.

[0004] The biggest feature of virtual simulation technology is that it can perform human-computer interaction. It is an effective means to enhance experimental teaching demonstrations and technical training. It solves the "three highs" problems of high cost, high risk, and high pollution in the training practice process, as well as the "four difficulties" of difficult observation, difficult access, difficult action, and difficult reproduction. Among them, virtual assembly technology is a technology that uses virtual simulation technology as the application basis to make relevant decisions on virtual assembly. It can design assembly processes based on the information and resources of the product model to obtain feasible assembly process solutions, such as assembly sequence and path, process route, interference verification of operation space, etc. to guide actual production.

[0005] Therefore, it is necessary to design a virtual assembly method of printing press based on virtual simulation technology. Summary of the invention

[0006] The purpose of the present invention is to provide a virtual assembly method of a printing press based on virtual simulation technology. By combining the fault simulation function with the virtual assembly system, it meets people's needs for developing a virtual simulation system for printing process flow, provides a solution for the virtual simulation of the causes of printing image faults, and helps to promote the expansion and development of the content of the virtual assembly system.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A printing press virtual assembly method based on virtual simulation technology comprises the following steps:

[0009] Step 1: Build the PZ1740E offset printing machine model using 3Ds MAX software;

[0010] Step 2: Import the constructed PZ1740E offset printing machine model into Blender for paper feeding animation design;

[0011] Step 3: Import the model and animation into Unity to implement the function.

[0012] Optionally, in step 1, a PZ1740E offset printing machine model is constructed using 3Ds MAX software, specifically:

[0013] The actual machine data of PZ1740E offset printing machine was tested to obtain the test data. A hierarchical relationship model was established according to the PZ1740E offset printing machine. The hierarchical relationship model was used to analyze whether the PZ1740E offset printing machine had the same part geometry model, assembly feature information and interaction features. The relevant structure modeling was carried out in 3Ds MAX software according to the test data and the hierarchical relationship model. The transformation operations of model vertices, line segments and faces were realized through polygonal modeling. The material properties of the PZ1740E offset printing machine were restored through mapping, rendering and material ball methods. According to the hierarchical relationship model, group structure modeling-group component detail modeling-group modeling was used to model the next sub-assembly after group modeling was completed. The sub-assemblies were integrated to construct the PZ1740E offset printing machine model.

[0014] Optionally, in step 2, import the constructed PZ1740E offset printing machine model into Blender for paper feeding animation design, specifically:

[0015] Import the constructed PZ1740E offset printing machine model into Blender, and realize the cyclic animation of paper movement through displacement animation, rotation animation and deformation animation.

[0016] Optionally, in step 3, import the model and animation into Unity to implement the function, specifically:

[0017] The PZ1740E offset printing machine model and the cyclic animation of paper running are imported into Unity 3D. Through the PZ1740E offset printing machine model and the cyclic animation of paper running, Unity 3D is used to design the main system interface, basic cognition module and printing fault module. The basic cognition module includes an equipment basic information display module, a basic theoretical knowledge learning module and a structure display and assembly module. The equipment basic information display module is used to display the basic information of the equipment. The basic theoretical knowledge learning module is used to display printing principles, common faults and operation and use information. The structure display and assembly module is used to display the automatic disassembly, function information introduction and assembly function of the host and part of the structure of the paper feeder of the PZ1740E offset printing machine model. The printing fault module is used to display the paper feeding animation and simulate the fault analysis. The main system interface is used for module selection.

[0018] Optionally, the main system interface can be designed using Unity 3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0019] The main system interface is implemented using UGUI and is provided with five options, namely, cognitive machine module, theoretical knowledge learning, structural cognitive module, printing fault module and exit system. Among them, the option of the cognitive machine module corresponds to the equipment basic information display module, the option of the theoretical knowledge learning corresponds to the basic theoretical knowledge learning module, the option of the structural cognitive module corresponds to the structural display and assembly module, the option of the printing fault module corresponds to the printing fault module. By clicking on different options with the mouse, you can enter the corresponding functional scene, and by listening to the OnClick behavior in the Insparent panel and assigning a value to nextScene, you can jump to the specified scene.

[0020] Optionally, use Unity 3D to design a basic equipment information display module through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0021] The basic information display module of the equipment is designed by Unity 3D through the PZ1740E offset printing machine model and the looping animation of paper running. The PZ1740E offset printing machine model in the basic information display module can be rotated and zoomed in and out by the mouse, so that the user can view the relevant structural position of the PZ1740E offset printing machine model.

[0022] Optionally, use Unity 3D to design basic theoretical knowledge learning modules through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0023] Collect open PZ1740E offset printing machine video resources and play them through VideoPlayer. Create component buttons in the playback scene and write scripts. Define parameters to obtain video components and RawImage components, declare playback components, determine whether to mute, set the logic of pausing video playback, and increase or decrease volume logic. The playlist specifies the target video by setting the video index parameter.

[0024] Optionally, use Unity 3D to design the structure display and assembly module through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0025] The structure display and assembly module divides the PZ1740E offset press model into a printing host and a paper feeder, and is equipped with functions of structure information visualization, display and hidden assembly, and automatic disassembly and assembly;

[0026] The target object of the structural information visualization function is each sub-assembly. A collision body is added to each sub-assembly, and the content is displayed using the GUI. Then, the interaction between the mouse and the assembly is judged by monitoring the mouse OnMouseEnter, OnMouseExit, and OnMouseDown events, which is used to display the main information of each sub-assembly.

[0027] The display and hide assembly function obtains all objects and related buttons in the scene by listening to mouse click events, and displays and hides each sub-assembly through HideObj and DisplayObj events according to the Tag attribute classification corresponding to the object;

[0028] The automatic disassembly and assembly function is aimed at the printing host and paper feeder of the PZ1740E offset printing machine model, which is realized by setting key points and key frames in Animation and moving the relative position of the target object model.

[0029] Optionally, a printing fault module can be designed using Unity 3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0030] The printing fault module includes a back smear module, a paper wrinkle module and a plate sticking module, which are respectively used to simulate the back smear, paper wrinkle and plate sticking faults in the printing paper feeding process animation. The back smear module realizes the transformation of the smear traces on the paper by applying URP in the sample state. A control bar is provided to adjust the powder spraying amount and the drying agent content. The input variables are adjusted by the control bar to change the paper smearing. The particle system of Unity 3D is used to simulate the toner to realize the effect of spraying the printing anti-adhesive agent on the paper. A collider is added to the paper to make the toner particles collide with the paper to simulate the process of the toner falling on the paper.

[0031] The paper wrinkle module represents uneven biting force by marking angles at the paper grippers of the PZ1740E offset printing machine model, and eliminates paper wrinkles by replacing image resources;

[0032] The paste plate module adjusts the printing dots and sample changes according to the printing pressure changes and adjusts the sample changes according to the ink content, wherein the dot changes are achieved by creating a shader through graphics rendering technology, and the ink content changes are achieved by replacing the sample picture in an array manner.

[0033] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects: the virtual assembly method of a printing press based on virtual simulation technology provided by the present invention uses three-dimensional modeling technology and image rendering technology to highly restore the PZ1740E single-sheet offset lithography press, and uses human-computer interaction technology and virtual assembly technology to realize the basic cognition, assembly and fault simulation functional modules of the system, ensuring good interaction between users and the virtual simulation offset press and vivid presentation of fault simulation. The method reasonably integrates some theoretical knowledge of printing, virtual assembly technology, and fault simulation into the same system, which not only enables users to master relevant theoretical knowledge, but also can use the system as a demonstration and exploration tool. Among them, the printing fault module can study the implementation and control methods of sample changes, dot changes, and smudge mark changes, providing a new way of thinking for the development and application content expansion of the virtual assembly system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 It is a flow chart of a method for virtual assembly of a printing press based on virtual simulation technology according to an embodiment of the present invention;

[0036] Figure 2 It is a schematic diagram of the structure of a printing press virtual assembly system based on virtual simulation technology according to an embodiment of the present invention;

[0037] Figure 3 It is a control framework diagram of a printing press virtual assembly method based on virtual simulation technology according to an embodiment of the present invention;

[0038] Figure 4 It is a hierarchical relationship model diagram;

[0039] Figure 5 This is a schematic diagram of the UI home page;

[0040] Figure 6a Main scene view for structure display and assembly module;

[0041] Figure 6b A side view of the main scene showing the structure and assembly modules;

[0042] Figure 7 It is a schematic diagram of the structure of the printing fault module;

[0043] Figure 8 To create a logic diagram for dirty traces;

[0044] Fig. 9 This is a schematic diagram of UV processing;

[0045] Fig.10 This is a schematic diagram of the ShaderGraph prototype. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] The purpose of the present invention is to provide a virtual assembly method of a printing press based on virtual simulation technology. By combining the fault simulation function with the virtual assembly system, it meets people's needs for developing a virtual simulation system for printing process flow, provides a solution for the virtual simulation of the causes of printing image faults, and helps to promote the expansion and development of the content of the virtual assembly system.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0049] like Figure 1As shown, the printing press virtual assembly method based on virtual simulation technology provided by the embodiment of the present invention includes the following steps:

[0050] Step 1: Build the PZ1740E offset printing machine model using 3Ds MAX software;

[0051] Step 2: Import the constructed PZ1740E offset printing machine model into Blender for paper feeding animation design;

[0052] Step 3: Import the model and animation into Unity to implement the function.

[0053] In step 1, the PZ1740E offset printing machine model is constructed using 3Ds MAX software, specifically:

[0054] The actual machine data of PZ1740E offset printing machine was tested to obtain the test data. In order to avoid the cumbersome modeling process caused by the complex model structure, the PZ1740E offset printing machine was sorted out and a hierarchical relationship model was established, such as Figure 4 As shown, the hierarchical relationship model is used to analyze whether the PZ1740E offset printing machine has the same part geometry model, assembly feature information and interaction features to avoid repeated modeling. The relevant structure modeling is performed in 3Ds MAX software according to the detection data and the hierarchical relationship model. The transformation operations of the model vertices, line segments and faces are realized through polygonal modeling. The material properties of the PZ1740E offset printing machine are restored through mapping, rendering and material ball methods. According to the hierarchical relationship model, group structure modeling-group component detail modeling-group modeling is performed to model the next sub-assembly after the group modeling is completed. The sub-assemblies are integrated to construct the PZ1740E offset printing machine model.

[0055] In step 2, the constructed PZ1740E offset printing machine model is imported into Blender for paper feeding animation design, specifically:

[0056] The basic process of paper operation is designed as follows: the paper delivery nozzle sucks the paper, and the paper delivery teeth deliver the paper to the double-sheet detection position. The paper is driven forward by the line belt on the paper feeding table. After reaching the paper gauge for position adjustment, the paper delivery teeth are connected with the roller grippers. The roller grippers grip the paper. The paper rotates with the impression roller grippers and reaches the paper collection chain grippers. Then, the paper continues to move with the chain grippers. After reaching the paper collection table, the grippers are released and the paper reaches the paper collection table.

[0057] Import the constructed PZ1740E offset printing machine model into Blender, and realize the cyclic animation of paper running through displacement animation, rotation animation, deformation animation and the combination of the three.

[0058] In step 3, import the model and animation into Unity to implement the function, specifically:

[0059] like Figure 3 As shown in the figure, the virtual experiment controls various multimedia resources such as graphics, videos, buttons and UI interfaces through the function scripts in the unity 3D development platform. After the user inputs information through the operating system through external devices such as mouse and keyboard, the virtual system makes corresponding scene and function feedback according to the monitoring events of the external devices, and finally displays the information above the computer screen to realize the interaction between the user and the computer.

[0060] The PZ1740E offset printing machine model and the cyclic animation of paper running are imported into Unity 3D. The main system interface, basic cognition module and printing fault module are designed by Unity 3D through the PZ1740E offset printing machine model and the cyclic animation of paper running. The basic cognition module includes an equipment basic information display module, a basic theoretical knowledge learning module and a structure display and assembly module. The equipment basic information display module is used to display equipment basic information. The basic theoretical knowledge learning module is used to display printing principles, common faults and operation and use information. The structure display and assembly module is used to display the automatic disassembly, function information introduction and assembly function of the host and part of the structure of the paper feeder of the PZ1740E offset printing machine model. The printing fault module includes a printing paper feeding process animation module and a fault analysis unit. The printing paper feeding process animation module is used to display the paper feeding animation. The fault analysis unit is used to simulate fault analysis. The main system interface is used to select modules.

[0061] The main system interface is designed using Unity 3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0062] like Figure 5 As shown, the main system interface is implemented using UGUI. The UGUI system has built-in most of the UI components needed, such as Button, Image, Text, Panel and other controls. The main system interface is set with five options, namely cognitive machine module, theoretical knowledge learning, structural cognitive module, printing fault module and exit system. Click on the cognitive machine module to enter the functional scene of the equipment basic information display module, click on the theoretical knowledge learning to enter the functional scene of the basic theoretical knowledge learning module, click on the structural cognitive module to enter the functional scene of the structure display and assembly module, and click on the printing fault module to enter the functional scene of the printing fault module;

[0063] Click different options with the mouse to enter the corresponding functional scene, and assign a value to nextScene by listening to the OnClick behavior in the Insparent panel to jump to the specified scene.

[0064] The basic information display module of the equipment is designed by using Unity 3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically:

[0065] Import the PZ1740E offset printing machine model into Unity 3D. Users can right-click and drag the model to rotate and scale it, helping users quickly understand the relevant location structure.

[0066] The main purpose of the equipment basic display module is to help users understand the overall appearance and specifications of the sheet-fed offset printing machine. The main contents include model introduction, product dimensions, paper and plate material consumables information, etc. The basic information display function allows users to drag the mouse to rotate, zoom in and out of the offset printing machine model, helping users quickly understand the basic information of the offset printing machine.

[0067] Through the PZ1740E offset printing machine model and the looping animation of paper running, the basic theoretical knowledge learning module of Unity 3D design is introduced, specifically:

[0068] Collect open PZ1740E offset press video resources and play them through VideoPlayer. Create component buttons in the playback scene and write scripts. Define parameters to obtain video components and RawImage components, declare playback components, determine whether to mute, set the logic of pausing video playback, and increase or decrease volume logic. The playlist specifies the target video by setting the video index parameter. The key code for video playback during the printing process is:

[0069]

[0070] The PZ1740E offset printing machine model and the paper running loop animation were used to design the equipment structure display and assembly module using Unity 3D, specifically:

[0071] As shown in Figure 6, the equipment structure display and assembly module divides the PZ1740E offset press model into a printing host and a paper feeder, and is equipped with the functions of structural information visualization, display and hidden assembly, and automatic disassembly and assembly. The automatic disassembly and assembly function involves the printing unit, paper collection system, and paper feeder of the PZ1740E offset press model.

[0072] Among them, the target object of the structural information visualization function is each sub-assembly. Its main goal is to display the name of the structure and the main related information of the part, including the function, working principle, common faults, precautions, etc. By adding collision bodies to each sub-assembly, using GUI to realize content display, and then by monitoring the mouse OnMouseEnter, OnMouseExit, OnMouseDown events, the interaction behavior between the mouse and the assembly is judged;

[0073] The display and hide assembly function listens to mouse click events, obtains all objects and related buttons in the scene, and classifies the Tag attributes corresponding to the objects. It displays and hides each sub-assembly through HideObj and DisplayObj events. Click the "show" and "hide" buttons to display or hide the current part and display the structure function information below. Click the "host part" and "feeder part" buttons on the right to enter the two major scenes.

[0074] The automatic disassembly and assembly function is aimed at the printing host and paper feeder of the PZ1740E offset printing machine model. By setting key points and key frames in the Animation and moving the relative position of the target object model, the disassembly effect of the assembly of the printing press paper delivery system is demonstrated.

[0075] The automatic disassembly function mainly displays relevant content for assemblies in hierarchical model relationships. For their specific structural information, users can click the structure recognition module to enter the unit structure automatic assembly module. This part of the assembly mainly includes the printing ink roller, drum unit (main machine part), printing press paper collection system, and paper feed table of the PZ1740E offset printing machine model. The realization of the disassembly function in this system is mainly completed by using the settings of key points and key frames in Animation, the relative position movement of the target object model, etc., to display the disassembly effect of the printing press paper collection system assembly.

[0076] like Figure 7 As shown, the printing fault module provides three major printing sheet faults, namely, back smudge, paper wrinkles, and plate sticking, to demonstrate and analyze the feasibility of applying fault simulation in virtual simulation and virtual assembly systems. The printing fault module includes a printing paper feeding process animation module and a fault analysis unit, wherein the left side is the printing paper feeding process animation module, and the right side is the fault analysis unit. The overall implementation effect of the printing paper feeding process animation module is: hold down the right button of the mouse to surround the observation model, and click the button above the model to display the relevant gif information or animation information about this part. For example, click the powder spraying device to view the animation of the powder to paper process, click the ink button to watch the movement of ink between the ink rollers, and click the hidden button in the function module below to hide the right bracket panel of the offset printing machine, so that the user can observe the paper feeding process from the side, and click the animation rate button to change the paper feeding speed. The specific implementation process of the camera surround function is: control the distance of the camera from the offset printing machine - monitor the logic of the mouse right button press event - interpolation processing - use quaternions to realize object rotation;

[0077] The printing fault module includes a back smearing module, a paper wrinkling module and a plate sticking module, wherein the cause of the back smearing module is designed as follows: ① the amount of spray powder (printing anti-sticking agent) is small, resulting in weak support between ink and paper; ② the ink drying speed is too slow due to the small content of drying agent. The back smearing fault caused by the common cause of the two aspects is specifically designed as follows Figure 8 As shown, at the 0-60% position of the powder spraying amount control bar, the smear marks gradually decrease to a state with less smear marks, and at the 60%-100% position, the smear marks no longer change. When the drying agent content is adjusted, the smear marks increase, decrease or disappear accordingly according to the content;

[0078] The URP is applied to the sample status to achieve the transformation of the smear marks on the paper. A control bar is set to adjust the amount of powder spraying and the content of the drying agent. The input variables are adjusted through the control bar to change the smear marks on the paper. The particle system of Unity 3D is used to simulate the toner to achieve the effect of spraying the anti-adhesive agent on the paper. A collider is added to the paper to make the toner particles collide with the paper, simulating the process of toner falling on the paper.

[0079] Common causes of the paper wrinkle module include wrinkles in the base paper, uneven biting force of the roller grippers, differences in ambient temperature and humidity, and other issues. In this module, the cause of paper wrinkles is designed to be a fault caused by uneven biting force of the roller grippers, the ambient relative temperature and humidity are within the normal range, and the base paper has no wrinkles. The scene displays the current ambient temperature and humidity. Click the "Base Paper" and "Grippers" buttons to view their current status. After clicking the "Adjust Positive Roller Grippers" button, the paper wrinkles disappear and the gripping status of the grippers returns to normal.

[0080] The paper wrinkle module represents uneven biting force by marking angles at the paper grippers of the PZ1740E offset printing machine model, and eliminates paper wrinkles by replacing image resources;

[0081] The plate-pasting module adjusts the printing dots and the sample changes according to the printing pressure changes and adjusts the sample changes according to the ink content;

[0082] Among them, the dot change is achieved by creating a shader through graphics rendering technology. First, UV information is obtained, and TillingAndOffset is used directly to achieve the offset. This offset is relative to the UV. The U direction value and the V direction value are separated through the split node. Here, since the Tilling attribute of UV is input, the UV needs to be scaled so that it returns 1 when it is an odd number and returns 0 when it is an even number, to achieve the change of the vertical value, and then multiply it by the horizontal value to get a column of black and white squares. The horizontal direction is processed in the same way as the vertical direction, but the difference is that the horizontal direction does not need to be multiplied by the offset value. Finally, the processed results are merged, and the fraction method is used to take the decimal part to make it change between 0-1, such as Fig. 9 As shown, you can intuitively see the processed UV appearance, which is arranged irregularly like bricks.

[0083] A prototype is dynamically generated through the Ellipse method of UnityShaderGraph. The size of the prototype is dynamically adjusted by exposing parameters. The prototype will appear as a dot. Then the UV prepared above is input into the UV node of the prototype. In this way, a prototype of a dot appears, such as Fig.10 As shown, in C#, the CircleScale value is controlled to dynamically change the size of the current dot. Since the dot changes are different, a conditional judgment module is required. Here, branch is used to judge different situations to simulate the actual dot situation, and then the CircleScale value is controlled in C#;

[0084] The principle of controlling the change of the sample by printing pressure is the same as the principle of back smearing, which mainly involves the changes of printing pressure and sample change, dot change and printing solid density. The printing solid density mainly selects the position where the image details change more. When the adjustment pressure is small, the print sample is not clear, the dark tone level is lost, and the printing dot is small. When the printing pressure is appropriate, the printed content is displayed normally, the light and dark tone level is normal, and the dot size is normal. When the printing pressure is too large, the dot is too large, the light tone level is lost, and the plate is blurred.

[0085] The change of ink content is achieved by replacing the sample picture in an array manner. The picture on the left side of the sample is a normal sample picture, and the picture on the right side of the sample changes with the change of ink amount: when the amount of water is less and the amount of ink is more, the image layers disappear and the bright tones are lost; when the amount of ink reaches the appropriate position, the sample picture is normal.

[0086] like Figure 2As shown, according to the above method, a printing press virtual assembly system can be established, which includes a basic cognitive module and a printing fault module. The basic cognitive module includes an equipment basic information display module, a basic theoretical knowledge learning module and a structure display and assembly module. The equipment basic information display module is used to display the equipment basic information, the basic theoretical knowledge learning module is used to display printing principles, common faults and operation and use information, the structure display and assembly module is used to display the automatic disassembly, function information introduction and assembly function of the main unit and part of the paper feeder of the PZ1740E offset printing press model, the printing fault module includes a printing paper feeding process animation module and a fault analysis unit, the printing paper feeding process animation module is used to display the paper feeding animation, and the fault analysis unit includes a back side smearing module, a paper wrinkle module and a printed sheet blur module.

[0087] The present invention provides a virtual assembly method for a printing press based on virtual simulation technology. The method uses three-dimensional modeling technology and image rendering technology to highly restore the PZ1740E sheet-fed offset printing press, and uses human-computer interaction technology and virtual assembly technology to realize the basic cognition, assembly and fault simulation functional modules of the system, thereby ensuring good interaction between the user and the virtual simulation offset printing press and vivid presentation of fault simulation. The method reasonably integrates some theoretical knowledge of printing, virtual assembly technology and fault simulation into the same system, which not only enables users to master relevant theoretical knowledge, but also allows the system to be used as a demonstration and exploration tool. Among them, the printing fault module can study the implementation and control methods of sample changes, dot changes and smudge mark changes, providing a new way of thinking for expanding the development and application content of the virtual assembly system.

[0088] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A printing press virtual assembly method based on virtual simulation technology, characterized in that: The steps include: Step 1: Build the PZ1740E offset printing machine model through 3DsMAX software; Step 2: Import the constructed PZ1740E offset printing machine model into Blender for paper feeding animation design; Step 3: Import the model and animation into Unity to implement the function; In step 2, the constructed PZ1740E offset printing machine model is imported into Blender for paper feeding animation design, specifically: The basic process of paper operation is designed as follows: the paper delivery nozzle sucks the paper, and the paper delivery teeth deliver the paper to the double-sheet detection position. The paper is driven forward by the line belt on the paper feeding table. After reaching the paper gauge for position adjustment, the paper delivery teeth are connected with the roller grippers. The roller grippers grip the paper. The paper rotates with the impression roller grippers and reaches the paper collection chain grippers. Then, the paper continues to move with the chain grippers. After reaching the paper collection table, the grippers are released and the paper reaches the paper collection table. Import the constructed PZ1740E offset printing machine model into Blender, and realize the cyclic animation of paper movement through displacement animation, rotation animation and deformation animation; In step 3, import the model and animation into Unity to implement the function, specifically: Import the PZ1740E offset printing machine model and the cyclic animation of paper running into Unity3D, and use Unity3D to design the main system interface, basic cognition module and printing fault module through the PZ1740E offset printing machine model and the cyclic animation of paper running. The basic cognition module includes an equipment basic information display module, a basic theoretical knowledge learning module and a structure display and assembly module. The equipment basic information display module is used to display equipment basic information, the basic theoretical knowledge learning module is used to display printing principles, common faults and operation information, the structure display and assembly module is used to display the automatic disassembly of the host and part of the structure of the paper feeder of the PZ1740E offset printing machine model, the function information introduction and assembly function, the printing fault module is used to display paper feeding animation and simulate fault analysis, and the main system interface is used to select modules; The printing fault module was designed by Unity3D through the PZ1740E offset printing machine model and the loop animation of paper running, specifically: The printing fault module includes a back smear module, a paper wrinkle module and a plate sticking module, which are respectively used to simulate the back smear, paper wrinkle and plate sticking faults in the printing paper feeding process animation. The back smear module realizes the transformation of the smear traces on the paper by applying URP in the sample state. A control bar is provided to adjust the spray powder amount and the drying agent content. The input variables are adjusted by the control bar to change the paper smear. The particle system of Unity3D is used to simulate the toner to realize the effect of spraying the printing anti-adhesive agent on the paper. A collider is added to the paper to make the toner particles collide with the paper to simulate the process of the toner falling on the paper. The paper wrinkle module represents uneven biting force by marking angles at the paper grippers of the PZ1740E offset printing machine model, and eliminates paper wrinkles by replacing image resources; The paste plate module adjusts the printing dots and the sample changes according to the printing pressure changes and adjusts the sample changes according to the ink content, wherein the dot changes are implemented by creating a shader through the graphics rendering technology. Specifically, in the process of implementing the dot changes, UV information is first obtained, and then TillingAndOffset is used to implement the offset. The U direction value and the V direction value are separated through the split node. After the values ​​in the two directions are processed separately, they are merged to form a new UV value. The fraction method is used to take the decimal part of the merged new UV value, so that it changes between 0-1; A prototype is dynamically generated through the Ellipse method of UnityShaderGraph, and the size of the prototype is dynamically adjusted by exposing parameters. The prototype appears as a dot, and then the merged UV value is input into the UV node of the prototype; the value of CircleScale is controlled in C# to dynamically change the size of the current dot, and branch is used to judge different situations to simulate the dot situation in reality; The principle of controlling the change of the sample by printing pressure is the same as that of the back smearing, which is achieved through the changes of printing pressure, sample change, dot change, and printing solid density. The printing solid density is to select the position where the image details change more. When the adjustment pressure is small, the print sample is unclear, the dark tone level is lost, and the printing dot is small. When the printing pressure is appropriate, the printed content is displayed normally, the light and dark tone levels are normal, and the dot size is normal. When the printing pressure is too high, the dot is too large, the light tone level is lost, and the plate is blurred. The change of ink content is achieved by replacing the sample picture in an array manner; the picture on the left side of the sample is a normal sample picture, and the picture on the right side of the sample changes with the change of ink volume: when the amount of water is less and the amount of ink is more, the image layers disappear and the bright tones are lost; when the amount of ink reaches the appropriate position, the sample picture is normal; The basic information display module of the equipment is designed by using Unity3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically: The basic information display module of the equipment is designed by using Unity3D through the PZ1740E offset printing machine model and the circular animation of paper running. The PZ1740E offset printing machine model in the basic information display module can be rotated and zoomed in and out by the mouse, so that the user can view the relevant structural position of the PZ1740E offset printing machine model. Through the PZ1740E offset printing machine model and the looping animation of paper running, Unity3D is used to design basic theoretical knowledge learning modules, specifically: Collect open PZ1740E offset printing machine video resources and play them through VideoPlayer. Create component buttons in the playback scene and write scripts. Define parameters to obtain video components and RawImage components, declare playback components, determine whether to mute, set the logic of pausing video playback, and increase or decrease volume logic. The playlist specifies the target video by setting the video index parameter.

2. The printing press virtual assembly method based on virtual simulation technology according to claim 1 is characterized in that: In step 1, the PZ1740E offset printing machine model is constructed using 3DsMAX software, specifically: The actual machine data of PZ1740E offset printing machine was tested to obtain the test data. A hierarchical relationship model was established according to the PZ1740E offset printing machine. The hierarchical relationship model was used to analyze whether the PZ1740E offset printing machine had the same part geometry model, assembly feature information and interaction features. The relevant structure modeling was carried out in 3DsMAX software according to the test data and the hierarchical relationship model. The transformation operations of model vertices, line segments and faces were realized through polygonal modeling. The material properties of the PZ1740E offset printing machine were restored through mapping, rendering and material ball methods. According to the hierarchical relationship model, group structure modeling-group component detail modeling-group modeling was used to model the next sub-assembly after group modeling was completed. The sub-assemblies were integrated to construct the PZ1740E offset printing machine model.

3. The printing press virtual assembly method based on virtual simulation technology according to claim 1 is characterized in that: The main system interface is designed using Unity3D through the PZ1740E offset printing machine model and the looping animation of paper running, specifically: The main system interface is implemented using UGUI and is provided with five options, namely, cognitive machine module, theoretical knowledge learning, structural cognitive module, printing fault module and exit system. Among them, the option of the cognitive machine module corresponds to the equipment basic information display module, the option of the theoretical knowledge learning corresponds to the basic theoretical knowledge learning module, the option of the structural cognitive module corresponds to the structural display and assembly module, the option of the printing fault module corresponds to the printing fault module. By clicking on different options with the mouse, you can enter the corresponding functional scene, and by listening to the OnClick behavior in the Insparent panel and assigning a value to nextScene, you can jump to the specified scene.

4. The printing press virtual assembly method based on virtual simulation technology according to claim 1 is characterized in that: The PZ1740E offset printing machine model and the paper running loop animation were used to design the structure display and assembly module using Unity3D, specifically: The structure display and assembly module divides the PZ1740E offset press model into a printing host and a paper feeder, and is equipped with functions of structure information visualization, display and hidden assembly, and automatic disassembly and assembly; The target object of the structural information visualization function is each sub-assembly. A collision body is added to each sub-assembly, and the content is displayed using the GUI. Then, the interaction between the mouse and the assembly is judged by monitoring the mouse OnMouseEnter, OnMouseExit, and OnMouseDown events, which is used to display the main information of each sub-assembly. The display and hide assembly function obtains all objects and related buttons in the scene by listening to mouse click events, and displays and hides each sub-assembly through HideObj and DisplayObj events according to the Tag attribute classification corresponding to the object; The automatic disassembly and assembly function is aimed at the printing host and paper feeder of the PZ1740E offset printing machine model, which is realized by setting key points and key frames in Animation and moving the relative position of the target object model.

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