Three-dimensional truss structure multi-axis slicing path design and printing manufacturing method

Abstract

The present application relates to a kind of three-dimensional truss structure multi-axis slice path design and printing manufacturing method, comprising the following steps: setting multi-axis 3D printing equipment and parameter;Face multi-axis 3D printing, sequentially carry out the slice layering of three-dimensional truss structure, path filling and control code generation;Selected model is virtually simulated, and multi-axis 3D printing manufacturing is carried out using printing path.The beneficial effects of the present application are: by triangle intersection algorithm, the intersection of each partition printing plane and structure unit is quickly and efficiently solved, and slice layer is generated layer by layer;By zigzag pattern path mode, the internal printing path of each layer printing path contour layer is effectively filled, continuous slice path is generated, and the force path is clear and understandable;The generated printing path is converted into control code, and the precise control of robot movement is realized using segmented straight line motion mode, the precise and rapid multi-axis 3D printing of complex three-dimensional truss structure is realized, and the printing efficiency is significantly improved.

Description

Technical Field

[0001] This invention belongs to the fields of structural engineering and additive manufacturing technology, and particularly relates to a method for designing and printing a multi-axis slice path for a three-dimensional rod structure. Background Technology

[0002] With the continuous development of 3D printing technology, multi-axis 3D printing has attracted widespread attention due to its ability to print complex and intricate structures. Multi-axis 3D printing requires structural slicing and layering, as well as path design. Compared to general three-axis 3D printing technology, the operation and programming of slicing, layering, and path design in multi-axis 3D printing are more complex and are still under continuous development.

[0003] To fully leverage the advantages of 3D truss structure optimization design for multi-axis 3D printing, a matching multi-axis structure slicing method was developed based on the optimized printing surface to achieve printing path design, providing new ideas and methods for the integration of multi-axis 3D printing manufacturing technology and 3D truss structure optimization technology.

[0004] In the process of studying the design and printing manufacturing method of multi-axis slicing path for three-dimensional rod structures, there are three main problems: 1) how to set the corresponding multi-axis 3D printing equipment and parameters; 2) how to perform multi-axis structure slicing layering, path filling and control code generation; 3) how to perform virtual simulation and multi-axis 3D printing manufacturing.

[0005] In summary, it is essential to study a multi-axis slicing path design and printing manufacturing method for three-dimensional rod structures. This method significantly reduces costs while considering multi-axis slicing path design, and enables multi-axis slicing layering, path planning design, control code generation, virtual simulation, and 3D printing manufacturing of complex three-dimensional rod structures. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for designing and printing a multi-axis slice path for a three-dimensional rod structure.

[0007] This method for designing and printing multi-axis slicing paths of three-dimensional rod structures includes the following steps:

[0008] S1. Set up the multi-axis 3D printing equipment and parameters;

[0009] S2. For multi-axis 3D printing, the three-dimensional rod structure is sliced ​​and layered, the path is filled and the control code is generated in sequence.

[0010] S2.1 Slicing and Layering: The three-dimensional rod structure model is sliced ​​and layered. The intersection of the printing plane of each partition and the structural model unit is calculated by computational geometry method, and slice layers are generated layer by layer as printing path contour layers.

[0011] S2.2 Path Fill: Select the print nozzle path method to fill the inner print path of each print path outline layer. Set the fill path spacing a and the fill indentation length b to generate a continuous print path.

[0012] S2.3 Control Code Generation: Convert the generated print path into control code;

[0013] S3. Perform virtual simulation on the selected model and apply the printing path to perform multi-axis 3D printing manufacturing.

[0014] Preferably, in step S1, the multi-axis 3D printing equipment includes a robotic arm, printing filament, printing nozzle, printing platform, and teach pendant; the robotic arm integrates a filament feeding and heating system, and the printing nozzle is located at the end of the robotic arm for extruding the printing filament; the printing platform provides rotational and flipping degrees of freedom, and the printing platform has a rotation axis and a flipping axis, the rotation range of the rotation axis is infinite angle, and the rotation range of the flipping axis is ±120°.

[0015] Preferably, before multi-axis 3D printing, the printing path is programmed and debugged using a teach pendant; during multi-axis 3D printing, the control code is executed using the teach pendant to implement 3D printing, the printing process is monitored in real time, and the movement trajectory and printing parameters of the robotic arm are adjusted in real time using the teach pendant.

[0016] Preferably, in step S2.1, the result information of the three-dimensional rod system optimization structure is obtained through the optimization algorithm, including the printing direction of each partition and the boundary coordinates of the partition; the intersection of the printing plane of each partition and the structural unit is solved by the triangle intersection algorithm, and the slicing layer is generated layer by layer; during the slicing process, the three-dimensional rod system structure model is decomposed into a series of two-dimensional layers, each layer corresponding to a structural cross section in the printing manufacturing process.

[0017] Preferably, in step S2.2, a sawtooth pattern, unidirectional path, or spiral path is selected to fill the printing path inside the cross-sectional outline of each structural section; the filling path spacing a and the filling indentation length b are set; and the printing process of the next section is started after two consecutive printing layers are printed in each partition.

[0018] Preferably, in step S2.3, control code is written based on the generated printing path; the control code is used for task execution, path planning and interaction with external systems; during the writing of the control code, linear interpolation instructions are used to control the printing nozzle to perform segmented linear motion, the segmented linear motion of the printing nozzle includes filament feeding motion and non-filament feeding motion, and the speed of the filament feeding motion is less than that of the non-filament feeding motion.

[0019] Throughout the printing process, the movement pattern of the print nozzle is as follows: start the filament feeding motion → lift upward after the filament feeding ends → move to above the next filament feeding point → move downward to the filament feeding point → restart the filament feeding motion → repeat the above process.

[0020] Preferably, in step S3, a geometric model of the printing nozzle is established in the virtual simulation software, and the printing path is converted into the corresponding control code of the software; the control code includes the setting of process parameters, the selection of the coordinate system of the printed workpiece and the absolute coordinates; the simulation module is started, and the movement of the printing nozzle is controlled according to the control code, and the relative position of the printing nozzle and the printed workpiece is monitored in real time.

[0021] As a preferred method, before multi-axis 3D printing, the control code file is uploaded to the robot arm's controller in the robot arm programming and configuration software; the control code is tested and debugged in the manual slow-speed running mode of the teach pendant to check the heating, filament feeding and movement; during multi-axis 3D printing, the control code file is started through the teach pendant, and the robot arm is controlled to perform precise movements according to the program instructions, and the printing process status is monitored in real time.

[0022] In multi-axis 3D printing manufacturing, different printing zones and different printing directions are used to optimize the curved printing surface, enabling multi-axis 3D printing without additional support structures and without collisions.

[0023] The beneficial effects of this invention are:

[0024] 1) The multi-axis slicing path design and printing manufacturing method for three-dimensional rod structures provided by this invention quickly and efficiently solves the intersection of the printing plane and structural unit of each partition through the triangle intersection algorithm, and generates slicing layers layer by layer; through the zigzag pattern path method, the internal printing path of each printing path contour layer is effectively filled to generate continuous slicing paths with clear force paths; the generated printing paths are converted into control codes, and the segmented linear motion mode is used to achieve precise control of robot motion, realizing accurate and rapid multi-axis 3D printing of complex three-dimensional rod structures, and significantly improving printing efficiency.

[0025] 2) The multi-axis slicing path design and printing manufacturing method for three-dimensional truss structures provided by this invention solves the collision problem in the printing process through virtual simulation; it realizes the multi-axis 3D printing manufacturing of complex three-dimensional truss structures through multi-axis 3D printing equipment; the printing process does not require additional support, saving material costs and printing time, and realizing the integrated molding design of unsupported trusses. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the multi-axis slicing path design and printing manufacturing method for the three-dimensional rod structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the multi-axis 3D printing equipment in step S1;

[0028] Figure 3 This is a schematic diagram of the printing surface of each layer of the multi-axis structure slicing and layering in step S2.1;

[0029] Figure 4 This is a schematic diagram of the local slice printing path for the multi-axis structure slice layering in step S2.1;

[0030] Figure 5 This is a schematic diagram of the path filling for multi-axis structure path filling in step S2.2;

[0031] Figure 6 This is a schematic diagram of virtual simulation of a selected model;

[0032] Figure 7 This is a schematic diagram of a three-dimensional rod structure manufactured by multi-axis 3D printing.

[0033] Explanation of reference numerals in the attached diagram: 1. Robotic arm; 2. Printing nozzle; 3. Teach pendant; 4. Printing platform; 5. Printing filament; 6. Structural cross-section; 7. Cross-sectional profile; 8. Printing path. Detailed Implementation

[0034] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0035] Example 1

[0036] As one embodiment, this method for designing and printing three-dimensional rod structures using multi-axis slicing paths, such as... Figure 1 As shown, it includes the following steps:

[0037] S1, Multi-axis 3D printing equipment and parameter settings, such as Figure 2 As shown: A three-dimensional rod structure is printed using a multi-axis 3D printing equipment. The filament feeding and heating system is integrated into the robotic arm 1. The printing filament 5 is extruded through the printing nozzle 2. The printing platform 4 is set with rotation and flipping degrees of freedom.

[0038] A multi-axis 3D printing equipment is used to print and manufacture a three-dimensional rod structure. The multi-axis 3D printing equipment consists of a robotic arm 1, printing filament 5, printing nozzle 2, printing platform 4 and teach pendant 3. The printing nozzle 2 is located at the end of the robotic arm 1.

[0039] In the multi-axis 3D printing equipment, the filament feeding and heating system is integrated into the robotic arm 1, and the printing filament 5 is extruded through the printing nozzle 2; the printing platform 4 provides rotation and flipping degrees of freedom, the rotation range of the rotation axis is infinite angle, and the rotation range of the flipping axis is ±120°; in this embodiment, the radius of the printing platform 4 is 200mm, and the distance from the surface of the printing platform 4 to the flipping axis is 170mm.

[0040] The robotic arm 1 and printing platform 4 are controlled by the teach pendant 3 for printing. Before multi-axis 3D printing, the printing path is programmed and debugged by the teach pendant 3. During the multi-axis 3D printing process, the teach pendant 3 executes control to implement 3D printing, monitors the printing process in real time, and allows the operator to adjust the robot's motion trajectory and printing parameters in real time to ensure the smooth printing process.

[0041] S2, Multi-axis Structure Slicing, Path and Code Generation: For multi-axis 3D printing, the 3D rod structure is sliced ​​and layered, the path is filled and the control code is generated in sequence.

[0042] Step S2.1, Multi-axis structural slicing and layering: Based on the node coordinates and cross-sectional area information of the three-dimensional rod structure, an STL format structural model is generated. The STL format structural model is sliced ​​and layered using programming software. The intersection of the printing plane of each partition and the structural model unit is calculated using computational geometry methods, and slice layers are generated layer by layer.

[0043] Step S2.2, Multi-axis structural path filling: Select the zigzag pattern path method to fill the printing path 8 inside the cross-sectional outline 7 of each layer of structural section 6. Set the filling path spacing a and filling indentation length b of the printing path 8 to generate a series of continuous printing paths 8. Each line segment represents the trajectory that the printing nozzle 2 needs to print in this layer.

[0044] Step S2.3, Multi-axis structure control code generation: The generated printing path 8 is converted into control code to achieve precise control of the movement of the robotic arm 1 and the printing nozzle 2. The main mode is segmented linear motion, including filament feeding motion and non-filament feeding motion.

[0045] S3, Virtual Simulation and Multi-Axis 3D Printing Manufacturing: Includes virtual simulation and multi-axis 3D printing manufacturing;

[0046] Step S3.1, Virtual simulation: Perform virtual simulation on the selected model to check for collisions during the printing process. Control the movement of the virtual printing nozzle 2 according to the control code and monitor the relative position of the printing nozzle 2 and the workpiece in real time.

[0047] Step S3.2, Multi-axis 3D printing manufacturing: Start the control code file on the teach pendant 3. The robotic arm 1 will perform precise motion control according to the program instructions and apply the printing path 8 to the actual multi-axis 3D printing manufacturing process.

[0048] Example 2

[0049] As another embodiment, this embodiment two proposes, based on embodiment one, a more specific method for designing and printing a multi-axis slicing path of a three-dimensional rod structure. Step two specifically includes:

[0050] like Figure 3 , Figure 4 As shown, in step S2.1:

[0051] In the 3D modeling software Rhino, an STL format structural model is generated based on the node coordinates and cross-sectional area of ​​the members of the 3D rod system optimization structure. Rhino software can create complex geometric shapes with high precision, providing an accurate basic model for the generation of the printing path 8 in step S2.2.

[0052] The STL format structural model is sliced ​​and layered using the programming software MATLAB. The specific steps are as follows: 1) Based on Python software, the result information of the three-dimensional truss structure optimization obtained by the Python optimization algorithm is read from the JSON file, including the printing direction of each partition and the boundary coordinates of the partition; 2) In MATLAB software, computational geometry methods such as the triangle intersection algorithm are used to solve the intersection of the printing plane of each partition with the STL format structural unit, and slice layers are generated layer by layer; 3) During the slicing process, the three-dimensional truss structure model is decomposed into a series of two-dimensional layers, each layer corresponding to a structural section 6 in the printing manufacturing process; In this embodiment, the three-dimensional truss structure model is sliced ​​and layered according to the optimized printing plane to generate the structural section 6 and section profile 7 of the printing layer, and the printing layer height of each layer is set to 0.4mm.

[0053] like Figure 5 As shown, in step S2.2: fill the printing path 8 inside the cross-sectional outline 7 of each structural section 6.

[0054] The zigzag pattern is selected to fill the internal printing path 8 of each layer. The zigzag pattern filling method can provide good structural strength and material utilization. The filling path spacing 'a' is set to ensure sufficient density and strength. The filling indentation length is set to avoid printing defects caused by material overflow during the printing process, so as to ensure that the internal structure of the printed model is uniform and stable. In order to improve printing efficiency without affecting the printing effect, the printing process of the next partition is started after printing two printing layers consecutively in each partition. In this embodiment, the filling path spacing 'a' is 0.4 mm and the filling indentation length 'b' is 0.1 mm.

[0055] In addition to the zigzag pattern path fill method, unidirectional path fill, spiral path fill, and other methods can also be used;

[0056] Through steps S2.1 and S2.2, a series of continuous slicing paths can be generated, each line segment representing the trajectory that the printing nozzle 2 needs to print in this layer; the generated slicing paths can accurately guide the multi-axis 3D printing equipment to print, so as to ensure that the printed three-dimensional rod structure model has good geometric accuracy and structural performance.

[0057] In step S2.3:

[0058] To meet the control requirements of robotic arm 1, the generated printing path 8 needs to be converted into control code. Control code is a programming language developed for industrial robots, which can realize precise control of robot motion, including task execution, path planning, and interaction with external systems. Commonly used motion control instructions in control code include PTP (point-to-point motion), LIN (linear interpolation), or CIRC (circular interpolation).

[0059] To achieve efficient and accurate 3D printing, the generated printing path 8 mainly adopts a segmented linear motion mode. When writing the control code, the LIN (linear interpolation) instruction is mainly used to enable the robotic arm 1 to move from one point to another along the straight path, thereby ensuring the continuity and smoothness of the printing path 8 and improving the printing quality.

[0060] In the control code, attention should be paid to the filament feeding motion and non-filament feeding motion of the printing nozzle 2; throughout the printing process, the basic motion pattern of the printing nozzle 2 is: start filament feeding motion → lift up after filament feeding ends → move to above the next filament feeding point → move down to the filament feeding point → start filament feeding motion again → repeat the above process;

[0061] To improve printing efficiency, different moving speeds of the printing nozzle 2 can be set for filament feeding and non-filament feeding scenarios. During filament feeding, a relatively small moving speed of the printing nozzle 2 is set to consider stable material extrusion, printing accuracy, and heat dissipation. After filament feeding, a relatively large moving speed of the printing nozzle 2 is set to shorten the time it takes for the printing nozzle 2 to move to the next filament feeding point. To quickly position the nozzle 2 to the next filament feeding point, a relatively large moving speed of the printing nozzle 2 is set to move downwards to the filament feeding point. In this embodiment, the moving speed of the printing nozzle 2 during filament feeding is 20 mm / s, the moving speed of the printing nozzle 2 after filament feeding is 50 mm / s, and the moving speed of the printing nozzle 2 to quickly position to the next filament feeding point is 100 mm / s. Through differentiated speed settings, both printing quality and printing efficiency are ensured.

[0062] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0063] Example 3

[0064] As another embodiment, this embodiment two proposes, based on embodiment one, a more specific method for designing and printing a multi-axis slicing path of a three-dimensional rod structure. Step three specifically includes:

[0065] like Figure 6 As shown, step S3.1, virtual simulation: To ensure the accuracy and safety of the multi-axis 3D printing process, virtual simulation software is used to perform virtual simulation and verification on the selected model to check whether the model will experience printing collisions during the printing process and whether it can be successfully formed; in this embodiment, the virtual simulation software is Vericut.

[0066] To ensure that the movement range of the printing nozzle 2 during the simulation matches the actual situation, a corresponding geometric model is established in the virtual simulation software based on the size of the heating nozzle in the actual multi-axis 3D printing system. The printing path 8 of the generated geometric model is converted into control code, which is then input into an MPF ​​format printing file for the software to read. The control code includes settings for parameters such as printing speed, and selection of the workpiece coordinate system and the absolute coordinate system. In this embodiment, the virtual simulation software is Vericut, the corresponding control code for Vericut software is G-code, the workpiece coordinate system is G54, and the absolute coordinate system is G90.

[0067] In the virtual simulation software, start the simulation process and control the movement of the virtual printing nozzle 2 according to the input control code. In the virtual simulation, the relative position of the printing nozzle 2 and the workpiece can be monitored in real time to ensure that no collision occurs during the printing process.

[0068] like Figure 7As shown, step S3.2, multi-axis 3D printing manufacturing: After virtual simulation verification, printing path 8 is applied to actual multi-axis 3D printing manufacturing; before starting printing, the controller of robotic arm 1 is connected via Ethernet or other interfaces, and communication settings are configured in the programming and configuration software of robotic arm 1 to ensure that the software can communicate normally with the controller of robotic arm 1; subsequently, the control code file is uploaded to the controller of robotic arm 1 through the programming and configuration software; before robotic arm 1 performs actual printing, the control code also needs to be fully tested and debugged using manual slow-speed running mode to ensure that the program heats, feeds filament and moves as expected, and avoids accidents such as collisions. In this embodiment, the programming and configuration software of robotic arm 1 is WorkVisual or RobotStudio, and the manual slow-speed running mode is T1 mode.

[0069] After the above preparations are completed, multi-axis 3D printing begins. The control code file is started on the teach pendant 3, and the robotic arm 1 will perform precise motion control according to the program instructions. During the printing process, the printing status is continuously monitored in real time to ensure that the robotic arm 1 prints according to the predetermined path and to promptly detect and handle any abnormalities. During the multi-axis 3D printing process, different printing partitions and different printing directions are used to optimize the curved printing surface, eliminating the need for additional support structures and preventing collisions.

[0070] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiments 1 and 2 can be referred to each other, and will not be repeated in this application.

[0071] Example 4

[0072] As another embodiment, this embodiment four proposes a more specific method for designing and printing a multi-axis slice path for a three-dimensional rod structure, based on embodiments one to three.

[0073] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

Claims

1. A method for designing and printing a multi-axis slicing path of a three-dimensional rod structure, characterized in that, Includes the following steps: S1. Set up the multi-axis 3D printing equipment and parameters; S2. For multi-axis 3D printing, the three-dimensional rod structure is sliced ​​and layered, the path is filled and the control code is generated in sequence. S2.1 Slicing and Layering: The three-dimensional rod structure model is sliced ​​and layered. The intersection of the printing plane of each partition and the structural model unit is calculated by computational geometry method, and slice layers are generated layer by layer as printing path contour layers. S2.2 Path Fill: Select the print nozzle path method to fill the internal print path of each print path outline layer. Set the fill path spacing 'a' and the fill indentation length 'b' to generate a continuous print path; S2.3 Control Code Generation: Convert the generated print path into control code; S3. Perform virtual simulation on the selected model and apply the printing path to manufacture multi-axis 3D printing. In step S1, the multi-axis 3D printing equipment includes a robotic arm, printing filament, printing nozzle, printing platform, and teach pendant; the robotic arm integrates a filament feeding and heating system, and the printing nozzle is located at the end of the robotic arm for extruding the printing filament; the printing platform provides rotational and flipping degrees of freedom, and the printing platform has a rotation axis and a flipping axis, the rotation range of the rotation axis is infinite angle, and the rotation range of the flipping axis is ±120°; Before multi-axis 3D printing, the printing path is programmed and debugged using a teach pendant; during multi-axis 3D printing, the control code is executed through the teach pendant to implement 3D printing, the printing process is monitored in real time, and the movement trajectory and printing parameters of the robotic arm are adjusted in real time through the teach pendant. In step S2.1, the result information of the three-dimensional rod system optimization structure is obtained through the optimization algorithm, including the printing direction of each partition and the partition boundary coordinates; the intersection of the printing plane of each partition and the structural unit is solved by the triangle intersection algorithm, and the slice layer is generated layer by layer. During the slicing process, the three-dimensional rod structure model is decomposed into a series of two-dimensional layers, each layer corresponding to a structural cross section in the printing and manufacturing process; In step S2.2, the printed path teach pendant inside the cross-sectional profile teach pendant of each layer of structure is filled by selecting a zigzag pattern, a one-way path, or a spiral path fill method. Set the fill path spacing 'a' and fill indentation length 'b' for the print path teach pendant, and set the print path to print two consecutive print layers for each partition before starting the print process for the next partition.

2. The method for designing and printing manufacturing multi-axis slice paths of a three-dimensional rod structure according to claim 1, characterized in that, In step S2.3, control code is written based on the generated printing path. The control code is used for task execution, path planning, and interaction with external systems. During the writing of the control code, linear interpolation instructions are used to control the printing nozzle to perform segmented linear motion. The segmented linear motion of the printing nozzle includes filament feeding motion and non-filament feeding motion, and the speed of the filament feeding motion is less than that of the non-filament feeding motion. Throughout the printing process, the movement pattern of the print nozzle is as follows: start the filament feeding motion → lift upward after the filament feeding ends → move to above the next filament feeding point → move downward to the filament feeding point → restart the filament feeding motion → repeat the above process.

3. The method for designing and printing manufacturing multi-axis slice paths of a three-dimensional rod structure according to claim 1, characterized in that, In step S3, a geometric model of the printing nozzle is established in the virtual simulation software, and the printing path is converted into the corresponding control code of the software; the control code includes the setting of process parameters, the selection of the coordinate system of the printed workpiece and the absolute coordinates; The simulation module is activated, and the movement of the printing nozzle is controlled according to the control code, while the relative position of the printing nozzle and the printed workpiece is monitored in real time.

4. The method for designing and printing manufacturing multi-axis slice paths of a three-dimensional rod structure according to claim 1, characterized in that, Before multi-axis 3D printing, the control code file is uploaded to the robot arm's controller in the robot arm programming and configuration software; the control code is tested and debugged in the manual slow-speed running mode of the teach pendant to check the heating, filament feeding and movement; during the multi-axis 3D printing process, the control code file is started through the teach pendant, and the robot arm is controlled to perform precise movements according to the program instructions, and the printing process status is monitored in real time. In multi-axis 3D printing manufacturing, different printing zones and different printing directions are used to optimize the curved printing surface, enabling multi-axis 3D printing without additional support structures and without collisions.

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