A large-scale printing method based on a crawling printer robot

Abstract

The application discloses a large-range printing method based on a crawling printer robot, and comprises the following steps: dividing a square space where a 3D slice of a part to be printed and a support are considered into a plurality of square block regions with the same size, wherein the square block regions comprise a hole region and a non-hole region; for a hole region of a certain layer, the robot moves by combining a coordinate system positioning mode with a visual recognition mode, fills the circular shallow pits passed on a printing path, prints a next layer region of an initial position, and until the printing of the current layer is completed; when the crawling printing robot is interfered during the printing of the current layer, the crawling printing robot is automatically lifted to a new layer and the vacancy part on the current layer is completed; the above steps are repeated until the printing of all the hole regions is completed; and according to a path planning logic of the printing of each layer of the hole region, the printing of the non-hole region is completed. The application realizes large-range printing without range limitation by using a small device, and ensures the printing precision.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a large-scale printing method based on a crawling printing robot. Background Technology

[0002] 3D printing has become a popular additive manufacturing method due to its simple operation, good economy, and low pollution. After years of development, 3D printing technology has basically formed a system. However, there are still many methodological problems and defects under this system. For example, the printing range of typical 3D printing methods is small and the printing area is fixed. It is limited by the movement range of the printing nozzle, making it difficult to print large-scale models.

[0003] If you want to print a large document that exceeds the printer's capacity, the main existing solutions include:

[0004] 1) By increasing the print head's travel range, a large printer matching the size of the part can be manufactured for printing. However, this solution has extremely high manufacturing costs and poor economic efficiency. Furthermore, after expanding the printing range, the precision of the parts decreases under the condition that the relative error remains unchanged.

[0005] 2) Multiple robotic arms fixed at points in the XY plane move to the top of the part for collaborative printing. However, the printing range in the XY plane is limited by the radius of the robotic arm's movable range in this direction. Furthermore, the height of the part is also limited by the robotic arm's movable range in the Z-axis direction. This only expands the printing range and cannot achieve unlimited printing.

[0006] Other solutions also cannot solve the limitations mentioned above, including poor cost-effectiveness, limited printing range, and limited printing height. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention proposes a large-scale printing method based on a crawling printing robot. This method is a 3D printing method that allows for simultaneous, unrestricted printing along the X, Y, and Z coordinate axes, enabling a single printer to print actual sizes far exceeding the printer's dimensions.

[0008] The specific technical solution is as follows:

[0009] A method for large-scale printing based on a crawling printing robot includes the following steps:

[0010] S1: Divide the square space where the 3D slice of the part to be printed is located into an array of square regions of the same size;

[0011] The block area includes a perforated area and a non-perforated area. The perforated area can safely accommodate a circular shallow pit and is not a surface block. The non-perforated area cannot safely accommodate a circular shallow pit or is a surface block. The circular shallow pit is located at the top center of the perforated area and its size is adapted to the size of the bottom surface of the mechanical foot of the crawling printing robot.

[0012] S2: For a certain layer with holes, the crawling printing robot positions itself at the initial position through the circular shallow pits, and fills the circular shallow pits along the printing path by combining coordinate system positioning and visual recognition, and prints the next layer area at the initial position.

[0013] S3: The crawling printing robot moves to the next group of perforated areas by combining coordinate system positioning and visual recognition, and repeats step S2 until the printing of the current layer is completed; when the crawling printing robot interferes with the printing of the current layer, the crawling printing robot autonomously lifts to a new layer and fills in the missing parts on the current layer to complete the printing of the current layer.

[0014] S4: Repeat steps S2 and S3 until all perforated areas are printed;

[0015] S5: Based on the path planning logic for printing each layer of the perforated area, complete the printing of the non-perforated area.

[0016] Furthermore, in step S1, the specific method of segmentation is as follows: using a spatial coordinate system as a reference, an array plane is used to segment the square space involved in printing, thereby dividing the square space into an array combination containing multiple square regions of the same size; wherein, the array plane includes three sets of mutually perpendicular plane groups, and in each plane group, the planes are parallel to each other and equidistant.

[0017] Furthermore, in step S3, the perforated area of ​​the current layer is divided into a connected region containing at least one perforated area based on connectivity, and the perforated areas of each connected region are printed according to the S-shaped printing sequence; for printing between different connected regions, the crawling printing robot crawls to another connected region according to the circular shallow pit and then prints.

[0018] Furthermore, in step S5, for a holeless area with fixed X and Y coordinates, the printing of all holeless areas in the Z direction under that coordinate is completed at once.

[0019] Furthermore, when printing the perforated areas of the bottom layer, a heated bed chassis with an array of circular patterns, having the same region segmentation parameters, is placed on the horizontal surface to provide the initial working environment for the crawling printing robot.

[0020] Furthermore, the crawling printing robot includes: a visual recognition mechanism, a printing nozzle, a three-degree-of-freedom robotic arm, and a quadrupedal mobile chassis; the quadrupedal mobile chassis includes a chassis and four foot linkage mechanisms; the top of each foot linkage mechanism is fixedly connected to the chassis, and a motor individually controls and drives the lifting, rotation, and translation of each foot linkage mechanism; the bottom of each foot linkage mechanism is fitted with a rubber pad, the shape and size of which are the same as the circular shallow pit in the perforated area;

[0021] The base of the three-degree-of-freedom robotic arm is fixed to the upper surface of the four-legged mobile chassis, and the end effector of the three-degree-of-freedom robotic arm is fixed to an end effector platform; the vision recognition mechanism includes a camera, which is fixed to the end effector platform, and the camera sends the collected information to the main control board for machine vision recognition via a data cable; the print head is fixed to the end effector platform, and during the printing process, molten printing filament is extruded from the print head nozzle by heating the printing material and the filament feeding structure.

[0022] The beneficial effects of this invention are:

[0023] (1) Based on a large-scale crawling printing robot, this invention realizes large-scale printing without range limitations, solving the problem that current technical solutions can only expand the range, but the actual printing range is still limited by the printing mechanism.

[0024] (2) The present invention uses a crawling printing robot whose actual size is much smaller than the size of the part to be printed. It can achieve large-scale printing with only smaller equipment, which has better economy and practicality.

[0025] (3) This invention can print parts whose actual printing size is much larger than the size of the robot. By developing multi-robot collaborative printing and researching ways to lighten and reduce the size of printing robots, high-precision and high-speed printing of parts can be achieved. Attached Figure Description

[0026] Figure 1 This is a flowchart of the method of the present invention.

[0027] Figure 2 This is a flowchart of the underlying printing process of this invention.

[0028] Figure 3 This is a flowchart of the process for printing the perforated area in the intermediate layer according to the present invention.

[0029] Figure 4 This is a flowchart of the hole-free area printing process of the present invention.

[0030] Figure 5 This is a schematic diagram of the crawling printing robot structure used in this invention.

[0031] Figure 6This is a schematic diagram of a square pyramid to be printed in an embodiment of the present invention.

[0032] Figure 7 This is a schematic diagram of the model obtained after dividing the square pyramid into regions in an embodiment of the present invention.

[0033] Figure 8 This is a schematic diagram of the printed bottom layer of a square pyramid in an embodiment of the present invention.

[0034] Figure 9 This is a schematic diagram of the model after the square pyramid with the hole area has been printed in an embodiment of the present invention.

[0035] In the figure, there are: visual recognition mechanism 1, printing nozzle 2, three-degree-of-freedom robotic arm 3, end effector platform 3a, copper column 3b, quadrupedal mobile chassis 4, and rubber pad 4a. Detailed Implementation

[0036] The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The objectives and effects of the present invention will become clearer as a result. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0037] like Figure 1 As shown, the large-scale printing method based on a crawling printing robot specifically includes the following steps:

[0038] S1: Divide the square space where the 3D slice of the part to be printed is located into an array of square regions of the same size.

[0039] The specific method for dividing a square space into square regions of the same size is as follows: using a spatial coordinate system as a reference, an array plane is used to divide the square space involved in printing, thereby dividing the square space into an array combination containing multiple square regions of the same size; wherein, the array plane includes three sets of mutually perpendicular plane groups, and in each plane group, the planes are parallel to each other and equidistant.

[0040] For each square area containing the actual printing area, the square area is divided into a perforated area and a non-perforated area based on whether it can completely accommodate the circular shallow pit and whether it is located on the surface of the printed part. The circular shallow pit is located at the top center of the square area, and its size is adapted to the size of the bottom surface of the crawling printing robot's mechanical foot. The purpose of setting the circular shallow pit is: the robot's foot can precisely step into the pit, facilitating positioning and stable printing; and leaving a feature element for each area to facilitate machine vision recognition. Square areas where the actual printing area can safely accommodate the circular shallow pit and where the square area is not on the surface of the printed part are classified as perforated areas; the remaining square areas containing the actual printing area are classified as non-perforated areas. For square areas classified as perforated areas, a circular shallow pit is pre-reserved on their surface during printing to prepare for the next layer of printing.

[0041] The parts to be printed must meet the following conditions:

[0042] (1) The height difference between the top holes of any four adjacent areas in the top view (when the four legs of the crawling printing robot are located in the four adjacent square areas) must be less than the adjustable range of the height of the crawling printing robot's legs. If this condition is not met, it can be met by adjusting the placement of the model to be printed and / or manually adding a small amount of support.

[0043] (2) When the part to be printed has a cantilever structure that requires additional support, the support should be arranged according to condition (1).

[0044] like Figure 2 As shown, print the bottom layer.

[0045] S2: A heated bed chassis with an array of circular patterns, identical to the region segmentation parameters, is placed on a horizontal surface to provide the initial working environment for the crawling printing robot. Initially, the crawling printing robot positions itself on its four legs at the initial position, which is an array area with M*N circular patterns. The size of M*N depends on the specifications of the crawling robot. The initial position of the crawling printing robot is preferably at a corner of the entire bottom layer printing area to improve printing efficiency. The crawling printing robot fills the shallow circular pits along the printing path using a combination of coordinate system positioning and visual recognition, and prints the next layer area from the initial position.

[0046] S3: The crawling printing robot uses a combination of coordinate system positioning and visual recognition to move smoothly on all four legs to the next set of perforated areas on the printing path, fill the shallow circular pits it passes through on the printing path, and print the next layer of the area at that position.

[0047] S4: Repeat step S3 until the printing of the current layer (i.e., the bottom layer) is completed. When the crawling printing robot interferes with the printing of the current layer, that is, when only the area where the crawling printing robot is located is not printed in the printing area of ​​the layer, the crawling printing robot autonomously lifts to the new layer and prints the missing part on the current layer, thus completing the printing of the current layer.

[0048] When printing a certain layer (i.e., the Z-axis coordinate remains unchanged, only the X and Y-axis coordinates change), all perforated areas involved in this layer are printed. These perforated areas are then divided into connected regions containing at least one perforated area based on connectivity. The perforated areas within each connected region are printed according to an S-shaped printing sequence. Printing between different connected regions requires a crawling printing robot to move to another connected region based on pre-reserved hole positions before printing. For example, consider a series of square areas numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 arranged in a straight line. Areas 3, 5, and 6 are non-perforated areas, while the rest are perforated. Perforated areas 1 and 2 form one connected region, area 4 forms another, and areas 7, 8, 9, and 10 form yet another. During printing, the crawling printing robot prints perforated areas 1 and 2 sequentially, then moves to the next connected region to print perforated area 4, and then moves to the next connected region to print perforated areas 7, 8, 9, and 10.

[0049] S5: As Figure 3 As shown, the perforated areas of the printing intermediate layer are printed. The crawling printing robot plans its path according to the logic of the bottom layer printing and prints the perforated areas of each layer layer by layer. That is, for each intermediate layer, steps S3 and S4 are repeated until all perforated areas are printed. Since the intermediate layers are printed on top of the bottom layers and do not involve the heated bed chassis, the crawling printing robot is positioned on its four legs in the shallow circular pits at the four corners of the perforated areas of the M*N connected region.

[0050] S6: As Figure 4 As shown, the hole-free areas are printed. The crawling printing robot moves to the initial position and plans the path according to the underlying printing logic. For a fixed (X,Y) coordinate position, all hole-free areas in the Z direction under that coordinate are printed at once.

[0051] The crawling printing robot used in this invention can achieve the following functions by adjusting its robotic arms and legs: Generally, it stands upright in a shallow circular pit with a quadrupedal structure, and can perform basic functions including automatic displacement, positioning, printing, and lifting; it can stand stably within the perforated areas at the four corners of a connected region of M*N with a height difference not exceeding the adjustable range of the leg height; it can print areas at different heights in the front, back, left, and right directions of its designated block area, with the specific blocks to be printed depending on the specific situation. To achieve the above functions, a method is provided as follows... Figure 5The crawling printing robot shown includes: a visual recognition mechanism 1, a printing nozzle 2, a three-degree-of-freedom robotic arm 3, and a quadrupedal mobile chassis 4.

[0052] The quadrupedal mobile chassis 4 includes a chassis and four foot linkage mechanisms. The top of each foot linkage mechanism is fixedly connected to the chassis, and a motor is fixedly mounted on the chassis. The motor individually controls and drives the lifting, rotation, and translation of each foot linkage mechanism. By controlling the movement of each foot linkage mechanism, the displacement and lifting functions of the crawling printing robot are realized. A circular rubber pad 4a is fitted on the bottom (i.e., the end of the foot) of each foot linkage mechanism. The shape and size of the rubber pad 4a are the same as the circular shallow pit in the perforated area. When the crawling printing robot is printing and positioning, it completes the positioning by stepping into the circular shallow pit with its four feet and stabilizes its posture, thus realizing the stable standing function of the crawling printing robot.

[0053] The base of the three-degree-of-freedom robotic arm 3 is fixed to the upper surface of the four-legged movable chassis 4 via copper pillars 3b. The end effector platform 3a is fixed to the end of the three-degree-of-freedom robotic arm 3. When the three-degree-of-freedom robotic arm 3 moves, the end effector platform 3a is always parallel to the horizontal plane. The movement of the three-degree-of-freedom robotic arm 3 is achieved by a motor driving a linkage mechanism.

[0054] The visual recognition mechanism 1 includes a camera, which is fixed to the end work platform 3a by screws. The camera sends the collected information to the main control board for machine vision recognition via a data cable, thereby detecting the position of the circular shallow pit in the workpiece to be printed relative to the foot linkage mechanism and the print head 2, and realizing the positioning function in the crawling printing robot.

[0055] The print head 2 is fixed to the end work platform 3a by screws. The print head 2 includes a heating device and a filament feeding structure, which are arranged in a conventional manner in the prior art. During the printing process, by heating the printing material and the filament feeding structure, molten printing filament is extruded from the nozzle of the print head 2, thereby realizing the printing function of the crawling printing robot.

[0056] The movement of the robotic arm drives the end-effector 3a to translate in three degrees of freedom in the X, Y, and Z directions, which in turn moves the print head 2 and the camera of the vision recognition mechanism 1, thereby realizing the function of the crawling printing robot to print in areas at different heights in front of, behind, left, and right of its own block area.

[0057] It should be noted that the crawling printing robot structure used in this invention is not limited to one type; any robot that meets the basic requirements can be used.

[0058] The present invention will be specifically illustrated below through an embodiment.

[0059] Example

[0060] Print as Figure 6 The specific steps for making the square pyramid shown are as follows:

[0061] Step 1: Divide the square space containing the 3D slice supporting the square pyramid into an array of equally sized square regions, as shown in the diagram. Figure 7 As shown.

[0062] Step 2: Print the bottom layer. For example... Figure 8 As shown, the bottom layer to be printed consists of areas with holes. For ease of explanation, all areas with holes are numbered sequentially (not all are marked in the figure, but follow the order). Let the direction from area 12 to area 2 be left, the direction from area 22 be right, the direction from area 11 be back, and the direction from area 13 be front.

[0063] (1) A heated bed chassis with an array of circular patterns with the same region segmentation parameters is placed on a horizontal plane. Initially, the crawling printing robot stands on the printing areas 11, 12, 21, 22 and prints the printing area 1 on the left front.

[0064] (2) The crawling printing robot moves forward one area with holes, that is, moves to the printing areas 12, 13, 22, 23, and prints the printing areas 2, 11, 21 on the left front and front.

[0065] (3) Repeat the logic of step (2) until the crawling printing robot moves to a position with a hole one distance from the edge of the bottom layer, i.e. the printing areas 18, 19, 28, 29, and completes the printing of the printing areas 8, 17, 27.

[0066] (4) The crawling printing robot moves forward one hole area to the edge of the bottom layer, that is, moves to the printing areas 19, 20, 29, 30, and prints the printing areas 9, 10, 18, 28 on the left and front.

[0067] (5) The crawling printing robot moves one perforated area to the right, that is, to the printing areas 29, 30, 39, 40, and prints the printing areas 19, 20 on the left. The crawling printing robot then moves one perforated area to the right, that is, to the printing areas 39, 40, 49, 50, and prints the printing areas 29, 30 on the left. This completes the printing of the first three perforated areas.

[0068] (6) The crawling printing robot moves to the printing areas 49, 50, 59, and 60, and prints according to the path planning logic in steps (1) to (5). Specifically: the printing area to be printed in the front left (i.e., printing area 40) is printed; the crawling printing robot moves upward by one perforated area and prints the printing areas to be printed in the front left and front left (i.e., printing areas 39, 50, and 60); the crawling printing robot moves backward by one perforated area step and prints the printing areas to be printed in the front left and front left until the crawling robot reaches the edge of the bottom layer (i.e., printing areas 41, 42, 51, and 52), at which point the printing areas to be printed in the left and front left (i.e., printing areas 31, 32, 43, and 53) are printed. The crawling printing robot moves to the right twice by one perforated area step, printing the printing area to be printed in the left left each time, thus completing the printing of the perforated areas in columns 4 to 6. The crawling printing robot moves to the right again by one perforated area and waits for the next step.

[0069] (7) Consider the path planning from back to front in steps (1) to (5) as the first half of the cycle, and the path planning from front to back in step (6) as the second half of the cycle. The path planning in steps (1) to (6) is a complete cycle. This cycle pattern is maintained regardless of how many perforated areas there are in the future. At the same time, the number of columns printed in each half cycle can be adjusted by adjusting the part printed by the crawling printing robot at each step. Since the crawling printing robot can print at different heights in the front, back, left and right directions of the block area it is in, the number of columns printed in each half cycle can be any one of 1 to 4 columns.

[0070] In this embodiment, the path planning logic of steps (1) to (5) is repeated, and the printing of the right-side area to be printed is added in each step until the area to be printed 79, 80, 89, 90 is moved to print the area to be printed 69, 70, 99, 100.

[0071] (8) The crawling printing robot moves backward to areas 78*, 79, 88*, 89 and prints areas 80 and 90; the crawling printing robot moves backward to areas 77*, 78*, 87*, 88* and prints areas 79 and 89, thus completing the bottom layer printing. The asterisk (*) after the numbers indicates that the crawling printing robot's mechanical feet are positioned one layer above the baseline (i.e., the current printing layer).

[0072] Step 3: Printing intermediate layers. The crawling printing robot plans its path according to the printing logic of the lower layers and prints the perforated areas of each layer sequentially. The final model, after printing all perforated areas, looks like this. Figure 9 As shown, each square in the figure should have a shallow circular hole on its top surface, but this is not shown in the figure.

[0073] Step 4: Print the hole-free areas. The crawling printing robot moves to the initial position area 11,12,21,22, and prints the hole-free areas according to the path planned by the underlying printing logic and the S-shaped printing sequence. For a fixed (X,Y) coordinate position, all hole-free areas in the Z direction at that coordinate are printed at once, completing the printing of the entire square pyramid.

[0074] This invention achieves large-area printing based on a crawling printing robot. This printing method decomposes and processes the large-area printing area, and uses a quadruped robot carrying a printing nozzle to be placed on the printing workpiece to perform commands such as movement, positioning, printing, and lifting, thereby achieving large-area printing without range limitations.

[0075] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for large-scale printing based on a crawling printing robot, characterized in that, Includes the following steps: S1: Divide the square space where the 3D slice of the part to be printed is located into an array of square regions of the same size; The block area includes a perforated area and a non-perforated area. The perforated area can safely accommodate a circular shallow pit and is not a surface block. The non-perforated area cannot safely accommodate a circular shallow pit or is a surface block. The circular shallow pit is located at the top center of the perforated area and its size is adapted to the size of the bottom surface of the mechanical foot of the crawling printing robot. S2: For a certain layer with holes, the crawling printing robot positions itself at the initial position through the circular shallow pits, and fills the circular shallow pits along the printing path by combining coordinate system positioning and visual recognition, and prints the next layer area at the initial position. S3: The crawling printing robot moves to the next group of perforated areas by combining coordinate system positioning and visual recognition, and repeats step S2 until the printing of the current layer is completed; when the crawling printing robot interferes with the printing of the current layer, the crawling printing robot autonomously lifts to a new layer and fills in the missing parts on the current layer to complete the printing of the current layer. S4: Repeat steps S2 and S3 until all perforated areas are printed; S5: Based on the path planning logic for printing each layer in the perforated area, complete the printing of the non-perforated area; In step S1, the specific method of segmentation is as follows: using a spatial coordinate system as a reference, an array plane is used to segment the square space involved in printing, thereby dividing the square space into an array combination containing multiple square regions of the same size; wherein, the array plane includes three sets of mutually perpendicular plane groups, and in each plane group, the planes are parallel to each other and equidistantly arranged; In step S3, the perforated area of ​​the current layer is divided into a connected region containing at least one perforated area based on connectivity. The perforated areas of each connected region are printed according to the S-shaped printing sequence. For printing between different connected regions, the crawling printing robot crawls to another connected region based on the circular shallow pit and then prints. In step S5, for a holeless area with fixed X and Y coordinates, the printing of all holeless areas in the Z direction under that coordinate is completed at once.

2. The large-scale printing method based on a crawling printing robot according to claim 1, characterized in that, When printing the perforated areas of the bottom layer, a heated bed chassis with an array of circular patterns, having the same area segmentation parameters as the printed area, is placed on a horizontal surface to provide the initial working environment for the crawling printing robot.

3. The large-scale printing method based on a crawling printing robot according to claim 1, characterized in that, The crawling printing robot includes: a vision recognition mechanism, a printing nozzle, a three-degree-of-freedom robotic arm, and a quadrupedal mobile chassis; the quadrupedal mobile chassis includes a chassis and four foot linkage mechanisms; the top of each foot linkage mechanism is fixed to the chassis, and a motor individually controls and drives the lifting, rotation, and translation of each foot linkage mechanism; the bottom of each foot linkage mechanism is fitted with a rubber pad, the shape and size of which are the same as the circular shallow pit in the perforated area; The base of the three-degree-of-freedom robotic arm is fixed to the upper surface of the four-legged mobile chassis, and the end effector of the three-degree-of-freedom robotic arm is fixed to an end effector platform; the vision recognition mechanism includes a camera, which is fixed to the end effector platform, and the camera sends the collected information to the main control board for machine vision recognition via a data cable; the print head is fixed to the end effector platform, and during the printing process, molten printing filament is extruded from the print head nozzle by heating the printing material and the filament feeding structure.

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