Portable multi-degree-of-freedom 3D printing device and method

Abstract

The invention discloses a portable multi-degree-of-freedom 3D printing device and method, belongs to the technical field of additive manufacturing, and is suitable for rapid repairing and convenient printing operation in a complex environment. The device comprises a mechanical arm assembly which comprises a mechanical arm base, a mechanical arm section and a three-dimensional scanner at the tail end; the mobile chassis comprises a platform, Mecanum wheels and a laser radar; the material tray is used for placing consumables; the printing head assembly comprises an extruder and a heating head; most printing targets are repairing work of uneven complex surfaces. A control system is arranged in the mechanical arm assembly, the mechanical arm assembly is installed on a chassis platform, and the platform moves through Mecanum wheels. The printing head is installed at the executing end of the mechanical arm and moves along with the mechanical arm. The mechanical arm obtains a three-dimensional model of a working environment through a scanner and automatically plans a route. Due to the high-degree-of-freedom characteristic of the mechanical arm, the printing head can print layer by layer at any angle, and a supporting structure is not needed; the steps of measurement, printing, model processing, post-processing and the like of complex environment repairing work are simplified, and printing is rapidly completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and relates to a portable multi-degree-of-freedom 3D printing device and method, which is particularly suitable for rapid repair operations on complex and uneven surfaces such as industrial equipment, pipeline systems, and building structures. Background Art

[0002] At present, the application of 3D printing technology in complex surface repair faces multiple technical bottlenecks. Traditional fixed 3D printers rely on a flat substrate as the printing basis, but in industrial equipment maintenance or building repair scenarios, the surface to be repaired is usually a curved surface, an inclined surface or an uneven structure. Traditional 3D printers are mostly Cartesian manipulators and cannot print directly. For this reason, existing technologies often solve this problem by adding support structures to the model to be printed, but the support structure not only increases material consumption, but also requires subsequent manual removal, significantly reducing work efficiency.

[0003] For example, a Chinese patent with publication number CN104626571A discloses a portable desktop printing system. This patent achieves the purpose of portability by reducing the size of the robotic arm and the weight of the entire machine. It is more convenient when processing small parts, but it is still a Cartesian manipulator arm, which limits the printing angle and cannot adapt to the normal attachment printing requirements of high-curvature surfaces.

[0004] In addition, most of the existing 3D printing equipment with articulated operating arms can only reduce the support structure, but have no movement and autonomous planning functions, cannot complete flexible control and movement in narrow spaces, and are difficult to accurately position.

[0005] For example, the Chinese patent with publication number CN118721727A discloses a multi-DOF light-curing 3D printing device, which reduces the need for support of the workpiece and simplifies the printing operation by replacing the traditional Cartesian operating arm with a hinged operating arm. However, the device is light-curing printing and is not equipped with movement and autonomous planning functions, so it is not suitable for the narrow space working conditions.

[0006] Furthermore, repair work on complex surfaces usually relies on manual measurement modeling and path planning, and the operation process is cumbersome. Work in narrow spaces, such as pipeline repair work, is often difficult to carry out due to equipment problems and requires excavation, which greatly increases the cost. Therefore, an integrated device that integrates high-precision environmental perception, omnidirectional motion control and multi-degree-of-freedom printing is needed to solve the above technical defects. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a portable multi-degree-of-freedom 3D printing device and method, which is suitable for rapid repair and convenient printing operations in complex environments. It can simplify the measurement, printing, model processing and post-processing steps of complex environment repair operations and quickly complete the printing goals.

[0008] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0009] A portable multi-degree-of-freedom 3D printing device, the portable multi-degree-of-freedom 3D printing device includes a mechanical arm assembly, a mobile chassis, a material tray 8, a laser radar 4, and a print head assembly, specifically:

[0010] The robot arm assembly includes a robot arm base 11, a primary robot arm segment 6 and a secondary robot arm segment 5 connected to the robot arm base 11 in sequence, and a three-dimensional scanner 3 arranged at the end of the robot arm, and the robot arm assembly is built with an integrated control system;

[0011] The mobile chassis is fixedly arranged at the bottom of the robot arm assembly, and includes a robot arm mounting plate 9, a chassis mounting plate 12 and a Mecanum wheel assembly 10 arranged from top to bottom. The Mecanum wheel assembly 10 is used to realize omnidirectional movement of the entire printing device. The end of the robot arm base 11 is installed on the robot arm mounting plate 9.

[0012] The material tray 8 is detachably mounted on the material tray bracket 7 for storing printing consumables; the material tray bracket 7 is mounted on the robot arm mounting plate 9.

[0013] The laser radar 4 is fixedly arranged on the surface of the mechanical arm mounting plate 9 and is used to construct an environmental space model;

[0014] The print head assembly is installed at the end effector position of the secondary mechanical arm segment 5 of the mechanical arm assembly, and includes an extrusion mechanism 2 and a heating head 1 connected to the extrusion mechanism, and the heating head 1 is used to melt the consumables and perform extrusion molding;

[0015] The three-dimensional scanner 3 is communicatively connected with the integrated control system for acquiring three-dimensional morphological data of the workpiece surface; the integrated control system is configured to generate a composite environment model based on the collected data of the three-dimensional scanner 3 and the laser radar 4, automatically plan the printing path according to the composite environment model, and coordinately control the movement of the Mecanum wheel 10 of the mobile chassis and the four-degree-of-freedom linkage of the robotic arm assembly, so that the heating head 1 can perform adaptive layer-by-layer printing along a non-flat or complex curved surface.

[0016] Furthermore, the primary robotic arm segment 6 and the secondary robotic arm segment 5 of the robotic arm assembly are connected via a harmonic reducer, and a servo motor is integrated in the robotic arm base 11. The servo motor communicates with the integrated control system via a CAN bus to achieve a positioning accuracy of ±0.1mm for the four-degree-of-freedom motion of the robotic arm.

[0017] Furthermore, the Mecanum wheel assembly 10 of the mobile chassis includes four Mecanum wheels distributed in a rectangular shape, each Mecanum wheel is independently connected to a DC brushless motor, and the DC brushless motor realizes differential control through an integrated control system, so that the device has planar omnidirectional movement and ±2° self-correction functions.

[0018] Furthermore, the three-dimensional scanner 3 is a laser radar scanner, and its scanning accuracy is not less than 0.1 mm.

[0019] Furthermore, the temperature control range of the heating head 1 is 100° C. to 450° C., and the extruder 2 has a closed-loop feedback control module, which can adjust the extrusion rate of the consumables in real time.

[0020] Furthermore, a shock-absorbing layer is provided between the robot arm mounting plate 9 and the chassis mounting plate 12. The shock-absorbing layer is composed of a composite of a silicone damping pad and a honeycomb aluminum plate, and can attenuate vibrations generated when the robot arm moves.

[0021] Furthermore, the control system has an integrated wireless communication module for human-computer interaction, supporting users to remotely issue task instructions, check progress and working status, and obtain scanning data.

[0022] A portable multi-degree-of-freedom 3D printing method is implemented based on the portable multi-degree-of-freedom 3D printing device, comprising the following steps:

[0023] First, the target repair area is scanned by a three-dimensional scanner 3 to generate a three-dimensional model including the surface morphology and defect location;

[0024] Secondly, the control system automatically divides the repair area and plans the printing path according to the three-dimensional model, and the path includes the walking route of the mobile chassis and the motion trajectory of the robot arm assembly;

[0025] Thirdly, the control system controls the Mecanum wheel 10 to move the device to the target area, and adjusts the spatial posture of the print head assembly through the robotic arm assembly, so that the heating head 1 prints layer by layer on the uneven surface according to the planned path;

[0026] Finally, during the printing process, the distance between the print head and the target surface is monitored in real time, and the position deviation is dynamically compensated through the multi-degree-of-freedom motion of the robotic arm assembly.

[0027] Furthermore, the path planning includes: dynamically adjusting the thickness and extrusion amount of the printing layer according to the curvature change of the target surface, so that the error of the printing material fitting the surface is less than 0.5 mm.

[0028] Furthermore, the three-dimensional scanner 3 acquires the topographic data of the printing area in real time and compares it with the original three-dimensional model. If an uncovered area is detected, a supplementary printing path is automatically planned.

[0029] Furthermore, in addition to the repair work, the 3D printing device can also receive a model from a terminal and perform common 3D printing work.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] (1) The robotic arm assembly can adjust the printing angle with multiple degrees of freedom, without the need for additional support structures, thus reducing material waste;

[0032] (2) Laser scanning and path planning ensure high accuracy of printed layers and surface adhesion;

[0033] (3) Supports on-site real-time operations, which greatly shortens the time compared to traditional workflows;

[0034] (4) Modular design supports replacement of print heads and scanners, expands applications, and facilitates fault repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of a portable multi-DOF 3D printing device;

[0036] In the figure: 1 heating head; 2 extruder; 3 three-dimensional scanner; 4 laser radar; 5 second-level robot arm segment; 6 first-level robot arm segment; 7 tray bracket; 8 tray; 9 robot arm mounting plate; 10 Mecanum wheel; 11 robot arm base; 12 chassis mounting plate. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0038] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0039] The portable multi-DOF 3D printing device of this example includes a robotic arm assembly, a mobile chassis, a material tray 8, a laser radar 4 and a print head assembly.

[0040] A robotic arm assembly, comprising a robotic arm base 11, a primary robotic arm segment 6 and a secondary robotic arm segment 5 connected in sequence, and a three-dimensional scanner 3 arranged at the end of the robotic arm, wherein the robotic arm assembly has an integrated control system built in;

[0041] A mobile chassis is fixedly arranged at the bottom of the mechanical arm assembly, including a mechanical arm mounting plate 9, a chassis mounting plate 12 and a Mecanum wheel assembly 10 arranged from top to bottom, wherein the Mecanum wheel assembly 10 is used to realize omnidirectional movement of the device, and a material tray bracket 7 is also arranged on the mechanical arm mounting plate;

[0042] A material tray 8, which is detachably mounted on the material tray bracket 7 and is used to store printing consumables;

[0043] A laser radar 4 is fixedly arranged on the surface of the mechanical arm mounting plate 9 and is used to construct an environmental space model;

[0044] A print head assembly, installed at the end effector position of the mechanical arm assembly, comprising an extrusion mechanism 2 and a heating head 1 connected to the extrusion mechanism, wherein the heating head 1 is used to melt the consumable material and perform extrusion molding;

[0045] The three-dimensional scanner 3 is communicatively connected with the integrated control system for acquiring three-dimensional morphological data of the workpiece surface; the integrated control system is configured to generate a composite environment model based on the collected data of the three-dimensional scanner and the laser radar, automatically plan the printing path according to the composite environment model, and coordinately control the Mecanum wheel movement of the mobile chassis and the four-degree-of-freedom linkage of the robotic arm assembly, so that the heating nozzle can perform adaptive layer-by-layer printing along a non-flat or complex curved surface.

[0046] Furthermore, the primary robotic arm segment 6 and the secondary robotic arm segment 5 of the robotic arm assembly are connected via a harmonic reducer, and a servo motor is integrated in the robotic arm base 11. The servo motor communicates with the integrated control system via a CAN bus to achieve a positioning accuracy of ±0.1mm for the four-degree-of-freedom motion of the robotic arm.

[0047] Furthermore, the Mecanum wheel assembly 10 of the mobile chassis includes four Mecanum wheels distributed in a rectangular shape, each Mecanum wheel is independently connected to a DC brushless motor, and the DC brushless motor realizes differential control through an integrated control system, so that the device has planar omnidirectional movement and ±2° self-correction functions.

[0048] Furthermore, the three-dimensional scanner 3 is a laser radar scanner, and its scanning accuracy is not less than 0.1 mm.

[0049] Furthermore, the temperature control range of the heating head 1 is 100° C. to 450° C., and the extruder 2 has a closed-loop feedback control module, which can adjust the extrusion rate of the consumables in real time.

[0050] Furthermore, a shock-absorbing layer is provided between the robot arm mounting plate 9 and the chassis mounting plate 12. The shock-absorbing layer is composed of a composite of a silicone damping pad and a honeycomb aluminum plate, and can attenuate vibrations generated when the robot arm moves.

[0051] Furthermore, the control system has an integrated wireless communication module for human-computer interaction, supporting users to remotely issue task instructions, check progress and working status, and obtain scanning data.

[0052] An embodiment of repairing industrial pipelines based on a portable multi-degree-of-freedom 3D printing device includes the following steps:

[0053] Step 1: Install the tray loaded with ABS plastic onto the mobile chassis and start the self-test program. Set the heating head temperature to 230°C through the wireless terminal and pre-extrude the filament with the extruder to eliminate bubbles.

[0054] Step 2: Control the robot arm to expand to the side of the pipeline, and the laser radar at the end scans the pipeline surface in a spiral trajectory to generate a three-dimensional grid model containing the location and size of the crack. The control system identifies the crack boundary and marks the area to be repaired as a groove with a length of 120 mm and a depth of 5 mm.

[0055] Step 3: Dynamically divide the printing layer thickness into 0.4mm according to the curvature of the pipe (radius 150mm) and generate the printing path. The path planning algorithm simultaneously calculates the moving speed of the chassis along the axial direction of the pipe (0.2m / s) and the angles of each joint of the robot arm to avoid motion interference.

[0056] Step 4: Start the omnidirectional chassis movement, the robot arm joint motor and the Mecanum wheel drive motor are controlled in coordination, so that the print head moves along the path at a speed of 50mm / s. The extruder adjusts the extrusion pressure to 0.25MPa according to the layer thickness, and the heating head maintains 230℃±5℃ to melt the consumables. During the printing process, the laser rangefinder monitors the distance between the print head and the surface in real time. When a deviation of more than 0.5mm is detected, the fourth joint of the robot arm triggers angle compensation to ensure that the extruded material fits the surface tightly.

[0057] Step 5: After the first round of printing, the laser radar scans the repair area again and finds two uncovered areas by comparing with the original model. The control system automatically generates a repair path and drives the print head to fill the defects in a local dot coating manner until the surface flatness error is less than 0.3mm.

[0058] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0059] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A portable multi-degree-of-freedom 3D printing device, characterized in that: The portable multi-degree-of-freedom 3D printing device comprises a mechanical arm assembly, a mobile chassis, a material tray (8), a laser radar (4), and a print head assembly, specifically: The robotic arm assembly comprises a robotic arm base (11), a primary robotic arm segment (6) and a secondary robotic arm segment (5) connected to the robotic arm base (11) in sequence, and a three-dimensional scanner (3) arranged at the end of the robotic arm, and the robotic arm assembly has an integrated control system built in; The mobile chassis is fixedly arranged at the bottom of the mechanical arm assembly, and comprises a mechanical arm mounting plate (9), a chassis mounting plate (12) and a Mecanum wheel assembly (10) arranged from top to bottom. The Mecanum wheel assembly (10) is used to realize omnidirectional movement of the entire printing device. The end of the mechanical arm base (11) is installed on the mechanical arm mounting plate (9); The material tray (8) is detachably mounted on the material tray bracket (7) and is used to store printing consumables; the material tray bracket (7) is mounted on the robot arm mounting plate (9); The laser radar (4) is fixedly mounted on the surface of the mechanical arm mounting plate (9) and is used to construct an environmental space model; The print head assembly is installed at the end effector position of the secondary mechanical arm segment (5) of the mechanical arm assembly, and comprises an extrusion mechanism (2) and a heating head (1) connected to the extrusion mechanism, wherein the heating head (1) is used to melt the consumable material and perform extrusion molding; The three-dimensional scanner (3) is connected to the integrated control system for communication and is used to obtain three-dimensional topographic data of the workpiece surface; the integrated control system is configured to generate a composite environment model based on the data collected by the three-dimensional scanner (3) and the laser radar (4), automatically plan a printing path according to the composite environment model, and coordinately control the movement of the Mecanum wheel assembly (10) of the mobile chassis and the four-degree-of-freedom linkage of the mechanical arm assembly, so that the heating head (1) performs adaptive layer-by-layer printing along a non-flat or complex curved surface.

2. A portable multi-degree-of-freedom 3D printing device according to claim 1, characterized in that: The primary robotic arm segment (6) and the secondary robotic arm segment (5) of the robotic arm assembly are connected via a harmonic reducer, and a servo motor is integrated in the robotic arm base (11); the servo motor communicates with the integrated control system via a CAN bus to achieve a ±0.1 mm positioning accuracy of the four-degree-of-freedom motion of the robotic arm.

3. A portable multi-degree-of-freedom 3D printing device according to claim 1, characterized in that: The Mecanum wheel assembly (10) of the mobile chassis includes four Mecanum wheels distributed in a rectangular shape, each Mecanum wheel is independently connected to a DC brushless motor, and the DC brushless motor realizes differential speed control through an integrated control system, so that the entire printing device has a planar omnidirectional movement and ±2° self-correction function.

4. The portable multi-DOF 3D printing device according to claim 1, characterized in that: The three-dimensional scanner (3) is a laser radar scanner, and its scanning accuracy is not less than 0.1 mm.

5. The portable multi-DOF 3D printing device according to claim 1, characterized in that: The temperature control range of the heating head (1) is 100° C. to 450° C., and the extrusion mechanism (2) has a closed-loop feedback control module capable of adjusting the consumable extrusion rate in real time.

6. The portable multi-DOF 3D printing device according to claim 1, characterized in that: A shock-absorbing layer is provided between the mechanical arm mounting plate (9) and the chassis mounting plate (12), and the shock-absorbing layer is composed of a composite of a silica gel damping pad and a honeycomb aluminum plate.

7. The portable multi-DOF 3D printing device according to claim 1, characterized in that: Furthermore, the control system has an integrated wireless communication module for human-computer interaction, supporting users to remotely issue task instructions, check progress and working status, and obtain scanning data.

8. A portable multi-degree-of-freedom 3D printing method, characterized in that: The portable multi-degree-of-freedom 3D printing device according to any one of claims 1 to 7 is implemented, comprising the following steps: First, the target repair area is scanned by a three-dimensional scanner (3) to generate a three-dimensional model including the surface morphology and defect location; Secondly, the control system automatically divides the repair area and plans the printing path according to the three-dimensional model, and the path includes the walking route of the mobile chassis and the motion trajectory of the robot arm assembly; Next, the control system controls the Mecanum wheel assembly (10) to move the device to the target area, and adjusts the spatial posture of the print head assembly through the mechanical arm assembly, so that the heating head (1) prints layer by layer on the uneven surface according to the planned path; Finally, during the printing process, the distance between the print head and the target surface is monitored in real time, and the position deviation is dynamically compensated through the multi-degree-of-freedom movement of the robotic arm assembly; and the three-dimensional scanner (3) acquires the topographic data of the printing area in real time and compares it with the original three-dimensional model. If an uncovered area is detected, a supplementary printing path is automatically planned.

9. A portable multi-DOF 3D printing method according to claim 8, characterized in that: The path planning includes: dynamically adjusting the thickness and extrusion amount of the printing layer according to the curvature change of the target surface, so that the error of the printing material and the surface fit is less than 0.5mm.

10. A portable multi-DOF 3D printing method according to claim 8, characterized in that: In addition to the repair work, the 3D printing device can also receive a model from a terminal and perform common 3D printing work.

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