Calibration method for 3D printer and 3D printer

Abstract

The present disclosure provides a calibration method for a 3D printer and a 3D printer. The calibration method includes: causing a first fluid extrusion head to draw a calibration figure on a preset plane; causing a camera to acquire an image of the calibration figure at a camera position to obtain a calibration image; based on the calibration image, determining a first coordinate of a feature point of the calibration figure in the coordinate system of the camera; based on the first coordinate and the acquired second coordinate, third coordinate, and fourth coordinate, determining a fifth coordinate of the first fluid extrusion head in the coordinate system of the second fluid extrusion head. The method according to an embodiment of the present disclosure can obtain the relative position relationship between two different extrusion heads, and in the subsequent 3D printing process, ensure that the first fluid is accurately applied to the target position on the 3D object to be printed based on the relative position relationship.

Description

Technical Field

[0001] The present disclosure relates to the technical field of 3D printing, and in particular to a calibration method for a 3D printer, a 3D printer, a computer-readable storage medium, and a computer program product. Background Art

[0002] 3D printer, also known as three-dimensional printer, stereo printer, is a kind of rapid prototyping process equipment, usually realized by printing materials with digital technology. 3D printers are often used to make models or parts in the fields of mold manufacturing, industrial design, etc. In recent years, 3D printing technology has great application prospects in jewelry, footwear, industrial design, architecture, engineering and construction (AEC), automobiles, aerospace, dental and medical industries, education, geographic information systems, civil engineering, firearms and other fields.

[0003] In the existing 3D printing technology, when printing an object to be printed that includes a suspended part, it is necessary to first print an additional support part, and then print the 3D object on the support part. Finally, after the printed object is formed, the additional support part is removed from the printed object. At present, a mainstream method for removing the support part from the printed object is to apply additional ink on the support part after printing the support part, which is easy to separate from the printed object. This requires that two extruders for outputting printing materials and ink are respectively set on the 3D printer.

[0004] The methods described in this section are not necessarily methods that have been previously conceived or employed. Unless otherwise indicated, it should not be assumed that any method described in this section is considered to be prior art simply because it is included in this section. Similarly, unless otherwise indicated, the issues mentioned in this section should not be considered to have been recognized in any prior art. Summary of the invention

[0005] According to one aspect of the present disclosure, the present disclosure provides a calibration method for a 3D printer. The 3D printer includes an extruder, a first fluid extrusion head disposed on the extruder, and a second fluid extrusion head and a camera disposed on the extruder. The method comprises: moving an extruder according to a predetermined trajectory to drive a first fluid extrusion head to draw a calibration figure on a preset plane using a first fluid; moving the extruder to a camera position so that a camera is aligned with feature points of a standard figure, wherein the standard figure is a figure drawn on a preset plane using the first fluid by driving the extruder according to a predetermined trajectory when the first fluid extrusion head is installed at a standard position on the extruder; enabling the camera to acquire an image of the calibration figure at the camera position to obtain a calibration image; determining first coordinates of feature points of the calibration figure in a coordinate system of the camera based on the calibration image, wherein the feature points of the calibration figure correspond to feature points of the standard figure; acquiring second coordinates of feature points of the standard figure in the coordinate system of the camera, third coordinates of the first fluid extrusion head in the coordinate system of the camera when the first fluid extrusion head is installed at the standard position, and fourth coordinates of the camera in the coordinate system of the second fluid extrusion head; and determining fifth coordinates of the first fluid extrusion head in the coordinate system of the second fluid extrusion head based on the first coordinate, the second coordinate, the third coordinate and the fourth coordinate.

[0006] According to another aspect of the present disclosure, a 3D printing method is also provided, comprising: executing the above-mentioned calibration method for a 3D printer; and when applying a first fluid using a first fluid extrusion head to a printed object that has been printed using a second fluid extrusion head, correcting a motion trajectory of the extruder according to a fifth coordinate.

[0007] According to another aspect of the present disclosure, a 3D printer is provided, comprising: an extruder; a first fluid extrusion head, disposed on the extruder and configured to output a first fluid; a second fluid extrusion head, disposed on the extruder and configured to output a second fluid; a camera, disposed on the extruder; and a processor, configured to implement the method described above when executing instructions.

[0008] According to another aspect of the present disclosure, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, wherein the computer program implements the steps of the above method when executed by a processor.

[0009] According to yet another aspect of the present disclosure, a computer program product is provided, including a computer program, wherein the steps of the above method are implemented when the computer program is executed by a processor.

[0010] According to the embodiments of the present disclosure, a calibration pattern is drawn on a preset plane, and the coordinates of the first fluid extrusion head relative to the second fluid extrusion head are finally obtained by analyzing the calibration image acquired by the camera. Thus, the relative position relationship between the two different extrusion heads can be obtained, so that in the subsequent 3D printing process, the first fluid can be accurately applied to the target position on the 3D object to be printed. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in accordance with the present disclosure and should not be regarded as limiting the scope of the present disclosure.

[0012] Figure 1 A schematic structural diagram of a 3D printer according to an embodiment of the present disclosure is shown;

[0013] Figure 2 A partial structural schematic diagram of an extruder part of a 3D printer according to an embodiment of the present disclosure is shown;

[0014] Figure 3 A flow chart of a calibration method for a 3D printer according to an embodiment of the present disclosure is shown;

[0015] Figure 4 A schematic diagram showing an imaging model of a camera of a 3D printer according to an embodiment of the present disclosure is shown;

[0016] Figure 5 A schematic diagram showing various coordinate relationships in a calibration method for a 3D printer according to an embodiment of the present disclosure is shown;

[0017] Figure 6 An embodiment according to the present disclosure is shown. Figure 3 A flowchart of an example process for determining a fifth coordinate in the method of;

[0018] Figure 7 A flow chart of a 3D printing method according to one embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0019] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0020] In practice, the ink extruder head is usually a consumable, which means that the extruder head needs to be replaced frequently, so the ink extruder head is generally set on the 3D printer in a detachable manner. The inventor found that this brings the following problems: there may be an error in the installation position each time the ink extruder head is installed, resulting in a difference between the actual installation position of the ink extruder head and its design value, which causes the ink extruder head to be unable to apply ink at the correct target position during the printing process, making the subsequent separation effect worse.

[0021] In view of this, the embodiments of the present disclosure provide a 3D printer 100 and a calibration method for a 3D printer, which can alleviate, mitigate or even eliminate the above-mentioned problems.

[0022] The following will refer to Figure 1 and Figure 2 The 3D printer 100 of the present disclosure is described in detail. Figure 1 FIG. 1 shows a schematic structural diagram of a 3D printer 100 according to an embodiment of the present disclosure. Figure 2 A partial structural schematic diagram of the extruder 140 of the 3D printer 100 according to one embodiment of the present disclosure is shown.

[0023] like Figure 1As shown, the 3D printer 100 includes: a printing platform (not shown in the figure), an extruder 140, a first fluid extrusion head 110, a second fluid extrusion head 120, a camera 130, a first guide rod 170, a second guide rod 180, a driving mechanism and a processor 190. The driving mechanism is used to drive the extruder to move. In this embodiment, the driving mechanism includes: a first motor 150 and a second motor 160. The printing platform is arranged at the bottom of the 3D printer 100, which is used to support the object to be printed, and its upper surface is a printing plane. The space above the printing platform is a printing space for printing the object to be printed. The extruder 140 can move in the above-mentioned printing space to control the corresponding extruder head to apply the fluid for printing toward the printing plane. The first guide rod 170 and the second guide rod 180 are two guide rods that cross each other, and the extruder 140 is arranged on these two guide rods, and can move bidirectionally on the first guide rod 170 and the second guide rod 180 respectively. The first motor 150 is arranged on the first guide rod 170 and connected to the extruder 140, and is used to drive the extruder 140 to move in the first direction where the first guide rod 170 is located. The second motor 160 is arranged on the second guide rod 180 and connected to the extruder 140, and is used to drive the extruder 140 to move in the second direction where the second guide rod 180 is located. In this embodiment, the above-mentioned first direction and the second direction can be perpendicular to each other. For the convenience of description, the first direction where the first guide rod 170 is located is defined as the X direction, and the second direction where the second guide rod 180 is located is defined as the Y direction. The extruder 140 can be driven by the first motor 150 and the second motor 160 to move on the XY plane of the printing space.

[0024] The first fluid extrusion head 110, the second fluid extrusion head 120 and the camera 130 are all arranged on the extruder 140. The first fluid extrusion head 110 is generally a consumable material and needs to be replaced frequently, so the first fluid extrusion head 110 is detachably arranged on the extruder 140 for easy replacement. Figure 2 As shown, the first fluid extrusion head 110 is arranged downward (toward the printing platform) for applying the first fluid to the object to be printed. Exemplarily, the first fluid extrusion head 110 can be arranged on the extruder 140 by means of a snap-on connection. The second fluid extrusion head 120 is a non-consumable material, which is fixedly arranged on the extruder 140 and is also arranged downward (toward the printing platform) for applying the second fluid to the object to be printed. There is a certain interval between the first fluid extrusion head 110 and the second fluid extrusion head 120 to prevent mutual interference between the two extrusion heads. In this embodiment, the camera 130 is fixedly arranged on the extruder 140, and the lens is arranged downward for shooting the printing platform. In some embodiments, the shooting direction of the camera 130 is perpendicular to the printing platform.

[0025] The first fluid and the second fluid may be different fluids for 3D printing. In the present embodiment, the first fluid may be a release material, and the second fluid may be a printing material. The printing material is the building material that ultimately forms the object to be printed (or the target object). The release material may be applied between the two parts formed by the printing material to facilitate the separation of the two parts. Examples of printing materials include, but are not limited to, liquid photosensitive resins, powdered materials such as nylon, etc. The release material may be ink. In the present embodiment, in order to facilitate the implementation of the calibration method, the release material is one or more of a thermal ink, an ultraviolet fluorescent ink, or a colored ink that can be captured by the camera 130.

[0026] Although in the present embodiment, the first fluid is a release material and the second fluid is a printing material, it is understandable that in other embodiments of the present invention, the first fluid can be a printing material, the second fluid can be a release material, or the first fluid and the second fluid can be printing materials of different materials. In addition, in the present embodiment, the first fluid extrusion head 110 is detachably arranged on the extruder, and the second fluid extrusion head 120 is fixedly arranged on the extruder, but it is also understandable that in other embodiments of the present invention, the second fluid extrusion head 120 is detachably arranged on the extruder, and the first fluid extrusion head 110 is fixedly arranged on the extruder, or both fluid extrusion heads are arranged on the extruder in a fixed / detachable manner. In short, the implementation of the present invention is not limited by the material type of the first fluid and the second fluid and the installation method of the first fluid extrusion head 110 and the second fluid extrusion head 120.

[0027] The processor 190 is configured to perform operations when executing instructions, and the operations include: causing the extruder 140 to move along a predetermined trajectory to drive the first fluid extrusion head 110 to draw a calibration pattern on a preset plane using the first fluid; causing the extruder 140 to move to a camera position so that the camera 130 is aligned with feature points of a standard pattern, the standard pattern being a pattern that, when the first fluid extrusion head 110 is installed in a standard position on the extruder 140, drives the extruder 140 to move along a predetermined trajectory and drives the first fluid extrusion head 110 to draw a pattern on a preset plane using the first fluid; causing the camera 130 to acquire an image of the calibration pattern at the camera position, and obtains to a calibration image; based on the calibration image, determining first coordinates of feature points of the calibration figure in the coordinate system of the camera 130, wherein the feature points of the calibration figure correspond to feature points of the standard figure; obtaining second coordinates of the feature points of the standard figure in the coordinate system of the camera 130, third coordinates of the first fluid extrusion head 110 in the coordinate system of the camera 130 when the first fluid extrusion head 110 is installed in the standard position, and fourth coordinates of the camera 130 in the coordinate system of the second fluid extrusion head 120; and determining a fifth coordinate of the first fluid extrusion head 110 in the coordinate system of the second fluid extrusion head 120 based on the first coordinate, the second coordinate, the third coordinate and the fourth coordinate.

[0028] In some embodiments, the above operations also include: determining the sixth coordinate of the feature point of the calibration figure relative to the feature point of the standard figure in the coordinate system of the camera 130 based on the first coordinate and the second coordinate; determining the fifth coordinate based on the third coordinate, the fourth coordinate and the sixth coordinate.

[0029] According to another aspect of the present disclosure, a calibration method for a 3D printer 100 is also provided. Figures 3 to 5 The calibration method is described in detail.

[0030] Figure 3 FIG. 1 is a flow chart of a calibration method 300 for a 3D printer 100 according to an embodiment of the present disclosure. The 3D printer 100 includes an extruder 140, a first fluid extrusion head 110 disposed on the extruder 140, and a second fluid extrusion head 120 and a camera 130 disposed on the extruder 140. Figure 3 As shown, the method 300 includes:

[0031] Step 301 : The extruder 140 is moved along a predetermined trajectory to drive the first fluid extrusion head 110 to draw a calibration pattern on a preset plane using the first fluid.

[0032] Step 302, the extruder 140 is moved to a camera position so that the camera 130 is aligned with the characteristic points of the standard pattern. The standard pattern is a pattern drawn by the first fluid extrusion head 110 on a preset plane using the first fluid when the first fluid extrusion head 110 is installed in a standard position on the extruder 140 and the extruder 140 is driven to move along a predetermined trajectory.

[0033] Step 303 , enabling the camera 130 to acquire an image of the calibration pattern at the camera position to obtain a calibration image.

[0034] Step 304: Based on the calibration image, determine the first coordinates of the feature points of the calibration figure in the coordinate system of the camera 130. The feature points of the calibration figure correspond to the feature points of the standard figure.

[0035] Step 305 , obtaining the second coordinates of the feature points of the standard figure in the coordinate system of the camera 130 , the third coordinates of the first fluid extrusion head 110 in the coordinate system of the camera 130 when the first fluid extrusion head 110 is installed in the standard position, and the fourth coordinates of the camera 130 in the coordinate system of the second fluid extrusion head 120 .

[0036] Step 306 : determining a fifth coordinate of the first fluid extrusion head 110 in the coordinate system of the second fluid extrusion head 120 based on the first coordinate, the second coordinate, the third coordinate, and the fourth coordinate.

[0037] In the calibration method for the 3D printer 100 according to this embodiment, a calibration pattern is drawn on a preset plane, and an image of the calibration pattern is acquired by using the camera 130, and the coordinates of the first fluid extrusion head 110 relative to the second fluid extrusion head 120 are obtained by analyzing the calibration image. Thus, the relative position relationship between the two different extrusion heads is obtained, and in the subsequent 3D printing process, the first fluid is accurately applied to the target position on the 3D object to be printed based on the relative position relationship.

[0038] In the present embodiment, the installation of the first fluid extrusion head 110 is generally performed manually by the user. Due to the poor accuracy of manual installation, the position of each installation may be different from the standard position during design. If the error is not corrected during the printing process, the first fluid may be applied to the wrong position of the object to be printed. The method of the disclosed embodiment can calibrate the position of the first fluid extrusion head 110 relative to the second fluid extrusion head 120 after each installation by the user, and use the calibration data in the subsequent printing process, thereby preventing the decrease in the printing effect caused by the error of each installation.

[0039] Before the method of this embodiment is executed, the user can replace the first fluid extrusion head 110 and manually install the new first fluid extrusion head 110 on the extruder 140. Before step 301, a step of determining that the first fluid extrusion head 110 has been installed on the extruder 140 can also be included. This determination step can be implemented, for example, by a sensor (not shown) on the extruder 140. In one example, a force sensor can be installed at the position of the extruder 140 where the first fluid extrusion head 110 is installed. When the first fluid extrusion head 110 is installed on the extruder 140, it touches the force sensor, and the force sensor transmits the sensing signal to the processor 190, and the processor 190 determines that the first fluid extrusion head 110 has been installed on the extruder 140 in response to the signal. Alternatively, the determination step can also be implemented by other methods such as receiving a confirmation input from the user.

[0040] In step 301, the processor 190 sends a pre-set motion instruction to a driving mechanism (e.g., the first motor 150 and the second motor 160). In response to the motion instruction, the first motor 150 and the second motor 160 start to drive the extruder 140 to move along a predetermined trajectory. The above-mentioned trajectory can be a trajectory of a regular figure, such as a circular trajectory, a square trajectory, a triangular trajectory, etc., or it can be a straight line or a point. During the movement of the extruder 140, the first fluid extrusion head 110 is driven to move along the same trajectory. While the first fluid extrusion head 110 is moving, the first fluid extrusion head 110 outputs the first fluid. Thus, the first fluid extrusion head 110 can draw a calibration figure on a preset plane. The shape of the above-mentioned calibration figure corresponds to the predetermined trajectory, which can be, for example, a circle, a square, a triangle, etc., and in particular, it can also be a straight line or a point. In the present embodiment, the above-mentioned calibration figure can be a central symmetrical figure, such as a square. The calibration figure is selected as a central symmetrical figure, which is convenient for subsequent use of a camera to determine its feature points. The above-mentioned preset plane can be the plane where the printing platform is located (i.e., the printing plane), or in order to prevent the first fluid from contaminating the printing platform, a layer of printing material can be printed on the printing plane first, and then the above-mentioned calibration pattern can be drawn on the plane where the material layer of the formed printing material is located.

[0041] In step 302, the processor 190 sends a control instruction to the first motor 150 and the second motor 160, so that the extruder 140 moves to the camera position so that the camera 130 is aligned with the characteristic points of the standard figure. The above-mentioned standard figure can be just an imaginary theoretical figure, which is defined as when the first fluid extrusion head 110 is installed in the standard position on the extruder 140, the extruder 140 is driven to move according to a predetermined trajectory to drive the first fluid extrusion head 110 to draw a figure using the first fluid on a preset plane. The characteristic points of the above-mentioned standard figure can include points representing the characteristics of the figure, such as the center of the figure, the starting point of the figure, the corner points of the figure, and the end point of the figure. It can be understood that since the calibration figure and the standard figure are both drawn by the same predetermined trajectory of the extruder movement, the shapes of the two should be exactly the same, but the position may be slightly offset. In this embodiment, the above-mentioned standard figure can also be a central symmetrical figure such as a square, and the characteristic point can be the center of the standard figure. Since the standard position and the predetermined trajectory of the first fluid extrusion head 110 are both known, the position of the standard figure and the coordinates of its characteristic points can also be determined in advance. The processor 190 can control the first motor 150 and the second motor 160 to drive the extruder 140 to move to a predetermined camera position according to a predetermined instruction. At the camera position, the camera 130 is aligned with the feature points of the standard figure. In an example, the camera 130 is aligned with the feature points of the standard figure, which means that the center position of the lens of the camera 130 coincides with the feature points of the standard figure.

[0042] In step 303 , the camera 130 is used to obtain an image of the calibration pattern at the camera position. The image is a calibration image, which is used to calibrate the actual position of the first fluid extrusion head 110 on the extruder 140 later.

[0043] Before describing step 304 in detail, first refer to Figure 4 The imaging model of the camera 130 is introduced. Figure 4 FIG. 4 is a schematic diagram showing an imaging model 400 of a camera 130 of a 3D printer 100 according to an embodiment of the present disclosure. Figure 4 As shown, an object in the three-dimensional world (shown as a point P(Xw, Yw, Zw)) is imaged by the camera 130 and becomes a two-dimensional image (shown as a pixel point P(x, y)). The camera 130 imaging model 400 may involve four coordinate systems: a world coordinate system, a camera 130 coordinate system, an image physical coordinate system, and an image pixel coordinate system.

[0044] The world coordinate system is a reference system that represents the coordinates of an object in the real world, and the unit is a unit of length (e.g., millimeters). The camera 130 coordinate system is a reference system with the optical center as the origin, which has an Xc axis and a Yc axis parallel to the x direction and y direction of the image, respectively, and a Zc axis parallel to the optical axis, wherein Xc, Yc, and Zc are perpendicular to each other, and the unit is a unit of length. The image physical coordinate system (also called the image coordinate system) is a reference system with the intersection of the optical axis and the image plane as the origin, which has the x and y directions as shown in the figure, and the unit is a unit of length. The image pixel coordinate system (also called the pixel coordinate system) is a reference system with the vertex of the image as the origin, which has the u and v directions parallel to the x and y directions, respectively, and the unit is a pixel. Typically, the world coordinate system can be converted to the camera 130 coordinate system by the external parameters of the camera 130, and vice versa. Moreover, the camera 130 coordinate system can be converted to the image pixel coordinate system by the internal parameters of the camera (which usually include the focal length diagonal matrix and the pixel conversion matrix), and vice versa. Based on the above principle, after the camera 130 acquires an image, the image pixel coordinates of a certain point in the acquired image can be converted into corresponding coordinates in the coordinate system of the camera 130 .

[0045] In step 304, based on the calibration image, the first coordinates of the feature points of the calibration figure in the coordinate system of the camera 130 are determined. As described above, the image pixel coordinates of the feature points of the calibration figure in the calibration image can be converted to the coordinate system of the camera 130, which is equivalent to converting the coordinates of the feature points of the calibration figure in the world coordinate system to the coordinate system of the camera 130. The feature points of the calibration figure correspond to the feature points of the standard figure. In this embodiment, the calibration figure and the standard figure are, for example, both centrally symmetrical figures, and the feature points are the center points of the centrally symmetrical figures.

[0046] Figure 5 5 is a schematic diagram of the relationship 500 between various coordinates used for calibration according to one embodiment of the present disclosure, wherein the solid line represents the actual position, such as the position of the calibration figure, the actual position of the first fluid extrusion head, and the dotted line represents the theoretical position, such as the position of the standard figure, the standard position of the first fluid extrusion head. Figure 5 In the vector The coordinates of the feature point (the center point in this example) of the calibration figure in the coordinate system of the camera 130 can be obtained from the calibration image using the imaging model as described above.

[0047] In step 305, the second coordinate, the third coordinate and the fourth coordinate are obtained respectively. The second coordinate is the coordinate of the feature point of the standard figure in the coordinate system of the camera 130, the third coordinate is the coordinate of the first fluid extrusion head 110 in the coordinate system of the camera 130 when it is installed in the standard position, and the fourth coordinate is the coordinate of the camera 130 in the coordinate system of the second fluid extrusion head 120. Figure 5 As shown, the second coordinate is represented as a vector It is the coordinate of the center point of the standard figure in the coordinate system of the camera 130, which may be known or pre-calibrated. The third coordinate is represented by a vector It is the coordinate of the first fluid extrusion head 110 in the coordinate system of the camera 130 when it is installed in the standard position. Since the standard position is known, the coordinate can also be known or calibrated in advance. The fourth coordinate is represented by the vector It is the relative coordinate of the camera 130 relative to the second fluid extrusion head 120. In one example, the second fluid extrusion head 120 can be taken as the origin in the real world coordinate system, and the coordinate of the position of the camera 130 in the coordinate system is the vector Since the positions of the camera 130 and the second fluid extrusion head 120 are both fixed and known, the vector It can also be known or pre-calibrated. These known coordinates (for example: The coordinate information of the 3D printer 100 (such as the coordinate information of the 3D printer 100) can be pre-stored in the local memory of the 3D printer 100 or in the relevant remote server. When the relevant calibration calculation is required, the above coordinates can be read from the local memory or downloaded from the remote server.

[0048] It will be appreciated that although step 305 is described above as occurring after step 304, other embodiments are possible. For example, step 305 may occur before any one of steps 301 to 304.

[0049] In step 306, based on the first coordinate, the second coordinate, the third coordinate and the fourth coordinate obtained above, the fifth coordinate of the first fluid extrusion head 110 in the coordinate system of the second fluid extrusion head 120 is determined. Figure 5 As shown, the fifth coordinate is represented as a vector It is the coordinate of the first fluid extrusion head 110 in the coordinate system of the second fluid extrusion head 120. As mentioned above, the second fluid extrusion head 120 can be regarded as the origin in the real world coordinate system, and the coordinate of the actual position of the first fluid extrusion head 110 installed in the extruder 140 in the coordinate system is the vector

[0050] Reference below Figure 6Explain in detail how to use the first to fourth coordinates to get the fifth coordinate. Figure 6 An embodiment according to the present disclosure is shown. Figure 3 Flow chart of an example process (step 306) of determining the fifth coordinate in method 300. Figure 6 As shown, step 306 includes:

[0051] Step 601 : Determine, based on the first coordinate and the second coordinate, the sixth coordinate of the feature point of the calibration figure relative to the feature point of the standard figure in the coordinate system of the camera 130 .

[0052] Step 602: Determine the fifth coordinate according to the third coordinate, the fourth coordinate and the sixth coordinate.

[0053] In step 601, using the first coordinate Subtract the second coordinate Get the sixth coordinate, such as Figure 5 As shown, the sixth coordinate is

[0054] It can be understood that since the coordinate difference between the center of the standard figure and the center of the calibration figure is determined by the difference between the standard position and the actual position of the first extruder head, it can be considered that Figure 5 The sixth coordinate in and represents the seventh coordinate of the actual position of the first fluid output device 110 relative to the standard position in the camera 130 coordinate system In step 602, the third coordinate The fourth coordinate and the sixth coordinate (Equivalent to the seventh coordinate ) can be added to get the final fifth coordinate vector The fifth coordinate mentioned above can be applied to the subsequent 3D printing process.

[0055] Next, combine Figure 7 A detailed description is given of how to improve the 3D printing process based on the fifth coordinate obtained in the above method. Figure 7 A flow chart of a 3D printing method 700 according to one embodiment of the present disclosure is shown. The method 700 includes:

[0056] Step 701 , executing the calibration method for the 3D printer 100 .

[0057] Step 702 : Printing is performed using the second fluid extrusion head 120 .

[0058] Step 703 : when the first fluid extrusion head 110 is used to apply the first fluid to the printed object that has been printed by the second fluid extrusion head 120 , the motion trajectory of the extruder 140 is corrected according to the fifth coordinate.

[0059] In the present embodiment, the first fluid may be a release material, and the second fluid may be a printing material. The printing material is the building material that ultimately forms the object to be printed (or the target object). The release material may be applied between the two parts formed by the printing material to facilitate the separation between the two parts. For example, when printing the suspended part in the 3D object, the processor 190 first controls the extruder 140 to print out the support part using the second fluid extrusion head 120, and then controls the extruder 140 to apply the release material on the upper surface of the support part using the first fluid extrusion head 110. Next, the 3D object itself is printed. After molding, the support part is removed from the entire printed object to obtain the object to be printed.

[0060] In step 701, you can use Figure 3 , Figure 6 The calibration method shown obtains the fifth coordinate

[0061] In step 702, the support portion is printed using the second fluid extrusion head 120 according to the actual shape of the object to be printed.

[0062] The first fluid is applied to the printing object formed in step 702 using the first fluid extrusion head 110. It is understood that due to the position difference between the first fluid extrusion head 110 and the second fluid extrusion head 120, the motion trajectory of the first fluid extrusion head 110 needs to be corrected to ensure that the first fluid is accurately applied to the printing support portion. In step 703, the fifth coordinate obtained in step 701 can be used to The motion trajectory of the first fluid extrusion head 110 is corrected. Specifically, the motion trajectory of the extruder 140 when the second fluid extrusion head 120 prints the support part can be first obtained, and the motion trajectory is corrected along the fifth coordinate system. Shift in the opposite direction of The length of the first fluid extrusion head 110 is obtained by using the corrected motion trajectory to control the extruder 140 to drive the first fluid extrusion head 110 to print, which can ensure that the first fluid is accurately applied to the support part.

[0063] The above printing method 700 is described for the first fluid as a release material. However, it is understood that in other embodiments of the present invention, the first fluid and the second fluid can be printing materials of different materials, for example, printing materials of different colors. The first fluid and the second fluid can respectively form two parts of different colors of the final printed object. In the printing method of this embodiment, the first part formed by the second fluid can be printed first, and then the first fluid can be applied to the first part to form the second part. When applying the first fluid, the fifth coordinate is used. The motion trajectory of the extruder 140 is corrected.

[0064] According to an embodiment of the present disclosure, a non-transitory computer-readable storage medium is further provided, on which a computer program is stored, wherein when the computer program is executed by the processor 190, the steps of the method in any embodiment of the present disclosure are implemented.

[0065] According to an embodiment of the present disclosure, a computer program product is further provided, wherein when the computer program is executed by the processor 190, the steps of the method in any embodiment of the present disclosure are implemented.

[0066] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this disclosure can be performed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions disclosed in this disclosure can be achieved, and this document is not limited here.

[0067] It should be understood that in this specification, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships or dimensions that are based on the orientations or positional relationships or dimensions shown in the accompanying drawings, and these terms are used only for the convenience of description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present disclosure.

[0068] In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", "third" may explicitly or implicitly include one or more of the feature. In the description of the present disclosure, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0069] In the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0070] In the present disclosure, unless otherwise expressly specified and limited, a first feature being “above” or “below” a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being “above”, “above”, and “above” a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0071] This specification provides many different embodiments or examples that can be used to implement the present disclosure. It should be understood that these different embodiments or examples are purely exemplary and are not intended to limit the scope of protection of the present disclosure in any way. Those skilled in the art can conceive of various changes or replacements based on the disclosure of the present specification, which should all be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection defined by the attached claims.

Claims

1. A calibration method for a 3D printer, wherein: The 3D printer comprises: an extruder, a first fluid extrusion head arranged on the extruder, and a second fluid extrusion head and a camera arranged on the extruder, and the method comprises: The extruder is moved along a predetermined trajectory to drive the first fluid extrusion head to draw a calibration pattern on a preset plane using the first fluid; The extruder is moved to a camera position so that the camera is aligned with a feature point of a standard pattern, wherein the standard pattern is a pattern drawn by the first fluid extrusion head on the preset plane using the first fluid when the first fluid extrusion head is installed in a standard position on the extruder, and the extruder is driven to move along the predetermined trajectory; The camera is enabled to acquire an image of the calibration pattern at the camera position to obtain a calibration image; Based on the calibration image, determining first coordinates of feature points of the calibration figure in the coordinate system of the camera, wherein the feature points of the calibration figure correspond to feature points of the standard figure; Acquire a second coordinate of a feature point of the standard graphic in the coordinate system of the camera, a third coordinate of the first fluid extrusion head in the coordinate system of the camera when the first fluid extrusion head is installed in the standard position, and a fourth coordinate of the camera in the coordinate system of the second fluid extrusion head; and Based on the first coordinate, the second coordinate, the third coordinate, and the fourth coordinate, a fifth coordinate of the first fluid extrusion head in a coordinate system of the second fluid extrusion head is determined.

2. The method according to claim 1, wherein: Determining a fifth coordinate of the first fluid extrusion head in the coordinate system of the second fluid extrusion head includes: Determine, according to the first coordinate and the second coordinate, a sixth coordinate of the feature point of the calibration figure relative to the feature point of the standard figure in the coordinate system of the camera; and The fifth coordinate is determined according to the third coordinate, the fourth coordinate and the sixth coordinate.

3. The method according to claim 1, wherein: Acquiring a second coordinate of a feature point of the standard graphic in the coordinate system of the camera, a third coordinate of the first fluid extrusion head in the coordinate system of the camera when the first fluid extrusion head is installed in the standard position, and a fourth coordinate of the camera in the coordinate system of the second fluid extrusion head, comprising: Reading the second coordinate, the third coordinate and the fourth coordinate from a local memory of the 3D printer; or The second coordinate, the third coordinate, and the fourth coordinate are downloaded from a remote server.

4. The method according to claim 1, further comprising: Before the extruder is moved according to a predetermined trajectory, it is determined that the first fluid extrusion head is installed on the extruder.

5. The method according to any one of claims 1 to 4, wherein: The calibration figure includes a central symmetric figure, and the characteristic point of the calibration figure includes a central point of the central symmetric figure.

6. The method according to any one of claims 1 to 4, wherein: The first fluid is a release material, and the second fluid is a printing material.

7. The method according to claim 6, wherein: The release material includes one or more of heat-sensitive ink, ultraviolet fluorescent ink or colored ink.

8. The method according to any one of claims 1 to 4, in, The 3D printer further comprises a printing platform, which is disposed below the extruder and configured to support an object to be printed, and The preset plane includes a plane where the printing platform is located or a plane where a material layer of the printing material formed on the printing platform is located.

9. The method according to any one of claims 1 to 4, wherein: The first fluid extrusion head is snap-fitted to the extruder.

10. A 3D printing method, comprising: Performing the method according to any one of claims 1 to 9; as well as When the first fluid extrusion head is used to apply the first fluid to the printed object that has been printed by the second fluid extrusion head, the motion trajectory of the extruder is corrected according to the fifth coordinate.

11. A 3D printer, comprising: Extruder; A first fluid extrusion head, disposed on the extruder and configured to output a first fluid; A second fluid extrusion head, disposed on the extruder and configured to output a second fluid; A camera is arranged on the extruder; and A processor configured to implement the method according to any one of claims 1 to 10 when executing instructions. 12 . The 3D printer according to claim 11 , further comprising a driving mechanism configured to drive the extruder to move.

13. The 3D printer according to claim 12, wherein: The driving mechanism comprises: A first motor configured to drive the extruder to move in a first direction; and The second motor is configured to drive the extruder to move in a second direction, wherein the second direction intersects the first direction.

14. A non-transitory computer-readable storage medium having a computer program stored thereon, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

15. A computer program product comprising a computer program, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 10 are implemented.

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