3D printing equipment and 3D printing control method

Abstract

The invention discloses 3D printing equipment and a 3D printing control method, and relates to the technical field of 3D printing, and the 3D printing equipment comprises a spray head, a printing platform, a fault detection module, a wire feeding module and a main control module; the fault detection modules are fixedly arranged on the two sides of the printing platform. The nozzle is arranged above the printing platform; the main control module is used for controlling the spinning printing operation of the nozzle, the movement of the printing platform and the wire feeding of the wire feeding module; the fault detection module is used for detecting whether printing errors occur or not. In the 3D printing operation execution process, the possible printing errors that a model cannot be firmly adhered to a substrate and the model is severely warped and deformed in the printing process can be rapidly detected in real time, the printing operation is terminated when the printing errors are detected, and unnecessary waste of materials and electric power is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a 3D printing device and a 3D printing control method. Background Art

[0002] When a 3D printer prints a 3D model, it controls the continuous movement of the 3D printing platform and nozzle according to the 3D model's slice file. The filament ejected from the nozzle is stacked layer by layer on the print platform to form the final model. During the lengthy 3D printing process, printing errors may occur. For example, a portion of the completed model may not adhere firmly to the substrate or the model may warp severely. These two types of printing errors are particularly prone to warping. If this bottom portion is a critical dimension of the model, such as a mounting surface or reference surface, this warping can render the final printed model unusable. Furthermore, when warping is severe, the contact surface between the bottom of the model and the substrate becomes minimal, resulting in poor adhesion between the model and the substrate. This makes it very likely that the model will peel off the substrate during subsequent printing, causing the print to fail. When one or more of these printing errors occurs, the printer will not generate an error alarm and will continue printing, resulting in wasted material, printing time, and power. Summary of the Invention

[0003] In order to solve the above problems, the present invention proposes a 3D printing device and a 3D printing control method.

[0004] The technical solution of the present invention is: a 3D printing device includes a nozzle, a printing platform, a fault detection module, a wire feeding module and a main control module;

[0005] The fault detection module is fixed on both sides of the printing platform; the nozzle is set above the printing platform;

[0006] The main control module is used to control the filament printing operation of the nozzle, the movement of the printing platform, and the filament feeding of the filament feeding module; the fault detection module is used to detect whether a printing error occurs.

[0007] Furthermore, the fault detection module includes several groups of acquisition components and detection control modules;

[0008] The acquisition component is used to collect key data of the 3D printing model of the printing platform;

[0009] The detection control module is used to process the key data collected by the acquisition component and determine whether there is any printing error.

[0010] Furthermore, the horizontal acquisition field of view of the fault detection module is a convex polygonal area.

[0011] The beneficial effects of the present invention are:

[0012] Based on the above device, the present invention also proposes a 3D printing control method, comprising the following steps:

[0013] S1. Generate correct slice data based on the horizontal acquisition field of view of the fault detection module and the data of the 3D model;

[0014] S2. Perform 3D printing based on the correct slice data until the 3D printing job is completed or an error occurs, and then enter S3;

[0015] S3. Terminate the 3D printing operation and the fault detection operation.

[0016] Furthermore, S2 includes the following sub-steps:

[0017] S21. After printing several layers, use an acquisition component to collect key data of the 3D model;

[0018] S22. Determine whether there is a printing error based on the key data of the 3D model. If so, issue a printing failure alarm and stop the fault detection operation; otherwise, proceed to S23.

[0019] S23. After the interval, collect key data of the 3D model and return to S22 until the 3D printing job is completed or an error printing occurs.

[0020] Furthermore, in S22, the specific method for determining whether there is a printing error is as follows: extracting the outer contour of the geometric body composed of the first k layers and the distance of each group of acquisition components from the correct slice data of the 3D model; extracting the outer contour of the geometric body composed of the first k layers and the distance of each group of acquisition components from the key data of the 3D model; calculating the similarity between each two groups of distances, and if the similarity exceeds a threshold, there is a printing error.

[0021] Furthermore, in S23, the interval time The calculation formula is:

[0022] ;

[0023] Where, Indicates the Printing time of the layer, Indicates the Printing time of the layer, represents an integer greater than 0, Indicates the total number of slices and the The ratio of the difference between layers to the detection frequency, Indicates the layer number.

[0024] The beneficial effect of the present invention is that: through the 3D printing device and 3D printing control method provided by the present invention, it is possible to quickly and in real time detect printing errors that may exist in the printing process, such as the model not being able to stick firmly to the substrate and the model being severely warped and deformed, during the execution of the 3D printing job, and terminate the printing job when such printing errors are detected, thereby avoiding unnecessary waste of materials and electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a 3D printing device provided in this application;

[0026] Figure 2 A schematic diagram of the acquisition field of view of a fault detection module provided in this application;

[0027] Figure 3 A flow chart of a 3D printing control method provided in this application;

[0028] Figure 4 A schematic diagram of a specific implementation of fault judgment of a 3D printing control method provided in this application. DETAILED DESCRIPTION

[0029] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0030] like Figure 1 As shown, the present invention provides a 3D printing device, including a nozzle 10, a printing platform 20, a fault detection module 30, a wire feeding module and a main control module;

[0031] The fault detection module 30 is fixedly arranged on both sides of the printing platform 20; the nozzle 10 is arranged above the printing platform 20;

[0032] The main control module is used to control the spinning and printing operation of the nozzle 10, the movement of the printing platform 20, and the feeding of the wire material by the wire feeding module; the fault detection module 30 is used to detect whether a printing error occurs.

[0033] In the embodiment of the present invention, the fault detection module 30 includes several groups of acquisition components and detection control modules;

[0034] The acquisition component is used to collect key data of the 3D printing model of the printing platform 20;

[0035] The detection control module is used to process the key data collected by the acquisition component and determine whether there is any printing error.

[0036] Figure 2 The fault detection module 30 shown in FIG includes three groups of acquisition components, namely, acquisition component 301, acquisition component 302, and acquisition component 303. The fault detection module 30 may include more than three groups of acquisition components.

[0037] Figure 2 In the figure, the acquisition component 301 and the acquisition component 302 are respectively arranged on the side of the printing platform 20 along the X direction, and the acquisition component 303 is arranged on the side of the printing platform 20 along the Y direction. The horizontal acquisition field of view of the acquisition component refers to the area of ​​the printing platform 20 where the acquisition component can acquire data information. The horizontal acquisition field of view of the fault detection module 30 is the area of ​​the printing platform 20 that is covered by the horizontal acquisition fields of view of the three groups of acquisition components. When the horizontal acquisition field of view of the fault detection module 30 is a convex polygonal area, the area accounts for a higher proportion of the printing area of ​​the printing platform 20, so that the utilization rate of the printing area of ​​the printing platform 20 is higher (refer to Figure 2 The convex polygon has a larger area, which means that a larger model or more models can be printed because they can be placed; only the monitored range can be printed, and the range that cannot be monitored cannot be printed). Figure 2 -a, when the horizontal acquisition field of view of the acquisition component 301 is an open area defined by rays ab and ac, the horizontal acquisition field of view of the acquisition component 302 is an open area defined by rays ca and cb, and the horizontal acquisition field of view of the acquisition component 303 is an open area defined by rays ba and bc, the three acquisition components together define the horizontal acquisition field of view of the fault monitoring module, which is the convex triangle area formed by the lines connecting the three points a, b, and c in the figure; when the horizontal acquisition field of view of the acquisition component 301 is an open area defined by rays ad and af, the horizontal acquisition field of view of the acquisition component 302 is an open area defined by rays The open area defined by ce and cf, the horizontal acquisition field of view of the acquisition component 303 is the open area defined by rays bd and be. The three acquisition components jointly define the horizontal acquisition field of view of the fault monitoring module, which is the convex hexagonal area formed by the lines connecting the six points a, d, b, e, c and f in the figure; similarly, the concave hexagonal area formed by the lines connecting the six points a, g, b, h, c and j in the figure; it is obvious that the area of ​​the abc triangle and the adbecf hexagon is significantly larger than the area of ​​the agbhcj hexagon, that is, the range of the convex polygonal area is much larger than the range of the concave polygonal area. The larger the area, the larger the model that can be placed in the area, or the more models that can be placed in the area. The vertical acquisition field of view of the acquisition component (related to the camera acquisition field of view fov. Once the camera is determined, the horizontal fov is determined.) refers to the coverage range of the data information that can be collected by the acquisition component along the Z direction, such as Figure 2 The height range shown in Hz is greater than 5mm.

[0038] The acquisition component can be an RGB camera or a range-scanning camera. A range-scanning camera is a device that can obtain distance information from the object being measured to the camera component, such as a structured light depth camera, a time-of-flight depth camera, or a line laser 3D camera. A time-of-flight depth camera operates by emitting a series of infrared laser pulses that reflect and scatter upon encountering an object. The reflected or scattered light is received by the camera, which calculates the time difference or phase difference between emission and reflection back to the camera. This data is then collected to form a set of distance and depth data.

[0039] The acquisition component is used to collect key data of the 3D printing model on the printing platform 20. The key data of the 3D printing model can be image information containing the outer contours of the printing platform 20 and the bottom layer of the 3D printing model, or the distance information between the outer contour of the bottom layer of the 3D printing model and the acquisition module 110. Under normal circumstances, the RGB camera component can collect image information containing the outer contours of the printing platform 20 and the bottom layer of the 3D printing model. Through conventional image processing and recognition operations, the outer contour of the bottom layer of the 3D model and the interface characteristics of the printing platform 20 can be obtained. However, when the color of the printing platform 20 and the color of the filament are close, for example, both are black, the image collected by the ordinary RGB camera is represented in grayscale, which is not conducive to the identification and distinction between the printing platform 20 and the bottom layer of the 3D printing model. Using the distance scanning camera component, the data information collected is the distance information between the outline of the bottom layer of the 3D printing model and the camera component, which can greatly improve the speed and accuracy of feature recognition. Therefore, the present application preferably uses the distance scanning camera component as the acquisition component.

[0040] The outer contour of the bottom layer of the 3D printing model refers to the outline of the geometric body formed by the 3D printing trajectory of the first k layers in the slice data of the 3D printing model. Figure 1 When the 3D printer shown above prints a 3D model, it first needs to be layered using the 3D printer's slicing software. This process involves slicing the 3D model along the Z axis into planes at a specific layer spacing, converting the 3D model information into layer-based model information. The value of k in the above example is typically between 20 and 40 (a single layer alone is not visible, so multiple layers and a certain thickness are required for visibility).

[0041] The bottom layer may warp or peel off after printing, so testing is required throughout the entire printing process.

[0042] The detection control module is used to process the key data of the 3D printing model collected by multiple sets of acquisition components and compare it with the preset benchmark data. Based on the comparison results, it determines whether printing faults such as bottom layer warping or demolding occur in the current 3D printing job. If the judgment result is that a printing fault has occurred, a printing fault message is sent to the main control system. After receiving the printing fault message, the main control system terminates the current 3D printing job task.

[0043] In the embodiment of the present invention, the horizontal acquisition field of view of the fault detection module is a convex polygonal area.

[0044] Based on the above device, the present invention also proposes a printing control method, such as Figure 3 As shown, the following steps are included:

[0045] S1. Generate correct slice data based on the horizontal acquisition field of view of the fault detection module and the data of the 3D model;

[0046] S2. Perform 3D printing based on the correct slice data until the 3D printing job is completed or an error occurs, and then enter S3;

[0047] S3. Terminate the 3D printing operation and the fault detection operation.

[0048] In this embodiment of the present invention, S2 includes the following sub-steps:

[0049] S21. After printing several layers, use an acquisition component to collect key data of the 3D model;

[0050] S22. Determine whether there is a printing error based on the key data of the 3D model. If so, issue a printing failure alarm and stop the fault detection operation; otherwise, proceed to S23.

[0051] S23. After the interval, collect key data of the 3D model and return to S22 until the 3D printing job is completed or an error printing occurs.

[0052] In an embodiment of the present invention, in S22, the specific method for determining whether there is a printing error is as follows: extracting the outer contour of the geometric body composed of the first k layers and the distances of each group of acquisition components from the correct slice data of the 3D model; extracting the outer contour of the geometric body composed of the first k layers and the distances of each group of acquisition components from the key data of the 3D model; calculating the similarity between each two groups of distances, and if the similarity exceeds a threshold, there is a printing error.

[0053] In the embodiment of the present invention, in S23, the interval time is The calculation formula is:

[0054] ;

[0055] Where, Indicates the Printing time of the layer, Indicates the Printing time of the layer, represents an integer greater than 0, Indicates the total number of slices and the The ratio of the difference between layers to the detection frequency, Indicates the layer number.

[0056] In an embodiment of the present invention, in S1, the 3D printing device determines whether the bottom-layer outer contour of the 3D model is within the horizontal acquisition field of view of the fault detection module 30 based on the horizontal acquisition field of view of the fault detection module 30 and the data of the 3D model. The 3D model data can be a 3D format file of the 3D model, such as a model in an STP format file, or a slice file of the 3D model. If the 3D model data is a 3D format file of the 3D model, the slicing software pre-installed in the 3D printing device configures the position of the 3D model on the printing platform 20 so that the bottom-layer outer contour of the 3D model is within the horizontal acquisition field of view of the fault detection module 30. The slicing software then processes the 3D model to obtain slice data, which is used as the correct slice data for the 3D printing device to execute the 3D printing operation. If the 3D model data is already slice data, i.e., data represented by a slice file format, the 3D printing device first analyzes the slice file, extracts the data of the first k layers, and determines whether these k layers are within the acquisition field of view of the acquisition module. The extracted layer data can be used to obtain the printing trajectory coordinates (X, Y) of the layer on the printing platform 20. If all (X, Y) coordinate values ​​are within the horizontal acquisition field of view, there is no need to update the slice data. If at least one (X, Y) coordinate value is not within the horizontal acquisition field of view, all (X, Y) coordinate values ​​need to be offset (ΔX, ΔY) so that the offset (X+ΔX, Y+ΔY) values ​​are within the horizontal acquisition field of view (the horizontal acquisition field of view is determined by the acquisition component. When the field of view and installation position of the acquisition component are determined, the acquisition field of view is determined. The user's slice data is correct, which means that it can be correctly printed on a device without a fault monitoring module. However, if it is printed on a device with such fault printing monitoring as described in the present invention, the position on the xy plane may be outside the acquisition field of view. In this case, the model needs to be moved within the acquisition field of view). New slice data is obtained by offsetting the values ​​associated with the X and Y coordinates in the original slice data, and the new slice data is used as the correct slice data for the 3D printing device to perform 3D printing operations.

[0057] In step S2, the 3D printing device executes the 3D printing job based on the correct slicing data obtained in step S1, and starts the fault detection job at the same time, controls the fault detection module 30 to execute the fault detection method, and S21 controls the acquisition component to acquire the key data of the 3D model after the first k layers are printed; S22: processes the acquired key data of the 3D model and determines whether there is an erroneous printing, specifically: uses the distance scanning camera component as the acquisition method for the key data of the 3D model, and the judgment reference distance information used is the distance from the bottom outer contour of the 3D model corresponding to the correct slicing data of the 3D model to the acquisition component, that is, the outer contour of the geometric body composed of the first k layers of slices obtained by extracting the data of the first k layers from the correct slicing data of the 3D model and the distance between each group of acquisition components. Specifically, as Figure 4 As shown, the horizontal acquisition field of view of the fault detection module 30 is a convex hexagonal area. The polygonal area formed by the dotted line in the figure is the maximum acquisition range that can be covered by the three sets of acquisition components. The geometric body 50 composed of the first k layers of the 3D model is located within the horizontal acquisition field of view. The acquisition components 301 are respectively along direction, , that is, the distance from the a1, a2, a3, a4, a5, and a6 directions to the outer contour of the geometric body 50 is Similarly, it can be obtained that the acquisition component 302 follows The distance from the direction to the outer contour of the geometric body 50 is , the collection component 303 respectively follows The distance from the direction to the outer contour of the geometric body 50 is ,Will 、 、 As a reference distance for judgment. Obviously, The value of can be more. More values ​​means richer distance information, which is more beneficial and accurate for subsequent comparison and judgment. The specific value can be set according to actual conditions.

[0058] During the 3D printing process, the fault detection module 30 controls the acquisition components 301, 302 and 303 to collect the contours of the first k layers of the 3D printing model and the distances between the acquisition components, and then 、 、 The direction information is extracted from the collected distance information. The corresponding actual distance value is recorded as 、 、 . This measured distance 、 、 Distance from the Judgment Criteria Theory 、 、 Compare and calculate the similarity between the two, that is, the data column and data columns Similarity between data columns and data columns Similarity between data columns and data columns The three similarities are calculated. If any one of the similarities exceeds a threshold, it is considered to be mold release or warping. It is considered normal only if all three similarities are normal. The similarity can be calculated by calculating the mean, variance, distribution, etc. If the similarities of the three groups are all within a preset tolerance (here, distance data refers to the similarity between numerical values, a common mathematical method for determining the probability that one set of data is identical to another), it is determined that no printing error has occurred. Otherwise, it is determined that a printing error has occurred.

[0059] The fault detection module 30 always collects data on the k layers (the first k layers) close to the base plate for the 3D printing model, and does not detect other layers.

[0060] In step S23, if it is determined that a printing error occurs, a printing failure alarm is issued and the fault detection operation is stopped; otherwise, step S24 is executed.

[0061] In step S24, the interval time It can be calculated by the following method:

[0062] ;

[0063] The total number of detections is the number of detections preset by the 3D detection system, such as 10 times or 20 times, which is not limited here.

[0064] When a 3D printing job begins and the first k layers are printed, the first key data collection of the 3D model is performed. If no printing failures are detected, a second collection is performed after a time interval T. If no printing failures are detected, a third collection is performed after another time interval T. This process continues until the 3D printing job is completed or a printing failure is detected, at which point the collection ends. During this process, the time interval T between two consecutive collections remains constant.

[0065] In addition, there is another way to calculate T, the time interval between two adjacent collections The changes follow the following rules:

[0066] ;

[0067] Where, Indicates the The printing time of the layer, the value of m is from arrive , represents an integer greater than 0, The initial value is 0, and every time the process jumps to step S24, The value of will increase by 1 ( It is just a numerical value, without any specific meaning. When combined together, they have a holistic meaning and represent a group of Time, such as time, Time), T value is based on this time Calculate the obtained value; , indicating the interval Collect slices layer by layer ( It is the number of interval layers, which is a fixed value. Once the model is fixed, the slices are also fixed. The total number of layers is a fixed value. The detection frequency refers to the total number of detections performed within the total printing time of the model).

[0068] The 3D printing job starts and after the first k layers are printed, the key data of the 3D model is collected for the first time. If it is determined that no printing failure has occurred, the key data of the 3D model is collected after the first k layers are printed. After printing layer by layer, After a certain period of time, the second collection is performed. If it is determined that there is still no printing failure, when the After printing layer by layer, After a certain time, the third acquisition is performed, and so on, until the 3D printing job is completed or a printing failure is detected, and the acquisition ends.

[0069] In step S4, if the fault detection module 30 does not detect any printing faults during the execution of the 3D printing job, the 3D printing device ends printing and stops fault detection after the 3D printing job is completed. If the fault detection module 30 detects a printing fault during the execution of the 3D printing job, the 3D printing device terminates the current unfinished 3D printing job and issues a printing fault alarm. The printing fault alarm can be displayed in the form of an audio prompt or in the form of a text prompt on the terminal display.

[0070] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and it should be understood that the scope of protection of the present invention is not limited to such specific descriptions and embodiments. Those skilled in the art can make various other specific variations and combinations based on the technical teachings disclosed in the present invention without departing from the essence of the present invention, and such variations and combinations are still within the scope of protection of the present invention.

Claims

1. A 3D printing device, characterized in that: It includes a nozzle (10), a printing platform (20), a fault detection module (30), a wire feeding module and a main control module; The fault detection module (30) is fixedly arranged on both sides of the printing platform (20); the nozzle (10) is arranged above the printing platform (20); The main control module is used to control the spinning printing operation of the nozzle (10), the movement of the printing platform (20), and the feeding of the wire material of the wire feeding module; the fault detection module (30) is used to detect whether a printing error occurs.

2. The 3D printing device according to claim 1, characterized in that The fault detection module (30) includes several groups of acquisition components and detection control modules; The acquisition component is used to acquire key data of the 3D printing model of the printing platform (20); The detection control module is used to process the key data collected by the collection component and determine whether there is any printing error.

3. The 3D printing device according to claim 2, characterized in that The horizontal acquisition field of view of the fault detection module is a convex polygonal area.

4. A 3D printing control method, characterized in that: The following steps are involved: S1. Generate correct slice data based on the horizontal acquisition field of view of the fault detection module and the data of the 3D model; S2. Perform 3D printing based on the correct slice data until the 3D printing job is completed or an error occurs, and then enter S3; S3. Terminate the 3D printing operation and the fault detection operation.

5. The 3D printing control method according to claim 4, characterized in that: The S2 includes the following sub-steps: S21. After printing several layers, use an acquisition component to collect key data of the 3D model; S22. Determine whether there is a printing error based on the key data of the 3D model. If so, issue a printing failure alarm and stop the fault detection operation; otherwise, proceed to S23. S23. After the interval, collect key data of the 3D model and return to S22 until the 3D printing job is completed or an error printing occurs.

6. The 3D printing control method according to claim 5, characterized in that: In S22, the specific method for determining whether there is a printing error is as follows: extracting the outer contour of the geometric body composed of the first k layers and the distances of each group of acquisition components from the correct slice data of the 3D model; extracting the outer contour of the geometric body composed of the first k layers and the distances of each group of acquisition components from the key data of the 3D model; calculating the similarity between each two groups of distances, and if the similarity exceeds a threshold, there is a printing error.

7. The 3D printing control method according to claim 5, characterized in that: In the S23, the interval time The calculation formula is: ； Where, Indicates the Printing time of the layer, Indicates the Printing time of the layer, represents an integer greater than 0, Indicates the total number of slices and the The ratio of the difference between layers to the detection frequency, Indicates the layer number.

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