Nozzle calibration method of multi-nozzle three-dimensional printing device, multi-nozzle three-dimensional printing device and computer readable storage medium

Abstract

The application provides a nozzle calibration method of a multi-nozzle three-dimensional printing device, a multi-nozzle three-dimensional printing device and a computer readable storage medium, and is applied to the technical field of three-dimensional printing. The method acquires a path mapping relationship of a consumable variable track device, determines a first consumable and a second consumable that meet a visual distinguishing condition based on the relationship, and respectively transports the consumables to corresponding feeding paths of a first nozzle and a second nozzle. After the two consumables reach a preset feeding position, a first calibration pattern and a second calibration pattern are sequentially formed, a calibration image containing the two calibration patterns is collected, a nozzle offset compensation amount is determined according to the calibration image, and nozzle calibration parameters are updated accordingly, so that the motion track of the first nozzle and / or the second nozzle can be corrected in a subsequent double-nozzle printing process. Therefore, in a complex scene in which the corresponding relationship between a feeding source, a feeding port, a discharging port and a nozzle is variable, the offset calibration precision and reliability of the multi-nozzle three-dimensional printing device with the consumable variable track device are improved.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and in particular to a nozzle calibration method for multi-nozzle 3D printing equipment, a multi-nozzle 3D printing equipment, and a computer-readable storage medium. Background Technology

[0002] 3D printing equipment typically uses nozzles to extrude molten filament onto a printing platform, forming the target model layer by layer along a preset path. To improve printing efficiency and expand the range of printing colors or material types, some 3D printing equipment is equipped with multiple nozzles or multiple feed channels, and uses filament switching mechanisms, filament track changers, and other structures to selectively deliver different filaments to the corresponding nozzles.

[0003] In multi-nozzle 3D printing equipment, nozzle offset calibration is usually required between different nozzles to ensure that the actual forming position of each nozzle on the printing platform is consistent with the theoretical position.

[0004] In related technologies, since the consumable track changer changes the original fixed feeding relationship between the material source and the nozzle, if the nozzle offset calibration process still determines the source of calibration consumables according to the fixed feeding relationship, problems may occur such as the calibration consumables not entering the target nozzle, the consumables used to print the calibration pattern being inconsistent with expectations, or the arrival status being inaccurate, which in turn affects the reliability of calibration pattern recognition and nozzle offset compensation. Summary of the Invention

[0005] The purpose of this invention is to provide a nozzle calibration method for a multi-nozzle 3D printing device, a multi-nozzle 3D printing device, and a computer-readable storage medium, so as to improve the offset calibration accuracy and calibration reliability between multiple nozzles in scenarios with consumable track changers.

[0006] According to a first aspect of the present invention, a calibration method for a multi-nozzle 3D printing device is provided. The multi-nozzle 3D printing device includes a filament guide device, a first nozzle, a second nozzle, a first extrusion mechanism, a second extrusion mechanism, an image acquisition device, and a controller. The filament guide device includes at least two feed inlets and at least two discharge outlets, the at least two discharge outlets being respectively connected to the feeding paths corresponding to the first nozzle and the second nozzle. The method is executed by the controller and includes: Obtain the path mapping relationship of the consumable track changer. The path mapping relationship is used to characterize the feeding correspondence between the material supply source, the inlet, the outlet and the target nozzle. The target nozzle includes the first nozzle and the second nozzle. Based on the path mapping relationship, a first consumable for calibrating the nozzle offset of the first nozzle and a second consumable for calibrating the nozzle offset of the second nozzle are determined, wherein the first consumable and the second consumable satisfy the visual discrimination conditions required for image recognition. According to the path mapping relationship, the consumable track changer is controlled to transport the first consumable to the feeding path corresponding to the first nozzle, and the second consumable to the feeding path corresponding to the second nozzle; Obtain arrival detection information for the first consumable and the second consumable; When the arrival detection information indicates that both the first consumable and the second consumable have reached the corresponding preset feeding position, the first extrusion mechanism is controlled to drive the first consumable to be extruded through the first nozzle to form a first calibration pattern. After the first calibration pattern is formed, the second extrusion mechanism is controlled to drive the second consumable to be extruded through the second nozzle to form the second calibration pattern; The image acquisition device is controlled to acquire a calibration image containing the first calibration pattern and the second calibration pattern; The nozzle offset compensation amount between the first nozzle and the second nozzle is determined based on the calibration image; The nozzle calibration parameters corresponding to the first nozzle and the second nozzle are updated according to the nozzle offset compensation amount, so that the nozzle calibration parameters are used to correct the motion trajectory of the first nozzle and / or the second nozzle in the subsequent dual-nozzle printing process.

[0007] By acquiring the path mapping relationship of the consumable track converter and making this path mapping relationship characterize the feeding correspondence between the feed source, inlet, outlet, and target nozzle, the actual feeding path of the calibration consumable can be clearly defined in the nozzle offset calibration process. This avoids feeding according to the fixed binding relationship between the feed source and the nozzle, which could lead to the consumable entering the wrong nozzle. Furthermore, by determining the first consumable for the first nozzle and the second consumable for the second nozzle based on the path mapping relationship, and controlling the consumable track converter to deliver the first and second consumables to the corresponding nozzles via their respective feeding paths, a consistent control link can be formed between consumable selection, consumable track converter switching, and nozzle feeding. This improves the automation level and path reliability of the nozzle offset calibration process after installing the consumable track converter.

[0008] Secondly, by acquiring the arrival detection information of the first and second consumables, and forming the first and second calibration patterns sequentially only after both have reached their corresponding preset feeding positions, it is possible to avoid starting to print the calibration pattern when the consumables are not in place, the feeding path is incorrect, or the nozzle is not ready to discharge. This reduces the occurrence of missing lines, broken lines, color mismatches, or abnormal pattern shapes in the calibration pattern. Forming the second calibration pattern after the first calibration pattern is formed ensures a clear sequential relationship between the printing actions of the two nozzles, reducing the risk of affecting the quality of the calibration pattern due to unstable states during the switching process between the two nozzles.

[0009] Furthermore, the first and second consumables meet the visual discrimination conditions required for image recognition, making the first and second calibration patterns visually distinguishable in the calibration image. After the image acquisition device acquires a calibration image containing the two calibration patterns, it determines the nozzle offset compensation amount based on the calibration image and updates the nozzle calibration parameters based on this compensation amount. This allows the subsequent dual-nozzle printing process to correct the movement trajectory of the first and / or second nozzles based on the actually measured relative positions of the nozzles. Thus, even when the consumable track changer alters the feeding path, dual-nozzle offset calibration can still be stably completed, improving the reliability of the calibration compensation amount and the positional consistency of subsequent dual-nozzle collaborative printing.

[0010] In some exemplary embodiments of the present invention, based on the foregoing scheme, obtaining the path mapping relationship of the consumable track changer includes: The control target material supply source delivers consumables to the consumable track changer; Acquire trigger information from sensors located at at least one feed inlet of the consumable track changer; The target feed port connected to the target material supply source is determined based on the feed port corresponding to the triggered sensor. Obtain the current switching gear of the consumable track converter; The path mapping relationship is generated or updated based on the target material source, the target inlet, the target outlet corresponding to the current switching gear, and the target nozzle connected to the target outlet.

[0011] By controlling the target feed source to deliver consumables to the consumable track converter and acquiring trigger information from sensors located at at least one inlet of the consumable track converter, the target inlet connected to the target feed source can be confirmed using the actual location of the triggering sensor, rather than relying solely on user memory or preset connection relationships. Furthermore, by determining the target inlet based on the inlet corresponding to the triggered sensor, and combining this with the current switching position of the consumable track converter, the target outlet, and the target nozzle to generate or update the path mapping relationship, the path mapping relationship can reflect the actual connection and switching status of the current equipment. This reduces path identification errors caused by incorrect feed source connection, changes in the insertion sequence of the feed tube, or changes in the consumable track converter's position, improving the accuracy of subsequent consumable selection and feed control based on the path mapping relationship.

[0012] In some exemplary embodiments of the present invention, based on the foregoing scheme, obtaining the path mapping relationship of the consumable track changer includes: Displays a settings interface for configuring the connection between the material supply source and the inlet; Receive connection information input by the user in the settings interface; The path mapping relationship is generated or updated based on the specified connection information and the preset connection relationship between the outlet and nozzle of the consumable track changer.

[0013] By displaying a settings interface for configuring the connection between the feed source and the inlet, and receiving user-inputted connection specifications, the system can still establish a correspondence between the feed source and the inlet even when automatic sensor recognition is insufficient, consumables are not yet loaded in the feed source, or the user wishes to manually specify the connection. Furthermore, by generating or updating the path mapping relationship based on this connection specification information and the preset connection relationship between the outlet and the nozzle, the nozzle offset calibration process can be compatible between automatic recognition and manual configuration. This improves the usability and fault tolerance of path mapping relationship acquisition in different installation scenarios, reducing situations where the calibration process cannot be started due to the inlet not being automatically recognized.

[0014] In some exemplary embodiments of the present invention, based on the foregoing scheme, the path mapping relationship includes a first mapping sub-relationship and a second mapping sub-relationship; The first mapping sub-relationship is used to characterize the feeding correspondence between the first material source, the first inlet, the first outlet, and the first nozzle; The second mapping relationship is used to characterize the feeding correspondence between the second material source, the second inlet, the second outlet, and the second nozzle; Determining a first consumable for nozzle offset calibration of the first nozzle and a second consumable for nozzle offset calibration of the second nozzle based on the path mapping relationship includes: At least one first candidate consumable that can be delivered to the first nozzle is determined based on the first mapping sub-relationship; At least one second candidate consumable that can be delivered to the second nozzle is determined based on the second mapping sub-relationship; The first consumable is determined from the at least one first candidate consumable, and the second consumable is determined from the at least one second candidate consumable.

[0015] By dividing the path mapping relationship into a first mapping sub-relationship and a second mapping sub-relationship, and respectively characterizing the feeding correspondence between the first material supply source, the first inlet, the first outlet, and the first nozzle, as well as the feeding correspondence between the second material supply source, the second inlet, the second outlet, and the second nozzle, the calibration consumable sources for the two nozzles can be analyzed separately, avoiding confusion of candidate consumables for different nozzles in scenarios with multiple material supply sources, multiple inlets, and multiple outlets. Furthermore, by separately identifying at least one first candidate consumable that can be delivered to the first nozzle and at least one second candidate consumable that can be delivered to the second nozzle, and then determining the first and second consumables from the corresponding candidate consumables, it can be ensured that the selected consumables not only meet the calibration requirements but can also actually be delivered to the corresponding nozzle. This improves the consistency between consumable selection and the feeding path, reducing the risk that the selected consumables may fail to enter the target nozzle or enter a non-target nozzle.

[0016] In some exemplary embodiments of the present invention, based on the foregoing scheme, the visual discrimination condition includes at least one of the following: The color attribute difference between the first consumable and the second consumable is greater than or equal to a preset color difference threshold; The first consumable and the second consumable correspond to dark-colored consumable and light-colored consumable, respectively.

[0017] By limiting the visual distinction condition to a color attribute difference greater than or equal to a preset color difference threshold, and / or limiting the first and second consumables to correspond to dark and light consumables respectively, the consumables used for nozzle offset calibration can be constrained in terms of color recognizability. Since the first and second calibration patterns are printed from the first and second consumables respectively, the aforementioned color attribute difference or lightness / darkness difference allows the two calibration patterns to be clearly distinguished in the calibration image, reducing the probability of misidentification, inaccurate boundary positioning, or unstable center position extraction during image recognition. Therefore, the visual recognizability of the calibration pattern can be improved, thereby enhancing the reliability of nozzle offset compensation calculation from the source.

[0018] In some exemplary embodiments of the present invention, based on the foregoing scheme, according to the path mapping relationship, the consumable track changer is controlled to transport the first consumable to the feeding path corresponding to the first nozzle, and to transport the second consumable to the feeding path corresponding to the second nozzle, including: The first target feeding channel between the first material supply source where the first consumable is located and the first nozzle is determined according to the path mapping relationship; Control the consumable track changer to switch to the first switching gear corresponding to the first target feeding channel, and control the first feeding source to deliver the first consumable to the feeding path corresponding to the first nozzle; The second target feeding channel between the second material supply source and the second nozzle is determined according to the path mapping relationship; The consumable track changer is controlled to switch to the second switching position corresponding to the second target feeding channel, and the second feeding source is controlled to deliver the second consumable to the feeding path corresponding to the second nozzle.

[0019] By determining the first target feeding channel from the first feed source to the first nozzle for the first consumable and the second target feeding channel from the second feed source to the second nozzle for the second consumable based on the path mapping relationship, the complete path for each consumable can be clearly defined before feeding. Furthermore, by controlling the consumable track converter to switch to the corresponding switching position and controlling the corresponding feed source to feed to the corresponding nozzle, a one-to-one execution relationship is established between the consumable track converter's position control, the feed source's feeding action, and the target nozzle. This reduces feeding anomalies caused by the consumable track converter not being switched to the correct position, incorrect feed source selection, or incorrect target nozzle selection, and improves the certainty that the two calibration consumables reach their respective nozzles.

[0020] In some exemplary embodiments of the present invention, based on the foregoing scheme, obtaining the arrival detection information of the first consumable and the second consumable includes: The trigger information of at least two of the multiple sensors is acquired, the multiple sensors including at least two of the following: a sensor located at the feed inlet of the consumable track changer, a sensor located at the first extrusion mechanism, a sensor located at the second extrusion mechanism, a sensor located upstream of the first nozzle, and a sensor located upstream of the second nozzle; Based on the trigger information from the at least two sensors, it is determined whether the first consumable has reached the preset feeding position corresponding to the first nozzle, and whether the second consumable has reached the preset feeding position corresponding to the second nozzle.

[0021] By acquiring trigger information from at least two of a plurality of sensors, including those located at the feed inlet of the consumable track changer, the first extrusion mechanism, the second extrusion mechanism, upstream of the first nozzle, and upstream of the second nozzle, the status of the consumable can be confirmed from multiple nodes along the feeding path. Compared to relying on a single sensor to determine whether the consumable has entered the path, multi-point trigger information can reflect the consumable's propulsion process and current position within the path. Further determining whether the first and second consumables have reached their corresponding preset feeding positions based on the trigger information from at least two sensors can reduce the risk of misjudgment caused by false triggering, missed triggering, or partial blockage of the path from a single sensor. This improves the accuracy of the arrival detection information and avoids initiating calibration pattern printing before the consumable has actually reached the vicinity of the target nozzle.

[0022] In some exemplary embodiments of the present invention, based on the foregoing scheme, the method further includes: The preset triggering sequence corresponding to the current feeding process is determined based on the path mapping relationship; Obtain the actual triggering sequence of multiple sensors during the current feeding process; If the actual triggering sequence is inconsistent with the preset triggering sequence, the nozzle offset calibration process is stopped, and a prompt message is output to indicate that the consumable track changer connection is abnormal, the material supply source connection is abnormal, the material tube connection is abnormal, or the consumable is not in place.

[0023] By determining the preset trigger sequence corresponding to the current feeding process based on the path mapping relationship, and comparing the actual trigger sequence of multiple sensors with this preset trigger sequence, it is possible to determine not only whether the sensors are triggered, but also whether the consumables pass through each detection position along the expected path and in the expected order. When the actual trigger sequence is inconsistent with the preset trigger sequence, it indicates that there may be an abnormality in the consumable track changer connection, the material supply source connection, the material tube connection, or the consumables arrival. At this time, the nozzle offset calibration process is stopped and a prompt message is output, which can prevent the printing of calibration patterns under abnormal path conditions, thereby preventing the generation of erroneous calibration data. This improves the fault identification capability and safety of the calibration process, and reduces the risk of users performing subsequent printing based on incorrect nozzle offset compensation amounts.

[0024] In some exemplary embodiments of the present invention, based on the foregoing scheme, before controlling the consumable track changer to transport the first consumable and the second consumable according to the path mapping relationship, the method further includes: Set the consumable source determination method in the nozzle offset calibration process to a consumable track changer feeding calibration mode that determines the consumable source based on the path mapping relationship. Based on the path mapping relationship, the feed source, inlet, outlet and feeding path corresponding to the nozzle to be calibrated are analyzed, and feeding control commands for controlling the consumable track changer and the corresponding feed source to perform feeding are generated according to the analysis results.

[0025] By setting the consumable source determination method in the nozzle offset calibration process to be based on path mapping before feeding, the calibration process can be transformed from control logic applicable to fixed feeding relationships to control logic applicable to switchable feeding paths. Furthermore, by parsing the feeding source, inlet, outlet, and feeding path corresponding to the nozzle to be calibrated based on the path mapping relationship, and generating feeding control commands based on the parsing results, the consumable source parsing results in the calibration process can directly correspond to the consumable track converter control commands. This avoids selecting the wrong feeding source or incorrectly controlling the consumable track converter setting due to using fixed nozzle binding logic in the calibration process, improving the software flow adaptability when the consumable track converter participates in nozzle offset calibration.

[0026] In some exemplary embodiments of the present invention, based on the foregoing scheme, controlling the first extrusion mechanism to drive the first consumable to be extruded via the first nozzle includes: The first extrusion mechanism is controlled to drive the first consumable to be extruded through the first nozzle to form at least one of a first calibration line extending in a first direction and a second calibration line extending in a second direction; Controlling the second extrusion mechanism to drive the second consumable to be extruded through the second nozzle includes: The second extrusion mechanism is controlled to drive the second consumable to be extruded through the second nozzle to form at least one of a third calibration line extending along the first direction and a fourth calibration line extending along the second direction. Wherein, the first direction is perpendicular to the second direction, the first calibration line and the third calibration line are used to determine the nozzle offset compensation amount in the second direction, and the second calibration line and the fourth calibration line are used to determine the nozzle offset compensation amount in the first direction.

[0027] By controlling the first extrusion mechanism to drive the first consumable to extrude through at least one of a first calibration line extending in a first direction and a second calibration line extending in a second direction from the first nozzle, and by controlling the second extrusion mechanism to drive the second consumable to extrude through at least one of a third calibration line extending in the first direction and a fourth calibration line extending in the second direction from the second nozzle, the relative offset of the two nozzles in different coordinate directions can be reflected using calibration lines in different directions. Since the first direction and the second direction are perpendicular to each other, the first and third calibration lines extending in the first direction can be used to determine the positional deviation in the second direction, and the second and fourth calibration lines extending in the second direction can be used to determine the positional deviation in the first direction. Thus, the nozzle offset compensation amount can be decomposed into two mutually perpendicular directions for calculation, improving the directionality and accuracy of nozzle offset identification, and is particularly suitable for calibrating the two-dimensional offset of dual nozzles in the printing plane.

[0028] In some exemplary embodiments of the present invention, based on the foregoing scheme, determining the nozzle offset compensation amount between the first nozzle and the second nozzle according to the calibration image includes: Identify the first pattern center position of the first calibration pattern and the second pattern center position of the second calibration pattern in the calibration image; The measured relative position between the first calibration pattern and the second calibration pattern is determined based on the center position of the first pattern and the center position of the second pattern. Obtain the theoretical relative position between the first nozzle and the second nozzle; The nozzle offset compensation amount is determined based on the difference between the measured relative position and the theoretical relative position.

[0029] By identifying the center positions of the first and second calibration patterns in the calibration image and determining their measured relative positions, the calibration patterns in the image can be converted into calculable positional data. Further, the theoretical relative positions between the first and second nozzles are obtained, and the nozzle offset compensation amount is determined based on the difference between the measured and theoretical relative positions. This transforms the deviation of the actual printing result from the theoretical nozzle spacing into compensation parameters required for subsequent motion trajectory correction. Therefore, compensation can avoid relying solely on assembly dimensions or mechanical design values, allowing the nozzle offset compensation amount to reflect actual equipment assembly errors, nozzle installation errors, and printing errors, thereby improving the practicality and accuracy of the calibration results.

[0030] In some exemplary embodiments of the present invention, based on the foregoing scheme, before controlling the image acquisition device to acquire a calibration image containing the first calibration pattern and the second calibration pattern, the method further includes: The image acquisition device is controlled to acquire a pre-acquired image containing the image regions corresponding to the first consumable and the second consumable; Based on the pre-acquired image, image difference parameters are obtained between the corresponding image regions of the first consumable and the second consumable. The image difference parameters include at least one of grayscale difference, brightness difference, hue difference, and saturation difference. Determine the image acquisition parameters and / or image recognition parameters based on the image difference parameters; The image acquisition device is controlled to acquire the calibration image according to the image acquisition parameters, and / or the first calibration pattern and the second calibration pattern are identified according to the image recognition parameters.

[0031] By controlling the image acquisition device to acquire a pre-acquired image containing the corresponding image areas of the first and second consumables before acquiring the formal calibration image, and obtaining image difference parameters such as grayscale difference, brightness difference, hue difference, or saturation difference between the corresponding image areas of the first and second consumables based on the pre-acquired image, the actual visual differences under the current lighting, consumable color, and imaging conditions can be obtained before formally recognizing the calibration pattern. Further determining image acquisition parameters and / or image recognition parameters based on the image difference parameters, and acquiring calibration images or recognizing calibration patterns according to the corresponding parameters, allows the exposure, threshold, or recognition rules to match the actual imaging state of the current calibration consumables. This reduces image recognition errors caused by ambient light, supplementary lighting, consumable surface reflection, or insufficient color difference, and improves the stability of center position recognition for the first and second calibration patterns.

[0032] In some exemplary embodiments of the present invention, based on the foregoing scheme, the first extrusion mechanism is a short-range extrusion mechanism located close to the first nozzle, the second extrusion mechanism is a long-range extrusion mechanism spaced apart from the second nozzle, and the feeding path corresponding to the second nozzle includes a long-range feeding path located between the second extrusion mechanism and the second nozzle. Controlling the second extrusion mechanism to drive the second consumable to be extruded through the second nozzle includes: The printing speed during the formation of the second calibration pattern is limited to no more than a preset speed threshold, and the printing acceleration during the formation of the second calibration pattern is limited to no more than a preset acceleration threshold; and / or, The extrusion compensation parameters corresponding to the remote feeding path are invoked, and the feeding action of the second extrusion mechanism is controlled based on the extrusion compensation parameters.

[0033] By defining the first extrusion mechanism as a short-range extrusion mechanism located close to the first nozzle, and the second extrusion mechanism as a long-range extrusion mechanism spaced apart from the second nozzle, and specifying that the feeding path corresponding to the second nozzle includes a long-range feeding path located between the second extrusion mechanism and the second nozzle, the printing control of the second calibration pattern can be adapted to the asymmetric extrusion architecture with varying distances. Since the long-range feeding path is more susceptible to factors such as path length, pipe friction, consumable elastic deformation, and pressure transmission hysteresis than the short-range feeding path, limiting the printing speed to no greater than a preset speed threshold and the printing acceleration to no greater than a preset acceleration threshold when the second extrusion mechanism drives the second consumable through the second nozzle can reduce the impact of delayed pressure build-up in the long-range feeding path on the linewidth and continuity of the calibration pattern under high-speed or high-acceleration motion. Furthermore, by calling the extrusion compensation parameters corresponding to the long-range feeding path and controlling the feeding action of the second extrusion mechanism based on these parameters, the ejection response of the second nozzle can be made closer to the printing command requirements. This improves the forming stability of the second calibration pattern and reduces the impact of discontinuous patterns, under-extrusion in the initial segment, or line deviation on the calculation of nozzle offset compensation on the long-range extrusion side.

[0034] According to a second aspect of the present invention, a multi-nozzle 3D printing apparatus is provided, comprising: A consumable track changer includes at least two inlets and at least two outlets, the consumable track changer being used to selectively connect any of the inlets and any of the outlets; The first nozzle and the second nozzle are respectively connected to the feeding paths corresponding to different discharge ports of the consumable track changer; A first extrusion mechanism is provided corresponding to the first nozzle; A second extrusion mechanism is provided corresponding to the second nozzle; An image acquisition device is used to acquire images of calibration patterns printed by the first nozzle and the second nozzle; At least one sensor is disposed at at least one of the following: the feed inlet of the consumable track changer, the first extrusion mechanism, the second extrusion mechanism, upstream of the first nozzle, and upstream of the second nozzle; for detecting the triggering state or the positioning state of the consumable. The controller is connected to the consumable track changer, the first extrusion mechanism, the second extrusion mechanism, the image acquisition device, and the at least one sensor, respectively, and the controller is configured to perform the calibration method of the multi-nozzle 3D printing equipment described above.

[0035] According to a third aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the above-described calibration method for a multi-nozzle 3D printing device.

[0036] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the specification, serve to explain the principles of the invention.

[0038] Figure 1 The schematic diagram illustrates a structural schematic of an embodiment of the multi-nozzle 3D printing device provided by the present invention; Figure 2 This schematically illustrates a flowchart of a first embodiment of the calibration method for a multi-nozzle 3D printing device provided by the present invention. Figure 3 This schematically illustrates a flowchart of a second embodiment of the calibration method for a multi-nozzle 3D printing device provided by the present invention. Figure 4 This schematically illustrates a flowchart of a third embodiment of the calibration method for a multi-nozzle 3D printing device provided by the present invention. Figure 5 This schematically illustrates a flowchart of a fourth embodiment of the calibration method for a multi-nozzle 3D printing device provided by the present invention. Figure 6 This schematically illustrates a flowchart of a fifth embodiment of the calibration method for a multi-nozzle 3D printing device provided by the present invention. Figure 7 A schematic diagram of a computer-readable storage medium according to some embodiments of the present invention is shown.

[0039] Explanation of reference numerals in the attached figures 100. Multi-nozzle 3D printing equipment; 110. Consumable trajectory changer; 111. First feed inlet; 112. Second feed inlet; 120. First nozzle; 130. Second nozzle; 140. First extrusion mechanism; 150. Second extrusion mechanism; 160. Controller; 170. Printing platform; 180. Tool head; 181. First sensor; 182. Second sensor; 183. Third sensor; 184. Image acquisition device; 191. First consumable; 192. Second consumable. Detailed Implementation

[0040] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0041] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0042] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of this invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0043] According to one aspect of the present invention, a multi-nozzle 3D printing apparatus 100 is provided. This multi-nozzle 3D printing apparatus 100 can be a fused deposition modeling (FDM) apparatus or other 3D printing apparatus that extrudes filaments through nozzles to form a printed model. The multi-nozzle 3D printing apparatus 100 is capable of feeding at least two types of filaments to different nozzles to achieve multi-material printing, multi-color printing, or multi-nozzle collaborative printing.

[0044] In some embodiments, reference Figure 1 As shown, the multi-nozzle 3D printing equipment 100 includes a filament converter 110, a first nozzle 120, a second nozzle 130, a first extrusion mechanism 140, a second extrusion mechanism 150, an image acquisition device 184, at least one sensor, and a controller 160. The filament converter 110 is used to feed at least two candidate filaments from a plurality of candidate filaments to the feeding paths corresponding to the first nozzle 120 and the second nozzle 130, respectively. The plurality of candidate filaments may include filaments with different colors, brightness, transparency, material types, or physical moduli. For example, the candidate filaments may be printing filaments of different colors, or printing filaments with different hardness, elasticity, or rigidity.

[0045] The consumable track changer 110 may have multiple feed inlets and at least two discharge outlets. Multiple candidate consumables can be dispensed from their respective feed inlets (e.g., ...). Figure 1 The first feed inlet 111 and the second feed inlet 112 of the consumable guideway converter 110 are fed into the consumable guideway converter 110. The consumable guideway converter 110 can selectively connect any feed inlet and any discharge outlet through an internal switching mechanism, thereby conveying at least one candidate consumable to the feeding path corresponding to the first nozzle 120 and conveying at least another candidate consumable to the feeding path corresponding to the second nozzle 130. In some embodiments, the first nozzle 120 and the second nozzle 130 are respectively connected to the feeding paths corresponding to different discharge outlets of the consumable guideway converter 110. That is, one discharge outlet of the consumable guideway converter 110 can be connected to the first nozzle 120 through the first feeding path, and the other discharge outlet of the consumable guideway converter 110 can be connected to the second nozzle 130 through the second feeding path.

[0046] In other words, the consumable track changer 110 can change the feeding correspondence between candidate consumables and nozzles, so that different candidate consumables can be assigned to different nozzles according to the needs of printing or calibration tasks. In some embodiments, the feed inlet, feed outlet, feed source and target nozzle of the consumable track changer 110 can be represented by a path mapping relationship, which is used to characterize the feeding correspondence between the feed source, feed inlet, feed outlet and target nozzle, and the target nozzle may include a first nozzle 120 and a second nozzle 130.

[0047] In some embodiments, a first extrusion mechanism 140 is correspondingly provided for the first nozzle 120. The first extrusion mechanism 140 can be a short-range extrusion mechanism. A short-range extrusion mechanism can be understood as an extrusion drive mechanism for driving the first consumable 191 to be conveyed to the first nozzle 120, which is located close to or integrated with the first nozzle 120. Therefore, the conveying path of the first consumable 191 from the extrusion drive mechanism to the first nozzle 120 is shorter, the discharge response of the first nozzle 120 is relatively faster, and the extrusion hysteresis is smaller.

[0048] A second extrusion mechanism 150 is correspondingly provided for the second nozzle 130. The second extrusion mechanism 150 can be a remote extrusion mechanism, or other extrusion mechanisms capable of feeding consumables to the second nozzle 130, depending on the equipment structure. When a remote extrusion mechanism is used, the second extrusion mechanism 150 and the second nozzle 130 are spaced apart, and the second extrusion mechanism 150 feeds the second consumable 192 to the second nozzle 130 through a remote feeding path. The remote feeding path can include a guide tube, a guide channel, a flexible guide tube, a rigid guide tube, or a combination thereof. Because there is a remote feeding path between the second extrusion mechanism 150 and the second nozzle 130, the second consumable 192 will be affected by factors such as path length, path bends, pipeline friction, and elastic deformation of the consumable during the feeding process, which may cause a lag between the driving action of the second extrusion mechanism 150 and the actual discharge response of the second nozzle 130. The above-mentioned remote feeding path can be used to support subsequent implementation methods such as limiting printing speed, limiting printing acceleration, or calling extrusion compensation parameters when forming the second calibration pattern.

[0049] In some embodiments, after the consumable track changer 110 delivers the second consumable 192 to the second nozzle 130, a current feeding path corresponding to the second consumable 192 can be formed. The current feeding path may include the channel inside the consumable track changer 110, the guide path between the consumable track changer 110 and the second extrusion mechanism 150, the second extrusion mechanism 150, and the remote feeding path between the second extrusion mechanism 150 and the second nozzle 130. That is, the current feeding path is the actual conveying path that the second consumable 192 takes from entering the consumable track changer 110 to finally reaching the upstream position of the second nozzle 130. Similarly, when the first consumable 191 is delivered to the first nozzle 120, a feeding path corresponding to the first consumable 191 can also be formed. The controller 160 can determine the feeding paths corresponding to the first consumable 191 and the second consumable 192 respectively according to the path mapping relationship, and control the consumable track changer 110 to switch to the corresponding switching position.

[0050] It is understandable that, with multiple candidate consumables and multiple feeding channels, the current feeding path may differ when different candidate consumables are fed to the second nozzle 130. For example, the path length, bending angle, frictional resistance, or assembly error may differ between different current feeding paths. Therefore, if the nozzle offset calibration process still determines the source of the calibration consumable according to the fixed correspondence between the feed source and the nozzle, it may be impossible to accurately identify whether the first consumable 191 and the second consumable 192 can be fed to the corresponding nozzles respectively, thereby affecting the reliability of calibration pattern printing and nozzle offset compensation calculation. In the embodiment where the second nozzle 130 adopts a remote extrusion mechanism, the printing speed, printing acceleration, or extrusion compensation parameters of the second calibration pattern can be further controlled by combining the discharge response characteristics of the remote feeding path.

[0051] In some embodiments, the multi-nozzle 3D printing apparatus 100 further includes a printing platform 170 and a tool head 180. A first nozzle 120 and a second nozzle 130 can be disposed on the tool head 180, which is movable relative to the printing platform 170 to drive the first nozzle 120 and the second nozzle 130 to form a calibration pattern or printed model on the printing platform 170. The first nozzle 120 and the second nozzle 130 can be spaced apart along the width, length, or other directions of the tool head 180. Because the first nozzle 120 and the second nozzle 130 are mounted at different positions on the tool head 180, their actual discharge positions may deviate from their theoretical relative positions. Therefore, before using the first nozzle 120 and the second nozzle 130 for collaborative printing, it is necessary to determine the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 to match the actual printing positions of the first nozzle 120 and the second nozzle 130 with their theoretical printing positions. In embodiments where the first extrusion mechanism 140 is a short-range extrusion mechanism and the second extrusion mechanism 150 is a long-range extrusion mechanism, the different extrusion structures may further affect the forming stability of the calibration pattern.

[0052] In some embodiments, the image acquisition device 184 can be a camera, webcam, vision sensor, or other device capable of acquiring images. The image acquisition device 184 can be disposed on the tool head 180, or near the frame or printing platform 170 of the multi-nozzle 3D printing equipment 100. The image acquisition device 184 is used to acquire a first calibration pattern formed when the first nozzle 120 extrudes the first consumable 191, and a second calibration pattern formed when the second nozzle 130 extrudes the second consumable 192, so that the controller 160 can determine the offset compensation amount between the first nozzle 120 and the second nozzle 130 based on the positional relationship between the first and second calibration patterns. In some embodiments, the image acquisition device 184 can also acquire a pre-acquisition image before acquiring the formal calibration image, so as to determine image acquisition parameters and / or image recognition parameters based on the image difference parameters between the corresponding image areas of the first consumable 191 and the second consumable 192.

[0053] In some embodiments, at least one sensor may be disposed at at least one of the following locations: the feed inlet of the consumable track changer 110, the first extrusion mechanism 140, the second extrusion mechanism 150, upstream of the first nozzle 120, and upstream of the second nozzle 130, for detecting the triggering state or the positioning state of the consumable. For example, it may include a first sensor 181, a second sensor 182, and a third sensor 183. The first sensor 181 may be located at the feed inlet of the consumable track changer 110 for detecting whether the consumable has entered the corresponding feed inlet of the consumable track changer 110. The second sensor 182 may be located at the first extrusion mechanism 140 or the second extrusion mechanism 150 for detecting whether the first consumable 191 or the second consumable 192 has reached the preset feeding position at the corresponding extrusion mechanism. The third sensor 183 may be located upstream of the first nozzle 120 or the second nozzle 130 for detecting whether the first consumable 191 or the second consumable 192 has reached the preset feeding position at the corresponding nozzle. The first sensor 181, the second sensor 182, and the third sensor 183 can be photoelectric sensors, micro switches, proximity sensors, Hall sensors, or other sensors capable of detecting the passing or arrival status of consumables.

[0054] The controller 160 is connected to the consumable track changer 110, the first extrusion mechanism 140, the second extrusion mechanism 150, the image acquisition device 184, and at least one sensor. Optionally, the controller 160 can also be connected to a motion actuator, a tool head 180, or a nozzle heating assembly for driving the movement of the first nozzle 120 and the second nozzle 130. The controller 160 can control the consumable track changer 110 to switch the feeding path, control the first extrusion mechanism 140 and the second extrusion mechanism 150 to drive the first consumable 191 and the second consumable 192 to move, respectively, to form a first calibration pattern and a second calibration pattern, and perform calibration calculations based on sensor signals and image signals. Specifically, the controller 160 can acquire the path mapping relationship of the consumable track changer 110, determine the first consumable 191 and the second consumable 192 according to the path mapping relationship, control the consumable track changer 110 to deliver the first consumable 191 and the second consumable 192 to the feeding path of the corresponding nozzle respectively, acquire the arrival detection information of the first consumable 191 and the second consumable 192, when the arrival detection information indicates that the first consumable 191 and the second consumable 192 have both reached the corresponding preset feeding position, control the first extrusion mechanism 140 to drive the first consumable 191 to be extruded through the first nozzle 120 to form the first calibration pattern, and after the first calibration pattern is printed, control the second extrusion mechanism 150 to drive the second consumable 192 to be extruded through the second nozzle 130 to form the second calibration pattern. Subsequently, the controller 160 can control the image acquisition device 184 to acquire a calibration image containing a first calibration pattern and a second calibration pattern, determine the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 based on the calibration image, and update the nozzle calibration parameters corresponding to the first nozzle 120 and the second nozzle 130 based on the nozzle offset compensation amount.

[0055] In some embodiments, the second extrusion mechanism 150 includes a motor and a conveying mechanism. The conveying mechanism may include an extrusion gear, a pressure roller, a clamping roller, or other structures capable of clamping and driving the consumable material. The motor drives the conveying mechanism to move the second consumable material 192 along the feeding direction or the unloading direction. In embodiments where the second extrusion mechanism 150 is a remote extrusion mechanism, the controller 160 may limit the printing speed and printing acceleration when forming the second calibration pattern, and / or invoke extrusion compensation parameters corresponding to the remote feeding path and control the feeding action of the second extrusion mechanism 150 based on the extrusion compensation parameters.

[0056] Based on the multi-nozzle 3D printing device 100 described above, this embodiment of the invention also provides a nozzle offset calibration method for the multi-nozzle 3D printing device 100. This nozzle offset calibration method is executed by a controller 160, wherein the controller 160 may include a main control board, processor, and control chip disposed within the multi-nozzle 3D printing device 100, or may include a host computer or computer device communicatively connected to the main control board and participating in control calculations. This nozzle offset calibration method is used to calibrate the nozzle offset between the first nozzle 120 and the second nozzle 130 in a device having a consumable track changer 110, a first nozzle 120, a second nozzle 130, a first extrusion mechanism 140, a second extrusion mechanism 150, an image acquisition device 184, and a controller 160. In some embodiments, the first extrusion mechanism 140 may be a short-range extrusion mechanism located close to the first nozzle 120, and the second extrusion mechanism 150 may be a long-range extrusion mechanism spaced apart from the second nozzle 130. In other embodiments, the nozzle offset calibration method may also be applied to other multi-nozzle 3D printing equipment 100 that needs to calibrate consumable selection and feeding control according to the path mapping relationship because the consumable track changer 110 changes the feeding correspondence between the feed source and the nozzle.

[0057] As an example implementation, refer to Figure 2 As shown, the nozzle offset calibration method for the multi-nozzle 3D printing equipment 100 includes: S210: Obtain the path mapping relationship of the consumable track changer 110. The path mapping relationship is used to characterize the feeding correspondence between the material supply source, the inlet and outlet of the consumable track changer 110 and the target nozzle. The target nozzle includes the first nozzle 120 and the second nozzle 130. S220: Determine a first consumable 191 for nozzle offset calibration of the first nozzle 120 and a second consumable 192 for nozzle offset calibration of the second nozzle 130 according to the path mapping relationship, wherein the first consumable 191 and the second consumable 192 satisfy the visual distinction conditions required for image recognition. S230: According to the path mapping relationship, control the consumable track changer 110 to transport the first consumable 191 to the feeding path corresponding to the first nozzle 120, and transport the second consumable 192 to the feeding path corresponding to the second nozzle 130. S240: Obtain arrival detection information for the first consumable 191 and the second consumable 192; S250: When the arrival detection information indicates that both the first consumable 191 and the second consumable 192 have reached the corresponding preset feeding position, the first extrusion mechanism 140 is controlled to drive the first consumable 191 to be extruded through the first nozzle 120 to form a first calibration pattern. S260: After the first calibration pattern is formed, the second extrusion mechanism 150 is controlled to drive the second consumable 192 to be extruded through the second nozzle 130 to form the second calibration pattern. S270: Control the image acquisition device 184 to acquire a calibration image containing a first calibration pattern and a second calibration pattern; S280: Determine the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 based on the calibration image; S290: Update the nozzle calibration parameters corresponding to the first nozzle 120 and the second nozzle 130 according to the nozzle offset compensation amount, so that the nozzle calibration parameters can be used to correct the motion trajectory of the first nozzle 120 and / or the second nozzle 130 in the subsequent dual-nozzle printing process.

[0058] In S210, the path mapping relationship can be used to characterize the feeding correspondence between the material supply source, the feed inlet of the consumable track changer 110, the discharge outlet of the consumable track changer 110, and the target nozzle. The target nozzle may include the first nozzle 120 and the second nozzle 130. The path mapping relationship can be stored in the controller 160 in the form of a mapping table, path number, configuration parameters, channel status information, or a combination of the above information. It can also be generated or updated by the controller 160 before the nozzle offset calibration process begins.

[0059] In some embodiments, obtaining the path mapping relationship of the consumable track changer 110 includes: the controller 160 can control the target material supply source to deliver consumables to the consumable track changer 110, and obtain trigger information from sensors located at at least one inlet of the consumable track changer 110. Since the consumables will trigger the corresponding sensors when entering different inlets, the controller 160 can determine the target inlet connected to the target material supply source based on the inlet corresponding to the triggered sensor. Subsequently, the controller 160 obtains the current switching position of the consumable track changer 110, and generates or updates the path mapping relationship based on the target material supply source, the target inlet, the target outlet corresponding to the current switching position, and the target nozzle connected to the target outlet.

[0060] In other embodiments, obtaining the path mapping relationship of the consumable track changer 110 includes: the controller 160 can display a setting interface for configuring the connection relationship between the feed source and the feed inlet, and receive connection specification information input by the user in the setting interface. The controller 160 can generate or update the path mapping relationship based on the connection specification information and the preset connection relationship between the discharge port and the nozzle of the consumable track changer 110. Thus, even when the automatic sensor identification conditions are insufficient, the feed source is not yet loaded with consumables, or the user wishes to manually specify the connection relationship, a path mapping relationship for nozzle offset calibration can still be obtained.

[0061] The supply source may include multiple candidate consumables, which may have different colors, brightness, transparency, material types, physical moduli, or surface reflective properties. For example, multiple candidate consumables may include white PLA (Polylactic Acid) consumables, black PLA consumables, red PLA consumables, blue PETG (ethyleneterephthalateco-1,4-cylclohexylenedimethylene terephthalate) consumables, transparent TPU (Thermoplastic Polyurethanes) consumables, etc.

[0062] In S220, the controller 160 determines, based on the path mapping relationship, a first consumable 191 for nozzle offset calibration of the first nozzle 120 and a second consumable 192 for nozzle offset calibration of the second nozzle 130.

[0063] Specifically, the path mapping relationship may include a first mapping sub-relationship and a second mapping sub-relationship. The first mapping sub-relationship is used to characterize the feeding correspondence between the first material supply source, the first inlet 111, the first outlet, and the first nozzle 120; the second mapping sub-relationship is used to characterize the feeding correspondence between the second material supply source, the second inlet 112, the second outlet, and the second nozzle 130. The controller 160 can determine at least one first candidate consumable that can be fed to the first nozzle 120 according to the first mapping sub-relationship, and determine at least one second candidate consumable that can be fed to the second nozzle 130 according to the second mapping sub-relationship. Subsequently, the controller 160 determines a first consumable 191 from the at least one first candidate consumable, and a second consumable 192 from the at least one second candidate consumable.

[0064] The first consumable 191 and the second consumable 192 meet the visual differentiation conditions required for image recognition. The visual differentiation conditions can be understood as follows: the calibration patterns printed by the first consumable 191 and the second consumable 192 can be distinguished in the calibration image acquired by the image acquisition device 184, or there is sufficient color attribute difference or lightness / darkness difference between the first consumable 191 and the second consumable 192 so that the subsequent image recognition algorithm can extract the positions of the first calibration pattern and the second calibration pattern respectively. For example, the visual differentiation conditions may include a color attribute difference between the first consumable 191 and the second consumable 192 greater than or equal to a preset color difference threshold, and / or, the first consumable 191 and the second consumable 192 corresponding to a dark-colored consumable and a light-colored consumable, respectively.

[0065] In some embodiments, the controller 160 can acquire visual features of multiple candidate consumables and determine the color attribute differences or shade differences between any two candidate consumables based on the visual features. Visual features may include color values, grayscale values, brightness values, hue values, saturation values, transparency, reflectivity, or combinations of the above features. For example, color values ​​may be RGB color values, HSV color values, Lab color values, or color parameters in other color spaces.

[0066] The visual characteristics of candidate consumables can be obtained in at least one of the following ways: reading the identification label on the consumable roll; reading the consumable color information pre-stored in the consumable management system; acquiring images of the end of the candidate consumable, the consumable filament, or the pre-printed color block through the image acquisition device 184 set on the multi-nozzle 3D printing equipment 100; receiving the consumable color information input by the user in the interactive interface; or calling the corresponding visual characteristics from the database according to the consumable model.

[0067] Color attribute differences can be the color difference, brightness difference, grayscale difference, hue difference, saturation difference, or a combination of the above differences between two candidate consumables. For example, the controller 160 can calculate the color difference between two candidate consumables in the Lab color space. When the color difference value is greater than a preset color difference threshold, it can be determined that the two candidate consumables meet the visual distinction criteria. In other embodiments, the controller 160 can determine whether two candidate consumables correspond to dark and light consumables respectively, based on the color identifier of the candidate consumables, the color information input by the user, or the consumable image acquired by the image acquisition device 184.

[0068] When multiple candidate consumables meet the visual discrimination criteria, the controller 160 can determine the first consumable 191 and the second consumable 192 according to a preset priority. For example, the controller 160 can prioritize the combination of consumables with larger color attribute differences (such as differences greater than or equal to a preset color difference threshold), or it can prioritize the combination of consumables corresponding to dark and light consumables respectively. It should be noted that the first consumable 191 and the second consumable 192 not only need to meet the visual discrimination criteria required for image recognition, but should also belong to the candidate consumables that can be delivered to the corresponding nozzle according to the path mapping relationship.

[0069] The first consumable 191 is used to feed the material to the feeding path corresponding to the first nozzle 120, and the second consumable 192 is used to feed the material to the feeding path corresponding to the second nozzle 130. Thus, the first consumable 191 and the second consumable 192 determined by the controller 160 can not only meet the visual discrimination conditions required for image recognition, but also be fed to the corresponding nozzles according to the path mapping relationship.

[0070] In S230, the controller 160 controls the consumable track changer 110 to deliver the first consumable 191 to the feeding path corresponding to the first nozzle 120 and the second consumable 192 to the feeding path corresponding to the second nozzle 130 according to the path mapping relationship.

[0071] In some embodiments, the consumable guideway changer 110 may include a plurality of inlets, at least two outlets, and a switching mechanism disposed between the plurality of inlets and at least two outlets. Multiple candidate consumables may enter the consumable guideway changer 110 from the plurality of inlets respectively. The switching mechanism is used to change the connectivity of the internal channels of the consumable guideway changer 110 to guide different candidate consumables to the feeding paths corresponding to different nozzles. The switching mechanism may include a rotary valve core, a slider, a swing arm, a guide block, a paddle, an electromagnetic switching element, or other structures capable of changing the consumable path.

[0072] After determining the first consumable 191 and the second consumable 192, the controller 160 can determine the first target feeding channel between the first feeding source and the first nozzle 120 where the first consumable 191 is located, according to the path mapping relationship. It then controls the consumable track changer 110 to switch to the first switching position corresponding to the first target feeding channel and controls the first feeding source to deliver the first consumable 191 to the feeding path corresponding to the first nozzle 120. The controller 160 can also determine the second target feeding channel between the second feeding source and the second nozzle 130 corresponding to the second consumable 192, according to the path mapping relationship. It then controls the consumable track changer 110 to switch to the second switching position corresponding to the second target feeding channel and controls the second feeding source to deliver the second consumable 192 to the feeding path corresponding to the second nozzle 130. The first and second target feeding channels can be formed simultaneously or sequentially.

[0073] In some embodiments, the consumable guideway 110 can change the connection position between the inlet and outlet by rotating a valve core. For example, the rotary valve core has multiple guide channels. After the controller 160 controls the rotary valve core to rotate to a preset angle, the channel containing the first consumable 191 is connected to the feeding path corresponding to the first nozzle 120, and the channel containing the second consumable 192 is connected to the feeding path corresponding to the second nozzle 130. In other embodiments, the consumable guideway 110 can change the channel connection relationship by sliding a switching member. For example, after the sliding switching member moves to the target position along a preset direction, the inlet channel corresponding to the second consumable 192 is aligned with the outlet channel leading to the second nozzle 130.

[0074] After the second consumable 192 is conveyed to the feeding path corresponding to the second nozzle 130, the actual path traversed by the second consumable 192 from the consumable track changer 110 to the second nozzle 130 can be used as the current feeding path. The current feeding path may include the selection channel inside the consumable track changer 110, the connecting pipeline between the consumable track changer 110 and the second extrusion mechanism 150, the clamping and conveying area inside the second extrusion mechanism 150, and the guide section near the second nozzle 130; in embodiments where the second extrusion mechanism 150 is a remote extrusion mechanism, the current feeding path may also include the remote feeding path between the second extrusion mechanism 150 and the second nozzle 130.

[0075] In embodiments where the second extrusion mechanism 150 is a remote extrusion mechanism, the remote feeding path may include a flexible guide tube, a rigid guide tube, a bent guide tube, a guide connector, or a combination of the above structures. Since there is a certain distance between the second extrusion mechanism 150 and the second nozzle 130, the second consumable 192 needs to travel through the remote feeding path to reach the second nozzle 130. Therefore, the path length, bending angle, and frictional load of the current feeding path will affect the actual discharge response of the second nozzle 130. The aforementioned remote feeding path can serve as one of the bases for subsequent speed limiting, acceleration limiting, or extrusion compensation control during the formation of the second calibration pattern.

[0076] After the consumable track changer 110 forms the current feeding path, the controller 160 can obtain the path identifier corresponding to the current feeding path. The path identifier may include the physical path number of the current feeding channel 113, the channel number of the consumable track changer 110, the inlet number of the second consumable 192, the outlet number corresponding to the second nozzle 130, or a combination of the above numbers. In some embodiments, the path identifier may be used as part of the path mapping relationship to determine the second target feeding channel corresponding to the second consumable 192.

[0077] In some embodiments, before controlling the consumable track changer 110 to deliver the first consumable 191 and the second consumable 192 according to the path mapping relationship, reference is made to... Figure 3 As shown, the nozzle offset calibration method also includes: S310: Set the consumable source determination method in the nozzle offset calibration process to the consumable track changer 110 feeding calibration mode based on path mapping relationship to determine the consumable source. S320: Based on the path mapping relationship, analyze the feed source, feed port, feed outlet and feeding path corresponding to the nozzle to be calibrated, and generate feeding control commands for controlling the consumable track changer 110 and the corresponding feed source to perform feeding according to the analysis results.

[0078] In S310, the consumable source determination method in the nozzle offset calibration process is set to the consumable track changer 110 feeding calibration mode based on path mapping relationship to determine the consumable source.

[0079] Specifically, in devices where the consumable track changer 110 is not installed or where there is a fixed correspondence between the feed source and the nozzle, the nozzle offset calibration process can determine the source of calibration consumables according to the fixed binding relationship between the preset nozzle and the preset feed source. However, in this embodiment of the invention, the consumable track changer 110 can change the feeding correspondence between the feed source, the inlet, the outlet, and the target nozzle. Therefore, the controller 160 can set the consumable source determination method to the consumable track changer 110 feeding calibration mode based on the path mapping relationship when the nozzle offset calibration process begins, so that the calibration process can adapt to the switchable feeding path formed by the consumable track changer 110.

[0080] The path mapping relationship may include a material source identifier, an inlet identifier, an outlet identifier, a target nozzle identifier, a switching gear information, a feeding path identifier, or a combination of the above information. The controller 160 can determine the first consumable 191 used for nozzle offset calibration of the first nozzle 120 and the second consumable 192 used for nozzle offset calibration of the second nozzle 130 based on the path mapping relationship, and determine the switching status of the material source and consumable track changer 110 that need to be controlled subsequently.

[0081] In S320, the controller 160 analyzes the feed source, inlet, outlet and feeding path corresponding to the nozzle to be calibrated based on the path mapping relationship, and generates a feeding control command for controlling the consumable track changer 110 and the corresponding feed source to perform feeding based on the analysis result.

[0082] For example, the controller 160 can parse the feeding path corresponding to the first feed source, first inlet 111, first outlet, and first nozzle 120 corresponding to the first consumable 191 according to the path mapping relationship, and generate a feeding control command for controlling the consumable track changer 110 to switch to the first switching position and controlling the feeding of the first feed source. The controller 160 can also parse the feeding path corresponding to the second feed source, second inlet 112, second outlet, and second nozzle 130 corresponding to the second consumable 192 according to the path mapping relationship, and generate a feeding control command for controlling the consumable track changer 110 to switch to the second switching position and controlling the feeding of the second feed source.

[0083] In some embodiments, the first consumable 191 and the second consumable 192 can be sequentially fed to the feeding path of the corresponding nozzle, or, if the equipment structure allows, they can be fed to the feeding path of the corresponding nozzle separately. The controller 160 can determine the feeding sequence of the first consumable 191 and the second consumable 192 according to the structure of the consumable track changer 110, the type of the material source, the nozzle status, and the current calibration process status.

[0084] In S240, the controller 160 acquires the arrival detection information of the first consumable 191 and the second consumable 192. The arrival detection information is used to characterize whether the first consumable 191 and the second consumable 192 have reached their respective preset feeding positions.

[0085] The preset feeding position can be at the first extrusion mechanism 140, the second extrusion mechanism 150, upstream of the first nozzle 120, upstream of the second nozzle 130, near the hot end inlet, or other positions that can indicate that the nozzle has the conditions for material discharge.

[0086] In some embodiments, after executing a feeding control command, the controller 160 can combine trigger information from at least two sensors located at the feed inlet of the consumable track changer 110, the first extrusion mechanism 140, the second extrusion mechanism 150, upstream of the first nozzle 120, and upstream of the second nozzle 130 to determine whether the first consumable 191 and the second consumable 192 have reached their respective preset feeding positions. Only when the position detection information indicates that both the first consumable 191 and the second consumable 192 have reached their respective preset feeding positions will the controller 160 control the first extrusion mechanism 140 to drive the first consumable 191 to be extruded through the first nozzle 120 to form a first calibration pattern, and after the first calibration pattern is printed, control the second extrusion mechanism 150 to drive the second consumable 192 to be extruded through the second nozzle 130 to form a second calibration pattern.

[0087] In some embodiments, reference Figure 4 As shown, the nozzle offset calibration method may also include a process of position detection and anomaly judgment based on sensor trigger information: S410: Acquire trigger information from at least two of the multiple sensors; S420: Based on the trigger information from at least two sensors, determine whether the first consumable 191 has reached the preset feeding position corresponding to the first nozzle 120, and determine whether the second consumable 192 has reached the preset feeding position corresponding to the second nozzle 130; S430: Determine the preset trigger sequence corresponding to the current feeding process based on the path mapping relationship; S440: Obtain the actual triggering sequence of multiple sensors during the current feeding process; S450: If the actual triggering sequence is inconsistent with the preset triggering sequence, stop the nozzle offset calibration process and output an abnormal prompt message.

[0088] In S410, the multiple sensors may include a sensor located at the feed inlet of the consumable track changer 110, a sensor located at the first extrusion mechanism 140, a sensor located at the second extrusion mechanism 150, a sensor located upstream of the first nozzle 120, and a sensor located upstream of the second nozzle 130. The controller 160 can acquire trigger information from at least two of the aforementioned multiple sensors. The trigger information may include whether the sensor is triggered, the trigger time, the trigger duration, or the trigger sequence.

[0089] In S420, the controller 160 determines the arrival status of the first consumable 191 and the second consumable 192 based on trigger information from at least two sensors. For example, when a sensor located at the first extrusion mechanism 140 is triggered, and / or a sensor located upstream of the first nozzle 120 is triggered, it can be determined that the first consumable 191 has reached the preset feeding position corresponding to the first nozzle 120. When a sensor located at the second extrusion mechanism 150 is triggered, and / or a sensor located upstream of the second nozzle 130 is triggered, it can be determined that the second consumable 192 has reached the preset feeding position corresponding to the second nozzle 130.

[0090] In S430, the preset triggering sequence can be determined based on the path mapping relationship. For example, for the first consumable 191, the preset triggering sequence may include the order in which the consumable passes upstream of the target feed port, the first extrusion mechanism 140, and the first nozzle 120 in sequence. For the second consumable 192, the preset triggering sequence may include the order in which the consumable passes upstream of the target feed port, the second extrusion mechanism 150, and the second nozzle 130 in sequence.

[0091] In S440, the actual triggering sequence can be the order in which multiple sensors output triggering information during the current feeding process. Controller 160 can determine the actual triggering sequence based on the triggering times of multiple sensors, or it can determine the actual triggering sequence based on the state change records of each sensor.

[0092] In S450, when the actual trigger sequence differs from the preset trigger sequence, the controller 160 can stop the nozzle offset calibration process and output a prompt message indicating an abnormal connection of the consumable guide converter 110, a abnormal connection of the material supply source, an abnormal connection of the material tube, or an abnormal consumable arrival. The prompt message can be output via a display screen, mobile terminal, host computer interface, indicator light, buzzer, or a combination of the above methods.

[0093] In some embodiments, even if the actual triggering sequence is consistent with the preset triggering sequence, the controller 160 can still further determine whether the first consumable 191 and the second consumable 192 have reached the corresponding preset feeding position within a preset time. If the first consumable 191 or the second consumable 192 has not reached the corresponding preset feeding position within a preset time, the controller 160 can also stop the nozzle offset calibration process and output a prompt message indicating that the consumable is not in place.

[0094] In S250, when the arrival detection information indicates that both the first consumable 191 and the second consumable 192 have reached the corresponding preset feeding position, the first extrusion mechanism 140 is controlled to drive the first consumable 191 to be extruded through the first nozzle 120 to form a first calibration pattern.

[0095] The first calibration pattern can be a test line, color block, crosshair, rectangle, dot matrix, grid, or other pattern that can be used to determine the position of the first nozzle 120. The first calibration pattern can be printed on the printing platform 170, printing plate, calibration plate, calibration paper, or other calibration media. The controller 160 can drive the first consumable 191 to be extruded through the first nozzle 120 after the first consumable 191 reaches the preset feeding position corresponding to the first nozzle 120 and the second consumable 192 reaches the preset feeding position corresponding to the second nozzle 130, so as to avoid starting the calibration pattern printing before the first consumable 191 or the second consumable 192 has reached the preset feeding position.

[0096] In some embodiments, controlling the first extrusion mechanism 140 to drive the first consumable 191 to be extruded via the first nozzle 120 may include: the first extrusion mechanism 140 driving the first consumable 191 via the first nozzle 120 to form at least one of a first calibration line extending in a first direction and a second calibration line extending in a second direction. The first direction and the second direction may be perpendicular to each other. For example, the first direction may be the X direction in the plane where the printing platform 170 is located, and the second direction may be the Y direction in the plane where the printing platform 170 is located.

[0097] In step S260, after the first calibration pattern is formed, the second extrusion mechanism 150 is controlled to drive the second consumable 192 to be extruded through the second nozzle 130 to form the second calibration pattern. The second calibration pattern can be arranged adjacent to the first calibration pattern, partially overlap with it, or arranged according to a preset theoretical relative position. After the first nozzle 120 completes the printing of the first calibration pattern, the controller 160 can switch to the second nozzle 130 and control the second extrusion mechanism 150 to drive the second consumable 192 to be extruded through the second nozzle 130 to form the second calibration pattern.

[0098] In some embodiments, the first calibration pattern and the second calibration pattern can be printed on the printing platform 170 or on a calibration medium disposed on the printing platform 170. The calibration medium can be a calibration plate, calibration paper, test film, or printing substrate. The first calibration pattern and the second calibration pattern can be test lines, crosshairs, rectangles, circular patterns, grid patterns, dot matrix patterns, color block patterns, or other patterns that can be used to determine the nozzle position relationship.

[0099] In some embodiments, the first calibration pattern and the second calibration pattern may include calibration lines for determining nozzle offset compensation amounts in different directions. Controlling the second extrusion mechanism 150 to drive the second consumable 192 to extrude via the second nozzle 130 may include: controlling the second extrusion mechanism 150 to drive the second consumable 192 to extrude via at least one of a third calibration line extending in a first direction and a fourth calibration line extending in a second direction.

[0100] The control of the first extrusion mechanism 140 to drive the first consumable 191 to extrude through the first nozzle 120 may include controlling the first extrusion mechanism 140 to drive the first consumable 191 to extrude through the first nozzle 120 to form at least one of a first calibration line extending along a first direction and a second calibration line extending along a second direction. The first direction and the second direction are perpendicular to each other. The first calibration line and the third calibration line are used to determine the nozzle offset compensation amount in the second direction, and the second calibration line and the fourth calibration line are used to determine the nozzle offset compensation amount in the first direction. Specifically, the first calibration line and the third calibration line both extend along the first direction, so the relative positional difference between them in the second direction can reflect the positional deviation between the first nozzle 120 and the second nozzle 130 in the second direction; the second calibration line and the fourth calibration line both extend along the second direction, so the relative positional difference between them in the first direction can reflect the positional deviation between the first nozzle 120 and the second nozzle 130 in the first direction.

[0101] In some embodiments, the first extrusion mechanism 140 is a short-range extrusion mechanism located close to the first nozzle 120, and the second extrusion mechanism 150 is a long-range extrusion mechanism spaced apart from the second nozzle 130. The feeding path corresponding to the second nozzle 130 includes a long-range feeding path located between the second extrusion mechanism 150 and the second nozzle 130. In this case, controlling the second extrusion mechanism 150 to drive the second consumable 192 to be extruded via the second nozzle 130 includes: limiting the printing speed when forming the second calibration pattern to no greater than a preset speed threshold, and limiting the printing acceleration when forming the second calibration pattern to no greater than a preset acceleration threshold; and / or, calling the extrusion compensation parameter corresponding to the long-range feeding path, and controlling the feeding action of the second extrusion mechanism 150 based on the extrusion compensation parameter.

[0102] The preset speed threshold and preset acceleration threshold can be determined based on the feeding capacity of the second extrusion mechanism 150, the length of the remote feeding path, the type of consumable, the nozzle diameter, the size of the calibration pattern, or a combination of the above factors. For example, the preset speed threshold can be 200 mm / s, or other speed values ​​determined according to the equipment structure, consumable type, length of the remote feeding path, or calibration accuracy requirements; the preset acceleration threshold can be 1000 mm / s², or other acceleration values ​​determined according to the equipment structure, consumable type, length of the remote feeding path, or calibration accuracy requirements. The printing speed can be the moving speed of the second nozzle 130 relative to the printing platform 170, and the printing acceleration can be the moving acceleration of the second nozzle 130 relative to the printing platform 170. By limiting the printing speed and printing acceleration, the output fluctuations of the second nozzle 130 caused by the lag in the remote feeding path during the calibration printing process can be reduced.

[0103] Extrusion compensation parameters can be used to compensate for response lag, pressure build-up delay, transient insufficient discharge, or flow fluctuations caused by the remote extrusion mechanism and remote feeding path when forming the second calibration pattern. Extrusion compensation parameters may include at least one of the following: flow compensation parameters, feed advance, initial stage compensation, pressure compensation parameters, dynamic flow compensation K value, extrusion phase lead parameters, and transient pressure pulse parameters.

[0104] In some embodiments, the controller 160 may determine or invoke extrusion compensation parameters corresponding to the remote feeding path based on the path length of the remote feeding path, the material type of the second consumable 192, the nozzle orifice diameter of the second nozzle 130, the feeding capacity of the second extrusion mechanism 150, the calibration pattern size, or a combination of the above parameters. For example, the longer the remote feeding path, the more significant the lag in the discharge response of the second nozzle 130 may be, and the controller 160 may accordingly increase the feeding advance amount or the initial segment compensation amount; the more easily the second consumable 192 undergoes elastic deformation, the controller 160 may accordingly increase the pressure compensation parameter or reduce the movement speed when forming the second calibration pattern.

[0105] In some embodiments, the controller 160 can determine the extrusion compensation parameters by looking up a table. The controller 160 may pre-store a compensation parameter table, which includes the correspondence between at least one of multiple path length ranges, multiple consumable types, multiple nozzle orifice diameters, and multiple speed ranges and the extrusion compensation parameters. After determining the path information corresponding to the remote feeding path and / or the consumable information corresponding to the second consumable 192, the controller 160 can retrieve the corresponding extrusion compensation parameters from the compensation parameter table.

[0106] In other embodiments, the controller 160 can determine extrusion compensation parameters through a computational model. The inputs to the computational model may include path length, material type, diameter of the second consumable 192, orifice diameter of the second nozzle 130, target printing speed, target printing acceleration, structural parameters of the remote feeding path, or a combination of the above parameters; the outputs of the computational model may include at least one of dynamic flow compensation K value, extrusion phase lead parameter, and transient pressure pulse parameter. The computational model can be an empirical formula, a linear model, a lookup table interpolation model, a neural network model, or other mapping model.

[0107] In some embodiments, invoking the extrusion compensation parameters corresponding to the remote feeding path and controlling the feeding action of the second extrusion mechanism 150 based on the extrusion compensation parameters may include at least one of the following methods.

[0108] First, the controller 160 can adjust the extrusion flow rate of the second nozzle 130 based on the dynamic flow compensation K value and the real-time acceleration of the tool head 180. The real-time acceleration of the tool head 180 can be obtained from motion control commands, or provided by an encoder, accelerometer, or motion planning module. Based on the dynamic flow compensation K value and real-time acceleration, the controller 160 can adjust the feeding speed, feeding amount, drive current, or motor steps of the second extrusion mechanism 150 to maintain a relatively stable actual output volume of the second nozzle 130 during the acceleration or deceleration of the tool head 180.

[0109] Second, during the initial printing phase, the controller 160 can control the second extrusion mechanism 150 to drive the second consumable 192 in advance based on the extrusion phase advance parameter. The initial printing phase can be a preset time period before the second calibration pattern begins printing, or it can be the stage when the second nozzle 130 enters the discharge state from the stop state. The extrusion phase advance parameter can be a time advance, a distance advance, or a motor step advance. For example, the controller 160 can control the second extrusion mechanism 150 to start feeding material a preset time before the second nozzle 130 reaches the theoretical starting position of the second calibration pattern.

[0110] Third, the controller 160 can adjust the moving speed of the second nozzle 130 relative to the printing platform 170 based on the extrusion compensation parameters to match the transient extrusion response of the second nozzle 130. For example, when the extrusion compensation parameters corresponding to the remote feeding path indicate that the output response of the second nozzle 130 is slow, the controller 160 can reduce the moving speed of the second nozzle 130 at the beginning of the second calibration pattern; after the second nozzle 130 enters a stable output state, the moving speed is restored to the preset speed.

[0111] Fourth, the controller 160 can increase the extrusion driving force of the second extrusion mechanism 150 on the second consumable 192 based on transient pressure pulse parameters. Transient pressure pulse parameters may include pulse driving force, pulse duration, pulse start time, pulse end time, or number of pulses. The controller 160 can increase the driving current, driving torque, feeding speed, or feeding steps of the second extrusion mechanism 150 during the initial stage of the second calibration pattern to quickly establish the discharge pressure at the second nozzle 130.

[0112] In some embodiments, the first calibration pattern and the second calibration pattern may have the same preset linewidth, or different preset linewidths may be set according to the differences in the extrusion structures of the first nozzle 120 and the second nozzle 130. For example, when the second extrusion mechanism 150 is a remote extrusion mechanism, the preset linewidth of some line segments in the second calibration pattern may be appropriately increased to improve the continuity of the second calibration pattern and the stability of subsequent recognition. This linewidth setting can be used as an optional implementation to improve the stability of pattern recognition, rather than as a necessary step in the nozzle offset calibration process.

[0113] It should be noted that the above-mentioned control of printing speed, printing acceleration and extrusion compensation parameters can be used as an optional implementation in the scenario of remote extrusion mechanism; in other implementations, the controller 160 can also complete nozzle offset calibration based on path mapping relationship, position detection information and calibration image without performing the above-mentioned remote extrusion compensation control.

[0114] In step S270, controller 160 controls image acquisition device 184 to acquire a calibration image containing a first calibration pattern and a second calibration pattern. Image acquisition device 184 can acquire the calibration image after both the first and second calibration patterns have been printed. The calibration image may include the first calibration pattern, the second calibration pattern, and at least a portion of the background of the printing platform 170.

[0115] In some embodiments, in order to improve the recognition stability of the first calibration pattern and the second calibration pattern in the calibration image, the controller 160 may determine the image acquisition parameters and / or image recognition parameters based on the image difference parameters between the corresponding image regions of the first consumable 191 and the second consumable 192 before acquiring the formal calibration image.

[0116] In some embodiments, reference Figure 5 As shown, before the image acquisition device 184 acquires a calibration image containing the first calibration pattern and the second calibration pattern, the nozzle offset calibration method further includes: S510: Control the image acquisition device 184 to acquire a pre-acquired image containing the image areas corresponding to the first consumable 191 and the second consumable 192; S520: Obtain image difference parameters between the corresponding image regions of the first consumable 191 and the second consumable 192 based on the pre-acquired image. The image difference parameters include at least one of grayscale difference, brightness difference, hue difference, and saturation difference. S530: Determine image acquisition parameters and / or image recognition parameters based on image difference parameters, and control the image acquisition device 184 to acquire calibration images according to the image acquisition parameters, and / or, identify the first calibration pattern and the second calibration pattern according to the image recognition parameters.

[0117] In S510, the pre-acquired image can be an image acquired before the formal acquisition of the calibration image. The pre-acquired image can include the image area corresponding to the first consumable 191 and the image area corresponding to the second consumable 192. The image area corresponding to the first consumable 191 can be a partial pattern area printed by the first consumable 191, a partial area of ​​the first calibration pattern, a first color block area, or an area of ​​the first consumable 191 within the device that can be acquired by the image acquisition device 184. The image area corresponding to the second consumable 192 can be a partial pattern area printed by the second consumable 192, a partial area of ​​the second calibration pattern, a second color block area, or an area of ​​the second consumable 192 within the device that can be acquired by the image acquisition device 184.

[0118] In some embodiments, the pre-acquired image can be obtained by acquiring local color patches output by the first nozzle 120 and the second nozzle 130 respectively; it can also be obtained by acquiring local areas in the first calibration pattern and the second calibration pattern; or it can be obtained by acquiring an image of the consumable end located near the feed path or nozzle. The pre-acquired image is not required to contain the complete first calibration pattern and the complete second calibration pattern, as long as the image difference parameters between the corresponding image areas of the first consumable 191 and the second consumable 192 can be obtained.

[0119] In S520, the controller 160 obtains image difference parameters between the corresponding image regions of the first consumable 191 and the second consumable 192 based on the pre-acquired image. The image difference parameters may include at least one of grayscale difference, brightness difference, hue difference, and saturation difference. The grayscale difference can be determined based on the grayscale values ​​of the image region corresponding to the first consumable 191 and the image region corresponding to the second consumable 192; the brightness difference can be determined based on the brightness values ​​of the two image regions; the hue difference and saturation difference can be determined based on the color parameters of the two image regions in a preset color space.

[0120] In some embodiments, the controller 160 may also determine image difference parameters in conjunction with the background image of the printing platform 170. For example, the controller 160 may calculate the brightness difference between the image area corresponding to the first consumable 191 and the background image, and the brightness difference between the image area corresponding to the second consumable 192 and the background image, and determine image acquisition parameters or image recognition parameters suitable for recognizing the first calibration pattern and the second calibration pattern accordingly.

[0121] In S530, the controller 160 determines image acquisition parameters and / or image recognition parameters based on image difference parameters. Image acquisition parameters may include exposure time, gain, light source brightness, white balance parameters, or focal length parameters. Image recognition parameters may include binarization threshold, edge detection threshold, color segmentation threshold, region filtering threshold, centerline extraction parameters, or combinations thereof. Subsequently, the controller 160 can control the image acquisition device 184 to acquire calibration images according to the image acquisition parameters, and / or recognize a first calibration pattern and a second calibration pattern according to the image recognition parameters.

[0122] For example, when the image difference parameter indicates a low brightness difference between the corresponding image regions of the first consumable 191 and the second consumable 192, the controller 160 can adjust the exposure time, increase the light source brightness, or adjust the binarization threshold to enhance the distinguishability between the first calibration pattern and the second calibration pattern. When the image difference parameter indicates a large hue difference between the two image regions, the controller 160 can use image recognition parameters based on color segmentation to identify the first calibration pattern and the second calibration pattern.

[0123] In S280, refer to Figure 6 As shown, determining the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 based on the calibration image includes: S610: Identify the center position of the first pattern of the first calibration pattern and the center position of the second pattern of the second calibration pattern in the calibration image; S620: Determine the measured relative position between the first calibration pattern and the second calibration pattern based on the center position of the first pattern and the center position of the second pattern; S630: Obtain the theoretical relative position between the first nozzle 120 and the second nozzle 130; S640: Determine the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 based on the difference between the measured relative position and the theoretical relative position.

[0124] In S610, the controller 160 identifies the first pattern center position of the first calibration pattern and the second pattern center position of the second calibration pattern in the calibration image. The calibration image can be an image containing the first and second calibration patterns acquired by the image acquisition device 184. The first pattern center position can be the geometric center, centroid, centerline position, intersection point position, or edge center position of the first calibration pattern. The second pattern center position can be the geometric center, centroid, centerline position, intersection point position, or edge center position of the second calibration pattern.

[0125] In some embodiments, both the first calibration pattern and the second calibration pattern may include linear patterns. The controller 160 can identify the positions of the first calibration pattern and the second calibration pattern through edge detection, grayscale thresholding, color segmentation, connected component analysis, centerline extraction, or a combination of the above methods. If the first calibration pattern includes a first calibration line extending along a first direction and a second calibration line extending along a second direction, and the second calibration pattern includes a third calibration line extending along the first direction and a fourth calibration line extending along the second direction, then the controller 160 can determine the nozzle offset compensation amount in the second direction based on the positional relationship between the first calibration line and the third calibration line, and determine the nozzle offset compensation amount in the first direction based on the positional relationship between the second calibration line and the fourth calibration line. The first direction and the second direction may be perpendicular to each other.

[0126] In S620, the controller 160 determines the measured relative position between the first calibration pattern and the second calibration pattern based on the center positions of the first and second patterns. The measured relative position may include the distance in a first direction, the distance in a second direction, or a two-dimensional relative position vector between the first and second calibration patterns in the plane of the printing platform 170.

[0127] In S630, the controller 160 acquires the theoretical relative position between the first nozzle 120 and the second nozzle 130. The theoretical relative position can be a device design value, a factory calibration value, a nozzle installation spacing, a default nozzle offset value, or a theoretical nozzle spacing read from a device configuration file. The theoretical relative position can include the theoretical relative position in a first direction and the theoretical relative position in a second direction.

[0128] In S640, the controller 160 determines the nozzle offset compensation amount based on the difference between the measured relative position and the theoretical relative position. The nozzle offset compensation amount may include the nozzle offset compensation amount in a first direction and the nozzle offset compensation amount in a second direction. For example, when the first direction is the X direction of the plane where the printing platform 170 is located and the second direction is the Y direction of the plane where the printing platform 170 is located, the nozzle offset compensation amount may include the X-direction offset compensation amount and the Y-direction offset compensation amount.

[0129] In some embodiments, the positional relationship may include the distance between the first calibration pattern and the second calibration pattern, the offset direction, the centerline difference, the centroid difference, the intersection deviation, or a combination of the above information. When both the first and second calibration patterns are linear patterns, the controller 160 can extract the centerline of the first calibration pattern and the centerline of the second calibration pattern, and determine the nozzle offset compensation amount based on the distance between the two centerlines. When the first and second calibration patterns are dot matrix patterns, the controller 160 can extract the center coordinates of the first and second dot matrix, and determine the nozzle offset compensation amount based on the difference between the center coordinates. When the first and second calibration patterns are intersecting patterns, the controller 160 can extract the intersection point coordinates, and determine the nozzle offset compensation amount based on the difference between the actual intersection point and the theoretical intersection point.

[0130] In some embodiments, the nozzle offset compensation amount may include an X-direction offset compensation amount and a Y-direction offset compensation amount. The X and Y directions may be two mutually perpendicular directions within the plane of the printing platform 170. The controller 160 may determine the offset of the second nozzle 130 relative to the first nozzle 120 in the X and Y directions based on the positional relationship between the first calibration pattern and the second calibration pattern, and use this offset amount as the nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130.

[0131] In some embodiments, the controller 160 may also associate and store the path mapping relationship and nozzle offset compensation amount during the current nozzle offset calibration process. The path mapping relationship may include a material source identifier, inlet identifier, outlet identifier, target nozzle identifier, gear switching information, feeding path identifier, or a combination of the above information. The associated storage may be represented by establishing a mapping table between the path mapping relationship and the nozzle offset compensation amount in the memory. The mapping table may include the path mapping relationship, first direction offset compensation amount, second direction offset compensation amount, calibration time, type of first consumable 191, type of second consumable 192, calibration result status, or a combination of the above information.

[0132] When dual-nozzle printing or nozzle offset calibration is performed again using the same or corresponding path mapping relationship, the controller 160 can read the nozzle offset compensation amount or nozzle calibration parameters associated with the path mapping relationship as a reference for subsequent printing control or recalibration. The aforementioned associated storage is used to record the correspondence between the nozzle offset calibration results and the actual feeding correspondence of the consumable track changer 110.

[0133] In S290, the controller 160 updates the nozzle calibration parameters corresponding to the first nozzle 120 and the second nozzle 130 according to the nozzle offset compensation amount, so that the nozzle calibration parameters are used to correct the motion trajectory of the first nozzle 120 and / or the second nozzle 130 in the subsequent dual-nozzle printing process.

[0134] In some embodiments, the controller 160 can update the nozzle offset parameters of the first nozzle 120 and / or the second nozzle 130 based on the nozzle offset compensation amount. The nozzle offset parameters can be stored in the controller 160's memory, or in a host computer, print control software, device configuration file, firmware parameter area, or other storage medium. The nozzle offset parameters may include the relative offset between the first nozzle 120 and the second nozzle 130 in the X and Y directions of the print platform 170, and may also include a first direction compensation value, a second direction compensation value, or motion correction parameters related to nozzle switching.

[0135] In some embodiments, when the first nozzle 120 is set as the reference nozzle, the controller 160 can keep the nozzle position parameters of the first nozzle 120 unchanged and update the nozzle offset parameters of the second nozzle 130 relative to the first nozzle 120 according to the nozzle offset compensation amount. In other embodiments, when the second nozzle 130 is set as the reference nozzle, the controller 160 can keep the nozzle position parameters of the second nozzle 130 unchanged and update the nozzle offset parameters of the first nozzle 120 relative to the second nozzle 130 according to the nozzle offset compensation amount. In still other embodiments, the controller 160 can also update the nozzle offset parameters of the first nozzle 120 and the second nozzle 130 simultaneously, so that they both match a preset coordinate system.

[0136] In some embodiments, during subsequent multi-nozzle collaborative printing, the controller 160 can adjust the motion trajectories of the first nozzle 120 and the second nozzle 130 according to the updated nozzle offset parameters. For example, when the printing task is switched from printing with the first nozzle 120 to printing with the second nozzle 130, the controller 160 can compensate the target motion coordinates of the second nozzle 130 based on the nozzle offset parameters, so that the actual discharge position of the second nozzle 130 is aligned with the pattern position formed by the first nozzle 120.

[0137] In some embodiments, after calibration is completed based on the nozzle offset compensation amount, the controller 160 can also control the filament converter 110 to reset to its original mapping state before calibration. The original mapping state can be the default correspondence between filaments and nozzles before calibration, or it can be the filament mapping relationship required by the user's printing task. By resetting the filament converter 110 to its original mapping state, the calibration process can be prevented from changing the feed relationship for subsequent normal printing.

[0138] In this embodiment of the invention, printing a calibration pattern with the first nozzle 120 or the second nozzle 130 may include controlling the corresponding extrusion mechanism to drive the material feeding, controlling the corresponding hot end to heat and melt the material, and controlling the transmission mechanism (not shown) to drive the tool head 180 to move relative to the printing platform, so that the molten material is deposited on the printing platform according to a preset trajectory.

[0139] In exemplary embodiments of the present invention, a computer-readable storage medium is also provided, on which a computer program capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the present invention can also be implemented as a program product comprising program code, which, when executed by a processor, causes the processor to perform the steps described in the "Exemplary Methods" section of the present invention, according to various exemplary embodiments. The processor may be a controller 160 in the multi-nozzle 3D printing apparatus 100, or a processor communicatively connected to the controller 160 and participating in control operations.

[0140] In some embodiments, when the computer program is executed by the processor, the processor acquires the path mapping relationship of the consumable track changer 110, determines the first consumable 191 for nozzle offset calibration of the first nozzle 120 and the second consumable 192 for nozzle offset calibration of the second nozzle 130 based on the path mapping relationship, controls the consumable track changer 110 to deliver the first consumable 191 to the feeding path corresponding to the first nozzle 120 and the second consumable 192 to the feeding path corresponding to the second nozzle 130, acquires the arrival detection information of the first consumable 191 and the second consumable 192, and controls the first extrusion... The extrusion mechanism 140 drives the first consumable 191 to be extruded through the first nozzle 120 to form a first calibration pattern. After the first calibration pattern is formed, the second extrusion mechanism 150 drives the second consumable 192 to be extruded through the second nozzle 130 to form a second calibration pattern. The image acquisition device 184 is controlled to acquire a calibration image containing the first calibration pattern and the second calibration pattern. The nozzle offset compensation amount between the first nozzle 120 and the second nozzle 130 is determined according to the calibration image. The nozzle calibration parameters corresponding to the first nozzle 120 and the second nozzle 130 are updated according to the nozzle offset compensation amount so that the nozzle calibration parameters are used to correct the movement trajectory of the first nozzle 120 and / or the second nozzle 130 in the subsequent dual-nozzle printing process.

[0141] refer to Figure 7 As shown, a program product 700 for implementing the above-described calibration method according to an embodiment of the present invention is described. It may employ a portable compact disc read-only memory (CD-ROM) and include program code, and may run on the controller 160 of the multi-nozzle 3D printing equipment 100, a host computer communicatively connected to the controller 160, or other computing devices. However, the program product of the present invention is not limited thereto. In the present invention, the readable storage medium may be any tangible medium containing or storing a program that may be used by or in conjunction with an instruction execution system, apparatus, or device.

[0142] The program product may employ any combination of one or more readable storage media. Readable storage media may be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0143] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can be executed entirely on the controller, partially on the controller, as a standalone software package, partially on the controller and partially on a host computer or computing device communicatively connected to the controller, or executed by a host computer or computing device communicatively connected to the controller in conjunction with the controller. In cases involving a host computer or remote computing device, the host computer or remote computing device can be connected to the controller via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0144] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously in multiple modules, for example, without violating the execution order and logical conditions defined in the claims.

[0145] Through the description of the above embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions of the embodiments of the present invention can be embodied in the form of a software product, which can be stored in a computer-readable storage medium, such as a CD-ROM, USB flash drive, portable hard drive, solid-state drive, memory card, flash memory, read-only memory, or other medium capable of storing computer programs, including several instructions to cause a computing device (which may be a personal computer, server, touch terminal, or network device, etc.) or a controller of a multi-nozzle 3D printing device to execute the method according to the embodiments of the present invention.

[0146] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0147] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A nozzle calibration method for a multi-nozzle 3D printing device, characterized in that, The multi-nozzle 3D printing equipment includes a filament guide changer, a first nozzle, a second nozzle, a first extrusion mechanism, a second extrusion mechanism, an image acquisition device, and a controller. The filament guide changer includes at least two feed inlets and at least two discharge outlets, with the at least two discharge outlets respectively connected to the feeding paths corresponding to the first nozzle and the second nozzle. The method is executed by the controller and includes: Obtain the path mapping relationship of the consumable track changer. The path mapping relationship is used to characterize the feeding correspondence between the material supply source, the inlet, the outlet and the target nozzle. The target nozzle includes the first nozzle and the second nozzle. Based on the path mapping relationship, a first consumable for calibrating the nozzle offset of the first nozzle and a second consumable for calibrating the nozzle offset of the second nozzle are determined, wherein the first consumable and the second consumable satisfy the visual discrimination conditions required for image recognition. According to the path mapping relationship, the consumable track changer is controlled to transport the first consumable to the feeding path corresponding to the first nozzle, and the second consumable to the feeding path corresponding to the second nozzle; Obtain arrival detection information for the first consumable and the second consumable; When the arrival detection information indicates that both the first consumable and the second consumable have reached the corresponding preset feeding position, the first extrusion mechanism is controlled to drive the first consumable to be extruded through the first nozzle to form a first calibration pattern. After the first calibration pattern is formed, the second extrusion mechanism is controlled to drive the second consumable to be extruded through the second nozzle to form the second calibration pattern; The image acquisition device is controlled to acquire a calibration image containing the first calibration pattern and the second calibration pattern; The nozzle offset compensation amount between the first nozzle and the second nozzle is determined based on the calibration image; The nozzle calibration parameters corresponding to the first nozzle and the second nozzle are updated according to the nozzle offset compensation amount, so that the nozzle calibration parameters are used to correct the motion trajectory of the first nozzle and / or the second nozzle in the subsequent dual-nozzle printing process.

2. The nozzle calibration method according to claim 1, characterized in that, Obtaining the path mapping relationship of the consumable track changer includes: The control target material supply source delivers consumables to the consumable track changer; Acquire trigger information from sensors located at at least one feed inlet of the consumable track changer; The target feed port connected to the target material supply source is determined based on the feed port corresponding to the triggered sensor. Obtain the current switching gear of the consumable track changer; The path mapping relationship is generated or updated based on the target material source, the target inlet, the target outlet corresponding to the current switching gear, and the target nozzle connected to the target outlet.

3. The nozzle calibration method according to claim 1, characterized in that, Obtaining the path mapping relationship of the consumable track changer includes: Displays a settings interface for configuring the connection between the material supply source and the inlet; Receive connection information input by the user in the settings interface; The path mapping relationship is generated or updated based on the specified connection information and the preset connection relationship between the outlet and nozzle of the consumable track changer.

4. The nozzle calibration method according to claim 1, characterized in that, The path mapping relationship includes a first mapping sub-relationship and a second mapping sub-relationship; The first mapping sub-relationship is used to characterize the feeding correspondence between the first material source, the first inlet, the first outlet, and the first nozzle; The second mapping relationship is used to characterize the feeding correspondence between the second material source, the second inlet, the second outlet, and the second nozzle; Determining a first consumable for nozzle offset calibration of the first nozzle and a second consumable for nozzle offset calibration of the second nozzle based on the path mapping relationship includes: At least one first candidate consumable that can be delivered to the first nozzle is determined based on the first mapping sub-relationship; At least one second candidate consumable that can be delivered to the second nozzle is determined based on the second mapping sub-relationship; The first consumable is determined from the at least one first candidate consumable, and the second consumable is determined from the at least one second candidate consumable.

5. The nozzle calibration method according to claim 1, characterized in that, The visual discrimination criteria include at least one of the following: The color attribute difference between the first consumable and the second consumable is greater than or equal to a preset color difference threshold; The first consumable and the second consumable correspond to dark-colored consumable and light-colored consumable, respectively.

6. The nozzle calibration method according to claim 1, characterized in that, According to the path mapping relationship, the consumable track changer is controlled to transport the first consumable to the feeding path corresponding to the first nozzle, and the second consumable to the feeding path corresponding to the second nozzle, including: The first target feeding channel between the first material supply source where the first consumable is located and the first nozzle is determined according to the path mapping relationship; Control the consumable track changer to switch to the first switching gear corresponding to the first target feeding channel, and control the first feeding source to deliver the first consumable to the feeding path corresponding to the first nozzle; The second target feeding channel between the second material supply source and the second nozzle is determined according to the path mapping relationship; The consumable track changer is controlled to switch to the second switching position corresponding to the second target feeding channel, and the second feeding source is controlled to deliver the second consumable to the feeding path corresponding to the second nozzle.

7. The nozzle calibration method according to claim 1, characterized in that, Obtain the arrival detection information of the first consumable and the second consumable, including: The trigger information of at least two of the multiple sensors is acquired, the multiple sensors including at least two of the following: a sensor located at the feed inlet of the consumable track changer, a sensor located at the first extrusion mechanism, a sensor located at the second extrusion mechanism, a sensor located upstream of the first nozzle, and a sensor located upstream of the second nozzle; Based on the trigger information from the at least two sensors, it is determined whether the first consumable has reached the preset feeding position corresponding to the first nozzle, and whether the second consumable has reached the preset feeding position corresponding to the second nozzle.

8. The nozzle calibration method according to claim 7, characterized in that, The method further includes: The preset triggering sequence corresponding to the current feeding process is determined based on the path mapping relationship; Obtain the actual triggering sequence of multiple sensors during the current feeding process; If the actual triggering sequence is inconsistent with the preset triggering sequence, the nozzle offset calibration process is stopped, and a prompt message is output to indicate that the consumable track changer connection is abnormal, the material supply source connection is abnormal, the material tube connection is abnormal, or the consumable is not in place.

9. The nozzle calibration method according to claim 1, characterized in that, Before controlling the consumable track changer to deliver the first consumable and the second consumable according to the path mapping relationship, the method further includes: Set the consumable source determination method in the nozzle offset calibration process to a consumable track changer feeding calibration mode that determines the consumable source based on the path mapping relationship. Based on the path mapping relationship, the feed source, inlet, outlet and feeding path corresponding to the nozzle to be calibrated are analyzed, and feeding control commands are generated to control the consumable track changer and the corresponding feed source to perform feeding based on the analysis results.

10. The nozzle calibration method according to claim 1, characterized in that, Controlling the first extrusion mechanism to drive the first consumable to be extruded through the first nozzle includes: The first extrusion mechanism is controlled to drive the first consumable to be extruded through the first nozzle to form at least one of a first calibration line extending in a first direction and a second calibration line extending in a second direction; Controlling the second extrusion mechanism to drive the second consumable to be extruded through the second nozzle includes: The second extrusion mechanism is controlled to drive the second consumable to be extruded through the second nozzle to form at least one of a third calibration line extending along the first direction and a fourth calibration line extending along the second direction; Wherein, the first direction is perpendicular to the second direction, the first calibration line and the third calibration line are used to determine the nozzle offset compensation amount in the second direction, and the second calibration line and the fourth calibration line are used to determine the nozzle offset compensation amount in the first direction.

11. The nozzle calibration method according to claim 1, characterized in that, Determining the nozzle offset compensation amount between the first nozzle and the second nozzle based on the calibration image includes: Identify the first pattern center position of the first calibration pattern and the second pattern center position of the second calibration pattern in the calibration image; The measured relative position between the first calibration pattern and the second calibration pattern is determined based on the center position of the first pattern and the center position of the second pattern. Obtain the theoretical relative position between the first nozzle and the second nozzle; The nozzle offset compensation amount is determined based on the difference between the measured relative position and the theoretical relative position.

12. The nozzle calibration method according to claim 1, characterized in that, Before controlling the image acquisition device to acquire a calibration image containing the first calibration pattern and the second calibration pattern, the method further includes: The image acquisition device is controlled to acquire a pre-acquired image containing the image regions corresponding to the first consumable and the second consumable; Based on the pre-acquired image, image difference parameters are obtained between the corresponding image regions of the first consumable and the second consumable. The image difference parameters include at least one of grayscale difference, brightness difference, hue difference, and saturation difference. Determine the image acquisition parameters and / or image recognition parameters based on the image difference parameters; The image acquisition device is controlled to acquire the calibration image according to the image acquisition parameters, and / or the first calibration pattern and the second calibration pattern are identified according to the image recognition parameters.

13. The nozzle calibration method according to claim 1, characterized in that, The first extrusion mechanism is a short-range extrusion mechanism located close to the first nozzle, and the second extrusion mechanism is a long-range extrusion mechanism spaced apart from the second nozzle. The feeding path corresponding to the second nozzle includes a long-range feeding path located between the second extrusion mechanism and the second nozzle. Controlling the second extrusion mechanism to drive the second consumable to be extruded through the second nozzle includes: The printing speed during the formation of the second calibration pattern is limited to no more than a preset speed threshold, and the printing acceleration during the formation of the second calibration pattern is limited to no more than a preset acceleration threshold; and / or, The extrusion compensation parameters corresponding to the remote feeding path are invoked, and the feeding action of the second extrusion mechanism is controlled based on the extrusion compensation parameters.

14. A multi-nozzle 3D printing device, characterized in that, include: A consumable track changer includes at least two inlets and at least two outlets, the consumable track changer being used to selectively connect any of the inlets and any of the outlets; The first nozzle and the second nozzle are respectively connected to the feeding paths corresponding to different discharge ports of the consumable track changer; A first extrusion mechanism is provided corresponding to the first nozzle; A second extrusion mechanism is provided corresponding to the second nozzle; An image acquisition device is used to acquire images of calibration patterns printed by the first nozzle and the second nozzle; At least one sensor is disposed at at least one of the following: the feed inlet of the consumable track changer, the first extrusion mechanism, the second extrusion mechanism, the upstream of the first nozzle, and the upstream of the second nozzle, for detecting the triggering state or the positioning state of the consumable; as well as A controller is connected to the consumable track changer, the first extrusion mechanism, the second extrusion mechanism, the image acquisition device, and the at least one sensor, respectively, and the controller is configured to perform the nozzle calibration method according to any one of claims 1 to 13.

15. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the nozzle calibration method for a multi-nozzle 3D printing apparatus according to any one of claims 1 to 13.

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