Control method and device of 3D printing equipment, equipment and storage medium

Abstract

The invention provides a control method and device of 3D printing equipment, the equipment and a storage medium, and relates to the field of 3D printing. The method comprises the steps that before the 3D printing equipment conducts model printing, extrusion pressure parameters of an extrusion mechanism of the 3D printing equipment at different extrusion speeds are obtained; and on the basis of the extrusion pressure parameters at different extrusion speeds, pressure advance coefficient calibration processing is conducted, and first pressure advance coefficients corresponding to the extrusion speeds are obtained. According to the embodiment of the invention, before the 3D printing equipment performs model printing, the corresponding extrusion pressure parameters are obtained by extruding the printing consumables according to different extrusion speeds, and the pressure advance coefficient is automatically calibrated based on the extrusion pressure parameters, so that compared with a manual observation calibration method, the calibration efficiency is greatly improved. The accuracy and efficiency of pressure advance coefficient calibration are improved, consumables do not need to be extruded on a hot bed platform, and the space of a hot bed can not be occupied.

Description

Technical Field

[0001] The present application relates to the field of 3D printing, and in particular to a control method and device for a 3D printing device, a 3D printing device, and a readable storage medium. Background Art

[0002] During 3D printing, when the print head needs to change direction or make curved movements, the printing consumables in the extruder mechanism will produce a certain pressure loss during the flow process. This pressure loss will lead to insufficient supply of printing consumables, which will affect the printing quality and cause problems such as blockage of the extruder head and uneven materials. In order to solve this problem, the flow rate of the extruder mechanism is increased in advance based on the pressure advance coefficient to compensate for this pressure loss.

[0003] The pressure advance coefficient is affected by factors such as the tightness of the spring inside the extruder, the degree of gear wear, the aging of the nozzle structure due to long-term heating, and consumables from different manufacturers or different colors or batches of consumables from the same manufacturer. Therefore, it is necessary to calibrate the pressure advance coefficient before printing the model.

[0004] In the related art, the pressure advance coefficient is calibrated by printing a model on a hot bed platform, observing the performance of the printed model with the human eye or tools such as a ruler, and debugging and setting the pressure advance coefficient. This calibration method is time-consuming, not accurate enough, and the printed model will occupy the hot bed space. Summary of the invention

[0005] In view of this, the present application provides a control method and device for a 3D printing device, a 3D printing device and a readable storage medium, which solve the problems of time-consuming, low-accuracy and occupied hot bed space in the pressure advance coefficient calibration in the related art.

[0006] In a first aspect, an embodiment of the present application provides a control method for a 3D printing device, comprising:

[0007] Before the 3D printing device performs model printing, obtaining extrusion pressure parameters of an extrusion mechanism of the 3D printing device at different extrusion speeds;

[0008] Calibrate the pressure advance coefficient based on the extrusion pressure parameters at different extrusion speeds to obtain the first pressure advance coefficient corresponding to each extrusion speed;

[0009] Based on the different extrusion speeds and the first pressure advance coefficients corresponding to the extrusion speeds, a correspondence between the extrusion speeds and the pressure advance coefficients is generated. The correspondence is used to determine a target pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism when the 3D printing device prints a model.

[0010] In a second aspect, an embodiment of the present application provides a 3D printing device, which includes a processor and a memory, wherein the memory stores programs or instructions that can be run on the processor, and when the programs or instructions are executed by the processor, the steps of the method of the first aspect are implemented.

[0011] In a third aspect, an embodiment of the present application provides a readable storage medium, on which a program or instruction is stored, and when the program or instruction is executed by a processor, the steps of the method of the first aspect are implemented.

[0012] In the embodiment of the present application, before the 3D printing device performs model printing, the extrusion mechanism of the 3D printing device extrude the printing consumables at different extrusion speeds, and when the printing consumables are extruded at different extrusion speeds, the extrusion pressure parameters of the extrusion mechanism are respectively obtained. For each extrusion speed, the pressure advance coefficient is calibrated based on the extrusion pressure parameter at the extrusion speed, so as to obtain the pressure advance coefficient corresponding to each extrusion speed, that is, the first pressure advance coefficient.

[0013] In the embodiment of the present application, before the 3D printing device prints the model, the corresponding extrusion pressure parameters are obtained by extruding the printing consumables at different extrusion speeds, and the pressure advance coefficient is automatically calibrated based on the extrusion pressure parameters. Compared with the method of calibration by manual observation, the accuracy and efficiency of the pressure advance coefficient calibration are improved, and there is no need to extrude the consumables on the hot bed platform, and the hot bed space is not occupied.

[0014] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0016] Figure 1 One of the flow charts of the control method of the 3D printing device according to the embodiment of the present application is shown;

[0017] Figure 2 A schematic diagram showing pressure curves corresponding to different pressure advance coefficients according to an embodiment of the present application;

[0018] Figure 3 A schematic diagram showing the planning of extrusion flow, extrusion speed and phase of an embodiment of the present application is shown;

[0019] Figure 4A second flow chart of the control method of the 3D printing device according to an embodiment of the present application is shown;

[0020] Figure 5 A structural block diagram of a 3D printing device according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments in the present application belong to the scope of protection of this application.

[0022] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0023] In conjunction with the accompanying drawings, the control method, device, 3D printing device and readable storage medium of the 3D printing device provided in the embodiments of the present application are described in detail through specific embodiments and their application scenarios.

[0024] The present application embodiment provides a control method for a 3D printing device, such as Figure 1 As shown, the method includes:

[0025] S101, before the 3D printing device prints the model, obtaining extrusion pressure parameters of an extrusion mechanism of the 3D printing device at different extrusion speeds.

[0026] In this step, before the 3D printing device prints the model, the extrusion mechanism of the 3D printing device extrude the printing consumables at different extrusion speeds, and when the printing consumables are extruded at different extrusion speeds, the extrusion pressure parameters of the extrusion mechanism are respectively obtained. When the printing consumables are extruded at different extrusion speeds, the printing consumables can be extruded with different compensation parameters.

[0027] In an optional embodiment, the 3D printing device includes a feeding device, a print head and a hot bed platform, and the feeding device can provide printing consumables to the print head. The print head includes an extrusion mechanism and a nozzle structure, and the extrusion mechanism is arranged between the nozzle structure and the feeding device. The extrusion mechanism provides the printing consumables to the nozzle structure, and the nozzle structure extrude the molten printing consumables onto the hot bed platform to form a printed model. It can be understood that the print head may not include the extrusion mechanism, but the feeding device includes the extrusion mechanism.

[0028] In one embodiment, the print head further includes a strain cantilever, one end of which is fixed and the other end is connected to the nozzle structure. A pressure detection component is attached to the surface of the strain cantilever, and the pressure detection component can be a strain gauge or other device capable of detecting pressure. When the extrusion mechanism squeezes the printing consumables toward the nozzle structure, the extrusion force applied by the printing consumables to the nozzle structure is transmitted to the strain cantilever, so that the surface of the strain cantilever generates strain. The pressure detection component can measure the deformation of the surface of the strain cantilever, thereby realizing the detection of the extrusion pressure of the extrusion mechanism.

[0029] By detecting the extrusion pressure of the extrusion mechanism when the printing consumables are extruded at different extrusion speeds, the extrusion pressure parameters of the extrusion mechanism at different extrusion speeds are obtained.

[0030] It should be noted that during the calibration, the print head may not move in the X, Y and Z directions, and the print head extrude the printing consumables in situ. After the calibration is completed, the accumulated consumables are thrown out through the ejector.

[0031] S102, performing calibration processing on the pressure advance coefficient based on the extrusion pressure parameters at different extrusion speeds, to obtain a first pressure advance coefficient corresponding to each extrusion speed.

[0032] In this step, for each extrusion speed, the pressure advance coefficient is calibrated based on the extrusion pressure parameter at the extrusion speed, so as to obtain the pressure advance coefficient corresponding to each extrusion speed, that is, the first pressure advance coefficient.

[0033] In the embodiment of the present application, before the 3D printing device prints the model, the corresponding extrusion pressure parameters are obtained by extruding the printing consumables at different extrusion speeds, and the pressure advance coefficient is automatically calibrated based on the extrusion pressure parameters. Compared with the method of calibration by manual observation, the accuracy and efficiency of the pressure advance coefficient calibration are improved, and there is no need to extrude the consumables on the hot bed platform, and the hot bed space is not occupied.

[0034] In one embodiment of the present application, the method further includes: generating a correspondence between the extrusion speed and the pressure advance coefficient based on different extrusion speeds and a first pressure advance coefficient corresponding to each extrusion speed, wherein the correspondence is used to determine a target pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism when the 3D printing device performs model printing, and the correspondence includes at least one of a functional relationship, a fitting curve, and a relationship table.

[0035] In this embodiment, the first pressure advance coefficient corresponding to different extrusion speeds is obtained through the above steps, and a corresponding relationship between the extrusion speed and the pressure advance coefficient is established. The corresponding relationship is a mapping relationship between the extrusion speed and the pressure advance coefficient, and one extrusion speed can correspond to one pressure advance coefficient.

[0036] When the 3D printing device performs model printing, the target pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism can be determined based on the corresponding relationship, so that the extrusion flow rate of the extrusion mechanism is calibrated according to the target pressure advance coefficient.

[0037] In one embodiment, the corresponding relationship between the extrusion speed and the pressure advance coefficient can be at least one of a functional relationship, a fitting curve, and a relationship table. For example, the extrusion speed is changed M times to obtain M extrusion speeds and M first pressure advance coefficients, as shown in Table 1:

[0038] Table 1

[0039] Extrusion speed <![CDATA[V1]]> <![CDATA[V2]]> ...... <![CDATA[V M ]]> First pressure advance coefficient <![CDATA[K best1 ]]> <![CDATA[K best2 ]]> ...... <![CDATA[K bestM ]]>

[0040] The extrusion speed and the first pressure advance coefficient are fitted using the least squares method to obtain a polynomial fitting equation. Here, a quadratic polynomial fitting equation is taken as an example:

[0041] K best =a1×V 2 +b1×V+c1

[0042] Among them, K best is the first pressure advance coefficient, V is the extrusion speed, and a1, b1, c1 are coefficients.

[0043] By establishing a corresponding relationship between the extrusion speed and the pressure advance coefficient, when performing actual model printing, the pressure advance coefficient corresponding to the current extrusion speed can be quickly and accurately obtained based on the corresponding relationship, thereby achieving extrusion flow calibration of the extrusion mechanism and improving printing quality.

[0044] In one embodiment of the present application, the method further includes:

[0045] When the 3D printing device is printing a model, obtaining the current extrusion speed of the extrusion mechanism for the printing consumables;

[0046] Based on the corresponding relationship between the extrusion speed and the pressure advance coefficient, determine the target pressure advance coefficient corresponding to the current extrusion speed;

[0047] According to the target pressure advance coefficient, the extrusion flow rate of the extrusion mechanism is adjusted.

[0048] In this embodiment, when the 3D printing device performs model printing, the current extrusion speed of the extruder for the printing consumables is obtained. Based on the established correspondence between the extrusion speed and the pressure advance coefficient, the target pressure advance coefficient corresponding to the current extrusion speed of the extruder is determined, so as to calibrate the extrusion flow rate of the extruder according to the target pressure advance coefficient.

[0049] In the embodiment of the present application, before the 3D printing device prints the model, the pressure advance coefficient is calibrated to obtain the corresponding relationship between the extrusion speed and the pressure advance coefficient. When the model is officially printed, a more accurate pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism can be determined based on the corresponding relationship, thereby achieving calibration of the extrusion flow rate of the extrusion mechanism, adjusting the extrusion speed in advance, avoiding the problem of insufficient supply of printing consumables, and ensuring the printing quality of the model.

[0050] In the embodiment of the present application, the extrusion flow rate needs to be calibrated in the following situations:

[0051] (1) Using new printing consumables of different brands or types; (2) The nozzle is worn, causing the friction inside the nozzle to change; (3) Replacing the nozzle with a new one; (4) The printing consumables are exposed to moisture, causing the viscosity of the consumables to change; (5) Changing the maximum speed or printing temperature of the printing consumables.

[0052] In the above cases, calibrate the extrusion flow rate to improve the printing quality.

[0053] According to Poiseuille's law, the extrusion flow rate of the extruder is proportional to the pressure difference of the extruder; the extrusion flow rate of the extruder is proportional to the extrusion speed, so the extrusion speed is proportional to the pressure difference of the extruder. Use the pressure detection device in the extruder to collect pressure data, and reflect the extrusion flow effect through the extrusion pressure.

[0054]

[0055] Among them, Q is the extrusion flow rate, r is the radius of the delivery pipeline of the printing consumables, p is the pressure difference at both ends of the pipeline; η is the dynamic viscosity coefficient of the printing consumables, L is the length of the delivery pipeline, A is the cross-sectional area of ​​the printing consumables passing through the delivery pipeline, and V is the extrusion speed.

[0056] like Figure 2As shown in the figure, when the pressure advance coefficient is small, the pressure lag is large in the acceleration and deceleration stages, resulting in insufficient extrusion flow; when the pressure advance coefficient is large, the pressure overshoot is obvious in the acceleration and deceleration stages, resulting in excessive extrusion flow; when the pressure advance coefficient is optimal, there is no lag and overshoot in the acceleration and deceleration stages, and the extrusion flow is appropriate.

[0057] Therefore, in the embodiment of the present application, an extrusion speed in the form of a square wave is used to simulate the acceleration stage and the deceleration stage, and a suitable pressure advance coefficient is determined based on the change in pressure during the acceleration stage and the deceleration stage.

[0058] In one embodiment of the present application, any extrusion speed includes N speed cycles, where N is a positive integer greater than or equal to 2, and each speed cycle includes a first speed and a second speed, and the first speed is less than the second speed.

[0059] In this embodiment, if Figure 3 As shown, the extrusion speed of the extrusion mechanism is planned: the extrusion speed of the extrusion mechanism is set in the form of a square wave with periodic changes. One extrusion speed includes N speed cycles, each speed cycle includes a first speed and a second speed, the first speed is less than the second speed, the first speed can be called a low speed, and the second speed can be called a high speed. In one speed cycle, the extrusion mechanism switches from the first speed to the second speed.

[0060] Plan the phase of extrusion speed: the phase is divided into calibration phase, non-calibration phase, high-speed phase, low-speed phase, and high-speed to low-speed identification phase. Execute calibration-related commands in the calibration phase. Since there is a certain lag in pressure, the identification phase is delayed for a period of time after the high-speed ends. There will be a higher pressure value in the identification phase. The pressure value in the identification phase can be used to determine the extrusion pressure parameters later.

[0061] In one embodiment of the present application, for an extrusion speed:

[0062] Get the extrusion pressure parameters of the extrusion mechanism at the extrusion speed, including:

[0063] Obtaining an extrusion pressure parameter of each speed cycle of the extrusion speed, wherein the method for obtaining the extrusion pressure parameter of any speed cycle includes: obtaining a target extrusion pressure when the extrusion mechanism switches from a first speed to a second speed, and a calibrated extrusion pressure when the extrusion mechanism switches from the second speed to the first speed; calculating a pressure difference between the target extrusion pressure and the calibrated extrusion pressure;

[0064] Calibration processing of the pressure advance coefficient is performed based on the extrusion pressure parameter at the extrusion speed to obtain a first pressure advance coefficient corresponding to the extrusion speed, including:

[0065] Determine a second pressure advance coefficient corresponding to the pressure difference of each speed cycle to obtain N second pressure advance coefficients;

[0066] Based on the N pressure differences and the second pressure advance coefficient corresponding to each pressure difference, a first pressure advance coefficient corresponding to the extrusion speed is determined.

[0067] In this embodiment, extrusion pressure parameters are obtained in each speed cycle, and the extrusion pressure parameters may include extrusion pressures corresponding to different speed switching processes and pressure differences of extrusion pressures corresponding to different speed switching processes. For any speed cycle, the target extrusion pressure when the first speed is switched to the second speed and the calibrated extrusion pressure when the second speed is switched to the first speed in the speed cycle are obtained, and the difference between the target extrusion pressure and the calibrated extrusion pressure is calculated to obtain the pressure difference between the two.

[0068] It should be noted that when the extrusion mechanism is accelerating, the data of the pressure detection component cannot reflect the changing trend of different pressure advance coefficients. However, when the extrusion mechanism is decelerating, the data of the pressure detection component can reflect the changing trend of different pressure advance coefficients. Therefore, the pressure when the first speed is switched to the second speed is used as the target extrusion pressure, and the pressure when the second speed is switched to the first speed is used as the calibration extrusion pressure.

[0069] Furthermore, for a speed cycle, the hysteresis and overshoot of the pressure are determined according to the pressure difference. If there is no hysteresis and overshoot, the pressure advance coefficient is determined to be optimal, and the pressure advance coefficient corresponding to the speed cycle is obtained, that is, the second pressure advance coefficient, and the pressure advance coefficient is used as the calibration base value for the next speed cycle. It should be noted that the calibration base value corresponding to the first speed cycle is the preset initial pressure advance coefficient. In this way, N second pressure advance coefficients are obtained. Based on the N pressure differences and the second pressure advance coefficients corresponding to each pressure difference, the first pressure advance coefficient corresponding to the extrusion speed is determined.

[0070] Since there is no pressure lag and overshoot in the acceleration and deceleration stages when the pressure advance coefficient is optimal, the embodiment of the present application determines the optimal pressure advance coefficient based on the pressure difference detected in the acceleration and deceleration stages, thereby ensuring the accuracy of the calibrated pressure advance coefficient.

[0071] In one embodiment of the present application, obtaining a target extrusion pressure when an extrusion mechanism switches from a first speed to a second speed, and a calibrated extrusion pressure when an extrusion mechanism switches from the second speed to the first speed, includes:

[0072] Acquire a plurality of first sampled pressures when the extrusion mechanism switches from the first speed to the second speed, and determine a target extrusion pressure according to the plurality of first sampled pressures;

[0073] When the extrusion mechanism switches from the second speed to the first speed, an identification phase of the extrusion speed is determined, and a plurality of second sampled pressures corresponding to the identification phase are acquired, and a calibration extrusion pressure is determined according to the plurality of second sampled pressures.

[0074] In this embodiment, multiple first sampled pressures are obtained when the first speed is switched to the second speed. The multiple first sampled pressures may be multiple pressure values ​​collected during the entire process of extruding the printing consumables at the first speed, or multiple pressure values ​​in an adjacent or spaced speed interval before the first speed is switched to the second speed. After the multiple first sampled pressures are obtained, the average value, median value or peak value of the multiple first sampled pressures may be used as the target extrusion pressure.

[0075] For example, after obtaining multiple first sampled pressures, the peak pressure can be obtained by the second-order difference method as the target extrusion pressure. Compared with the increasing or decreasing calculation method, the peak pressure obtained by the second-order difference method improves efficiency. In addition, since the average or median value may be unstable when there is vibration or noise, taking the minimum point, that is, the peak pressure, can ensure a smaller error and improve the accuracy of the subsequent calibration pressure advance coefficient.

[0076] In one embodiment, it is also possible not to sample multiple pressures, but to directly use the pressure at the minimum point of the first speed, that is, the pressure corresponding to the end of the first speed, as the target extrusion pressure.

[0077] In the embodiment of the present application, when the first speed is switched to the second speed, an accurate target extrusion pressure is obtained so that an accurate calibration of the pressure advance coefficient can be performed subsequently.

[0078] When the extrusion mechanism switches from the second speed to the first speed, due to a certain lag in pressure, the identification phase will be delayed for a period of time after the second speed ends, and the calibration extrusion pressure is determined within the identification phase.

[0079] Multiple second sampled pressures are obtained in the identification phase. The multiple second sampled pressures may be multiple pressure values ​​collected during the entire process of the identification phase, or may be multiple pressure values ​​in an adjacent or spaced speed interval in the identification phase after the second speed switches to the first speed. After obtaining multiple second sampled pressures, the average, median or peak value of the multiple second sampled pressures may be used as the target extrusion pressure. For example, after obtaining multiple second sampled pressures, the peak pressure may be obtained by the second-order difference method as the calibration extrusion pressure. The peak pressure obtained by the second-order difference method improves efficiency compared to the increasing or decreasing operation method.

[0080] In one embodiment, instead of sampling multiple pressures, the pressure at the minimum point in the identification phase, that is, the pressure corresponding to the end of the identification phase, is directly used as the calibration extrusion pressure.

[0081] The embodiment of the present application can accurately obtain the target extrusion pressure in the acceleration phase and the calibrated extrusion pressure in the deceleration phase, thereby ensuring the accuracy of the subsequent pressure advance coefficient calibration.

[0082] In one embodiment of the present application, determining a second pressure advance coefficient corresponding to the pressure difference includes:

[0083] If the absolute value of the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is used as the second pressure advance coefficient corresponding to the pressure difference;

[0084] If the absolute value of the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed period is adjusted according to the pressure difference, and the adjusted pressure advance coefficient is used as the second pressure advance coefficient corresponding to the pressure difference.

[0085] In this embodiment, the absolute value of the pressure difference between the target extrusion pressure and the calibrated extrusion pressure is compared with a preset pressure judgment threshold, wherein the preset pressure judgment threshold is used to judge the size of the pressure difference between the target extrusion pressure and the calibrated extrusion pressure, and the preset pressure judgment threshold is greater than or equal to 0.

[0086] When the absolute value of the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle, that is, the pressure advance coefficient under the current calibration process, is used as the second pressure advance coefficient corresponding to the pressure difference of the current speed cycle. Usually, the pressure advance coefficient is the optimal value when the pressure difference is equal to 0. Considering that the optimal pressure advance coefficient is normally distributed, when the absolute value of the pressure difference is less than a smaller threshold, it can also be considered as the optimal pressure advance coefficient.

[0087] When the absolute value of the pressure difference is greater than the preset pressure judgment threshold, it indicates that the pressure advance coefficient corresponding to the current speed cycle is smaller or larger. The pressure advance coefficient corresponding to the current speed cycle is adjusted according to the pressure difference, and the adjusted pressure advance coefficient is used as the second pressure advance coefficient corresponding to the pressure difference.

[0088] It should be noted that the calibration base value corresponding to the first speed cycle is a preset initial pressure advance coefficient. Except for the first speed cycle, the pressure advance coefficients corresponding to other speed cycles are determined based on the previous speed cycle. For example, if the absolute value of the pressure difference in the first speed cycle is less than or equal to the preset pressure judgment threshold, the initial pressure advance coefficient corresponding to the first speed cycle is used as the second pressure advance coefficient corresponding to the pressure difference of the current speed cycle, and the initial pressure advance coefficient, or the second pressure advance coefficient corresponding to the pressure difference of the first speed cycle, is used as the pressure advance coefficient corresponding to the second speed cycle. If the absolute value of the pressure difference in the second speed cycle is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the second speed cycle is adjusted according to the pressure difference, and the adjusted pressure advance coefficient is used as the second pressure advance coefficient corresponding to the pressure difference of the second speed cycle. The second pressure advance coefficient corresponding to the pressure difference of the second speed cycle is used as the pressure advance coefficient corresponding to the third speed cycle, and the second pressure advance coefficients corresponding to the pressure differences of subsequent speed cycles are determined in sequence.

[0089] In the embodiment of the present application, when the absolute value of the pressure difference is less than or equal to the preset pressure judgment threshold, the optimal pressure advance coefficient is directly determined, and when the absolute value of the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient is adjusted to obtain the optimal pressure advance coefficient, thereby realizing the determination of the optimal pressure advance coefficient.

[0090] In one embodiment of the present application, adjusting the pressure advance coefficient corresponding to the current speed cycle according to the pressure difference includes:

[0091] If the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is reduced;

[0092] If the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is increased;

[0093] The method further includes:

[0094] The reduced or increased pressure advance coefficient is used as the pressure advance coefficient corresponding to the next speed cycle.

[0095] In this embodiment, if the absolute value of the pressure difference is greater than the preset pressure judgment threshold, the magnitude relationship between the pressure difference and the preset pressure judgment threshold is further determined. If the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is reduced by a first preset multiple, for example, by 1 / 2, 1 / 3, 2 / 3 times, etc.; if the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is increased by a second preset multiple, for example, by 1 / 2, 1 / 3, 2 / 3 times, etc. The second preset multiple may be equal to or unequal to the first preset multiple.

[0096] By determining the magnitude relationship between the pressure difference and a preset pressure determination threshold, the pressure advance coefficient is adjusted so that the adjusted pressure advance coefficient is closer to the optimal pressure advance coefficient.

[0097] In an implementable manner, if the pressure difference is greater than a preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is reduced, and the reduced pressure advance coefficient is used as the pressure advance coefficient corresponding to the next speed cycle, that is, the calibration base value of the next speed cycle; or, if the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is increased, and the increased pressure advance coefficient is used as the pressure advance coefficient corresponding to the next speed cycle, that is, the calibration base value of the next speed cycle. In this way, the pressure advance coefficient corresponding to the next speed cycle can be determined, so as to adjust the pressure advance coefficient corresponding to the next speed cycle.

[0098] In one embodiment of the present application, determining a first pressure advance coefficient corresponding to an extrusion speed based on N pressure differences and a second pressure advance coefficient corresponding to each pressure difference includes:

[0099] Based on N-1 pressure differences except the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences, a first pressure advance coefficient corresponding to the extrusion speed is determined.

[0100] In this embodiment, the first speed cycle is used to release the pressure in the nozzle assembly, and the pressure value is unstable, so the pressure difference in the first speed cycle is excluded, that is, the pressure difference in the first speed cycle is not included in the calibration calculation. The first pressure advance coefficient corresponding to the extrusion speed is determined by using N-1 pressure differences other than the first pressure difference and the second pressure advance coefficient corresponding to each pressure difference in the N-1 pressure differences, thereby improving accuracy.

[0101] In one embodiment of the present application, based on N-1 pressure differences other than the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences, determining the first pressure advance coefficient corresponding to the extrusion speed includes:

[0102] Based on N-1 pressure differences and the second pressure advance coefficient corresponding to each pressure difference, construct a functional relationship between the pressure difference and the second pressure advance coefficient;

[0103] Based on the functional relationship, the second pressure advance coefficient corresponding to the pressure difference being 0 is used as the first pressure advance coefficient corresponding to the extrusion speed.

[0104] In this embodiment, based on N-1 pressure differences and the second pressure advance coefficient corresponding to each pressure difference, a functional relationship between the pressure difference and the second pressure advance coefficient is constructed. The functional relationship can be a linear relationship or a nonlinear relationship. For example, the least squares method or the Lagrange algorithm can be used to establish the functional relationship between the pressure difference and the second pressure advance coefficient. Based on the functional relationship, the second pressure advance coefficient corresponding to the pressure difference of 0 is calculated as the first pressure advance coefficient corresponding to the extrusion speed.

[0105] Exemplarily, N-1 pressure differences and N-1 second pressure advance coefficients are shown in Table 2:

[0106] Table 2

[0107] Pressure difference <![CDATA[△p1]]> <![CDATA[△p2]]> ...... <![CDATA[△p N-1 ]]> Second pressure advance coefficient <![CDATA[K1]]> <![CDATA[K2]]> ...... <![CDATA[K N-1 ]]>

[0108] The pressure difference and the second pressure advance coefficient are fitted using the least squares method to obtain a polynomial fitting equation. In the embodiment of the present application, a second-order polynomial fitting equation can be taken as an example to establish a second-order polynomial fitting equation between the pressure difference and the second pressure advance coefficient:

[0109] K=a2×△p 2 +b2×△p+c2

[0110] Among them, K is the second pressure advance coefficient, △p is the pressure difference, and a2, b2, and c2 are coefficients.

[0111] The pressure advance value corresponding to the pressure difference Δp being 0 is calculated as the first pressure advance coefficient corresponding to the extrusion speed.

[0112] It should be noted that in the actual calibration process, in order to shorten the calibration time, the amount of calibration data is small. If a higher-order polynomial fitting greater than 2 is used, there will be abnormal fitting values ​​outside the calibration range due to the parabolic characteristics. Therefore, the embodiment of the present application adopts a 2nd-order polynomial fitting equation to avoid the above problem.

[0113] In the embodiment of the present application, the optimal pressure advance coefficient corresponding to the extrusion speed is calculated through the functional relationship between the pressure difference and the second pressure advance coefficient, thereby realizing automatic calibration of the pressure advance coefficient.

[0114] In one embodiment of the present application, the method further includes:

[0115] If the target extrusion pressure and / or the calibrated extrusion pressure is not obtained in any speed cycle of the extrusion speed, it is confirmed that the speed cycle sampling is abnormal;

[0116] If the number of speed cycles in which the sampling of the extrusion speed is abnormal is greater than a preset number, it is determined that the calibration process corresponding to the extrusion speed has failed;

[0117] The method further includes: if the calibration process corresponding to the extrusion speed fails, using the default pressure advance coefficient as the first pressure advance coefficient corresponding to the extrusion speed.

[0118] In this embodiment, if the target extrusion pressure and / or the calibrated extrusion pressure is not obtained in any speed cycle of the extrusion speed, it is determined that a sampling abnormality problem occurs in the current speed cycle. The number of speed cycles in which the sampling abnormality problem occurs is recorded, and if the number is greater than a preset number, that is, the number of groups of the obtained pressure difference and the second pressure advance coefficient is less than a certain number, it is determined that the calibration process corresponding to the extrusion speed has failed.

[0119] In one embodiment, if it is confirmed that the calibration process corresponding to the extrusion speed fails, the default pressure advance coefficient in the slice file is used as the first pressure advance coefficient corresponding to the extrusion speed. In the case of a calibration process failure, the first pressure advance coefficient corresponding to the extrusion speed is set to ensure that when the model is printed, the corresponding optimal pressure advance coefficient can be obtained for each extrusion speed, thereby improving the model printing quality.

[0120] In one embodiment of the present application, after determining the second pressure advance coefficient corresponding to the pressure difference, the method further includes: if the calibration processing corresponding to the extrusion speed is successful, then based on a preset pressure advance coefficient range, limiting the first pressure advance coefficient corresponding to the determined extrusion speed.

[0121] In this embodiment, if the calibration is successful, the first pressure advance coefficient is limited based on the preset pressure advance coefficient range. For example, the preset pressure advance coefficient range is 0 to 0.1, that is, the upper limit value is 0.1 and the lower limit value is 0. If the first pressure advance coefficient is greater than the upper limit value, it is set equal to the upper limit value; if the first pressure advance coefficient is less than or equal to the upper limit value and greater than or equal to the lower limit value, its value is not changed; if the first pressure advance coefficient is less than the upper limit value, it is set equal to the lower limit value.

[0122] Through the above method, the first pressure advance coefficient is within the preset pressure advance coefficient range, thereby ensuring the rationality of the first pressure advance coefficient.

[0123] In one embodiment of the present application, Figure 4As shown, before calibration begins, set the pressure advance coefficient range (Kmin, Kmax), set the initial pressure advance coefficient Kinit, set the pressure judgment threshold Coef, the low-speed corner speed or the minimum extrusion speed Vlow, and the initial extrusion speed Vinit. Perform calibration of N different pressure advance coefficients at M different extrusion speeds. The pressure advance coefficient is also called the K value.

[0124] Start to perform calibration. The extrusion speed of the extruder mechanism switches from low speed to high speed. The extrusion pressure corresponding to the minimum speed point when switching from low speed to high speed is taken as the target value TargetPress. The extruder mechanism switches from high speed to low speed. The extrusion pressure corresponding to the minimum point in the identification phase is taken as the calibration value CaliPress. The target value TargetPress is subtracted from the calibration value CaliPress to obtain the pressure difference △P:

[0125] △P=TargetPress-CaliPress

[0126] If the absolute value of △P is less than or equal to the pressure judgment threshold Coef, the K value at this time is the optimal value, and the extrusion speed is changed to continue calibration.

[0127] If the absolute value of △P is greater than the pressure judgment threshold Coef, the binary method is further used to determine the K value. If △P is greater than the pressure judgment threshold Coef, the K value is reduced by half and used as the K value for the next cycle calibration; if △P is less than the pressure judgment threshold Coef, the K value is increased by half and used as the K value for the next cycle calibration.

[0128] When the extrusion speed remains unchanged, N calibrations are performed to obtain N pressure differences and N pressure advance coefficients, ie, the second pressure advance coefficients.

[0129] The pressure difference and pressure advance coefficient are fitted using the least squares method to obtain a polynomial fitting equation. Here, a quadratic polynomial fitting equation is taken as an example:

[0130] K=a2×△p 2 +b2×△p+c2

[0131] Among them, K is the pressure advance coefficient, △p is the pressure difference, and a2, b2, and c2 are coefficients.

[0132] When the pressure difference △p of the fitting point is 0, the optimal pressure advance coefficient K corresponding to the extrusion speed is obtained. best .

[0133] Change the extrusion speed M times, repeat the above operation, and obtain M extrusion speeds and M optimal pressure advance coefficients K best , which is the above-mentioned first pressure advance coefficient.

[0134] The extrusion speed and the optimal pressure advance coefficient are fitted using the least squares method to obtain a polynomial fitting equation. Here, a quadratic polynomial fitting equation is taken as an example.

[0135] K best =a1×V 2 +b1×V+c1

[0136] Among them, K best is the optimal pressure advance coefficient, V is the extrusion speed, and a1, b1, c1 are coefficients.

[0137] In the actual model printing process, the optimal pressure advance coefficient is obtained according to the current extrusion speed set to adjust the extrusion flow rate.

[0138] In the embodiment of the present application, the calibration before printing does not require the extrusion of consumables on the hot bed printing platform, does not occupy the hot bed space, and reduces the time cost of human intervention compared to the calibration method of observing the printed model by human eyes. In addition, the embodiment of the present application shortens the calibration time and enhances the stability and noise resistance of the calibration result by combining the dichotomy method and the least squares fitting method.

[0139] The present application also provides a 3D printing device, such as Figure 5 As shown, the 3D printing device 500 includes a processor 501 and a memory 502. The memory 502 stores a program or instruction that can be run on the processor 501. When the program or instruction is executed by the processor 501, each step of the control method embodiment of the above-mentioned 3D printing device is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0140] The memory 502 can be used to store software programs and various data. The memory 502 may mainly include a first storage area for storing programs or instructions and a second storage area for storing data, wherein the first storage area may store an operating system, an application program or instructions required for at least one function (such as a sound playback function, an image playback function, etc.), etc. In addition, the memory 502 may include a volatile memory or a non-volatile memory, or the memory 502 may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), a static random access memory (SRAM), a dynamic random access memory (DRAM), a synchronous dynamic random access memory (SDRAM), a double data rate synchronous dynamic random access memory (DDRSDRAM), an enhanced synchronous dynamic random access memory (ESDRAM), a synchronous link dynamic random access memory (SLDRAM) and a direct memory bus random access memory (DRRAM). The memory 502 in the embodiment of the present application includes but is not limited to these and any other suitable types of memory.

[0141] The processor 501 may include one or more processing units; optionally, the processor 501 integrates an application processor and a modem processor, wherein the application processor mainly processes operations related to an operating system, a user interface, and application programs, and the modem processor mainly processes wireless communication signals, such as a baseband processor. It is understandable that the modem processor may not be integrated into the processor 501.

[0142] The embodiment of the present application further provides a readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, each process of the control method embodiment of the above-mentioned 3D printing device is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0143] The present application also provides the following embodiments:

[0144] Embodiment 1, a control method of a 3D printing device, comprising:

[0145] Before the 3D printing device performs model printing, obtaining extrusion pressure parameters of an extrusion mechanism of the 3D printing device at different extrusion speeds;

[0146] The pressure advance coefficient is calibrated based on the extrusion pressure parameters at different extrusion speeds to obtain the first pressure advance coefficient corresponding to each extrusion speed.

[0147] Embodiment 2, based on embodiment 1, the method further comprises:

[0148] Based on the different extrusion speeds and the first pressure advance coefficients corresponding to the extrusion speeds, a correspondence between the extrusion speeds and the pressure advance coefficients is generated. The correspondence is used to determine the target pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism when the 3D printing device prints the model. The correspondence includes at least one of a functional relationship, a fitting curve, and a relationship table.

[0149] Embodiment 3, based on embodiment 2, the method further comprises:

[0150] When the 3D printing device performs model printing, obtaining the current extrusion speed of the printing consumables by the extrusion mechanism;

[0151] Based on the corresponding relationship between the extrusion speed and the pressure advance coefficient, determining the target pressure advance coefficient corresponding to the current extrusion speed;

[0152] The extrusion flow rate of the extrusion mechanism is adjusted according to the target pressure advance coefficient.

[0153] Embodiment 4, based on Embodiment 1, any of the extrusion speeds includes N speed cycles, N is a positive integer greater than or equal to 2, each of the speed cycles includes a first speed and a second speed, the first speed is less than the second speed; for one of the extrusion speeds:

[0154] Obtaining an extrusion pressure parameter of the extrusion mechanism at the extrusion speed includes:

[0155] Acquire the extrusion pressure parameter of each speed cycle of the extrusion speed, wherein the method for acquiring the extrusion pressure parameter of any speed cycle includes: acquiring the target extrusion pressure when the extrusion mechanism switches from the first speed to the second speed, and the calibrated extrusion pressure when the extrusion mechanism switches from the second speed to the first speed; and calculating the pressure difference between the target extrusion pressure and the calibrated extrusion pressure;

[0156] Calibration processing of a pressure advance coefficient is performed based on an extrusion pressure parameter at the extrusion speed to obtain a first pressure advance coefficient corresponding to the extrusion speed, including:

[0157] Determine a second pressure advance coefficient corresponding to the pressure difference in each speed cycle to obtain N second pressure advance coefficients;

[0158] Based on the N pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences, a first pressure advance coefficient corresponding to the extrusion speed is determined.

[0159] Embodiment 5, based on embodiment 4, the step of obtaining the target extrusion pressure when the extrusion mechanism switches from the first speed to the second speed, and the calibrated extrusion pressure when the extrusion mechanism switches from the second speed to the first speed, comprises:

[0160] acquiring a plurality of first sampled pressures when the extrusion mechanism switches from the first speed to the second speed, and determining the target extrusion pressure according to the plurality of first sampled pressures;

[0161] When the extrusion mechanism switches from the second speed to the first speed, an identification phase of the extrusion speed is determined, and a plurality of second sampling pressures corresponding to the identification phase are acquired, and the calibration extrusion pressure is determined according to the plurality of second sampling pressures.

[0162] Embodiment 6, based on embodiment 4, determines a second pressure advance coefficient corresponding to the pressure difference, including:

[0163] If the absolute value of the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is used as the second pressure advance coefficient corresponding to the pressure difference;

[0164] If the absolute value of the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is adjusted according to the pressure difference, and the adjusted pressure advance coefficient is used as the second pressure advance coefficient corresponding to the pressure difference.

[0165] Embodiment 7, based on embodiment 6, adjusting the pressure advance coefficient corresponding to the current speed cycle according to the pressure difference includes:

[0166] If the pressure difference is greater than the preset pressure judgment threshold, reducing the pressure advance coefficient corresponding to the current speed cycle;

[0167] If the pressure difference is less than or equal to the preset pressure judgment threshold, then increasing the pressure advance coefficient corresponding to the current speed cycle;

[0168] The method further includes:

[0169] The reduced or increased pressure advance coefficient is used as the pressure advance coefficient corresponding to the next speed cycle.

[0170] Embodiment 8, on the basis of embodiment 4, determining the first pressure advance coefficient corresponding to the extrusion speed based on the N pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences includes:

[0171] Based on the N-1 pressure differences except the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences, a first pressure advance coefficient corresponding to the extrusion speed is determined.

[0172] Embodiment 9, based on Embodiment 8, determining the first pressure advance coefficient corresponding to the extrusion speed based on the N-1 pressure differences other than the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences comprises:

[0173] Based on N-1 pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences, constructing a functional relationship between the pressure difference and the second pressure advance coefficient;

[0174] Based on the functional relationship, the second pressure advance coefficient corresponding to when the pressure difference is 0 is used as the first pressure advance coefficient corresponding to the extrusion speed.

[0175] Embodiment 10, based on embodiment 4, the method further comprises:

[0176] If the target extrusion pressure and / or the calibrated extrusion pressure is not obtained in any of the speed cycles of the extrusion speed, confirming that the speed cycle sampling is abnormal;

[0177] If the number of speed cycles in which the sampling of the extrusion speed is abnormal is greater than a preset number, it is determined that the calibration process corresponding to the extrusion speed has failed;

[0178] The method further comprises:

[0179] If the calibration process corresponding to the extrusion speed fails, a default pressure advance coefficient is used as the first pressure advance coefficient corresponding to the extrusion speed.

[0180] Embodiment 11, based on embodiment 10, after determining the second pressure advance coefficient corresponding to the pressure difference, the method further includes:

[0181] If the calibration process corresponding to the extrusion speed is successful, a limiting process is performed on the first pressure advance coefficient corresponding to the determined extrusion speed based on a preset pressure advance coefficient range.

[0182] It should be noted that, in this article, the term "comprises", "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0183] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present application, ordinary technicians in this field can also make many forms without departing from the purpose of the present application and the scope of protection of the claims, all of which are within the protection of the present application.

Claims

1. A control method for a 3D printing device, characterized in that: include: Before the 3D printing device performs model printing, obtaining extrusion pressure parameters of an extrusion mechanism of the 3D printing device at different extrusion speeds; The pressure advance coefficient is calibrated based on the extrusion pressure parameters at different extrusion speeds to obtain the first pressure advance coefficient corresponding to each extrusion speed.

2. The method according to claim 1, characterized in that The method further comprises: Based on the different extrusion speeds and the first pressure advance coefficients corresponding to the extrusion speeds, a correspondence between the extrusion speeds and the pressure advance coefficients is generated. The correspondence is used to determine the target pressure advance coefficient corresponding to the current extrusion speed of the extrusion mechanism when the 3D printing device prints the model. The correspondence includes at least one of a functional relationship, a fitting curve, and a relationship table.

3. The method according to claim 2, characterized in that The method further comprises: When the 3D printing device performs model printing, obtaining the current extrusion speed of the printing consumables by the extrusion mechanism; Based on the corresponding relationship between the extrusion speed and the pressure advance coefficient, determining the target pressure advance coefficient corresponding to the current extrusion speed; The extrusion flow rate of the extrusion mechanism is adjusted according to the target pressure advance coefficient.

4. The method according to claim 1, characterized in that: Any of the extrusion speeds includes N speed cycles, where N is a positive integer greater than or equal to 2, and each of the speed cycles includes a first speed and a second speed, where the first speed is less than the second speed; for one of the extrusion speeds: Obtaining an extrusion pressure parameter of the extrusion mechanism at the extrusion speed includes: Acquire the extrusion pressure parameter of each speed cycle of the extrusion speed, wherein the method for acquiring the extrusion pressure parameter of any speed cycle includes: acquiring the target extrusion pressure when the extrusion mechanism switches from the first speed to the second speed, and the calibrated extrusion pressure when the extrusion mechanism switches from the second speed to the first speed; and calculating the pressure difference between the target extrusion pressure and the calibrated extrusion pressure; Calibration processing of a pressure advance coefficient is performed based on an extrusion pressure parameter at the extrusion speed to obtain a first pressure advance coefficient corresponding to the extrusion speed, including: Determine a second pressure advance coefficient corresponding to the pressure difference in each speed cycle to obtain N second pressure advance coefficients; Based on the N pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences, a first pressure advance coefficient corresponding to the extrusion speed is determined.

5. The method according to claim 4, characterized in that The obtaining of the target extrusion pressure when the extrusion mechanism switches from the first speed to the second speed, and the calibrated extrusion pressure when the extrusion mechanism switches from the second speed to the first speed, comprises: acquiring a plurality of first sampled pressures when the extrusion mechanism switches from the first speed to the second speed, and determining the target extrusion pressure according to the plurality of first sampled pressures; When the extrusion mechanism switches from the second speed to the first speed, an identification phase of the extrusion speed is determined, and a plurality of second sampling pressures corresponding to the identification phase are acquired, and the calibration extrusion pressure is determined according to the plurality of second sampling pressures.

6. The method according to claim 4, characterized in that Determining a second pressure advance coefficient corresponding to the pressure difference includes: If the absolute value of the pressure difference is less than or equal to the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed cycle is used as the second pressure advance coefficient corresponding to the pressure difference; If the absolute value of the pressure difference is greater than the preset pressure judgment threshold, the pressure advance coefficient corresponding to the current speed period is adjusted according to the pressure difference, and the adjusted pressure advance coefficient is used as the second pressure advance coefficient corresponding to the pressure difference; wherein, the pressure advance coefficient corresponding to the current speed period is adjusted according to the pressure difference, including: If the pressure difference is greater than the preset pressure judgment threshold, reducing the pressure advance coefficient corresponding to the current speed cycle; If the pressure difference is less than or equal to the preset pressure judgment threshold, then increasing the pressure advance coefficient corresponding to the current speed cycle; The method further comprises: The reduced or increased pressure advance coefficient is used as the pressure advance coefficient corresponding to the next speed cycle.

7. The method according to claim 4, characterized in that The determining the first pressure advance coefficient corresponding to the extrusion speed based on the N pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences includes: Based on N-1 pressure differences other than the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences, determining the first pressure advance coefficient corresponding to the extrusion speed; wherein, based on the N-1 pressure differences other than the first pressure difference and the second pressure advance coefficient corresponding to each of the N-1 pressure differences, determining the first pressure advance coefficient corresponding to the extrusion speed comprises: Based on N-1 pressure differences and the second pressure advance coefficient corresponding to each of the pressure differences, constructing a functional relationship between the pressure difference and the second pressure advance coefficient; Based on the functional relationship, the second pressure advance coefficient corresponding to when the pressure difference is 0 is used as the first pressure advance coefficient corresponding to the extrusion speed.

8. The method according to claim 4, characterized in that The method further comprises: If the target extrusion pressure and / or the calibrated extrusion pressure is not obtained in any of the speed cycles of the extrusion speed, confirming that the speed cycle sampling is abnormal; If the number of speed cycles in which the sampling of the extrusion speed is abnormal is greater than a preset number, it is determined that the calibration process corresponding to the extrusion speed has failed; The method further comprises: If the calibration process corresponding to the extrusion speed fails, a default pressure advance coefficient is used as the first pressure advance coefficient corresponding to the extrusion speed; After determining the second pressure advance coefficient corresponding to the pressure difference, the method further includes: If the calibration process corresponding to the extrusion speed is successful, a limiting process is performed on the first pressure advance coefficient corresponding to the determined extrusion speed based on a preset pressure advance coefficient range.

9. A 3D printing device, characterized in that: The device comprises a processor and a memory, wherein the memory stores a program or instruction running on the processor, and when the program or instruction is executed by the processor, the steps of the control method of the 3D printing device according to any one of claims 1 to 8 are implemented.

10. A readable storage medium having a program or instruction stored thereon, characterized in that: When the program or instruction is executed by a processor, the steps of the control method of the 3D printing device according to any one of claims 1 to 8 are implemented.

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