Liquid level control method, system, storage medium and electronic device

Abstract

The application discloses a liquid level control method and system, a storage medium and an electronic device. The method comprises the following steps: acquiring slice data of a three-dimensional model to be printed, and acquiring a current liquid level height of liquid material placed in a container; obtaining a height deviation according to the current liquid level height and a preset target liquid level height; determining an estimated consumption of the liquid material by each n layers of the three-dimensional model to be printed according to the slice data; determining a liquid adding speed according to the estimated consumption and the height deviation; and adding the liquid material into the container based on the liquid adding speed, so that the liquid level is maintained at the target liquid level height. The application solves the technical problem that the liquid adding speed is too fast or the liquid level fluctuates greatly in the printing process in the related art, and the surface quality of the printed three-dimensional model cannot be guaranteed.

Description

Technical Field

[0001] This invention relates to the field of liquid level control, and more specifically, to a liquid level control method, system, storage medium, and electronic device. Background Technology

[0002] Photopolymer 3D printing utilizes the principle that liquid photosensitive resin can rapidly transform from a liquid to a solid state under ultraviolet light. During printing, the raw material, liquid photosensitive resin, is stored in a container. As the molding platform moves within the container, the model is printed layer by layer through steps such as ultraviolet light curing and platform peeling. However, the liquid level of the photosensitive resin in the container affects the peeling force of the molding platform, the resin recirculation rate, and ultimately the surface quality of the printed 3D model, such as the appearance of layering defects.

[0003] In existing technologies, liquid level control systems initiate liquid addition when the liquid level is detected to be below the minimum level, continuously adding liquid at a certain rate until the maximum level is reached. Such automatic liquid level control systems are too simplistic, only able to keep the liquid level within a predetermined range, rather than maintaining a precise level throughout the entire printing process. This results in excessively fast liquid addition or large fluctuations in the liquid level, leading to poor surface quality of the printed model and failing to guarantee the surface quality of the printed 3D model. Summary of the Invention

[0004] This invention provides a liquid level control method, system, storage medium, and electronic device to at least solve the technical problem in the related art where the liquid addition speed is too fast or the liquid level fluctuates greatly during the printing process, making it impossible to guarantee the surface quality of the printed three-dimensional model.

[0005] According to one aspect of the present invention, a liquid level control method is provided, comprising: acquiring slice data of a three-dimensional model to be printed, acquiring the current liquid level height of liquid material placed in a container; obtaining a height deviation based on the current liquid level height and a preset target liquid level height; determining the estimated consumption of liquid material per n layers of the three-dimensional model to be printed based on the slice data; determining a liquid addition rate based on the estimated consumption and the height deviation; and adding liquid material to the container based on the liquid addition rate to maintain the liquid level at the target liquid level height.

[0006] Optionally, before acquiring the current liquid level height, target liquid level height, and slice data of the 3D model to be printed, the method further includes: in response to a printing start command, controlling the liquid adding device to add liquid at a maximum speed so that the liquid material in the container reaches the target liquid level height.

[0007] Optionally, the liquid addition rate is determined based on the estimated consumption and height deviation, including: obtaining the liquid addition volume based on the container cross-sectional area and height deviation; obtaining the target liquid addition volume based on the liquid addition volume and estimated consumption; and obtaining the liquid addition rate required for the current printing layer based on the number of layers n, the printing time per layer, and the target liquid addition volume.

[0008] Optionally, the basic liquid addition rate required for the current printing layer is obtained by: obtaining the liquid addition volume based on the product of the container cross-sectional area and height deviation; obtaining the target liquid addition amount based on the sum of the liquid addition volume and the estimated consumption; obtaining a first parameter based on the product of the target liquid addition amount and the density of the liquid material; obtaining a target coefficient based on the reciprocal of the product of the number of layers n and the printing time per layer; obtaining a second parameter based on the product of the first parameter and the target coefficient; and obtaining the basic liquid addition rate required for the current printing layer based on the product of the second parameter and the target liquid addition amount.

[0009] Optionally, after determining the liquid addition rate based on the estimated consumption and height deviation, the method further includes: summing the height deviations after each liquid level measurement to obtain the total historical height deviation; and adjusting the liquid addition rate based on the total historical height deviation.

[0010] Optionally, after determining the liquid addition rate based on the estimated consumption and height deviation, the method further includes: determining the additional material consumption, adjusting the liquid addition rate based on the additional material consumption, wherein the additional material consumption includes the amount of material carried away by the molding platform and / or the amount of material carried away by the support structure of the 3D model to be printed; and / or determining the material temperature in the current environment, adjusting the liquid addition rate based on the material temperature.

[0011] Optionally, obtaining the current liquid level of the liquid material placed in the container includes: performing the step of obtaining the current liquid level of the liquid material placed in the container before printing every n layers; where n depends on the estimated amount of material consumed during the printing of the 3D model, n is an integer, and n≥1.

[0012] Optionally, the method further includes: obtaining multiple material consumption amounts corresponding to multiple printing layers based on the slice data, wherein the starting layer number of the multiple printing layers is the current printing layer number; summing the multiple material consumption amounts one by one to obtain multiple total material consumption amounts; matching the multiple total material consumption amounts with a preset consumption threshold to obtain a target layer number n, wherein the total material consumption amount corresponding to the target layer number n is less than or equal to the preset consumption threshold, and the total material consumption amount corresponding to the next layer of the target layer number n is greater than the preset consumption threshold.

[0013] Optionally, obtaining the current liquid level of the liquid material placed in the container includes: responding to a received liquid level detection command, outputting a drive signal according to a preset sampling frequency to cause the ultrasonic probe to emit an ultrasonic signal into the container containing the liquid medium; obtaining the echo signal output by the ultrasonic probe based on the current liquid level and the ultrasonic signal; determining the ultrasonic transmission time based on the echo signal; wherein the ultrasonic transmission time is used to characterize the time from sending the ultrasonic signal to receiving the echo signal; obtaining the ultrasonic propagation distance based on the ultrasonic transmission time and ultrasonic propagation speed, and obtaining the current liquid level based on the ultrasonic propagation distance and the ultrasonic probe setting height.

[0014] Optionally, determining the ultrasonic transmission time based on the echo signal includes: obtaining the voltage sequence of the echo based on the echo signal, summing the voltage sequence to obtain the total equivalent area S of the echo on the time axis, summing each term of the voltage sequence to obtain the sub-equivalent area corresponding to each voltage, and determining the echo arrival time corresponding to the voltage with a sub-equivalent area greater than or equal to S / 2 as the echo reception time; or obtaining the voltage sequence of the echo based on the echo signal, constructing a three-dimensional model of a periodic function according to the sampling frequency and the voltage sequence, solving the three-dimensional model of the periodic function to obtain the maximum value of the function, and determining the voltage echo arrival time corresponding to the maximum value of the function as the echo reception time; or obtaining the high and low level state sequence of the echo based on the echo signal, and determining the time corresponding to the Nth high level in the high and low level state sequence as the echo reception time; and obtaining the ultrasonic transmission time based on the ultrasonic emission time and the echo reception time.

[0015] Optionally, the method further includes: obtaining multiple ultrasonic propagation distances by continuously measuring m times; taking the arithmetic mean of the multiple ultrasonic propagation distances to obtain the filtered ultrasonic distance output value; and obtaining the current liquid level height based on the ultrasonic distance output value and the ultrasonic probe setting height.

[0016] According to one aspect of the present invention, a liquid level control system for a 3D printer is also provided, including a main control device and a liquid level detection device and a liquid filling device communicatively connected to the main control device; the liquid level detection device is used to acquire the current liquid level height of liquid material placed in a container; the main control device is used to obtain a height deviation based on the current liquid level height and a preset target liquid level height; acquire slice data of the three-dimensional model to be printed, and determine the estimated consumption of liquid material for each n layers of the three-dimensional model to be printed based on the slice data; determine the liquid filling speed based on the estimated consumption and the height deviation; the liquid filling device is used to add liquid material to the container based on the liquid filling speed so that the liquid level is maintained at the target liquid level height.

[0017] According to one aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the above-described liquid level control methods.

[0018] According to one aspect of the present invention, an electronic device is also provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform any of the above-described liquid level control methods.

[0019] In this embodiment of the invention, the following methods are employed: acquiring slice data of the 3D model to be printed; obtaining the current liquid level of the liquid material placed in the container; obtaining the height deviation based on the current liquid level and the preset target liquid level; determining the estimated consumption of liquid material for each n layers of the 3D model to be printed based on the slice data; determining the liquid addition rate based on the estimated consumption and the height deviation; and adding liquid material to the container based on the liquid addition rate to maintain the liquid level at the target liquid level. By limiting the liquid addition rate during printing according to the height deviation between the current liquid level and the target liquid level, and the estimated consumption required for each n layers, the liquid addition rate during the printing process can be kept relatively low, ensuring a more stable liquid addition process. This results in smaller fluctuations in the liquid level of the liquid medium in the container, reducing the probability of printing layer marks and improving the quality of the printed model. This solves the technical problem in related technologies where excessively fast liquid addition or large liquid level fluctuations during the printing process cannot guarantee the surface quality of the printed 3D model. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Figure 1 This is a flowchart illustrating a liquid level control method according to an embodiment of the present invention;

[0022] Figure 2 This is a structural block diagram of a three-dimensional model printing system according to an embodiment of this application;

[0023] Figure 3 This is a schematic diagram illustrating a liquid level control process according to an embodiment of this application;

[0024] Figure 4 This is a schematic diagram of a driving waveform and an echo waveform according to an embodiment of the present invention;

[0025] Figure 5 This is a structural block diagram of a liquid level control system according to an embodiment of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] According to an embodiment of the present invention, a method embodiment for liquid level control is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0029] Figure 1 This is a flowchart illustrating a liquid level control method according to an embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0030] Step S102: Obtain the slice data of the 3D model to be printed, and obtain the current liquid level height of the liquid material placed in the container.

[0031] The liquid material mentioned above can refer to the medium used to print the three-dimensional model to be printed, and may include, but is not limited to, photosensitive resin, nylon, paraffin wax, etc.

[0032] To ensure a suitable liquid level in the container, preventing the peeling force of the molding platform and the resin recirculation rate from affecting the surface quality of the 3D model to be printed, liquid can be added to the container in real time. In traditional manual liquid addition, more liquid material than the 3D model needs to be added to the container at once, resulting in a high initial liquid level. As the process continues, the liquid level gradually decreases, potentially causing uncontrollable fluctuations that affect the quality of the 3D model. In contrast, most traditional automatic liquid addition devices have low precision, only able to maintain the liquid level within a fixed range, rather than consistently maintaining a high-precision value. Liquid level fluctuations are likely to occur during the addition process, impacting the quality of the 3D model to be printed. Furthermore, considering that the amount of liquid material used and the printing time may differ in different parts of the 3D model to be printed, such as different slice data, if the rate at which the liquid material is added to the container is unstable during the printing process, it is likely that parameters such as the outflow rate of the liquid material, the peeling force of the platform, and the backflow rate of the liquid material will become unstable. This could lead to uneven density distribution of the solid medium in different parts of the printed 3D model, poor surface texture, and consequently, poor quality of the printed 3D model. Therefore, to ensure stability during the printing of the 3D model, the liquid level control system can first acquire the slice data of the 3D model and the current liquid level height of the liquid medium placed in the container. The slice data can be set by the user when building the virtual 3D model and is not limited here. The method for detecting the current liquid level height can include, but is not limited to, hydraulic, float, and probe methods. The specific detection method can be set by the user and is not limited here.

[0033] Step S104: Calculate the height deviation based on the current liquid level and the preset target liquid level.

[0034] The aforementioned target liquid level height can refer to the liquid level height that meets the preset liquid level conditions. When the current liquid level height of the liquid material is greater than the target liquid level height, it can be assumed that factors such as the platform's peeling force and the liquid material's backflow rate are within the normal range, and the container does not need to be filled with liquid.

[0035] In one optional embodiment, to determine whether it is necessary to add liquid to the container, after obtaining the current liquid level, the height deviation can be obtained based on the difference between the current liquid level and the preset target liquid level. This height deviation is then used to determine whether adding liquid is necessary. For example, if the height deviation shows that the current liquid level is lower than the target liquid level, it can be determined that the current liquid level is low, which may affect factors such as the platform's peeling force and the return speed of the liquid material, leading to surface texture during the printing of the 3D model. In this case, it can be determined that adding liquid to the container is necessary. If the height deviation shows that the current liquid level is higher than or equal to the target liquid level, it can be considered that factors such as the platform's peeling force and the return speed of the liquid material are within normal ranges, and adding liquid to the container is not required.

[0036] Step S106: Determine the estimated consumption of liquid material for each n layers of the 3D model to be printed based on the slice data.

[0037] In one optional embodiment, during the 3D model printing process, the molding platform descends to its lowest point at each layer. After the liquid medium in the container is cured by ultraviolet light, the molding platform moves upward to the liquid surface to achieve peeling. The liquid level in the container fluctuates greatly during this process, especially in the first few dozen layers of printing, when the entire molding platform is submerged in the liquid medium. At this time, it is meaningless to continuously measure the liquid level in the container and adjust the liquid addition speed according to the real-time liquid level. Therefore, in this application, the volume of liquid medium expected to be consumed in the printing process of the above-mentioned 3D model in every n layers can be determined based on the slice data of the 3D model obtained above. That is, the estimated consumption is determined, and the liquid addition speed of the liquid addition device is adjusted based on the estimated consumption. The liquid addition device is used to replenish liquid material in the container.

[0038] Step S108: Determine the liquid addition rate based on the estimated consumption and height deviation.

[0039] In one optional embodiment, in order to reasonably determine the rate at which the liquid medium is added to the container, and considering that the aforementioned estimated consumption, height deviation, and other data are parameters related to adding the liquid medium using a liquid adding device, the liquid adding rate in this application can be determined based on the obtained estimated consumption and height deviation. For example, to ensure liquid adding efficiency and improve the efficiency of printing the 3D model, a relatively short time can be preset. Then, based on the estimated consumption and the preset time, a first liquid adding rate is determined, and based on the height deviation and the preset time, a second liquid adding rate is determined. Then, the first liquid adding rate and the second liquid adding rate are weighted to obtain the aforementioned liquid adding rate.

[0040] Step S110: Add liquid material to the container based on the liquid addition rate to maintain the liquid level at the target liquid level height.

[0041] In one optional embodiment, after determining the liquid addition rate, the liquid medium can be added to the container using the aforementioned liquid addition device according to the liquid addition rate to ensure that the liquid level of the liquid medium in the container can be maintained at the target liquid level. As a result, factors such as the peeling force of the platform and the backflow rate of the liquid material are within the normal range, thereby ensuring the quality of the three-dimensional model generated using the liquid medium.

[0042] In this embodiment of the invention, the following methods are employed: acquiring slice data of the 3D model to be printed; obtaining the current liquid level of the liquid material placed in the container; obtaining the height deviation based on the current liquid level and the preset target liquid level; determining the estimated consumption of liquid material for each n layers of the 3D model to be printed based on the slice data; determining the liquid addition rate based on the estimated consumption and the height deviation; and adding liquid material to the container based on the liquid addition rate to maintain the liquid level at the target liquid level. By limiting the liquid addition rate during printing according to the height deviation between the current liquid level and the target liquid level, and the estimated consumption required for each n layers, the liquid addition rate during the printing process can be kept relatively low, ensuring a more stable liquid addition process. This results in smaller fluctuations in the liquid level of the liquid medium in the container, reducing the probability of printing layer marks and improving the quality of the printed model. This solves the technical problem in related technologies where excessively fast liquid addition or large liquid level fluctuations during the printing process cannot guarantee the surface quality of the printed 3D model.

[0043] Optionally, before acquiring the current liquid level height, target liquid level height, and slice data of the 3D model to be printed, the method further includes: in response to a printing start command, controlling the liquid adding device to add liquid at a maximum speed so that the liquid material in the container reaches the target liquid level height.

[0044] In one optional embodiment, before acquiring the current liquid level, target liquid level, and slice data of the 3D model to be printed, to ensure printing efficiency and improve the user's experience of printing the 3D model, the liquid adding device can be controlled to add liquid to the container at maximum speed when the printing start command for the 3D model is received. This ensures that the liquid level in the container can quickly reach the target liquid level, allowing the 3D model printing device to quickly enter the printing state and begin printing the 3D model.

[0045] Optionally, the liquid addition rate is determined based on the estimated consumption and height deviation, including: obtaining the liquid addition volume based on the container cross-sectional area and height deviation; obtaining the target liquid addition volume based on the liquid addition volume and estimated consumption; and obtaining the liquid addition rate required for the current printing layer based on the number of layers n, the printing time per layer, and the target liquid addition volume.

[0046] In one optional embodiment, to ensure the accuracy of the determined liquid addition rate and avoid situations where the liquid addition rate is too fast, resulting in wasted resources, or too slow, affecting the printing efficiency of the 3D model, when determining the liquid addition rate based on the estimated consumption and height deviation, the volume of liquid medium that needs to be added (i.e., the aforementioned liquid addition volume) can be determined based on the cross-sectional area and height deviation of the container. Then, based on the liquid addition volume and the estimated consumption, the target liquid addition amount is determined. Finally, based on the target liquid addition amount, the previously determined number of layers n, and the estimated printing time for each slice, the required liquid addition rate for the current printing layer is determined.

[0047] Optionally, the basic liquid addition rate required for the current printing layer is obtained by: obtaining the liquid addition volume based on the product of the container cross-sectional area and height deviation; obtaining the target liquid addition amount based on the sum of the liquid addition volume and the estimated consumption; obtaining a first parameter based on the product of the target liquid addition amount and the density of the liquid material; obtaining a target coefficient based on the reciprocal of the product of the number of layers n and the printing time per layer; obtaining a second parameter based on the product of the first parameter and the target coefficient; and obtaining the basic liquid addition rate required for the current printing layer based on the product of the second parameter and the target liquid addition amount.

[0048] In an optional embodiment, to improve the accuracy of the determined basic liquid addition rate, this application can also combine container parameters, such as the cross-sectional area of ​​the container, and parameters of the liquid medium, such as the material density of the liquid medium, to determine the basic liquid addition rate. Specifically, the first parameter can be obtained first by multiplying the target liquid addition amount by the medium density of the liquid material, and the target coefficient can be obtained by multiplying the number of layers n by the reciprocal of the product of the printing time per layer. Then, the second parameter can be obtained by multiplying the target coefficient by the first parameter. Finally, the basic liquid addition rate required for the current printing layer can be obtained by multiplying the second parameter by the target liquid addition amount.

[0049] The formula for determining the basic liquid addition rate is as follows:

[0050]

[0051] Where ρ represents the density of the liquid material, t represents the printing time for each layer, s represents the cross-sectional area of ​​the container, ΔH represents the height deviation, and ∑Vi represents the estimated consumption.

[0052] Optionally, after determining the liquid addition rate based on the estimated consumption and height deviation, the method further includes: summing the height deviations after each liquid level measurement to obtain the total historical height deviation; and adjusting the liquid addition rate based on the total historical height deviation.

[0053] In one optional embodiment, to improve the accuracy of the determined liquid addition rate, after determining the basic liquid addition rate, the height deviations obtained from each measurement can be summed to obtain the total historical height deviation. Then, the liquid addition rate can be adjusted using the total historical height deviation to ensure the rationality of the adjusted liquid addition rate.

[0054] The formula for determining the liquid addition rate can be:

[0055]

[0056] Wherein, k∑ΔH represents the total historical height deviation mentioned above. This historical height deviation can reflect the overall height deviation generated during the current liquid addition process of the control liquid addition device to the liquid medium in the container. When this historical height deviation is applied to the next n-layer liquid addition process, the liquid addition speed can be adjusted in time, thereby making the liquid level fluctuation smaller.

[0057] Optionally, after determining the liquid addition rate based on the estimated consumption and height deviation, the method further includes: determining the additional material consumption, adjusting the liquid addition rate based on the additional material consumption, wherein the additional material consumption includes the amount of material carried away by the molding platform and / or the amount of material carried away by the support structure of the 3D model to be printed; and / or determining the material temperature in the current environment, adjusting the liquid addition rate based on the material temperature.

[0058] In one optional embodiment of this application, considering that the molding platform and the three-dimensional model support structure will carry away a portion of the liquid medium as they move upward away from the liquid medium, and the volume of this portion of the liquid medium will also affect the volume of liquid that the liquid adding device needs to add to the container, when actually determining the liquid adding speed, the additional material consumption can be determined based on the first material amount carried away by the molding platform, or the second material amount carried away by the three-dimensional model support structure, or both the first material consumption and the second material amount. The liquid adding speed can then be adjusted based on the additional material consumption. For example, the additional material consumption can be added to the target liquid adding amount, and the liquid adding speed can be re-determined according to the aforementioned process. In addition, considering that the flow rate of some liquid media is also affected by the ambient temperature, the material temperature under the current environment can be obtained when determining the liquid addition rate, and the liquid addition rate can be adjusted accordingly. For example, if the current material temperature is too low, resulting in a slow flow rate of the liquid medium, the liquid addition rate can be increased; if the current material temperature is too high, resulting in a fast flow rate of the liquid medium, the liquid addition rate can be decreased.

[0059] Optionally, obtaining the current liquid level of the liquid material placed in the container includes: performing the step of obtaining the current liquid level of the liquid material placed in the container before printing every n layers; where n depends on the estimated amount of material consumed during the printing of the 3D model, n is an integer, and n≥1.

[0060] In one optional embodiment of this application, the aforementioned value n is an integer greater than or equal to 1, which can be determined by the slice data of the 3D model. If the slice data of the next few layers indicates that a large amount of liquid medium is needed to print the 3D model, that is, the estimated consumption in the next few layers is large, then to avoid excessive consumption of liquid medium at one time, which could lead to abnormal peeling force of the platform or abnormal backflow speed of the liquid material, the aforementioned n can be taken as a small value, such as 1. Otherwise, a larger value can be taken to ensure sufficient liquid medium during the 3D model printing process, thereby ensuring the printing speed of the 3D model. In order to reasonably control the liquid addition speed to ensure the quality of the printed 3D model, between each more than n layers of the model, a step of obtaining the current liquid level height of the liquid medium placed in the container can also be performed to ensure the accuracy of the determined liquid addition speed.

[0061] Optionally, the method further includes: obtaining multiple material consumption amounts corresponding to multiple printing layers based on the slice data, wherein the starting layer number of the multiple printing layers is the current printing layer number; summing the multiple material consumption amounts one by one to obtain multiple total material consumption amounts; matching the multiple total material consumption amounts with a preset consumption threshold to obtain a target layer number n, wherein the total material consumption amount corresponding to the target layer number n is less than or equal to the preset consumption threshold, and the total material consumption amount corresponding to the next layer of the target layer number n is greater than the preset consumption threshold.

[0062] In one optional embodiment, to ensure the reasonableness of the determined n, multiple material consumption amounts corresponding to multiple printing layers starting from the current printing layer number can be obtained first. These multiple volume quantities are then summed item by item to obtain multiple total material consumption amounts. To avoid excessive liquid material consumption at once, which could lead to an overly coarse quality of the printed 3D model, the liquid level control system can match the aforementioned multiple total material consumption amounts with a preset consumption threshold to obtain a target layer number. This target layer number is then determined as n, and the total material consumption amount corresponding to the target layer number n is determined as the aforementioned estimated consumption amount. Specifically, the sum of the total material consumption amounts corresponding to the target layer number n is less than or equal to the preset total material consumption threshold, and the total material consumption amount corresponding to the next layer after the target layer is greater than the preset total material consumption threshold.

[0063] Figure 2 This is a structural block diagram of a three-dimensional model printing system according to an embodiment of this application, such as... Figure 2As shown, the liquid filling device may include at least: a container 201, a high-precision liquid level detection device 202, a liquid level medium storage device 203, a molding platform 204, and a liquid filling valve 205. When the high-precision liquid level detection device detects that the container needs to be filled with liquid, the liquid material storage device containing liquid material can be used to fill the container with liquid through the liquid filling valve, and then the corresponding three-dimensional model to be printed can be printed using the liquid material in the molding platform.

[0064] Figure 3 This is a schematic diagram illustrating a liquid level control process according to an embodiment of this application, such as... Figure 3 The process may include at least:

[0065] Step 1: When the user starts a printing task, the liquid level control system can perform environmental verification, detecting the current liquid level of the liquid material in the container, i.e., whether the current liquid level meets the preset conditions, such as whether the current liquid level is greater than the preset liquid level. At the same time, it can detect the status of the 3D model to be printed, such as determining whether the 3D model to be printed is being printed. If the current liquid level does not meet the preset liquid level conditions, such as the current liquid level being lower than the preset target height, it means that the container needs to be filled with liquid. Furthermore, if the 3D model to be printed has not started printing, the control system can control the liquid filling device to fill the container with liquid at the fastest liquid filling speed until the target liquid level is reached, thereby shortening the preparation time before printing.

[0066] Step 2: During the printing process of the 3D model, the forming platform descends to the lowest point of each layer before moving upwards to peel off the liquid material after UV curing. This causes significant fluctuations in the liquid level, especially in the first few dozen layers when the platform is submerged. Therefore, continuously measuring the liquid level and adjusting the filling speed is meaningless. To address this, the liquid level control system can measure the liquid level before each nth layer (where n depends on the estimated consumption of the most recent layers; if the estimated consumption is high, n can be smaller, even n=1). Simultaneously, the main control device raises the forming platform and waits for resin recirculation before using the measured liquid level as the level before that nth layer. Furthermore, the main control device can estimate the amount of resin needed for the next n layers (V1-Vn) based on the slicing file of the 3D model, thus determining the current filling speed of the liquid feeding device.

[0067] Table 1

[0068]

[0069] Table 1 shows a parameter table used to determine the liquid addition rate according to an embodiment of this application. According to Table 1, before printing the i-th layer, several necessary constants can be queried, such as the container cross-sectional area s, the printing time per layer t, the liquid material density ρ, and the target liquid level height H0. The current liquid level height H is collected, and the estimated consumption Vi of the 3D model in the i-th layer is calculated. Based on these parameters, the deviation ΔH between the current liquid level and the target liquid level, and the current liquid addition rate v of the liquid addition device can be determined. Based on this, the formula for determining the liquid addition rate can be:

[0070]

[0071] Here, ΔH represents the difference between the current height and the target height. The product of ΔH and the container cross-sectional area s represents the volume of liquid to be added relative to the target liquid level, sΔH. Adding sΔH to the estimated resin consumption ∑Vi for the next n layers yields the total amount of liquid material to be added. Finally, based on the density ρ of the liquid material, the number of layers n, and the printing time t for each layer, the basic liquid addition rate required for the current printing layer can be calculated. In addition, the above formula also includes a term ∑ΔH, which represents the sum of the height deviations from the target height since each distance measurement. This can reflect the overall height deviation under the current control methods and affect the control quantity of the next n layers, so as to adjust the liquid addition speed in a timely manner and make the liquid level fluctuation smaller.

[0072] Step 3: If printing is not complete, increment the current number of printed layers by 1 and return to Step 2. If the last layer is printed, stop adding liquid and end printing.

[0073] By differentiating between the liquid addition before and during printing through the above control process, the efficiency of adding liquid to the container before printing can be ensured, reducing the user's waiting time for printing. At the same time, during printing, the liquid addition speed can be limited according to the current liquid level deviation and the small amount of resin required per n layers as the required liquid addition amount. This results in a smaller liquid addition speed and less liquid level fluctuation during the printing process, thereby reducing the probability of printing layer lines and improving the quality of the printed 3D model.

[0074] Optionally, obtaining the current liquid level of the liquid material placed in the container includes: responding to a received liquid level detection command, outputting a drive signal according to a preset sampling frequency to cause the ultrasonic probe to emit an ultrasonic signal into the container containing the liquid medium; obtaining the echo signal output by the ultrasonic probe based on the current liquid level and the ultrasonic signal; determining the ultrasonic transmission time based on the echo signal; wherein the ultrasonic transmission time is used to characterize the time from sending the ultrasonic signal to receiving the echo signal; obtaining the ultrasonic propagation distance based on the ultrasonic transmission time and ultrasonic propagation speed, and obtaining the current liquid level based on the ultrasonic propagation distance and the ultrasonic probe setting height.

[0075] The aforementioned liquid level detection command can refer to a command for detecting the liquid level of the liquid medium in a container.

[0076] In this embodiment, in addition to determining the current liquid level using the aforementioned methods such as hydraulic, float, and probe methods, an ultrasonic signal can also be used to determine the current liquid level to ensure accuracy. Specifically, when determining the current liquid level of the liquid material placed in the container, upon receiving a liquid level detection command from the host computer system, a drive signal can be sent to the ultrasonic probe at the preset sampling frequency via a transmission drive circuit. This allows the ultrasonic probe to send an ultrasonic signal into the container based on the drive signal and begin detecting the current liquid level using ultrasound. Correspondingly, the ultrasonic signal sent by the ultrasonic probe to the container based on the drive signal will reflect on the surface of the liquid medium inside the container, generating an echo signal related to the current liquid level. To accurately detect the current liquid level, the echo signal output by the ultrasonic probe based on the current liquid level and the ultrasonic signal can be acquired. By using the echo signal sent by the ultrasonic probe, the propagation time of the ultrasonic signal and the echo signal in the air can be determined, i.e., the ultrasonic transmission time from sending the ultrasonic signal to receiving the echo signal. After obtaining the ultrasonic transmission time, the distance between the ultrasonic probe and the surface of the liquid medium placed in the container can be determined by multiplying the current transmission speed of the ultrasonic wave in the air by the ultrasonic transmission time. This distance is the ultrasonic propagation distance. Finally, based on the height of the ultrasonic probe relative to the bottom of the container, the height of the liquid medium placed in the container corresponding to the current liquid level can be determined.

[0077] Optionally, determining the ultrasonic transmission time based on the echo signal includes: obtaining the voltage sequence of the echo based on the echo signal, summing the voltage sequence to obtain the total equivalent area S of the echo on the time axis, summing each term of the voltage sequence to obtain the sub-equivalent area corresponding to each voltage, and determining the echo arrival time corresponding to the voltage with a sub-equivalent area greater than or equal to S / 2 as the echo reception time; or obtaining the voltage sequence of the echo based on the echo signal, constructing a three-dimensional model of a periodic function according to the sampling frequency and the voltage sequence, solving the three-dimensional model of the periodic function to obtain the maximum value of the function, and determining the voltage echo arrival time corresponding to the maximum value of the function as the echo reception time; or obtaining the high and low level state sequence of the echo based on the echo signal, and determining the time corresponding to the Nth high level in the high and low level state sequence as the echo reception time; and obtaining the ultrasonic transmission time based on the ultrasonic emission time and the echo reception time.

[0078] The above voltage sequence can refer to... Figure 4 The voltage sequence received during the time interval from t0 to t2 is shown in the figure. Figure 4 This is a schematic diagram of a driving waveform and an echo waveform according to an embodiment of the present invention, wherein the driving waveform A and the echo waveform B used to control the ultrasonic probe to emit ultrasonic signals can be as follows: Figure 4 As shown on the left, the echo waveform C can be as follows: Figure 4 As shown on the right, when an interrupt is triggered at t0, ADC acquisition can be started and stopped at t2. The peak value of the received echo waveform is at t1. By using t1 and the current propagation speed of the ultrasonic signal, the distance between the ultrasonic probe and the surface of the liquid medium placed in the container can be initially determined. Then, based on the aforementioned environmental parameters, such as ambient temperature and humidity, this distance can be adjusted to obtain a more accurate distance between the ultrasonic probe and the surface of the liquid medium placed in the container. Finally, based on the relative distance between the ultrasonic probe and the bottom of the container, the current liquid level of the liquid medium placed in the container can be determined.

[0079] In this embodiment, when determining the ultrasonic transmission time, multiple voltages in the voltage sequence can be summed first to obtain the total equivalent area S of the echo on the time axis. Then, according to the order of multiple voltages in the voltage sequence, the main line of the multiple voltages is summed to obtain the sub-equivalent area corresponding to each voltage. The sub-equivalent area is compared with half of the total equivalent area. When the sub-equivalent area is greater than or equal to S / 2, the echo arrival time of the voltage corresponding to the sub-equivalent area can be considered as the time when the ultrasonic probe receives the echo signal. At this time, the ultrasonic transmission time can be determined based on the ultrasonic transmission time when the ultrasonic probe sends the ultrasonic signal and the echo reception time.

[0080] Alternatively, a voltage sequence of the echo can be generated based on the echo signal received by the ultrasonic probe, and a voltage change curve can be fitted according to the sampling frequency and the voltage sequence, that is, the periodic function model mentioned above can be constructed. Then, the maximum value of the function can be obtained by solving the periodic function model. The arrival time of the voltage echo corresponding to the maximum value of the function can be the echo reception time mentioned above. Based on the ultrasonic transmission time of the ultrasonic probe sending ultrasonic signal and the echo reception time, the ultrasonic transmission time mentioned above can be determined.

[0081] Alternatively, the high and low level sequence of the echo can be determined based on the echo signal. The time corresponding to the Nth high level in the high and low level sequence is determined as the echo reception time. Based on the ultrasonic transmission time of the ultrasonic probe and the echo reception time, the ultrasonic transmission time can be determined. Here, N refers to the number of fixed square waves sent by the controller. The transmission drive circuit can convert the fixed square waves into a drive signal to drive the ultrasonic probe to send ultrasonic waves.

[0082] Optionally, the method further includes: obtaining multiple ultrasonic propagation distances by continuously measuring m times; taking the arithmetic mean of the multiple ultrasonic propagation distances to obtain the filtered ultrasonic distance output value; and obtaining the current liquid level height based on the ultrasonic distance output value and the ultrasonic probe setting height.

[0083] In this embodiment, in order to improve the accuracy of the measured height corresponding to the current liquid level, the ultrasonic propagation distance can be sampled multiple times continuously when determining the ultrasonic distance output value, and the ultrasonic propagation distances obtained from multiple samplings can be processed by arithmetic averaging to obtain the filtered ultrasonic distance output value. Finally, the height corresponding to the current liquid level can be determined based on the ultrasonic distance output value and the height set by the ultrasonic probe.

[0084] In one optional embodiment, when determining the target time, the sum of multiple voltages in the voltage sequence can be first obtained to get a first sum value. Then, a first area value can be obtained by multiplying the first sum value by a preset coefficient. While determining the first area value, the multiple voltages in the voltage sequence are summed item by item to obtain a second area value. Then, the first area value and multiple second area values ​​are matched to determine a target voltage from the multiple voltages. The subscript value of the target voltage can be the target subscript value mentioned above. The second area corresponding to the target subscript value is greater than or equal to the first area value, and the second area value corresponding to the previous subscript value of the target subscript value is less than the first area value. Finally, the target time can be determined based on the target subscript value, the number of multiple voltages, the first time and the second time mentioned above.

[0085] According to one aspect of the present invention, corresponding to the above-described liquid level control method, a liquid level control system for a 3D printer is also provided. Figure 5 This is a structural block diagram of a liquid level control system according to an embodiment of the present invention. The liquid level control system 500 includes: a main control device 502, a liquid level detection device 504 communicatively connected to the main control device, a liquid adding device 506, and a container 508.

[0086] The liquid level detection device 504 is used to obtain the current liquid level height of the liquid material placed in the container; the main control device 502 is used to obtain the height deviation based on the current liquid level height and the preset target liquid level height; obtain the slice data of the three-dimensional model to be printed, and determine the estimated consumption of liquid material for each n layers of the three-dimensional model to be printed based on the slice data; determine the liquid addition speed based on the estimated consumption and the height deviation; and the liquid addition device 506 is used to add liquid material to the container 508 based on the liquid addition speed so that the liquid level is maintained at the target liquid level height.

[0087] For ease of understanding, this process may include:

[0088] After the MCU powers on, it begins an initialization process, configuring the parameters of each I / O input / output attribute, UART, I2C, ADC, and timer. Simultaneously, it sets the PWM frequency to the probe's resonant frequency and fixes the duty cycle at 50%. Then, it executes the following steps:

[0089] Step 1: Pull the control level output by the controller via GPIO1 high, simultaneously enabling PWM transmission and activating the corresponding Timer 1 interrupt. This process is to output the initial waveform of GPIO1 and PWM during a single measurement. To transmit a fixed number of N square waves, a Timer 1 interrupt is needed. Each successful transmission of a square wave triggers the Timer 1 interrupt service routine. When the count reaches N, PWM transmission is automatically disabled, and the control level output by GPIO1 is pulled low, thus transmitting the complete drive waveform. The control process of the timer interrupt service routine can be described as follows: Figure 5 As shown on the right, when the reset interrupt flag is triggered, the interrupt entry count of the timer can be incremented by 1. When the interrupt entry count is less than the preset count N, the interrupt entry count can be set to 0, and PWM transmission can be turned off. At the same time, GPIO1 is pulled low, so that the control terminal of the aforementioned single-pole double-throw analog switch can be connected to the first terminal. That is, no drive signal is sent to drive the ultrasonic probe to send ultrasonic waves at this time. When the interrupt entry count reaches the preset count N, the interrupt server program can be stopped.

[0090] Step 2: After the driver analysis is completed, Timer 2 can be started. The input source of Timer 2 is the internal clock of the MCU. The timing t0 triggers an interrupt to enable DMA (Direct Memory Access) acquisition of the ADC (Analog-Digital Converter).

[0091] In one optional embodiment, after acquiring the voltage sequence in ADC mode, a template sequence can be created based on the periodicity of the sequence according to the sampling frequency to perform convolution calculation on the voltage sequence, or to calculate the cross-correlation function of the two sequences. The sequence index corresponding to the maximum value of the cross-correlation function can be regarded as the echo reception time. Alternatively, the high and low level state sequence of the echo can be obtained according to the aforementioned GPIO mode. When N high levels are counted, an echo is considered received, where N is related to the number of transmitted waves. For example, in determining the echo reception time, after starting Timer 2, the GPIO2 pin level state is read cyclically. If the number of times the GPIO2 level is high has not reached N, the process continues to wait until N times are reached, indicating that the MCU has received all echoes, and proceeds to Step 3.

[0092] Step 3: Reset Timer 2 and continue timing, set the duration to t2-t0, and disable DMA acquisition of ADC when an interrupt is triggered to obtain a voltage sequence a[n] from t0 to t2.

[0093] Step 4: For the first time, traverse the acquisition sequence a[n] and sum it to obtain the equivalent total area S of the echo on the time axis, and calculate half of the area value S / 2. The corresponding formula is:

[0094]

[0095] Step 5: Perform a second traversal of the sequence a[n], i.e., the ADC acquisition sequence, to obtain the term-by-term summation sequence s[n]. When s[n]...

[0096] ​Step 6: The time t1 experienced by the ultrasound can be calculated using the values ​​of k, n, t0, and t2. Additionally, by reading the temperature sensor value via the I2C interface and obtaining the current sound velocity v using a lookup table, the distance d_temp of this measurement can be calculated. Since the measurement time is less than 1 ms and the resin level fluctuation is small, a filtering algorithm that takes the arithmetic mean of 20 consecutive d_temp measurements is used to obtain a more stable output value, distance. Other filtering algorithms can also be used. The corresponding formula for determining t1 can be:

[0097] t1 = (k(t2-t0)) / n.

[0098] The formula for determining d_temp can be:

[0099] d_temp = t1 * v.

[0100] While calculating d_temp, the distance measurement completion count can be increased by one. If the distance measurement completion count is less than the preset count, such as 20, the above steps can be repeated. If the distance measurement completion count reaches the preset count, Step 7 can be executed.

[0101] Step 7: Set the distance measurement completion count to 0, calculate the final distance value that needs to be replied to the host computer, and send it back to the host computer. The above 7 steps are continuously executed in a loop. Each complete measurement and data transmission back to the host computer is considered a heartbeat packet. The heartbeat packet delay is fixed at 500ms. The host computer can continuously capture the latest distance data and analyze the current height of the liquid medium in the material tray in real time according to the installation position, thereby obtaining the current liquid level.

[0102] The above algorithm measures distance without being affected by changes in distance that affect the overall amplitude of the echo. The equivalent area method, due to its good symmetry, can effectively capture the center beam of the echo in each measurement, greatly improving the stability of the acquisition and calculation. Combined with the method of taking the average of multiple measurements, the stability of the data is further improved, and the measurement accuracy of this device is enhanced.

[0103] According to one aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored program, wherein, when the program is executed, it controls the device where the computer-readable storage medium is located to perform any of the above-described liquid level control methods.

[0104] According to one aspect of the present invention, an electronic device is also provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform any of the above-described liquid level control methods.

[0105] It should be noted that the sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0106] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0107] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between units or modules may be electrical or other forms.

[0108] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0109] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0110] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0111] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A liquid level control method, characterized in that, include: Obtain the slice data of the 3D model to be printed, and obtain the current liquid level height of the liquid material placed in the container; The height deviation is obtained based on the current liquid level and the preset target liquid level. Based on the slice data, determine the estimated consumption of liquid material for printing each n layers of the 3D model to be printed; The liquid addition rate during the printing process is determined based on the estimated consumption and the height deviation; the liquid addition rate is used to ensure a smooth liquid addition process and reduce liquid level fluctuations. Liquid material is added to the container based on the added rate to maintain the liquid level at the target liquid level height; The formula for the liquid addition rate is: ， in, This represents the density of liquid materials. This represents the printing time for each layer. This represents the cross-sectional area of ​​the container. This represents a height deviation. This represents the estimated consumption, and n represents the number of layers to be printed.

2. The method according to claim 1, characterized in that, Before acquiring the current liquid level height, target liquid level height, and slice data of the 3D model to be printed from the liquid material placed in the container, the method further includes: In response to the print start command, the liquid adding device is controlled to add liquid at the maximum speed so that the liquid material in the container reaches the target liquid level.

3. The method according to claim 1, characterized in that, After determining the liquid addition rate based on the estimated consumption and the height deviation, the method further includes: The total historical height deviation is obtained by summing the height deviations after each liquid level measurement. The liquid addition rate is adjusted based on the total historical height deviation.

4. The method according to claim 1, characterized in that, After determining the liquid addition rate based on the estimated consumption and the height deviation, the method further includes: Determine the additional material consumption, and adjust the liquid addition rate based on the additional material consumption, wherein the additional material consumption includes the amount of material carried away by the molding platform and / or the amount of material carried away by the supporting structure of the 3D model to be printed; and / or Determine the material temperature under the current environment, and adjust the liquid addition rate based on the material temperature.

5. The method according to claim 1, characterized in that, The process of obtaining the current liquid level height of the liquid material placed in the container includes: Before printing every n layers, perform the step of obtaining the current liquid level height of the liquid material placed in the container; Where n depends on the estimated amount of material to be consumed during model printing, n is an integer, n≥1.

6. The method according to claim 5, characterized in that, The method further includes: Based on the slice data, multiple material consumption amounts corresponding to multiple printing layers are obtained, wherein the starting layer number of the multiple printing layers is the current printing layer number; The summation of the multiple material consumption amounts is performed item by item to obtain multiple total material consumption amounts; The total material consumption is matched with a preset consumption threshold to obtain a target layer number n, wherein the total material consumption corresponding to the target layer number n is less than or equal to the preset consumption threshold, and the total material consumption corresponding to the next layer of the target layer number n is greater than the preset consumption threshold.

7. The method according to claim 1, characterized in that, The process of obtaining the current liquid level height of the liquid material placed in the container includes: In response to the received liquid level detection command, a drive signal is output according to a preset sampling frequency so that the ultrasonic probe emits ultrasonic signals into the container containing the liquid medium; Acquire the echo signal output by the ultrasonic probe based on the current liquid level and the ultrasonic signal; The ultrasonic transmission time is determined based on the echo signal; wherein the ultrasonic transmission time is used to characterize the time from sending the ultrasonic signal to receiving the echo signal; Based on the ultrasonic transmission time and ultrasonic transmission speed, the ultrasonic propagation distance is obtained, and the current liquid level height is obtained according to the ultrasonic propagation distance and the ultrasonic probe setting height.

8. The method according to claim 7, characterized in that, Determining the ultrasonic transmission time based on the echo signal includes: Based on the echo signal, the voltage sequence of the echo is obtained. The total equivalent area S of the echo along the time axis is obtained by summing the voltage sequence. The sub-equivalent area corresponding to each voltage is obtained by summing the voltage sequence item by item. The arrival time of the echo corresponding to the voltage with a sub-equivalent area greater than or equal to S / 2 is determined as the echo reception time; or Based on the echo signal, an echo voltage sequence is obtained. A periodic function model is constructed according to the sampling frequency and the voltage sequence. The maximum value of the function is obtained by solving the periodic function model. The arrival time of the voltage echo corresponding to the maximum value of the function is determined as the echo reception time; or Based on the echo signal, a high and low level state sequence of the echo is obtained, and the time corresponding to the Nth high level in the high and low level state sequence is determined as the echo reception time. The ultrasonic transmission time is obtained based on the ultrasonic emission time and the echo reception time.

9. The method according to claim 7, characterized in that, The method further includes: Multiple ultrasonic propagation distances were obtained by continuously measuring m times. The arithmetic mean of the multiple ultrasonic propagation distances is taken to obtain the filtered ultrasonic distance output value; The current liquid level is obtained based on the ultrasonic distance output value and the ultrasonic probe setting height.

10. A liquid level control system for a 3D printer, characterized in that, It includes a main control unit and a liquid level detection device and a liquid adding device that are communicatively connected to the main control unit; The liquid level detection device is used to obtain the current liquid level height of the liquid material placed in the container; The main control device is used to obtain the height deviation based on the current liquid level and the preset target liquid level; acquire the slice data of the three-dimensional model to be printed, and determine the estimated consumption of liquid material for each n layers of the three-dimensional model to be printed based on the slice data; and determine the liquid addition speed during the printing process based on the estimated consumption and the height deviation, wherein the liquid addition speed is used to make the liquid addition process smooth and reduce liquid level fluctuations. The liquid adding device is used to add liquid material to the container based on the liquid adding rate, so as to maintain the liquid level at the target liquid level height; The formula for the liquid addition rate is: ， in, This represents the density of liquid materials. This represents the printing time for each layer. This represents the cross-sectional area of ​​the container. This represents a height deviation. This represents the estimated consumption, and n represents the number of layers to be printed.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the liquid level control method according to any one of claims 1 to 9.

12. An electronic device, characterized in that, include: At least one processor; as well as The memory is communicatively connected to the at least one processor; in The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the liquid level control method according to any one of claims 1 to 9.

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