Method of monitoring a 3D printing device and 3D printing device

Abstract

The embodiment of the present application provides a 3D printing device monitoring method and a 3D printing device, the monitoring method comprises the following steps: acquiring a receiving signal strength when a detection light beam emitted to a nozzle is received; determining a monitoring result matched with the receiving signal strength for material accumulation monitoring of the nozzle based on the receiving signal strength. Through the above manner, the present application can improve the problem that the existing 3D printing device cannot effectively monitor the material accumulation of the nozzle.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of 3D printing equipment, in particular to a 3D printing equipment monitoring method and 3D printing equipment. BACKGROUND

[0002] 3D printing equipment, also known as a three-dimensional printer, is based on a digital model file, and uses special wax materials, powdered metals or plastics, and other materials to construct objects through layer-by-layer printing.

[0003] Among them, the nozzle is a commonly used component for outputting the material to be printed, but the nozzle is prone to material accumulation (consumable filament adhesion or accumulation) when outputting the material to be printed. Most 3D printing equipment on the market cannot effectively monitor the material accumulation of the nozzle. SUMMARY

[0004] The technical problem solved by the present application is to provide a 3D printing equipment monitoring method and 3D printing equipment, which can improve the problem that existing 3D printing equipment cannot effectively monitor the material accumulation of the nozzle.

[0005] The first aspect of the present application provides a 3D printing equipment monitoring method, which includes obtaining a receiving signal strength when a detection light beam emitted to the nozzle is received; determining a monitoring result matched with the receiving signal strength for material accumulation monitoring of the nozzle based on the receiving signal strength.

[0006] Unlike the related art, by emitting a detection light beam to the nozzle and obtaining a receiving signal strength when the detection light beam is received, the degree of obstruction of the detection light beam can be determined, and the degree of material accumulation of the nozzle can be determined.

[0007] Optionally, determining a monitoring result matched with the receiving signal strength for material accumulation monitoring of the nozzle based on the receiving signal strength includes comparing the receiving signal strength with a reference signal strength to obtain a comparison result; and determining a monitoring result matched with the comparison result according to the comparison result.

[0008] Optionally, determining a monitoring result matched with the comparison result according to the comparison result includes: if the comparison result is that the receiving signal strength is not less than the reference signal strength, determining that the monitoring result of the nozzle is an unmaterial accumulation state; and if the comparison result is that the receiving signal strength is less than the reference signal strength, determining that the monitoring result of the nozzle is a material accumulation state.

[0009] Optionally, determining the monitoring result of the clogging monitoring of the nozzle based on the received signal strength comprises: calculating a relative strength parameter value between the reference signal strength and the received signal strength; the reference signal strength is a signal strength of the detection light beam received when the nozzle is not in a clogging state; determining a preset parameter value range in which the relative strength parameter value is located among different preset parameter value ranges, and determining a clogging degree of the nozzle corresponding to the determined preset parameter value range; wherein the relative strength parameter value comprises an intensity difference value between the received signal strength and the reference signal strength, or an intensity ratio value between the received signal strength and the reference signal strength.

[0010] Optionally, determining the monitoring result of the clogging monitoring of the nozzle based on the received signal strength comprises: determining a threshold intensity range in which the received signal strength is located among different threshold intensity ranges, and determining a clogging degree of the nozzle corresponding to the determined preset threshold intensity range; wherein the threshold intensity ranges are divided between the preset minimum signal strength and the reference signal strength; the reference signal strength is a signal strength of the detection light beam received when the nozzle is not in a clogging state.

[0011] Optionally, after determining the monitoring result of the clogging monitoring of the nozzle based on the received signal strength, comprising: executing a control strategy corresponding to the monitoring result.

[0012] Optionally, executing the control strategy corresponding to the monitoring result comprises: if it is determined that the monitoring result is a first grade of clogging, controlling the printing device to stop model printing; if it is determined that the monitoring result is a second grade of clogging, controlling the cleaning device to clean the nozzle, and returning to acquire the received signal strength when the detection light beam emitted to the nozzle is received; wherein the first grade of clogging has a more serious clogging degree than the second grade of clogging.

[0013] Optionally, before acquiring the received signal strength when the detection light beam emitted to the nozzle is received, comprising: detecting whether the nozzle and / or the environment of the nozzle meets a preset light measurement condition; if yes, acquiring the received signal strength when the detection light beam emitted to the nozzle is received.

[0014] Optionally, detecting whether the nozzle and / or the environment of the nozzle meets a preset light measurement condition comprises: detecting an initial clogging degree of the nozzle; determining whether the initial clogging degree of the nozzle is within a preset clogging degree range; if yes, determining that the nozzle meets the preset light measurement condition; if no, determining that the nozzle does not meet the preset light measurement condition, and then controlling the printing device to stop model printing.

[0015] Optionally, the initial clogging degree of the nozzle is detected by: capturing the nozzle by the first camera to obtain a nozzle image, and identifying the initial clogging degree of the nozzle in the nozzle image.

[0016] Optionally, the determination of whether the nozzle meets the preset light measurement condition comprises: obtaining a model image of a current model obtained by the second camera during the printing of the model, and calculating a probability of successful printing of the current model according to the model image; determining whether the probability is less than a preset probability; and if the probability is less than the preset probability, controlling the printing device to stop printing the model and / or prompting the user.

[0017] Optionally, the detection of whether the nozzle and / or the environment of the nozzle meets the preset light measurement condition comprises: detecting whether there is an obstruction in the emission path of the detection light beam; and if not, determining that the environment of the nozzle meets the preset light measurement condition.

[0018] Optionally, the detection of whether there is an obstruction in the emission path of the detection light beam comprises: obtaining an environment image of the environment of the nozzle obtained by the second camera, and identifying whether there is an obstruction in the emission path in the environment image.

[0019] Optionally, the acquisition of the received signal strength of the detection light beam emitted to the nozzle when received comprises: emitting the detection light beam to the nozzle by the light emitter; and receiving the received signal strength of the detection light beam after passing through the nozzle by the light receiver.

[0020] The second aspect of the present application provides a 3D printing device, comprising a device main body, a photoelectric sensor, a memory and a processor; wherein the device main body has a nozzle for controlling the outflow of the heated consumables; the photoelectric sensor is arranged on the printing device main body and is used to emit and receive a detection light beam passing through the nozzle; the processor is coupled to the photoelectric sensor and the memory, and the memory stores program instructions, and the processor reads the program instructions to realize the monitoring method of the printing device. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the principle of the photoelectric sensor of the 3D printing device embodiment of the present application monitoring the nozzle;

[0022] Figure 2 is a flowchart of the monitoring method embodiment of the present application;

[0023] Figure 3 is a sub-step of step S050 of the monitoring method embodiment of the present application;

[0024] Figure 4 is a sub-step of step S050 of the monitoring method embodiment of the present application. DETAILED DESCRIPTION

[0025] The embodiments of the present application will be described in detail below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and therefore can only be used as examples, but cannot limit the protection scope of the present application.

[0026] In the description of the embodiments of the present application, the technical terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0027] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing", "setting" and the like should be understood in a broad sense, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be directly connected, or can be indirectly connected. For those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0028] The following embodiments of the 3D printing device of the present application describe an exemplary structure of the 3D printing device.

[0029] The 3D printing device (which can also be abbreviated as printing device) can include a device main body. The device main body can include a consumable output device and a carrying pallet. The consumable output device can be used to output consumables or materials to be printed. The carrying pallet can be used to carry the finished product model or semi-finished product model printed by the consumable output device.

[0030] Referring to Figure 1 Optionally, the consumable output device can include a nozzle 10 and a hot end 15. The hot end 15 can be used to heat the consumables. The nozzle 10 can control the flow of the heated consumables.

[0031] Optionally, the carrying pallet can also have a heating function, for example, the carrying pallet can have a heating element. In this case, the carrying pallet can also be called a hot bed. The hot bed can maintain the temperature of the printed semi-finished product model during printing, so that the semi-finished product model and the consumables output by the nozzle 10 can be firmly bonded together. In addition, the hot bed can keep the printed semi-finished product model or finished product model, reducing the possibility of warping deformation of the printed model (semi-finished product model or finished product model) due to thermal expansion and contraction.

[0032] Optionally, the 3D printing device can further comprise a frame. The frame is used to form a printing space, so that the printing model can be formed inside the printing space. The nozzle 10 can be located inside the frame. The bearing plate can also be arranged inside the frame. The frame can be used to isolate the printing space from the outside space, so as to reduce the possibility of the semi-finished model or the finished model being polluted by external factors during the printing process.

[0033] Optionally, the 3D printing device can further comprise a photoelectric sensor 20. The photoelectric sensor 20 is arranged on the main body of the 3D printing device, and is used to emit and / or receive a detection light beam passing through the nozzle 10. The photoelectric sensor 20 can comprise a light receiver 22 and a light emitter 21. The light emitter 21 can emit a detection light beam to the light receiver 22. The light receiver 22 can be used to receive the detection light beam. The nozzle 10 can be arranged between the light emitter 21 and the light receiver 22, so that the detection light beam emitted by the photoelectric sensor 20 to the light receiver 22 can pass through the nozzle 10. Generally, the shape of the nozzle 10 is fixed, so the light intensity of the detection light beam obtained by the light receiver 22 is generally fixed. When the intensity of the detection light beam obtained by the light receiver 22 decreases, it means that the blocked part of the detection light beam during propagation increases, and correspondingly, it can be judged that the accumulation at the nozzle 10 increases. Further, according to the intensity of the detection light beam obtained by the light receiver 22, the severity of the accumulation can also be calculated.

[0034] Optionally, the photoelectric sensor 20 can be a laser transmission sensor. In this way, the accumulation of the nozzle 10 can be stably monitored.

[0035] Optionally, the 3D printing device further comprises a memory and a processor. The memory stores program instructions. The processor is coupled to the photoelectric sensor 20 to obtain data of the photoelectric sensor 20. In addition, the memory can be coupled to the memory for reading program instructions to realize the monitoring method of the 3D printing device.

[0036] The processing circuit can also be referred to as a CPU (Central Processing Unit). The processing circuit can be an integrated circuit chip with processing capability of signals. The processing circuit can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a graphics processor (GPU) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. The general-purpose processor can be a microprocessor (MCU) or the processor can also be any conventional processor.

[0037] Optionally, the 3D printing device further comprises a camera. The camera can be configured to acquire image data. The processor can acquire the image data acquired by the camera and process the image data. Optionally, the camera can be configured to acquire image data of the nozzle 10. In this case, the processor can determine the clogging condition of the nozzle 10 according to the image data of the nozzle 10. Optionally, the camera can be configured to acquire image data of the printed model (semi-finished model or finished model). In this case, the processor can determine the printing quality of the model according to the image data of the printed model.

[0038] The camera can comprise a first camera and a second camera. The first camera and the second camera can be coupled to the processor. The first camera can be disposed at the nozzle 10 to acquire image data of the nozzle 10. The second camera can be disposed at the frame and face the printing space to acquire image data of the nozzle 10 and / or image data of the printed model. The field of view of the first camera can be smaller than the field of view of the second camera.

[0039] The present inventors have found that, in the related art of identifying clogging of a nozzle by machine vision, the recognition algorithm may not be mature enough, and only when the clogging of the nozzle is very serious can the clogging be accurately identified. When the clogging of the nozzle is very serious, the clogging will affect the printing of the model, thereby greatly reducing the success rate of the model printing. To solve the above problems, the present application proposes the following embodiments.

[0040] The following embodiment of the monitoring method of the 3D printing device (hereinafter referred to as the monitoring method embodiment) describes exemplary steps of the monitoring method of the 3D printing device. The monitoring method embodiment of the present application can be used in the above-mentioned 3D printing device embodiments.

[0041] Referring to Figure 2 , the monitoring method can comprise: acquiring a received signal strength when a detection light beam emitted to the nozzle is received (step S100); determining a monitoring result matching the received signal strength for clogging monitoring of the nozzle based on the received signal strength (step S200).

[0042] Unlike the related art, by emitting a detection light beam to the nozzle and acquiring a received signal strength when the detection light beam is received, the degree of obstruction of the detection light beam can be determined, and thus the degree of clogging of the nozzle can be determined.

[0043] In some embodiments, step S100 comprises: emitting a detection light beam to the nozzle by a light emitter; and receiving a received signal strength of the detection light beam after passing through the nozzle by a light receiver.

[0044] In some embodiments, the step S200 can include: comparing the received signal strength with the reference signal strength to obtain a comparison result; and determining the monitoring result of the nozzle according to the comparison result.

[0045] In some embodiments, the step S200 can include: comparing the received signal strength with the reference signal strength to obtain a comparison result; and determining the monitoring result of the nozzle according to the comparison result.

[0046] In some embodiments, the step S200 can include: calculating a relative intensity parameter value between the reference signal strength and the received signal strength; determining a preset parameter value range in which the relative intensity parameter value is located among different preset parameter value ranges, and determining the degree of material accumulation of the nozzle corresponding to the determined preset parameter value range.

[0047] In some embodiments, the reference signal strength can be the signal strength of the detection beam received when the nozzle is in a non-material accumulation state. In other embodiments, the reference signal strength can also be the signal strength of the detection beam received without the nozzle. Optionally, the relative intensity parameter value includes an intensity difference value of the reference signal strength and the received signal strength.

[0048] For example, the relative intensity parameter value is the intensity ratio of the received signal strength and the reference signal strength. Assuming that the preset parameter ranges are 0-30%, 31%-80%, and 81%-100%, respectively, and the relative intensity parameter value is 85%, it means that the nozzle is in a degree of material accumulation corresponding to 81%-100% (e.g., slight material accumulation). Of course, the above-mentioned multiple preset parameter ranges are only exemplary, and therefore, users or engineers can also divide the multiple preset parameter ranges according to experience. In addition, multiple preset parameter ranges are set, and then the specific preset parameter range in which the relative intensity parameter value of the nozzle is located is determined, in which case, different control strategies can be executed according to the specific preset parameter range in which the relative parameter value of the nozzle is located.

[0049] In other embodiments, the step S200 can include: determining a threshold intensity range in which the received signal strength is located among different multiple threshold intensity ranges, and determining the degree of material accumulation of the nozzle corresponding to the determined preset threshold intensity range.

[0050] In some embodiments, the multiple threshold intensity ranges are divided between the preset minimum signal strength and the reference signal strength. Optionally, the reference signal strength is the signal strength of the detection beam received when the nozzle is in a non-material accumulation state.

[0051] For example, if the reference signal strength is 70% (which means that the nozzle can block 30% of the detection light beam), multiple threshold intensity ranges are 0-30%, 31%-60%, and 61%-70%. If the signal receiving strength is 65%, it means that the nozzle is in the material accumulation degree corresponding to 61%-70% (e.g., slight material accumulation). Similarly, the division of the above multiple threshold intensity ranges is only exemplary, and therefore, the user or engineer can also divide the multiple threshold intensity ranges according to experience. In addition, multiple threshold intensity ranges are set, and the specific range of the signal receiving strength of the nozzle is determined. In this case, different control strategies can be performed according to the specific threshold intensity range in which the signal receiving strength of the nozzle is located.

[0052] It should be noted that step S200 can include at least one of the above multiple specific embodiments to generate a corresponding monitoring result.

[0053] It should be noted that step S200 can include at least one of the above multiple specific embodiments to generate a corresponding monitoring result.

[0054] In some embodiments, after step S200, the method further includes: executing a control strategy matched with the monitoring result (step S300).

[0055] Optionally, step S300 includes: if it is determined that the monitoring result is first grade material accumulation, controlling the 3D printing device to stop model printing; and if it is determined that the monitoring result is second grade material accumulation, controlling the cleaning device to clean the nozzle and returning to execute step S100. The first grade material accumulation has a material accumulation severity greater than that of the second grade material accumulation.

[0056] Optionally, the first grade material accumulation and the second grade material accumulation can correspond to at least two of the multiple preset parameter ranges or at least two of the multiple threshold intensity ranges. For example, the multiple preset parameter ranges include 0-30%, 31%-80%, and 81%-100%. If the receiving signal strength falls within the preset parameter range of 0-30% at this time, it can be concluded that the monitoring result is that the nozzle is in the first grade material accumulation state. If the receiving signal strength falls within the preset parameter range of 31%-80% at this time, it can be concluded that the monitoring result is that the nozzle is in the second grade material accumulation state.

[0057] Similarly, for the multiple threshold intensity ranges including 0-30%, 31%-60%, and 61%-70%, if the received signal intensity falls into the threshold intensity range of 0-30% at this time, it can be concluded that the monitoring result is that the nozzle is in the first level of the accumulated material state; if the received signal intensity falls into the threshold intensity range of 31-60% at this time, it can be concluded that the monitoring result is that the nozzle is in the second level of the accumulated material state.

[0058] In addition, it should be noted that the percentage division of the above-mentioned multiple threshold intensity ranges and the preset parameter range is only exemplary and should not be construed as limiting the present application.

[0059] In some embodiments, before step S100, it includes: detecting whether the nozzle and / or the environment of the nozzle meets the preset light measurement condition (step S050); if yes, step S100 is performed.

[0060] As described above, even if the algorithm is not mature enough, machine vision can still effectively identify that the nozzle is in a state of serious accumulation. Therefore, before step S100, it can also be preliminarily judged by machine vision whether the nozzle is in a state of serious accumulation. Specifically, the image data of the nozzle can be obtained, and the real-time obtained image data of the nozzle is compared with the pre-configured image data of the nozzle without accumulated material to determine whether there is foreign matter (accumulation) on the nozzle. Of course, in other examples, the neural network can also be trained in advance by a large amount of image data of the nozzle with accumulation to obtain a neural network with foreign matter recognition function, and then the real-time obtained image data of the nozzle is identified by using the neural network to determine whether there is foreign matter (accumulation) on the nozzle.

[0061] Referring to Figure 3 Optionally, step S050 can include: detecting the initial accumulation degree of the nozzle (step S060); determining whether the initial accumulation degree of the nozzle is within the preset accumulation degree range (step S061); if yes, determining that the nozzle meets the preset light measurement condition (step S062). Correspondingly, if no, it is determined that the nozzle does not meet the preset light measurement condition, and the printing device is controlled to stop model printing (step S063). That is, if the nozzle accumulation is identified by machine vision to be serious, the printing can be directly stopped, so that the printing device can respond sensitively.

[0062] Optionally, step S060 includes: obtaining a nozzle image by photographing the nozzle by a first camera device, and identifying the initial accumulation degree of the nozzle in the nozzle image. Of course, in other embodiments, step S060 can also include obtaining a nozzle image by photographing the nozzle by a second camera device, and identifying the initial accumulation degree of the nozzle in the nozzle image.

[0063] In some embodiments, after step S062, the method further comprises: obtaining a model image of the current model taken by the second camera during the model printing process, and calculating a probability of success of the current model printing according to the model image; if the probability is less than a preset probability, controlling the printing device to stop the model printing; and / or, controlling the printing device to remind the user.

[0064] That is, the model image of the current model taken by the second camera can be used to calculate the probability of success of the current model printing. If the probability of success of the printing is high (e.g., more than 80%), the printing can continue, and if the probability of success of the printing is low (e.g., the degree of accumulation is serious or the current model is damaged), the model printing can be stopped or the user can be reminded to check in time.

[0065] Further, if the nozzle accumulation is not very serious, the model still has a probability of success. For example, when the nozzle has slight accumulation, the probability of success of the model printing is high, and at this time, the printing can continue. If the degree of accumulation of the nozzle increases during further printing, the probability of success of the corresponding model printing decreases, and then the printing can be stopped or the user can be reminded to clean the nozzle. In addition, after stopping the printing, the nozzle can be controlled to move to the cleaning area of the cleaning device, and then the cleaning device can be controlled to clean the nozzle. After cleaning is completed, the nozzle can be controlled to reset and continue the printing work. In this case, the 3D printing device can automatically clean the nozzle, and after cleaning, the printing can also continue, thereby improving the printing efficiency. In other examples, after the nozzle moves to the cleaning area, the user can also wait for manual cleaning.

[0066] Considering that the photoelectric sensor may not be able to identify whether there is an obstruction other than the nozzle on the emission light path, if the obstruction and the nozzle together block the detection light beam, the receiving signal strength of the detection light beam cannot accurately reflect the degree of accumulation. Therefore, in order to improve the accuracy of the photoelectric sensor in identifying the degree of accumulation, the machine vision can be used to pre-judge whether the obstruction on the emission light path affects the working of the photoelectric sensor.

[0067] Referring to Figure 4 Optionally, step S050 comprises: detecting whether there is an obstruction on the emission light path of the detection light beam (step S070); if not, determining that the environment of the nozzle meets the preset light measurement condition (step S071); if yes, determining that the environment of the nozzle does not meet the preset light measurement condition (step S072).

[0068] In the step S070, the second camera can be used to capture an environment image of the environment of the nozzle, and the environment image can be used to determine whether there is an obstacle in the light path of the detection light beam. That is, if there is an obstacle in the light path of the detection light beam, it can be determined that the environment of the nozzle does not meet the preset light measurement condition; if there is no obstacle in the light path, it can be determined that the environment of the nozzle meets the preset light measurement condition.

[0069] In addition, the step S050 (detecting whether the nozzle and / or the environment of the nozzle meets the preset light measurement condition) can be used to preliminarily identify the initial material accumulation degree, and can also be used to determine whether there is an obstacle in the light path. Of course, the step S050 can also be used only to preliminarily identify the initial material accumulation degree, or only to determine whether there is an obstacle in the light path.

[0070] In summary, by emitting a detection light beam to the nozzle and obtaining the received signal strength when the detection light beam is received, the degree of obstruction of the detection light beam can be determined, and the material accumulation degree of the nozzle can be determined.

[0071] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A monitoring method for a 3D printing device, characterized in that, include: Acquire the received signal strength when the detection beam emitted towards the nozzle is received; Based on the received signal strength, a monitoring result matching the received signal strength is determined for monitoring material accumulation in the nozzle; The step of determining a monitoring result that matches the received signal strength for monitoring material accumulation in the nozzle, based on the received signal strength, includes: Calculate the relative intensity parameter value between the reference signal intensity and the received signal intensity; the reference signal intensity is the signal intensity received by the detection beam when the nozzle is not accumulating material. Determine the range of preset parameter values ​​in which the relative intensity parameter value falls within a range of different preset parameter values, and determine the degree of material accumulation of the nozzle that matches the determined range of preset parameter values; The relative intensity parameter value includes the intensity difference between the reference signal intensity and the received signal intensity, or the intensity ratio between the received signal intensity and the reference signal intensity.

2. The monitoring method according to claim 1, characterized in that, The preset parameter value range includes a threshold intensity range, wherein the method further includes: Determine the threshold intensity range in which the received signal intensity is located among multiple different threshold intensity ranges, and determine the degree of material accumulation corresponding to the determined preset threshold intensity range of the nozzle; The plurality of threshold intensity ranges are obtained by dividing between a preset minimum signal intensity and a reference signal intensity; the reference signal intensity is the signal intensity received by the detection beam when the nozzle is not accumulating material.

3. The monitoring method according to claim 1, characterized in that, After determining a monitoring result that matches the received signal strength for monitoring material accumulation at the nozzle based on the received signal strength, the process includes: Implement control strategies that match the monitoring results.

4. The monitoring method according to claim 3, characterized in that, The execution of a control strategy that matches the monitoring results includes: If the monitoring result is determined to be a first-level accumulation of material, then the printing equipment is controlled to stop printing the model; If the monitoring result is determined to be a second-level accumulation, the cleaning device is controlled to clean the nozzle, and the process returns to acquiring the received signal strength when the detection beam emitted towards the nozzle is received; wherein the severity of the first-level accumulation is greater than the severity of the second-level accumulation.

5. The monitoring method according to claim 1, characterized in that, Before acquiring the received signal strength when the detection beam emitted towards the nozzle is received, the process includes: Detect whether the nozzle and / or the environment of the nozzle meet the preset photometry conditions; If the conditions are met, then the process of obtaining the received signal strength when the detection beam emitted towards the nozzle is received is performed.

6. The monitoring method according to claim 5, characterized in that, The detection of whether the nozzle and / or the environment of the nozzle meet the preset photometric conditions includes: Detect the initial material accumulation level of the nozzle; Determine whether the initial material accumulation level of the nozzle is within the preset material accumulation level range; If so, the nozzle is determined to meet the preset photometric conditions; If not, it is determined that the printhead does not meet the preset photometric conditions, and the printing device is then controlled to stop printing the model.

7. The monitoring method according to claim 6, characterized in that, The detection of the initial material accumulation degree of the nozzle includes: taking a picture of the nozzle with a first camera device to obtain a nozzle image, and identifying the initial material accumulation degree of the nozzle in the nozzle image.

8. The monitoring method according to claim 6, characterized in that, The determination that the nozzle meets the preset photometric conditions includes: The system acquires a model image captured by the second camera device during the model printing process, and calculates the probability of successful printing of the current model based on the model image. Determine whether the probability is less than a preset probability; If the probability is less than the preset probability, then control the printing device to stop printing the model, and / or control the printing device to remind the user.

9. The monitoring method according to claim 5, characterized in that, The detection of whether the nozzle and / or the environment of the nozzle meet the preset photometric conditions includes: Detect whether there is an obstruction in the emission path of the detection beam; If not, it is determined that the environment of the nozzle meets the preset photometry conditions.

10. The monitoring method according to claim 9, characterized in that, The detection of whether there is an obstruction in the emission path of the detection beam includes: An environmental image of the environment of the nozzle is obtained by the second camera device, and an obstruction is identified in the environmental image on the path of the emitted light.

11. The monitoring method according to claim 1, characterized in that, The process of acquiring the received signal strength when the detection beam emitted towards the nozzle is received includes: The detection beam is emitted into the nozzle via a light emitter; The intensity of the received signal of the detection beam after passing through the nozzle is received by a light receiver.

12. A 3D printing device, characterized in that, include: The main body of the equipment has a nozzle that controls the flow of consumables after heating; A photoelectric sensor, disposed on the main body of the device, is used to emit and receive a detection beam passing through the nozzle; A processor and a memory, the processor being coupled to the photoelectric sensor and the memory, the memory storing program instructions, the processor reading the program instructions to implement the monitoring method of the printing device according to any one of claims 1-11.

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