A powder recovery system

Abstract

The present invention relates to the technical field of powder recovery, and specifically to a powder recovery system, which can realize the following steps through the mutual cooperation between multiple modules: obtaining the powder force data of the current grading screen used for 3D printing powder screening and recovery at each historical moment in the historical recovery time period and the powder force data at the current moment; determining the initial screening efficiency at each moment; determining the current relative screening degree at the current moment; determining the current screening fluctuation degree at the current moment according to the difference between the powder force data at the current moment and the powder force data at the historical moment in the historical recovery time period; determining the current power correction factor, and based on the current power correction factor, adjusting the operating power of the servo motor used to control the jitter of the current grading screen at the current moment. The present invention realizes powder screening and recovery, thereby improving the efficiency of powder screening and recovery.

Description

Technical Field

[0001] The invention relates to the technical field of powder recovery, and in particular to a powder recovery system. Background Art

[0002] 3D (Three Dimensional, additive manufacturing technology) printing is a manufacturing method that builds objects by adding materials layer by layer. It allows physical products to be directly manufactured from digital models, bringing huge innovation potential to multiple industries. In the process of 3D printing, powder residue is often inevitable, and these residual powders are often recycled in the forming cylinder. In order to facilitate the subsequent recycling and reuse of these residual powders, powders of different sizes can often be screened out through a sieve. At present, when screening objects through a sieve, the method usually used is: placing the object on the sieve, and the object is screened by its own weight, that is, due to the gravity of the object, the object moves downward. If the size of the object is smaller than the pores of the sieve, the object will be screened down, otherwise the object will be left on the sieve, thereby achieving object screening.

[0003] However, when the powder is screened by its own weight, the following technical problems often occur:

[0004] Since the weight of the powder itself is often light, the force that causes the powder to move downward based on the effect of the powder's own gravity is often small. Therefore, when the powder is screened by the powder's own weight, the efficiency of powder screening and recovery is often poor. Summary of the invention

[0005] In order to solve the technical problem of poor efficiency of powder screening and recovery, the present invention proposes a powder recovery system.

[0006] In a first aspect, the present invention provides a powder recovery system, the system comprising:

[0007] A powder force data acquisition module is used to obtain the powder force data of the current grading screen used for 3D printing powder screening and recovery at each historical moment in the historical recovery time period and the powder force data at the current moment;

[0008] A screening efficiency determination module is used to determine the initial screening efficiency at each moment according to the change between the powder force data at each moment and the powder force data at the previous moment;

[0009] A relative screening degree determination module is used to determine the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recycling time period;

[0010] A screen fall fluctuation degree determination module is used to determine the current screen fall fluctuation degree at the current moment according to the difference between the powder force data at the current moment and the powder force data at the historical moment in the historical recovery time period;

[0011] The adjustment module is used to determine the current power correction factor according to the current relative screen drop degree and the current screen drop fluctuation degree, and based on the current power correction factor, adjust the operating power of the servo motor used to control the current grading screen jitter at the current moment.

[0012] In combination with the first aspect above, in a possible implementation, determining the initial screening efficiency at each moment according to the change between the force data of the powder at each moment and the force data of the powder at the previous moment includes:

[0013] The current moment or any historical moment in the historical recycling time period is determined as the marking moment, and the ratio between the powder force data at the moment before the marking moment and the powder force data at the marking moment is determined as the initial screening efficiency at the marking moment.

[0014] In combination with the first aspect above, in a possible implementation, determining the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recovery time period includes:

[0015] Determine the historical overall screening efficiency according to the initial screening efficiency at the historical moment in the historical recycling time period, wherein the initial screening efficiency is positively correlated with the historical overall screening efficiency;

[0016] The current relative screening degree at the current moment is determined according to the difference between the initial screening efficiency at the current moment and the historical overall screening efficiency.

[0017] In combination with the first aspect above, in a possible implementation, the formula corresponding to the current relative screening degree is:

[0018] ;

[0019] ; Among them, MR is the current relative screening degree at the current moment; is a normalized function; v is the initial screening efficiency at the current moment; is the historical overall screening efficiency; n is the number of historical moments in the historical recovery period; a is the sequence number of the historical moment in the historical recovery period; It is the initial screening efficiency at the ath historical moment in the historical recovery period.

[0020] In combination with the first aspect above, in a possible implementation, determining the current screen fall fluctuation degree at the current moment according to the difference between the powder force data at the current moment and the powder force data at the historical moment in the historical recovery time period includes:

[0021] Determine the screening fluctuation influence index between the current moment and each historical moment according to the difference between the powder stress data at the current moment and the powder stress data at each historical moment, and the time between the current moment and each historical moment;

[0022] The current screen fall fluctuation degree at the current moment is determined according to the screen fall fluctuation influence index between the current moment and the historical moments within the historical recovery time period.

[0023] In combination with the first aspect above, in a possible implementation, the formula corresponding to the screening fluctuation impact index between the current moment and the historical moment is:

[0024] ;in, is the impact index of the screening fluctuation between the current moment and the ath historical moment; a is the sequence number of the historical moment in the historical recovery period; is a natural exponential function; is the duration between the current moment and the ath historical moment; It is the absolute value function; is the force data of the powder at the ath historical moment; f is the force data of the powder at the current moment.

[0025] In combination with the first aspect above, in a possible implementation, determining the current screen fall fluctuation degree at the current moment according to the screen fall fluctuation impact index between the current moment and the historical moments within the historical recovery time period includes:

[0026] The accumulated value of the screening fluctuation impact index between the current moment and all historical moments in the historical recycling time period is normalized to obtain the current screening fluctuation degree at the current moment.

[0027] In combination with the first aspect above, in a possible implementation, determining the current power correction factor according to the current relative screening degree and the current screening fluctuation degree includes:

[0028] Normalizing the product of the current relative screen drop degree and the current screen drop fluctuation degree to obtain an initial correction factor;

[0029] A current power correction factor is determined according to the initial correction factor, wherein the initial correction factor is positively correlated with the current power correction factor.

[0030] In combination with the first aspect, in a possible implementation manner, determining the current power correction factor according to the initial correction factor includes:

[0031] The sum of the initial correction factor and the preset factor is determined as the current power correction factor.

[0032] In combination with the first aspect above, in a possible implementation, adjusting the operating power of the servo motor for controlling the vibration of the current grading screen at the current moment based on the current power correction factor includes:

[0033] The operating power of the servo motor used to control the shaking of the current grading screen at the current moment is determined as the current operating power;

[0034] The product of the current operating power and the current power correction factor is determined as the target operating power, and the operating power of the servo motor used to control the current grading screen vibration is adjusted to the target operating power.

[0035] In a second aspect, the present invention provides a powder recovery method implemented by a powder recovery system, the method comprising:

[0036] Obtain the powder force data of the current grading screen used for 3D printing powder screening and recovery at each historical moment in the historical recovery period and the powder force data at the current moment;

[0037] According to the change between the force data of the powder at each moment and the force data of the powder at the previous moment, the initial screening efficiency at each moment is determined;

[0038] Determine the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recycling period;

[0039] According to the difference between the force data of the powder at the current moment and the force data of the powder at the historical moment in the historical recovery period, the current screen fall fluctuation degree at the current moment is determined;

[0040] According to the current relative screen drop degree and the current screen drop fluctuation degree, the current power correction factor is determined, and based on the current power correction factor, the operating power of the servo motor used to control the jitter of the current grading screen at the current moment is adjusted.

[0041] In a third aspect, a server is provided, comprising a memory and a processor, wherein the memory is used to store executable program codes, and the processor is used to call and run the executable program codes from the memory, so that the device executes the above-mentioned powder recovery method.

[0042] In a fourth aspect, a computer program product is provided, the computer program product comprising: a computer program code, when the computer program code is run on a computer, the computer is caused to execute the above-mentioned powder recovery method.

[0043] In a fifth aspect, a computer-readable storage medium is provided, which stores a computer program code. When the computer program code is executed on a computer, the computer executes the above-mentioned powder recovery method.

[0044] The present invention has the following beneficial effects:

[0045] A powder recovery system of the present invention realizes powder screening and recovery, solves the technical problem of poor efficiency of powder screening and recovery, and thus improves the efficiency of powder screening and recovery. The present invention realizes screening and recovery of powders of different sizes through a graded screen. Secondly, when screening powders, the present invention does not only rely on the weight of the powder itself, but also causes the graded screen to vibrate through a servo motor to speed up the screening of powders. Finally, in the process of causing the graded screen to vibrate through a servo motor, the present invention comprehensively considers multiple characteristics related to screening efficiency, such as initial screening efficiency, current relative screening degree, and current screening fluctuation degree, thereby quantifying the current power correction factor and realizing adaptive adjustment of the operating power of the servo motor, so as to adaptively speed up the efficiency of powder screening and recovery by the current graded screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 It is a structural schematic diagram of a powder recovery system of the present invention;

[0048] Figure 2 A schematic diagram of a powder recovery method of the present invention;

[0049] Figure 3 The figure is a schematic diagram of the structure of a computer device of the present invention. DETAILED DESCRIPTION

[0050] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the technical solutions proposed by the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "another embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics in one or more embodiments may be combined in any suitable form.

[0051] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0052] refer to Figure 1 , shows a schematic diagram of the structure of a powder recovery system according to the present invention. The powder recovery system comprises:

[0053] The powder force data acquisition module 101 is used to obtain the powder force data of the current grading screen used for 3D printing powder screening and recovery at each historical moment in the historical recovery time period and the powder force data at the current moment.

[0054] Among them, 3D printing powder screening and recycling refers to the classification, screening and recycling of powder generated in the 3D (Three Dimensional, additive manufacturing technology) printing process. The powder generated in the 3D printing process, that is, the material residue generated in the 3D printing process, is often collected in the molding cylinder of the 3D printing device. The classification, screening and recycling of powder can be achieved by installing a preset number of grading screens in the molding cylinder. The preset number can be a pre-set number of grading screens, which can be 6. Different grading screens have different pore sizes, that is, different grading screens can be screens with different pore sizes.

[0055] It should be noted that in actual situations, different grading screens can be arranged from top to bottom in the molding cylinder in the order of pore size from large to small, that is, the grading screens with larger pores are arranged at the top and need to be used for powder screening first. In the 3D printing process, the printed materials are often formed in the molding cylinder, so the corresponding excess powder is also deposited in the molding cylinder. Therefore, when screening and collecting the powder generated by 3D printing, the grading screen can be installed at the bottom of the molding cylinder to facilitate the screening and collection of the powder. In the process of powder grading, screening and recycling, after 3D printing is completed, all the powder is collected on the top grading screen. At this time, the servo motor controlling the shaking of the top grading screen is turned on to cause the top grading screen to shake, so that the powder falls to the second grading screen until the screening of the top grading screen is completed, and the servo motor controlling the shaking of the top grading screen is turned off. During the shaking of the grading screen, if the weight of the powder on the grading screen no longer changes, it can be considered that the screening of the grading screen is completed; then, the servo motor controlling the shaking of the second grading screen is turned on to cause the second grading screen to shake, so that the powder falls to the third grading screen until the screening of the second grading screen is completed, and the servo motor controlling the shaking of the second grading screen is turned off; then, the servo motor controlling the shaking of the third grading screen is turned on to cause the third grading screen to shake, so that the powder falls to the fourth grading screen until the screening of the third grading screen is completed, and the servo motor controlling the shaking of the third grading screen is turned off; and so on, until the screening is completed, the grading, screening and recycling of the powder is achieved.

[0056] During the entire screening and recovery process, the powder has been screened by its own weight. However, before the servo motor for controlling the shaking of a certain layer of grading screen is turned on, the powder is often screened on the grading screen only by its own weight. However, after the servo motor for controlling the shaking of the grading screen is turned on, the powder is screened on the grading screen by its own weight and the screening and recovery of the powder is accelerated by the shaking of the screen.

[0057] The current grading screen may be a grading screen that is currently being shaken and screened. The shaking during the shaking of the screen is usually intermittent shaking, so the moment for collecting the force data of the powder may be the moment when the screen stops shaking each time during the shaking of the screen. The current moment and the historical moment in the historical recovery time period may be the moment when the current grading screen stops shaking each time. The starting moment of the historical recovery time period may be the start moment of the servo motor used to control the shaking of the current grading screen. The end moment of the historical recovery time period may be the moment before the current moment. The embodiment of the present invention mainly adjusts the power of the servo motor used to control the shaking of the current grading screen. Generally, when the servo motor just starts working, it is often not necessary to adjust it. Therefore, the historical recovery time period may include multiple moments, for example, the historical recovery time period may include at least 3 moments, that is, the power adjustment may be performed from the fourth moment after the servo motor starts working. The force data of the powder may characterize the force of the grading screen on the powder. The force data of the powder at a certain moment of the current grading screen may be characterized by the weight of the powder of the current grading screen at that moment.

[0058] As an example, a weight sensor installed on the current grading screen can be used to collect the weight of the powder on the current grading screen at the current moment or at each historical moment as the force data of the powder.

[0059] The screening efficiency determination module 102 is used to determine the initial screening efficiency at each moment according to the change between the powder force data at each moment and the powder force data at the previous moment.

[0060] As an example, the current moment or any historical moment within the historical recovery time period can be determined as the marking moment, and the ratio between the powder force data at the moment before the above-mentioned marking moment and the powder force data at the above-mentioned marking moment can be determined as the initial screening efficiency at the above-mentioned marking moment.

[0061] It should be noted that it is not necessary to calculate the initial screening efficiency at the first historical moment in the historical recovery time period.

[0062] For example, the formula for determining the initial screening efficiency at each moment can be:

[0063] ;in, is the initial screening efficiency at the tth moment. t is the sequence number of the moment in the union of the historical recovery time period and the current moment. It is the force data of the powder on the current grading screen at the t-1th moment. It is the force data of the powder in the current grading screen at the tth moment. Generally speaking, if the weight of the powder in a grading screen is 0 during the powder screening and recovery process, it often means that the placement of the grading screen is meaningless. Therefore, in actual situations, the placement of the grading screen is often meaningful. Therefore, during the powder screening and recovery process, the weight of the powder in the grading screen is often not 0. The t-1th moment and the tth moment are adjacent moments, and the t-1th moment is the moment before the tth moment.

[0064] It should be noted that in actual situations, during the screening process of the grading screen, some powder will often fall through the sieve, resulting in a reduction in the powder on the grading screen, and further a reduction in the collected powder force data. When it is larger, it often means that the current grading screen has sifted out relatively more powder between the t-1th moment and the tth moment. It often means that the current grading screen sifted out powder at a faster rate between the t-1th moment and the tth moment. It often means that at the tth moment, there is more powder that needs to be sifted out on the current grading screen.

[0065] The relative screening degree determination module 103 is used to determine the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recovery time period.

[0066] As an example, determining the current relative screening degree at the current moment may include the following steps:

[0067] The first step is to determine the historical overall screening efficiency based on the initial screening efficiency at historical moments within the above historical recovery time period.

[0068] Among them, the initial screening efficiency can be positively correlated with the historical overall screening efficiency.

[0069] The second step is to determine the current relative screening degree at the current moment based on the difference between the initial screening efficiency at the current moment and the historical overall screening efficiency.

[0070] For example, the formula for determining the current relative screening degree can be:

[0071] ;

[0072] ; Among them, MR is the current relative screening degree at the current moment. is a normalized function. v is the initial screening efficiency at the current moment. is the historical overall screening efficiency. n is the number of historical moments in the historical recovery period. a is the sequence number of the historical moment in the historical recovery period. It is the initial screening efficiency at the ath historical moment in the historical recovery period.

[0073] It should be noted that, when v is larger, it often means that the current grading screen is screening out powder at a faster rate at the current moment. It can characterize the overall rate of powder falling from the current grading screen in the historical recovery period. When MR is larger, it often means that the rate of powder falling from the current grading screen at the current moment is greater than that in the historical recovery period, which often means that there is more powder that needs to be sieved on the current grading screen at the current moment.

[0074] The screen fall fluctuation degree determination module 104 is used to determine the current screen fall fluctuation degree at the current moment according to the difference between the powder stress data at the current moment and the powder stress data at the historical moment in the historical recovery time period.

[0075] As an example, determining the current screen drop fluctuation degree at the current moment may include the following steps:

[0076] The first step is to determine the screening fluctuation impact index between the current moment and each historical moment based on the difference between the powder stress data at the current moment and the powder stress data at each historical moment, as well as the time between the current moment and each historical moment.

[0077] For example, the formula for determining the impact index of the screen drop fluctuation between the current moment and the historical moment can be:

[0078] ;in, is the impact index of the screening fluctuation between the current moment and the ath historical moment. a is the serial number of the historical moment in the historical recovery period. is a natural exponential function. It is the duration between the current moment and the ath historical moment. It is the absolute value function. is the force data of the powder at the ath historical moment. f is the force data of the powder at the current moment.

[0079] It should be noted that Can be used as When The smaller the value, the shorter the time between the current moment and the a-th historical moment, and the greater the impact of the a-th historical moment on the current moment. The larger the value is, the greater the change of powder between the current moment and the ath historical moment on the current grading screen. When it is larger, it often means that the a-th historical moment is closer to the current moment, and the powder change between the current moment and the a-th historical moment on the current grading screen is greater; it often means that the degree of powder fluctuation on the current grading screen at the current moment is greater.

[0080] The second step is to determine the current screen fall fluctuation degree at the current moment based on the screen fall fluctuation impact index between the above current moment and the historical moments within the above historical recovery time period.

[0081] For example, the accumulated value of the screening fluctuation impact index between the current moment and all historical moments in the historical recovery time period may be normalized to obtain the current screening fluctuation degree at the current moment.

[0082] For example, the formula for determining the current screen fluctuation degree at the current moment can be:

[0083] ; Among them, AR is the current screen fluctuation degree at the current moment. is a normalized function. n is the number of historical moments in the historical recycling period. a is the sequence number of the historical moment in the historical recycling period. It is the index of the impact of the screening fluctuation between the current moment and the ath historical moment.

[0084] It should be noted that when When AR is larger, it often means that the a-th historical moment is closer to the current moment, and the powder changes between the current moment and the a-th historical moment on the current grading screen are greater; it often means that the powder fluctuation at the current moment on the current grading screen is greater. Therefore, when AR is larger, it often means that the powder on the current grading screen is more likely to fluctuate continuously, and it often means that there is more powder that needs to be screened on the current grading screen at the current moment.

[0085] The determination adjustment module 105 is used to determine the current power correction factor according to the current relative screen drop degree and the current screen drop fluctuation degree, and based on the current power correction factor, adjust the operating power of the servo motor used to control the current grading screen vibration at the current moment.

[0086] As an example, the determination adjustment module 105 may implement the following steps:

[0087] In the first step, the product of the current relative screening degree and the current screening fluctuation degree is normalized to obtain an initial correction factor.

[0088] The second step is to determine the current power correction factor based on the above initial correction factor.

[0089] The initial correction factor may be positively correlated with the current power correction factor.

[0090] For example, the sum of the initial correction factor and the preset factor may be determined as the current power correction factor.

[0091] The preset factor may be a pre-set factor greater than 0, and its value range may be [0.5, 1).

[0092] For example, the formula for determining the current power correction factor may be:

[0093] ;

[0094] Wherein, GR is the current power correction factor. is a normalized function. MR is the current relative screening degree at the current moment. AR is the current screening fluctuation degree at the current moment. is the initial correction factor. It is a preset factor, which is mainly used to control the degree of power correction adjustment, and it can be 0.5.

[0095] It should be noted that when MR is larger, it often means that the rate at which the current grading screen screens out powder at the current moment is greater than that of the historical recovery period, which often means that at the current moment, there is more powder that needs to be screened out on the current grading screen. When AR is larger, it often means that the powder on the current grading screen is more likely to fluctuate continuously, which often means that at the current moment, there is more powder that needs to be screened out on the current grading screen. Therefore, when GR is larger, it often means that at the current moment, there is more powder that needs to be screened out on the current grading screen, which often means that the operating power of the servo motor can be increased to speed up the powder screening.

[0096] The third step is to determine the operating power of the servo motor used to control the shaking of the current grading screen at the current moment as the current operating power.

[0097] The fourth step is to determine the target operating power as the product of the current operating power and the current power correction factor, and adjust the operating power of the servo motor used to control the current grading screen vibration to the target operating power.

[0098] It should be noted that when the target operating power is greater than the maximum power allowed by the servo motor, for the safety of the servo motor operation, the operating power of the servo motor can be adjusted to the maximum power allowed.

[0099] refer to Figure 2Based on the same inventive concept as the above method embodiment, the present invention provides a powder recovery method, comprising the following steps:

[0100] Step S1, obtaining the force data of the powder at each historical moment in the historical recovery time period and the force data of the powder at the current moment of the current grading screen used for 3D printing powder screening and recovery;

[0101] Step S2, determining the initial screening efficiency at each moment according to the change between the force data of the powder at each moment and the force data of the powder at the previous moment;

[0102] Step S3, determining the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recycling time period;

[0103] Step S4, determining the current screen drop fluctuation degree at the current moment according to the difference between the powder force data at the current moment and the powder force data at the historical moment in the historical recovery time period;

[0104] Step S5, determining a current power correction factor according to the current relative screen drop degree and the current screen drop fluctuation degree, and adjusting the operating power of the servo motor for controlling the vibration of the current grading screen at the current moment based on the current power correction factor.

[0105] Figure 3 is a schematic diagram of the structure of a computer device provided by an embodiment of the present invention. Figure 3 As shown, the computer device 300 includes: a memory 301, a processor 302, and a computer program 303 stored in the memory 301 and running on the processor 302, wherein when the processor 302 executes the computer program 303, the computer device can execute a powder recovery method introduced above.

[0106] Based on the same inventive concept as the above method embodiment, the present invention provides a server, including a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the device performs the above powder recovery method.

[0107] Based on the same inventive concept as the above method embodiment, the present invention provides a computer program product, which includes: computer program code, when the computer program code is run on a computer, the computer executes the above powder recovery method.

[0108] Based on the same inventive concept as the above method embodiment, the present invention provides a computer-readable storage medium, which stores a computer program code. When the computer program code runs on a computer, the computer executes the above powder recovery method.

[0109] In summary, the present invention realizes the screening and recovery of powders of different sizes through the grading screens. Compared with the recovery and screening after the forming cylinder, the present invention realizes the screening of powders while recovering the powders. Secondly, when screening the powders, the present invention does not only rely on the weight of the powders themselves, but also causes the grading screens to vibrate through the servo motor to speed up the screening of the powders. Finally, in the process of causing the grading screens to vibrate through the servo motor, the present invention comprehensively considers a plurality of characteristics related to the screening efficiency, such as the initial screening efficiency, the current relative screening degree and the current screening fluctuation degree, thereby quantifying the current power correction factor and realizing the adaptive adjustment of the operating power of the servo motor, so as to adaptively speed up the efficiency of the current grading screen for powder screening and recovery.

[0110] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A powder recovery system, characterized in that: The system comprises: A powder force data acquisition module is used to obtain the powder force data of the current grading screen used for 3D printing powder screening and recovery at each historical moment in the historical recovery time period and the powder force data at the current moment; A screening efficiency determination module is used to determine the initial screening efficiency at each moment according to the change between the powder force data at each moment and the powder force data at the previous moment; A relative screening degree determination module is used to determine the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recycling time period; A screen fall fluctuation degree determination module is used to determine the current screen fall fluctuation degree at the current moment according to the difference between the powder force data at the current moment and the powder force data at the historical moment in the historical recovery time period; A determination adjustment module is used to determine a current power correction factor according to a current relative screen drop degree and a current screen drop fluctuation degree, and based on the current power correction factor, adjust the operating power of a servo motor used to control the vibration of the current grading screen at the current moment; Determining the initial screening efficiency at each moment according to the change between the force data of the powder at each moment and the force data of the powder at the previous moment includes: The current moment or any historical moment in the historical recycling time period is determined as the marking moment, and the ratio between the powder force data at the moment before the marking moment and the powder force data at the marking moment is determined as the initial screening efficiency at the marking moment.

2. A powder recovery system according to claim 1, characterized in that: Determining the current relative screening degree at the current moment according to the difference between the initial screening efficiency at the current moment and the initial screening efficiency at the historical moment in the historical recovery time period includes: Determine the historical overall screening efficiency according to the initial screening efficiency at the historical moment in the historical recycling time period, wherein the initial screening efficiency is positively correlated with the historical overall screening efficiency; The current relative screening degree at the current moment is determined according to the difference between the initial screening efficiency at the current moment and the historical overall screening efficiency.

3. A powder recovery system according to claim 2, characterized in that: The formula corresponding to the current relative screening degree is: ； ; Among them, MR is the current relative screening degree at the current moment; is a normalized function; v is the initial screening efficiency at the current moment; is the historical overall screening efficiency; n is the number of historical moments in the historical recovery period; a is the sequence number of the historical moment in the historical recovery period; It is the initial screening efficiency at the ath historical moment in the historical recovery period.

4. A powder recovery system according to claim 1, characterized in that: Determining the current screen fall fluctuation degree at the current moment according to the difference between the powder stress data at the current moment and the powder stress data at the historical moment in the historical recovery time period includes: Determine the screening fluctuation influence index between the current moment and each historical moment according to the difference between the powder stress data at the current moment and the powder stress data at each historical moment, and the time between the current moment and each historical moment; The current screen fall fluctuation degree at the current moment is determined according to the screen fall fluctuation influence index between the current moment and the historical moments within the historical recovery time period.

5. A powder recovery system according to claim 4, characterized in that: The formula corresponding to the index of the impact of the screen fluctuation between the current moment and the historical moment is: ;in, is the current moment and a The impact index of the screen fluctuation between historical moments; a is the serial number of the historical moment in the historical recycling period; is a natural exponential function; is the current moment and a the length of time between historical moments; It is the absolute value function; It is a Powder force data at each historical moment; f It is the force data of the powder at the current moment.

6. A powder recovery system according to claim 4, characterized in that: Determining the current screen fall fluctuation degree at the current moment according to the screen fall fluctuation impact index between the current moment and the historical moment in the historical recovery time period includes: The accumulated value of the screening fluctuation impact index between the current moment and all historical moments in the historical recycling time period is normalized to obtain the current screening fluctuation degree at the current moment.

7. A powder recovery system according to claim 1, characterized in that: Determining the current power correction factor according to the current relative screening degree and the current screening fluctuation degree includes: Normalizing the product of the current relative screen drop degree and the current screen drop fluctuation degree to obtain an initial correction factor; A current power correction factor is determined according to the initial correction factor, wherein the initial correction factor is positively correlated with the current power correction factor.

8. A powder recovery system according to claim 7, characterized in that: The determining of the current power correction factor according to the initial correction factor includes: The sum of the initial correction factor and the preset factor is determined as the current power correction factor.

9. A powder recovery system according to claim 1, characterized in that: The operation power of the servo motor used to control the vibration of the current grading screen at the current moment is adjusted based on the current power correction factor, including: The operating power of the servo motor used to control the shaking of the current grading screen at the current moment is determined as the current operating power; The product of the current operating power and the current power correction factor is determined as the target operating power, and the operating power of the servo motor used to control the current grading screen vibration is adjusted to the target operating power.

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