A method and system for highly real-time regulation of additive manufacturing components

Abstract

The present application belongs to the field of additive manufacturing, and particularly discloses an additive manufacturing component height real-time regulation method and system, which comprises the following steps: obtaining a first height before printing and a second height after printing of a printing point; obtaining a current layer height sequence of the current printing point based on the first height and the second height of multiple printing points, wherein the current layer height sequence comprises layer height data of the current printing point and a plurality of historical printing points in sequence; determining a printing deviation value of the current printing point based on the current layer height sequence and a preset layer height; and realizing real-time correction of the printing height based on the relationship between a preset revision threshold and the printing deviation value. The present application can realize real-time and accurate regulation of the additive manufacturing component height.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of additive manufacturing, and more particularly, relates to a method and system for real-time regulation of the height of an additive manufacturing component. BACKGROUND

[0002] Additive manufacturing technology is a kind of bottom-up direct rapid accumulation forming technology based on three-dimensional model. It has great application prospects in the fields of aerospace, ship, automobile, weapon equipment and biological medicine, etc. due to its unique advantages of short product design and development cycle, high production efficiency and complex parts forming.

[0003] The wire additive manufacturing technology refers to the use of high-energy beam heat sources such as electric arc, laser and electron beam to melt the wire-shaped raw material, and then accumulate layer by layer according to the set forming path until the forming is completed. This additive manufacturing method has high accumulation efficiency due to its high energy density. However, high accumulation efficiency also brings great size error, which makes it difficult to control the distance between the additive gun and the printed workpiece, and it is difficult to maintain the parameter consistency, which affects the stability of the forming process, the surface quality and the dimensional accuracy of the formed parts. Therefore, for the wire additive manufacturing technology, real-time regulation of the height of the additive layer is essential. SUMMARY

[0004] In view of the above defects or improvement needs of the prior art, the present application provides a method and system for real-time regulation of the height of an additive manufacturing component, which aims to realize real-time and accurate regulation of the height of an additive manufacturing component.

[0005] To achieve the above-mentioned purpose, according to one aspect of the present application, a method for real-time regulation of the height of an additive manufacturing component is provided, comprising the following steps:

[0006] Obtaining a first height before printing and a second height after printing of a printing point;

[0007] Obtaining a current layer height sequence of a current printing point based on the first height and the second height of a plurality of printing points, wherein the current layer height sequence includes layer height data of the current printing point and a plurality of historical printing points in sequence;

[0008] Determining a printing deviation value of the current printing point based on the current layer height sequence and a preset layer height;

[0009] Realizing real-time correction of the printing height based on the relationship between a preset revision threshold and the printing deviation value, comprising:

[0010] When the printing deviation value is less than the revision threshold, automatically correcting the printing height based on a printing parameter database;

[0011] When the printing deviation value is not less than the revision threshold, a maximum correction of the printing height is implemented based on the printing parameter database; the maximum correction of the printing height is set based on a maximum fusing height value that can be reached by the printing parameter database.

[0012] The printing parameter database at least includes the following parameters: input power, printing head moving speed, and wire / sand feeding speed.

[0013] As a further preferred, the automatic correction of the printing height is implemented based on the printing parameter database, including:

[0014] The current printing parameter of the current printing point is obtained, and the current printing parameter is characterized to obtain a first parameter vector;

[0015] The parameters in the printing parameter database are characterized to obtain historical parameter characteristics, and then a plurality of parameter characteristic sets are obtained;

[0016] The first parameter vector is matched with the plurality of parameter characteristic sets corresponding to the printing parameter database to obtain a parameter characteristic set to which the first parameter vector belongs;

[0017] Based on the printing deviation value, a corresponding historical parameter characteristic is searched in the parameter characteristic set to which the first parameter vector belongs, and the current printing parameter is corrected based on the historical parameter characteristic corresponding to the parameter, to implement the automatic correction of the printing height.

[0018] As a further preferred, the printing deviation value of the current printing point is determined based on the current layer height sequence and the preset layer height, including:

[0019] Based on the current layer height sequence, a layer height fluctuation curve is obtained through curve fitting;

[0020] Corresponding curve slopes of each point on the layer height fluctuation curve are obtained;

[0021] Based on the fluctuation of the curve slope, an ambiguity point of the layer height fluctuation curve is determined;

[0022] The layer height fluctuation curve is refitted after excluding the ambiguity point;

[0023] The printing deviation value of the current printing point is obtained based on the refitted layer height fluctuation curve.

[0024] As a further preferred, the printing deviation value of the current printing point is obtained based on the refitted layer height fluctuation curve, including:

[0025] A plurality of historical printing points and the current printing point are obtained at intervals on the refitted layer height fluctuation curve;

[0026] obtaining a curve slope corresponding to the plurality of historical printing points and the current printing point, and assigning a correction factor based on the corresponding curve slope;

[0027] based on the correction factor, performing a weighted summation on the layer height of the historical printing points and the current printing point to obtain a real layer height of the current printing point, and combining the preset layer height to obtain a printing deviation value of the current printing point.

[0028] As a further preferred, based on the current layer height sequence and the preset layer height, determining the printing deviation value of the current printing point, comprising:

[0029] based on the current layer height sequence, obtaining the current layer height of the current printing point and the historical layer height of the previous historical printing points;

[0030] based on the weighted summation of the current layer height and the historical layer height, obtaining the real layer height of the current printing point;

[0031] based on the preset layer height and the real layer height, determining the printing deviation value of the current printing point.

[0032] As a further preferred, obtaining the current layer height of the current printing point and the historical layer height of the previous historical printing points, comprising:

[0033] The historical printing points are obtained at equal intervals.

[0034] As a further preferred, based on the first height and the second height of the plurality of printing points, obtaining the current layer height sequence of the current printing point, comprising:

[0035] obtaining the first height and the second height corresponding to the current printing point and the previous plurality of historical printing points, and sequentially obtaining the corresponding current layer height sequence based on the difference between the first height and the second height.

[0036] As a further preferred, obtaining the first height before printing and the second height after printing of the printing point, comprising:

[0037] obtaining the first height before printing based on the first sensing device;

[0038] obtaining the second height after printing based on the second sensing device;

[0039] The second sensing device and the first sensing device are arranged in front of and behind the additive gun in the direction of movement of the additive gun, and move with the additive gun. The measurement points corresponding to the second sensing device and the first sensing device are located on the front side and the rear side of the additive molten pool, respectively, and are a certain distance away from the molten pool.

[0040] As a further preferred, the first sensing device and the second sensor use laser probes to obtain the height data of the printing point.

[0041] According to another aspect of the present application, there is provided an additive manufacturing component height real-time regulation system, comprising:

[0042] a first height acquisition module for acquiring a first height before printing of a printing point;

[0043] a second height acquisition module for acquiring a second height after printing of the printing point;

[0044] a current layer height sequence determination module for determining a current layer height sequence of the current printing point based on the first height and the second height of the plurality of printing points, the current layer height sequence comprising layer height data of the current printing point and a plurality of previous historical printing points thereof;

[0045] a printing deviation value determination module for determining a printing deviation value of the current printing point based on the current layer height sequence and a preset layer height;

[0046] a printing height real-time correction value determination module for implementing printing height real-time correction based on a relationship between a preset correction threshold and the printing deviation value, comprising:

[0047] when the printing deviation value is less than the correction threshold, implementing automatic correction of the printing height based on a printing parameter database;

[0048] when the printing deviation value is not less than the correction threshold, implementing maximum correction of the printing height based on the printing parameter database; the maximum correction of the printing height is set based on a maximum melt height value that can be achieved by the printing parameter database;

[0049] wherein the printing parameter database comprises at least the following parameters: input power, printing head moving speed, and wire / sand feeding speed.

[0050] Overall, compared with the prior art, the above technical solutions conceived by the present application mainly have the following technical advantages:

[0051] 1. The printing point layer height data is quickly obtained based on the height data before and after printing, so as to quickly determine the printing deviation value, and then the printing height is real-time corrected based on the printing parameter database, and the adaptive height adjustment of the additive manufacturing process is realized.

[0052] 2. The current printing parameter of the current printing point is acquired, the current printing parameter is characterized, the characterized printing parameter is matched with the parameters in the printing parameter database for target optimization, the printing parameter is corrected, and the automatic correction of the printing height is realized.

[0053] 3. In determining the printing deviation value, the data processing method is used to filter the data ambiguity point, and the layer height is gradually corrected based on the additive manufacturing layer height uniform transition principle, which avoids the influence of the dramatic fluctuation of additive parameters on the quality of the workpiece.

[0054] 4. Based on the double sensors arranged in front of and behind the additive gun and moving synchronously with the additive gun, the height data before and after printing is collected, the layer height data can be quickly and accurately obtained, and a good foundation is provided for the real-time adjustment of the additive manufacturing component height. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 The figure is a schematic diagram of the additive manufacturing component height real-time regulation system of the embodiment of the present application.

[0056] Figure 2 The figure is a schematic flow chart of the additive manufacturing component height real-time regulation method of the embodiment of the present application.

[0057] Figure 3 The figure is a schematic diagram of the layer height data storage corresponding to multiple printing layers of the embodiment of the present application.

[0058] Figure 4 The figure is a schematic flow chart of the printing deviation value acquisition method of the embodiment of the present application.

[0059] Figure 5 The figure is a schematic diagram of the parameter feature set acquisition of the historical parameters in a typical printing parameter database in the vector space of the embodiment of the present application.

[0060] In all the drawings, the same reference signs are used to represent the same elements or structures, wherein: 100-control system, 161-first sensing device, 162-second sensing device, 170-additive gun. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0062] Figure 1 The figure is a schematic diagram of an exemplary additive manufacturing component height real-time regulation system according to some embodiments of the present application.

[0063] As Figure 1As shown, the system can include: a control system 100, a first sensing device 161, a second sensing device 162, an additive gun 170, and a motion execution mechanism (not shown in the figure). The motion execution mechanism can be a multi-axis gantry robot, a mechanical arm, etc., such as a three-axis, four-axis, five-axis, six-axis, seven-axis, etc., which is not limited in the present specification.

[0064] In some embodiments, the additive gun 170 can be any one of an electric arc additive gun, a laser powder feeding additive gun, and an electron beam additive gun. In some embodiments, the additive gun 170 is connected to the motion execution mechanism and is driven by the motion execution mechanism to move along a trajectory.

[0065] The second sensing device 162 is arranged in front of and behind the first sensing device 161 in the direction of travel of the additive gun 170 and moves with the additive gun. The measurement points of the second sensing device 162 and the first sensing device 161 correspond to the front side and the rear side of the additive molten pool, respectively, and are at a certain distance from the molten pool. In some embodiments, the first sensing device 161 and the second sensing device 162 measure the distance between the workpiece surface and the probe by infrared distance measurement, and are adjustably designed based on the installation position between the sensing device and the additive gun 170.

[0066] In some embodiments, the first sensing device 161 and the second sensing device 162 are fixedly connected with the additive gun 170 and move with the motion execution mechanism. In some embodiments, the first sensing device 161 and the second sensing device 162 are detachably or adjustably connected with the additive gun 170. The corresponding control system 100 of the system can include a computer device that can process programs, such as a PC and a PLC. The control system 100 can include a first height acquisition module 110, a second height acquisition module 120, a current layer height sequence determination module 130, a printing deviation value determination module 140, and a printing height real-time correction value determination module 150.

[0067] The first height acquisition module 110 is configured to acquire a first height of a historical printing point based on the first sensing device;

[0068] The second height acquisition module 120 is configured to acquire a second height of the historical printing point based on the second sensing device;

[0069] The current layer height sequence determination module 130 is configured to acquire a current layer height sequence of a current printing point, the current layer height sequence including layer height data of the current printing point and a plurality of historical printing points in sequence before the current printing point; the layer height data of each printing point is determined according to the first height before printing and the second height after printing of each printing point;

[0070] The printing deviation value determination module 140 is configured to acquire a preset layer height, and determine a printing deviation value of the current printing point based on the preset layer height and the current layer height sequence;

[0071] The printing height real-time correction value determination module 150 is configured to set a revision threshold value, and determine a printing height real-time correction value based on a relationship between the revision threshold value and the printing deviation value.

[0072] In some embodiments, the printing height real-time correction value determination module 150 is further configured to: when the printing deviation value is less than the revision threshold value, implement automatic correction of the printing height of the current printing point based on a printing parameter database; or when the printing deviation value is greater than the revision threshold value, implement maximum correction of the printing height of the current printing point based on the printing parameter database; wherein the printing parameter database at least includes process parameters related to the printing height, such as input power, printing head moving speed, and wire / powder feeding speed.

[0073] In some embodiments, the current layer height sequence determination module 130 is further configured to: obtain the first height and the second height corresponding to the current printing point and a plurality of historical printing points before the current printing point, and obtain a current layer height sequence in order based on a difference between the first height and the second height.

[0074] In some embodiments, the printing deviation value determination module 140 is further configured to: obtain historical layer heights corresponding to a plurality of historical printing points; obtain a current layer height of a current printing point in real time; and obtain a true layer height of the current printing point based on a weighted sum of the current layer height and the historical layer heights. In some embodiments, the historical printing points are obtained at equal intervals.

[0075] In some embodiments, the printing deviation value determination module 140 is further configured to: obtain a layer height fluctuation curve based on curve fitting based on the current layer height sequence; obtain a curve slope corresponding to the layer height fluctuation curve point by point; obtain an ambiguous point of the layer height fluctuation curve based on fluctuation of the curve slope; re-fit the layer height fluctuation curve after excluding the ambiguous point; and obtain the printing deviation value of the current printing point based on the re-fitted layer height fluctuation curve.

[0076] In some embodiments, the printing deviation value determination module 140 is further configured to: obtain a plurality of historical printing points and the current printing point at intervals on the re-fitted layer height fluctuation curve; obtain a curve slope corresponding to the plurality of historical printing points and the current printing point; assign a correction factor based on the corresponding curve slope; and correct the printing deviation value of the current printing point based on the correction factor in a weighted sum manner.

[0077] In some embodiments, the printing height real-time correction value determination module 150 is further configured to: obtain a current printing parameter of the current printing point; characterize the current printing parameter to obtain a first parameter vector;

[0078] Obtaining parameter characteristics combination in the printing parameter database; target optimization matching the first parameter vector with the parameters in the printing parameter database, and near-neighbor matching to a corrected printing parameter, wherein a parameter difference between the corrected printing parameter and the current printing parameter is less than a set near-neighbor threshold; and automatically correcting the printing height of the current printing point based on the corrected printing parameter.

[0079] It should be understood that the system and its modules in one or more embodiments of the present specification can be implemented in various ways. For example, in some embodiments, the system and its modules can be implemented by hardware, software, or a combination of software and hardware. Among them, the hardware part can be implemented by special logic; the software part can be stored in the memory and executed by the appropriate instruction execution system, such as a microprocessor or a specially designed hardware. Those skilled in the art can understand that the above-mentioned method and system can be implemented using computer executable instructions and / or contained in processor control code, such as carrier media, such as magnetic disk, CD or DVD-ROM, programmable memory, such as read-only memory (firmware), or data carrier, such as optical or electronic signal carrier. The system and its modules of the present specification can not only have hardware circuit implementation, such as very large scale integrated circuit or gate array, semiconductor, such as logic chip, transistor, or programmable hardware device, such as field programmable gate array, programmable logic device, etc. It can also be implemented by software, for example, executed by various types of processors, and can also be implemented by a combination of the above hardware circuit and software (for example, firmware).

[0080] It should be noted that the above description of the processing device and its modules is for convenience of description only, and cannot limit the scope of the present specification to the embodiments described. It can be understood that, for those skilled in the art, after understanding the principle of the system, any combination of the modules can be made, or the subsystems can be connected with other modules without departing from the principle.

[0081] Figure 2 is a schematic flow chart of the additive manufacturing component height real-time regulation method according to some embodiments of the present specification. In some embodiments, the method 200 can be further executed by the system 100.

[0082] Step 210, obtaining the first height of the printing point based on the first sensing device.

[0083] In some embodiments, step 210 can be executed by the first height obtaining module 110.

[0084] The first height obtaining module 110 can be connected to the first sensing device in a communication manner to obtain the height data obtained by the first sensing device in real time. The first sensing device can be a point laser measuring device to obtain the positional relationship between the sensing device and the printing surface. In some embodiments, in order to prevent the influence of strong light on the detection accuracy during the additive manufacturing process, a light shielding plate or a strong light shielding device can be installed on the surface of the first sensing device to shield the strong light. The strong light shielding device can be variously arranged according to the additive manufacturing process. For example, for electric arc additive manufacturing, the strong light shielding device can be a 808nm light shielding sheet to shield light other than 808nm.

[0085] In step 220, the second height of the printing point is obtained based on the second sensing device.

[0086] In some embodiments, step 220 can be performed by the second height obtaining module 120.

[0087] Similarly, the second height obtaining module 120 can be connected to the second sensing device in a communication manner to obtain the height data obtained by the second sensing device in real time, which will not be repeated here.

[0088] In step 230, the current layer height sequence of the current printing point is determined based on the first height and the second height of the plurality of printing points.

[0089] In some embodiments, step 230 can be performed by the current layer height sequence determining module 130.

[0090] The current layer height sequence determining module 130 can obtain the first height and the second height corresponding to the printing point and its previous historical printing points, obtain the layer height of the corresponding point in sequence based on the difference between the first height and the second height, and at least include the layer height data corresponding to the plurality of historical printing points in the current layer height data.

[0091] In some embodiments, the first height and the second height can only reflect the absolute height value change before and after the printing point is printed. If the layer height corresponding to the current printing point and the layer height corresponding to the previous historical printing point are to be obtained, data processing is needed to obtain the current layer height sequence corresponding to the printing point. In some embodiments, the coordinate comparison method can be used to compare the coordinates based on the obtained first height and the obtained second height, so as to obtain the corresponding layer height data. However, this method needs to call a database and perform data retrieval, and then perform data processing, which is relatively slow.

[0092] In one or more embodiments of the present disclosure, a fast data alignment method is also included. In some embodiments, the first sensing device and the second sensing device sample based on the same sampling interval. For example, the sampling interval is 0.4 ms. In an embodiment of this scenario, the current layer height sequence determination module 130 can obtain an alignment deviation, which represents the difference in the number of storage bits between the first height sequence and the second height sequence in the database; based on the alignment deviation, the first height sequence and the second height sequence data are aligned in the database.

[0093] In one or more embodiments of the present disclosure, as shown in Figure 1 As the first sensing device and the second sensing device are distributed on both sides of the molten pool, there is a relative distance between the two probes, based on which there is a storage bit number deviation in the cache. In order to quickly obtain the height information of the current additive point, the difference in the number of storage bits of the data of the two in the cache, i.e. the alignment deviation, can be obtained, and then the first height sequence and the second height sequence data are aligned in the database. In some embodiments, this alignment deviation can be obtained or calibrated by manual before printing. For example, the second sensing device obtains the part height X1' without additive, and the first sensing device obtains the part height X1 after additive, based on (X1'-X1) in the database after alignment, the layer height increment of point 1 after additive is obtained. Such a method can obtain the most accurate layer height increment, and the calculation efficiency is extremely high, almost without any calculation process and hysteresis, and is suitable for real-time additive walking mechanism adjustment.

[0094] In step 240, a preset layer height is obtained, and a printing deviation value of the current printing point is determined based on the preset layer height and the current layer height sequence.

[0095] In some embodiments, step 240 can be performed by the printing deviation value determination module 140.

[0096] In some embodiments, the printing deviation value determination module 140 can further compare the preset layer height and the current layer height sequence to determine the printing deviation value of the current printing point. For example, the printing deviation value determination module 140 can directly compare the current layer height corresponding to the current point with the preset layer height to obtain the printing deviation value corresponding to the current printing point. However, due to the strong light intervention in the additive manufacturing process or the arc flash-out situation caused by the electric arc additive process, the printing height obtained by the first / second sensor will have deviation, and the printing deviation value obtained by this method is easy to be affected by the coupling error, and the value will have a large randomness, and the determination result is not accurate.

[0097] In some embodiments, the current layer height sequence includes the layer height of the current printing point and the layer heights corresponding to the aforementioned printing points. In the embodiment of this scenario, the printing deviation value determination module 140 can obtain the historical layer heights corresponding to multiple historical printing points, obtain the current layer height of the current printing point in real time, and obtain the actual layer height of the current printing point based on the weighted sum of the current layer height and the historical layer height. For example, Figure 3 The above is a schematic diagram of the storage of layer height data corresponding to multiple printing layers. To obtain the layer height of the k+2th point in the current printing layer (within the i+1th layer), the current layer height sequence determination module 130 can perform a weighted summation based on the layer height data corresponding to the k+2th, k+1th, k, k-1, and k-2th points in the i+1th layer to avoid coupling errors caused by measurement data jitter.

[0098] It is understandable that when using sensors for real-time monitoring of additive height, it will inevitably be affected by strong arc light such as laser / arc. When performing real-time height processing, it is necessary to avoid data distortion caused by coupling errors. Therefore, it becomes necessary to introduce historical data to perform peak removal of layer height. Preferably, the total weight value of historical layer height data should not be higher than 0.5. Furthermore, the closer the measurement point is to the current test point, the greater the weight of the corresponding layer height data should be. For example, when measuring the layer height of the k+2th point, the weight value corresponding to the k+1th point should be greater than the weight value corresponding to the kth point.

[0099] In some embodiments, the printing points should be obtained at equal time intervals or at equal distance intervals. By setting this, the historical printing points can be reused in series. Figure 3 In the example above, the floor height calculation for point k+2 can be performed based on points k+2, k+1, k, k-1, and k-2 in the i+1th floor. The floor height calculation for point k+1 can be performed based on points k+1, k, k-1, k-2, and k-3. This means that some data can be reused in subsequent calculations, making the calculation more efficient.

[0100] In some embodiments, the print deviation value determination module 140 may further obtain a layer height fluctuation curve based on the current layer height sequence through curve fitting; obtain the curve slope corresponding to the layer height fluctuation curve point by point; obtain the ambiguous point of the layer height fluctuation curve based on the fluctuation of the curve slope; re-fit the layer height fluctuation curve after eliminating the ambiguous point; and obtain the print deviation value of the current print point based on the re-fitted layer height fluctuation curve. Specifically, the relevant instructions for obtaining the print deviation value using this method can be found in Figure 4 The corresponding description is not repeated here.

[0101] Step 250, setting a revision threshold, determining a printing height real-time correction value based on the relationship between the revision threshold and the printing deviation value.

[0102] In some embodiments, step 250 can be performed by the printing height real-time correction value determination module 150.

[0103] The printing height real-time correction value determination module 150 can make a decision based on the set revision threshold. When the printing deviation value is less than the revision threshold, automatic correction of the printing height of the current printing point is realized based on the printing parameter database; or when the printing deviation value is greater than the revision threshold, the maximum correction of the printing height of the current printing point is realized based on the printing parameter database; wherein the printing parameter database at least includes the process parameters related to the printing height of the input power, the printing head moving speed and the wire / powder feeding speed. In the embodiment of this scenario, the maximum correction of the printing height should be set based on the maximum melt height value that can be involved in the database.

[0104] When the printing deviation value is less than the revision threshold, automatic correction of the printing height of the current printing point is realized based on the printing parameter database, and further using data feature driving, neighbor matching optimization of printing parameters is realized, which specifically includes the following steps:

[0105] S1: Obtain the current printing parameter of the current printing point.

[0106] S2: Characterize the current printing parameter to obtain a first parameter vector.

[0107] The printing height real-time correction value determination module 150 can obtain the corresponding first parameter vector based on the feature extraction processing. Feature extraction processing can refer to processing and extracting feature data from original information, which can improve the expression of original information to facilitate subsequent tasks. In some embodiments, the feature extraction processing can use statistical methods (such as principal component analysis method), dimension reduction techniques (such as linear discriminant analysis method), feature normalization, data bucketing, etc. For example, the current can be proportionally corresponding to [1, 0, 0] when the current is 0-50A, the current is proportionally corresponding to [0, 1, 0] when the current is 50-160A, and the current is corresponding to [0, 0, 1] when the current is above 160A. In some embodiments, the feature extraction processing can also use machine learning methods (such as using a feature extraction model), which can automatically learn from the collected information to form a predictable model, thereby obtaining higher accuracy. For example, it can be a deep learning model using yolo series algorithm, FasterRCNN algorithm or EfficientDet algorithm, etc.

[0108] S3: Obtain a parameter feature set in the printing parameter database.

[0109] Specifically, the printing height real-time correction value determination module 150 can obtain historical parameter information in the printing parameter database, and perform feature extraction based on the same manner as in step S2 to obtain historical parameter features in the printing parameter database. The obtained historical parameter features are projected in the vector space to establish a projection distribution of the historical parameter features in the vector space. Based on the projection distribution, the near neighbor threshold parameters (ε, MinPts) are determined, where ε corresponds to the radius of the parameter feature set in the vector space, and MinPts corresponds to the minimum value of the number of samples required to form the parameter feature set, a number of parameter feature sets Q are obtained, and the near neighbor threshold parameters (ε, MinPts) are adjusted multiple times and the plurality of historical shape features are processed by the parameter feature set until the number Q of the obtained parameter feature sets is greater than or equal to the preset value P, and the set centers corresponding to the Q parameter feature sets are determined.

[0110] S4: The first parameter vector is matched with the parameters in the printing parameter database for target optimization, and is matched to the corrected printing parameter by near neighbors. The parameter difference between the corrected printing parameter and the current printing parameter is less than the set near neighbor threshold. Specifically, the first parameter vector is projected into the vector space, and the parameter feature set to which the first parameter vector belongs is determined based on the distance from the Q parameter feature set centers.

[0111] S5: Based on the printing deviation value, the automatic correction of the printing height of the current printing point is realized.

[0112] Further, based on the printing deviation value, the corresponding parameter feature is searched in the parameter feature set, and the printing parameter is corrected in real time based on the printing parameter corresponding to the parameter feature, so that the automatic correction of the printing height is realized.

[0113] As Figure 5 shown in the figure is a schematic diagram of obtaining historical parameters in a typical printing parameter database in the vector space by parameter feature set. Among them, 510, 520, 530, and 540 are different printing parameter sets. 532 is the projection of the first parameter vector corresponding to the printing parameter of the current printing point in the vector space. As can be seen from the distance between the first parameter vector 532 and the printing parameter sets 510, 520, 530, and 540, 532 belongs to the printing parameter set 530. At this time, the corresponding historical parameters in the printing parameter set 530 have similar parameter values because they are similar to the vector value of the first parameter vector 532 corresponding to the current printing parameter. Further, the printing deviation value corresponding to the first parameter vector 532 is obtained, the target value is determined according to the printing deviation value and the preset layer height, the target value is matched in the printing parameter set 530 to obtain the corresponding historical printing parameter, and then the automatic adjustment of the parameter is realized based on the selected historical printing parameter.

[0114] It can be understood that through the above operations S1-S5, the printing height real-time correction value determination module 150 realizes the nearest neighbor matching of the current printing parameter in the printing parameter database based on the printing parameter database and the printing deviation value, which minimizes the fluctuation of the printing parameter and avoids the problem of poor forming precision caused by excessive parameter fluctuation.

[0115] Figure 4 is a schematic flowchart of a printing deviation value acquisition method according to some embodiments of the present specification. In some embodiments, the method 400 can be further executed in the system 100. Further, the method 400 can be executed by the printing deviation value determination module 140.

[0116] Step 410: obtaining a layer height fluctuation curve based on the current layer height sequence based on curve fitting.

[0117] The layer height fluctuation curve can be fitted by methods such as least squares, spline curve fitting, and polynomial fitting. Those skilled in the art can adaptively set based on relevant knowledge in the art, which will not be repeated here.

[0118] Step 420: obtaining the curve slope corresponding to the layer height fluctuation curve point by point.

[0119] Step 430: obtaining the ambiguity point of the layer height fluctuation curve based on the fluctuation of the curve slope.

[0120] In the process of electric arc additive / laser powder feeding additive manufacturing, due to the high volume of deposited metal, the deposited height inevitably fluctuates, which is usually due to the error caused by the inability of the wire feeding mechanism and the motion execution mechanism to cooperate with high precision. The change of these errors will not suddenly increase or decrease, and the fluctuation of the corresponding curve slope will not suddenly rise or fall. Based on this, the threshold of the curve slope can be adaptively designed to exclude the curve ambiguity point caused by the layer height fluctuation.

[0121] Step 440: refitting the layer height fluctuation curve after excluding the ambiguity point.

[0122] Step 450: obtaining the printing deviation value of the current printing point based on the refitted layer height fluctuation curve. For example, the mean or weighted mean of the layer height fluctuation curve can be used to determine the printing deviation value of the current printing point. In some embodiments, the layer height fluctuation curve corresponding to the current layer and the previous layer printing process can also be directly compared, and the local layer height fluctuation curve corresponding to the previous printing point related to the current printing point can be intercepted. The local layer height fluctuation curve is divided into multiple sub-regions, the curve difference in the multiple sub-regions is determined, and then the printing deviation value corresponding to the current printing point is obtained based on weighted summation.

[0123] In some embodiments, in step 450, the printing deviation value determination module 140 can further obtain a plurality of historical printing points and the current printing point on the re-fitted layer height fluctuation curve at intervals; obtain the corresponding curve slopes of the plurality of historical printing points and the current printing point; assign a correction factor based on the corresponding curve slopes; and correct the printing deviation value of the current printing point in a weighted summation manner based on the correction factor.

[0124] The present specification uses certain terms to describe embodiments of the present specification. As used in the present specification, the terms “one embodiment”, “an embodiment” or “some embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present specification. Therefore, it is emphasized and should be appreciated that a referenced “one embodiment” or “an embodiment” or “one alternative embodiment” at

[0125] Aspects of the present specification can be illustrated and described by several kinds or categories of patentable subject matter including any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Accordingly, the aspects of the present specification can be entirely implemented by hardware, entirely implemented by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as “data blocks”, “modules”, “engines”, “units”, “components”, or “systems”. In addition, aspects of the present specification can be manifested as computer products in one or more computer readable media including computer readable program codes.

[0126] Computer storage media can include a propagated data signal with computer program code embodied therein, for example, in baseband or as a carrier wave. The propagated signal can take on many forms, including but not limited to electro-magnetic, optical, or any suitable combination thereof. Computer storage media can be any medium (tangible or non-tangible) that can store program codes thereon for use by a processing system to implement the disclosed aspects. A computer storage medium can be any available medium that can be accessed by a processing system to implement the disclosed aspects. By way of example, and not limitation, such computer storage media can comprise RAM, ROM, EEPROM, CD-ROM or any other similar storage media. On the other hand, such computer storage media do not include connecting lines that are used to program functionally configured processors such as gates and the like. It should be understood that the computer storage media discussed above can be included without being limited to any specific one or more of a computer-readable medium or a computer module.

[0127] The computer program codes required for the operation of the various parts of this specification can be written in any one or more programming languages, including object-oriented programming languages ​​such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, etc., conventional procedural programming languages ​​such as C, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages ​​such as Python, Ruby and Groovy, or other programming languages. The program code can be run entirely on the device computer, or as a separate software package on the device computer, or partly on the device computer and partly on a remote computer, or entirely on a remote computer or processing device. In the latter case, the remote computer can be connected to the device computer through any network form, such as a local area network (LAN) or a wide area network (WAN), or connected to an external computer (e.g., via the Internet), or in a cloud computing environment, or used as a service such as software as a service (SaaS).

[0128] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for real-time height control of additively manufactured components, characterized in that: The steps include: Get the first height of the printing point before printing and the second height after printing; Acquire a current layer height sequence of a current printing point based on first heights and second heights of the plurality of printing points, wherein the current layer height sequence includes layer height data of the current printing point and a plurality of previous historical printing points; Determining a printing deviation value of a current printing point based on the current layer height sequence and a preset layer height; Based on the relationship between the preset revision threshold and the printing deviation value, the printing height is corrected in real time, including: When the printing deviation value is less than the revision threshold, automatically correcting the printing height based on the printing parameter database includes: Acquiring current printing parameters of the current printing point, characterizing the current printing parameters to obtain a first parameter vector; Characterizing the parameters in the printing parameter database to obtain historical parameter features, and then obtaining multiple parameter feature sets; Matching the first parameter vector with a plurality of parameter feature sets corresponding to the printing parameter database to obtain the parameter feature set to which the first parameter vector belongs; Based on the printing deviation value, a corresponding historical parameter feature is searched in the parameter feature set to which the first parameter vector belongs, and the current printing parameter is corrected based on the parameter corresponding to the historical parameter feature to achieve automatic correction of the printing height; When the printing deviation value is not less than the revision threshold, a maximum correction of the printing height is achieved based on the printing parameter database; the maximum correction of the printing height is set based on the maximum melt height value that can be achieved in the printing parameter database; The printing parameter database includes at least the following parameters: input power, print head speed, and wire / powder feeding speed.

2. The method for real-time height control of additive manufacturing components according to claim 1, wherein: Determining a printing deviation value of a current printing point based on the current layer height sequence and a preset layer height includes: Based on the current floor height sequence, obtaining a floor height fluctuation curve by curve fitting; Obtaining the slope of the curve corresponding to each point on the floor height fluctuation curve; determining an ambiguous point of the floor height fluctuation curve based on fluctuations in the slope of the curve; After eliminating the ambiguous points, refit the floor height fluctuation curve; A printing deviation value of the current printing point is obtained based on the re-fitted layer height fluctuation curve.

3. The method for real-time height control of additive manufacturing components according to claim 2, wherein: Obtaining a printing deviation value of the current printing point based on the re-fitted layer height fluctuation curve includes: Obtaining multiple historical printing points and current printing points at intervals on the re-fitted layer height fluctuation curve; Obtaining slopes of curves corresponding to the plurality of historical printing points and the current printing point, and allocating a correction factor based on the corresponding slopes of the curves; Based on the correction factor, the weighted sum of the layer heights of the historical printing points and the current printing point is performed to obtain the actual layer height of the current printing point, and the printing deviation value of the current printing point is obtained in combination with the preset layer height.

4. The method for real-time height control of additive manufacturing components according to claim 1, wherein: Determining a printing deviation value of a current printing point based on the current layer height sequence and a preset layer height includes: Based on the current layer height sequence, obtaining the current layer height of the current printing point and the historical layer heights of several preceding historical printing points; Obtaining the actual floor height of the current printing point based on the weighted sum of the current floor height and the historical floor height; A printing deviation value of a current printing point is determined based on the preset layer height and the actual layer height.

5. The method for real-time height control of additive manufacturing components according to claim 4, characterized in that: Get the current layer height of the current printing point and the historical layer heights of several previous historical printing points, including: The historical printing points are acquired at equal intervals.

6. The method for real-time height control of additive manufacturing components according to claim 1, wherein: Obtaining a current layer height sequence of a current printing point based on first heights and second heights of a plurality of printing points, including: A first height and a second height corresponding to the current printing point and a plurality of previous historical printing points are obtained, and a corresponding current layer height sequence is obtained in sequence based on a difference between the first height and the second height.

7. The method for real-time height control of an additively manufactured component according to any one of claims 1 to 6, wherein: Get the first height of the print point before printing and the second height after printing, including: obtaining a first height of the printing dot before printing based on the first sensing device; obtaining a second height of the printed dot based on the second sensing device; The second sensing device is arranged in front and behind the first sensing device in the direction of travel of the additive gun and moves with the additive gun. The measurement points corresponding to the second sensing device and the first sensing device are respectively located in front and rear sides of the additive melt pool and at a certain distance from the melt pool.

8. The method for real-time height control of additive manufacturing components according to claim 7, wherein: The first sensing device and the second sensing device use laser probes to obtain height data of printing points.

9. A system for real-time control of the height of an additive manufacturing component for implementing the method for real-time control of the height of an additive manufacturing component according to any one of claims 1 to 8, characterized in that: include: A first height acquisition module, used to acquire a first height of a printing point before printing; A second height acquisition module, used to acquire a second height of the printed dot after printing; a current layer height sequence determining module, configured to obtain a current layer height sequence of a current printing point based on first heights and second heights of a plurality of printing points, wherein the current layer height sequence includes layer height data of the current printing point and a plurality of previous historical printing points; a printing deviation value determining module, configured to determine a printing deviation value of a current printing point based on the current layer height sequence and a preset layer height; A print height real-time correction value determination module is used to implement real-time correction of the print height based on the relationship between a preset revision threshold and the print deviation value, including: When the printing deviation value is less than the revision threshold, automatically correcting the printing height based on the printing parameter database; When the printing deviation value is not less than the revision threshold, a maximum correction of the printing height is achieved based on the printing parameter database; the maximum correction of the printing height is set based on the maximum melt height value that can be achieved in the printing parameter database; The printing parameter database includes at least the following parameters: input power, print head speed, and wire / powder feeding speed.

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