A production control method for cemented carbide additives

Abstract

The present invention relates to the technical field of metal powder processing, and specifically to a production control method for cemented carbide additives. The method first collects laser power and powder feeding speed during the cemented carbide additive processing; determines process difference parameters based on the matching difference and characteristic consistency of laser power and powder feeding speed; compares the process difference parameters of each processing layer with other processing layers, and screens out the comparison layer of each processing layer; combines the matching difference and process difference parameters of laser power and powder feeding speed between the processing layer and the corresponding comparison layer, determines the process control influence coefficient of each processing layer, corrects the feedback error of laser power and powder feeding speed collected by the PID controller, and controls the laser power in the cemented carbide additive processing and the powder feeding speed when adding metal powder according to the corrected feedback error. The present invention improves the accuracy of production process control for cemented carbide additives.

Description

Technical Field

[0001] The invention relates to the technical field of metal powder processing, and in particular to a production control method for cemented carbide additives. Background Art

[0002] Additive manufacturing is a technology that can accumulate materials layer by layer to form complex parts according to the designed CAD files; additive manufacturing technology can easily realize the production and preparation of parts with complex geometric shapes, and is expected to reduce production costs in the production and application of cemented carbide. Therefore, the additive manufacturing of cemented carbide has received more and more attention. Due to the extremely high melting point of cemented carbide, the use of additive manufacturing technology is still very challenging. At present, the additive manufacturing technologies that have been used in cemented carbide mainly include: Selective Laser Melting (SLM), Selective Laser Sintering (SLS), Laser Engineered Net Shaping (LENS), Adhesive Jet 3D Printing (3DP), and 3D Gel Printing (3DGP).

[0003] Among them, laser near-net forming is a direct energy deposition technology. When the laser focused by LENS moves along the specified path, the powder nozzle sprays metal powder directly into the molten pool formed by the laser spot on the substrate, and then stacks layer by layer to form a solid. However, unlike the pre-powdering form of SLM, changing the layer thickness in LENS is achieved by increasing the laser power or the powder feeding speed.

[0004] At present, the common method of adjusting the laser power and powder feeding speed in LENS is to control it according to the feedback error detected by the PID controller. However, in the actual production process of cemented carbide additives, due to the different shapes of the products produced, the matching change characteristics of the laser power and the powder feeding speed vary greatly during the processing of different layers; the traditional control of the laser power and the powder feeding speed in the production process is only controlled by the current feedback error. When processing products with greater complexity, it is greatly affected by the cumulative influence of the matching change characteristics between the laser energy and the powder feeding amount, resulting in an increase in the feedback error of the laser power and the powder feeding speed, which may cause the melting and accumulation of metal powder to have mismatching characteristics, thereby reducing the dimensional accuracy of the produced products. Summary of the invention

[0005] In order to solve the technical problem that the feedback error between laser power and powder feeding speed is large when processing products with greater complexity, the purpose of the present invention is to provide a production control method for cemented carbide additives. The technical solution adopted is as follows:

[0006] In a first aspect, an embodiment of the present invention provides a production control method for cemented carbide additives, the method comprising:

[0007] During the cemented carbide additive manufacturing process, the laser power during each layer processing and the powder feeding speed when adding metal powder are collected;

[0008] According to the matching difference and characteristic consistency of laser power and powder feeding speed, the process difference parameters of each processing layer are determined; the process difference parameters of each processing layer are compared with other processing layers, and the comparison layer of each processing layer is screened out; the process control influence coefficient of each processing layer is determined by combining the matching difference and process difference parameters of laser power and powder feeding speed between each processing layer and the corresponding comparison layer;

[0009] The feedback errors of laser power and powder feeding speed collected by the PID controller are corrected through the process control influence coefficient. The laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder are controlled according to the corrected feedback errors.

[0010] Wherein, according to the matching difference and characteristic consistency of laser power and powder feeding speed, the process difference parameters in each layer processing process are determined, including: analyzing the characteristic consistency between laser power and powder feeding speed in each layer processing process, and determining the matching difference parameters between energy and powder feeding amount; analyzing the matching difference between laser power and powder feeding speed in each layer processing process, and determining the cumulative difference parameters of metal powder melting at the current moment; combining the matching difference parameters and the cumulative difference parameters, determining the process difference parameters in each layer processing process;

[0011] Among them, comparing the process difference parameters of each processing layer with other processing layers and screening out the comparison layer of each processing layer includes: taking any processing layer as the target layer, and determining the confidence parameters of the target layer and each other processing layer according to the difference between the process difference parameters of the target layer and each other processing layer; taking the confidence parameter as the numerator and the process difference parameter of the target layer as the denominator, and taking the ratio composed of the numerator and the denominator as the confidence coefficient of the target layer and each other processing layer; and screening out the processing layer with a confidence coefficient less than or equal to a preset screening threshold as the comparison layer of the target layer.

[0012] Furthermore, the analysis of the characteristic consistency between the laser power and the powder feeding speed during each layer processing to determine the matching difference parameters between the energy and the powder feeding amount includes:

[0013] Construct the laser power sequence and powder feeding speed sequence according to the order of processing time;

[0014] The correlation coefficient between the laser power sequence and the powder feeding speed sequence is determined as a matching difference parameter between energy and powder feeding amount.

[0015] Furthermore, the analysis of the matching difference between the laser power and the powder feeding speed during each layer processing to determine the cumulative difference parameters of the metal powder melting at the current moment includes:

[0016] Standardizing the laser power sequence and the powder feeding speed sequence respectively to obtain a standard power sequence and a standard speed sequence;

[0017] Calculating the absolute value of the difference between the elements at the same position in the standard power sequence and the standard speed sequence to form a difference sequence; wherein each element in the difference sequence corresponds to a moment;

[0018] Taking any element in the difference sequence as the target element, the sum of the difference values ​​between the target element and each element before the target element is calculated as the cumulative difference parameter of the metal powder melting at the time corresponding to the target element.

[0019] Furthermore, the combining the matching difference parameter and the cumulative difference parameter to determine the process difference parameter in each layer processing process includes:

[0020] Determine a range value of a maximum fluctuation range of a cumulative difference parameter as a first process parameter;

[0021] The maximum value of the accumulated difference parameter in the current layer processing process is used as the second process parameter;

[0022] Using a positive correlation mapping value of the matching difference parameter as the third process parameter;

[0023] According to the first process parameter, the second process parameter and the third process parameter, the process difference parameter in each layer processing process is determined; wherein the first process parameter is negatively correlated with the process difference parameter, and the second process parameter and the third process parameter are both positively correlated with the process difference parameter.

[0024] Furthermore, the process control influence coefficient of each processing layer is determined by combining the matching difference of laser power and powder feeding speed between each processing layer and the corresponding comparison layer and the process difference parameter, including:

[0025] Taking any processed layer as the target layer, the target layer and the corresponding comparison layer are constructed according to the order of processing time.

[0026] Match the cumulative difference parameter sequence of the target layer and each comparison layer to obtain the sequence distance parameter;

[0027] The sequence distance parameter is weighted by taking the proportion of the process difference parameter of the target layer and the comparison layer as the weight to obtain the impact base value of the target layer and each comparison layer;

[0028] The process control influence coefficient of the target layer is determined by combining the process difference parameters of the target layer, the influence base values ​​of the target layer and each comparison layer.

[0029] Furthermore, the feedback errors of the laser power and powder feeding speed collected by the PID controller are corrected by the process control influence coefficient, including:

[0030] Compare the normalized process control influence coefficient with the preset judgment threshold. When the normalized process control influence coefficient is greater than the preset judgment threshold, the initial feedback error is increased based on the initial feedback errors of laser power and powder feeding speed collected by the PID controller; when the normalized process control influence coefficient is less than or equal to the preset judgment threshold, the initial feedback error is kept unchanged.

[0031] Furthermore, the controlling of the laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder according to the corrected feedback error includes:

[0032] The corrected feedback error is used as the feedback error of the PID controller, and the corrected laser power and powder feeding speed in the cemented carbide additive processing process are output through the PID controller.

[0033] Furthermore, after collecting the laser power during each layer processing and the powder feeding speed when adding metal powder during the cemented carbide additive processing, the method further comprises:

[0034] The collected laser power and powder feeding speed are subjected to denoising by using a Wiener filter to obtain the denoised laser power and powder feeding speed.

[0035] In a second aspect, a production control system for cemented carbide additives is provided, the system comprising the following modules:

[0036] The data acquisition module is used to collect the laser power during each layer processing and the powder feeding speed when adding metal powder during the cemented carbide additive processing;

[0037] The control analysis module is used to determine the process difference parameters in each processing layer according to the matching difference and feature consistency of laser power and powder feeding speed; compare the process difference parameters of each processing layer with other processing layers, and screen out the comparison layer of each processing layer; combine the matching difference of laser power and powder feeding speed and process difference parameters between each processing layer and the corresponding comparison layer to determine the process control influence coefficient of each processing layer;

[0038] The correction module is used to correct the feedback errors of the laser power and powder feeding speed collected by the PID controller through the process control influence coefficient, and control the laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder according to the corrected feedback error.

[0039] In a third aspect, an embodiment of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores executable code, and when the processor executes the executable code, various possible embodiments of the first aspect are implemented.

[0040] In a fourth aspect, an embodiment of the present invention provides a computer program product, which includes: a computer program code, which, when executed on a computer, enables the computer to execute the method in the first aspect or any possible implementation of the first aspect.

[0041] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute various possible implementations of the first aspect.

[0042] The embodiments of the present invention have at least the following beneficial effects:

[0043] The embodiment of the present invention considers that when producing cemented carbide additives, the change of layer thickness is mainly achieved by laser power and powder feeding speed. Therefore, in the actual processing process, the matching characteristics of the laser power and powder feeding speed corresponding to the processing of different layers of metal powder should be consistent. After obtaining the laser power and powder feeding speed, the consistency characteristics and matching characteristics of the collected laser power and powder feeding speed changes in each layer are analyzed to obtain the process difference parameters. The process difference parameters are obtained by combining the stage instability characteristics of the matching deviation in the production process, and by extracting the matching characteristics of the laser power and powder feeding speed of each layer. The process difference parameters accurately reflect the degree of influence of the cumulative matching on the feedback deviation of each layer of the processing process. By combining the analysis of the matching difference characteristics of each layer and the process difference parameters, the process control influence coefficient is obtained, and the feedback error is adjusted based on the process control influence coefficient. According to the corrected feedback error, the laser power and powder feeding speed in the cemented carbide additive processing process are controlled to avoid the situation where the actual production control process is affected by the cumulative matching through real-time monitoring and closed-loop control, resulting in a large feedback deviation, thereby improving the accuracy of the production process control for cemented carbide additives. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] 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.

[0045] Figure 1 A method flow chart of a production control method for cemented carbide additives provided by one embodiment of the present invention;

[0046] Figure 2 A method flow chart of a method for obtaining a process control influence coefficient provided by an embodiment of the present invention;

[0047] Figure 3 A method flow chart of a method for obtaining process difference parameters provided by an embodiment of the present invention;

[0048] Figure 4 A system block diagram of a production control system for cemented carbide additives provided by one embodiment of the present invention;

[0049] Figure 5 A schematic diagram of the structure of a computer device provided by an embodiment 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 purpose of the invention, the following is a detailed description of the specific implementation method, structure, characteristics and effects of a production control method for cemented carbide additives proposed by the present invention in combination with the accompanying drawings and preferred embodiments.

[0051] In the following description, different "one embodiment" or "another embodiment" do 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.

[0052] Among them, in the description of the embodiments of the present invention, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a way to describe the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present invention, "multiple" refers to two or more than two.

[0053] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0054] 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.

[0055] The embodiments of the present invention are described below in conjunction with the accompanying drawings. Those skilled in the art will appreciate that, with the development of technology and the emergence of new scenarios, the technical solutions provided by the embodiments of the present invention are also applicable to similar technical problems.

[0056] The specific scheme of the production control method for cemented carbide additive provided by the present invention is described in detail below with reference to the accompanying drawings.

[0057] See also Figure 1 , which shows a flowchart of a production control method for cemented carbide additives provided by an embodiment of the present invention, the method comprising the following steps:

[0058] Step S100, during the cemented carbide additive processing, the laser power during each layer processing and the powder feeding speed when adding metal powder are collected.

[0059] In the process of cemented carbide additive production, laser near-net shaping technology (LENS) is usually used for production. First, a CAD solid model of the part is generated in the computer, the model is sliced ​​and layered, and the digital three-dimensional solid data of the part is discretized into a series of two-dimensional contour data information; under the CNC system, according to the path generated by the two-dimensional contour data information, a laser beam is used to scan and irradiate to form a molten pool on the substrate, and the powder feeding nozzle synchronously feeds the metal powder into the molten pool for point-by-point laser cladding; according to the layered data, it is stacked and deposited layer by layer to form a part entity. Among them, LENS mainly changes the layer thickness by increasing the laser power or the powder feeding speed. Therefore, in the actual production process, it is necessary to ensure that during the processing of each layer, the laser power and the powder feeding speed remain relatively stable to ensure the accuracy of the production size and surface roughness.

[0060] However, due to the large differences in the shapes of cemented carbide additives during the production process, the thickness settings for different layers in the actual production process vary greatly. In the actual processing process, the stability of the process control parameters is analyzed in real time, and only the process control parameters currently monitored in real time are adjusted, while the mismatch between the actual laser energy heating time and the amount of metal powder added is ignored. That is, the current laser energy may not be able to fully melt the metal powder or may excessively dissolve the metal powder, resulting in increased thermal stress, which in turn causes deviations in the control of the metal powder processing process; and the stability of the changes between the laser energy and the amount of metal powder added during the processing of different layers should be consistent. Therefore, the process control parameters are collected during the cemented carbide additive processing. Specifically, the power sensor and speed sensor are used to collect the laser power data and the powder feeding speed data, and the data collection time interval is 0.1 seconds.

[0061] Since the acquisition process may be disturbed by the environment, in a preferred embodiment of the present invention, a Wiener filter is used to perform noise reduction processing on the acquired process control parameters to obtain the noise-reduced process control parameters, wherein the process control parameters include laser power and powder feeding speed. The laser power and powder feeding speed mentioned in the subsequent step processing process are all noise-reduced data.

[0062] Step S200, determining the process difference parameters in the processing of each layer according to the matching difference and characteristic consistency of laser power and powder feeding speed; comparing the process difference parameters of each processing layer with other processing layers, and screening out the comparison layer of each processing layer; and determining the process control influence coefficient of each processing layer in combination with the matching difference and process difference parameters of laser power and powder feeding speed between each processing layer and the corresponding comparison layer.

[0063] Normally, in the process of producing cemented carbide additives using LENS technology, in order to ensure the accuracy and quality of molding, the process parameters of the production process are collected in real time through the set sensors, and the collected data are fed back to the closed-loop control system for feedback control, so as to adjust the process parameters of the processing process in time; and in the feedback control process, due to the differences in the structure of the produced parts, different layer thickness parameters are set when layering for the production of different parts. During the laser processing of each layer, the stability of the laser power and the stability of the powder feeding speed affect the processing accuracy; if the laser power is too large, it may cause the thermal stress in the processing process to increase and cause fracture; if the laser power is too small, the metal powder may not be fully melted and bulges may occur; and at the same time, the powder feeding speed should be consistent with the laser power. If there is a deviation in the consistency between the laser power and the powder feeding speed, the laser power and the amount of metal powder added may not match, resulting in low processing accuracy.

[0064] Therefore, in the process of cemented carbide additive production, when considering the use of LENS technology to process parts, the matching characteristics of the laser power and powder feed speed between different layers should be consistent. If there is a deviation in the matching of the laser power and the powder feed amount between different layers, it may lead to the inability to accurately reflect the change of the production status through the implementation of monitoring feedback; therefore, in the metal powder processing process, for the current production parameter control feedback analysis, in addition to the analysis of the process control parameter error at the current moment, the matching difference between the laser power and the powder feed speed of different layers is also considered, so as to accurately feedback the cemented carbide additive production process control signal. The greater the matching difference between the laser power and the powder feed speed during the processing process, the less consistent the matching characteristics of the laser power and the powder feed speed are, the greater the probability of feedback error, and the more necessary it is to adjust the laser power and the powder feed speed.

[0065] When using LENS technology to process cemented carbide additive materials, they are first layered based on the three-dimensional information of the cemented carbide additive materials, and the path information of the two-dimensional contour is generated, and then the production is carried out in conjunction with the laser energy and powder feed amount; in this process, due to the different shapes of different parts, there are large differences in the path length and layer thickness settings between different layers, but due to the LENS technology, the change of layer thickness is mainly achieved by controlling the laser power and powder feed speed.

[0066] For the process control parameters after noise reduction obtained during the production process, the process control parameters are divided according to the set hierarchical information, so that each processing layer has its own corresponding process control parameters, that is, each processing layer has its own corresponding laser power and powder feeding speed when adding metal powder.

[0067] In some possible implementations, the above step S200 can be performed by Figure 2 The steps shown achieve:

[0068] Step S210, determining the process difference parameters in each layer processing process according to the matching difference and feature consistency of the laser power and the powder feeding speed.

[0069] In some embodiments, by analyzing the matching difference and consistency of laser power and powder feeding speed, the process difference parameters in each layer processing process are determined, that is, the above step S210 can be performed by Figure 3 The steps shown achieve:

[0070] Step S211, analyzing the characteristic consistency between the laser power and the powder feeding speed during each layer processing, and determining the matching difference parameters between the energy and the powder feeding amount.

[0071] The change in layer thickness during the production process is not only consistent with the change in laser power and powder feeding speed, but the matching characteristics between the two parameters at different points of the two-dimensional contour information during the processing of each layer should also be consistent.

[0072] The process control parameters corresponding to each layer are respectively used as the laser power sequence and the powder feeding speed sequence in the order of the processing moments, that is, the laser power sequence and the powder feeding speed sequence are constructed in the order of the processing moments; the correlation coefficient between the laser power sequence and the powder feeding speed sequence is determined as the matching difference parameter between the energy and the powder feeding amount. In the embodiment of the present invention, the Pearson correlation coefficient between the laser power sequence and the powder feeding speed sequence is calculated as the matching difference parameter.

[0073] Under the set layer thickness data, the laser power and powder feeding speed of each layer should be correlated and stably changed, that is, the larger the correlation coefficient, the more stable the cemented carbide additive processing process is based on the stable consistency of laser energy and metal powder feeding amount.

[0074] Step S212, analyzing the matching difference between the laser power and the powder feeding speed during each layer processing, and determining the cumulative difference parameter of the metal powder melting at the current moment.

[0075] During the processing of each layer of the part, the changes in laser energy and powder feed rate at different points of the path information of the two-dimensional contour should be consistent. If there is a deviation between the energy and the powder feed rate, the energy and powder feed rate may increase or decrease, causing the continuous matching deviation of the laser energy and powder feed rate during the unstable period of layer thickness processing, resulting in cumulative bulges or fractures. Then, the matching difference of laser power and powder feed rate during the processing process is analyzed to determine the cumulative difference parameters of financial powder melting.

[0076] First, the laser power sequence and the powder feeding speed sequence are standardized to obtain a standard power sequence and a standard speed sequence. In a preferred embodiment of the present invention, a Z-score algorithm is used to standardize the laser power sequence and the powder feeding speed sequence, where the standardization process is to normalize each element in the sequence.

[0077] The absolute value of the difference between the elements at the same position in the standard power sequence and the standard speed sequence is calculated to form a difference sequence; wherein each element in the difference sequence corresponds to a moment. That is, the absolute value of the difference between the elements at the corresponding positions from left to right between the standardized standard power sequence and the standard speed sequence is calculated, and the sequence composed of the absolute value of the difference is used as the difference sequence. This difference sequence is a sequence that reflects the matching analysis of energy and powder input.

[0078] Take any element in the difference sequence as the target element, calculate the sum of the difference values ​​between the target element and each element before the target element, and use it as the cumulative difference parameter of the metal powder melting at the time corresponding to the target element. Traverse all elements in the difference sequence to obtain the cumulative difference parameter of the metal powder melting at the time corresponding to each element. The larger the cumulative difference parameter, the greater the deviation of the matching characteristics of energy and powder feed amount due to unstable parameter changes during the processing.

[0079] Step S213, combining the matching difference parameter and the cumulative difference parameter to determine the process difference parameter in the processing of each layer.

[0080] Since the accumulation of the matching difference between the laser power and the powder feed rate during the processing process occurs in stages, the different stability characteristics of the cumulative difference parameters obtained by the above calculation in different time periods may lead to large differences in the changing trends of the accumulated deviations. According to the consistency characteristics and matching characteristics of the stability of the laser power and the powder feed rate during each layer of processing, the process difference parameters of the cemented carbide additive production control process are determined. In the embodiment of the present invention, the matching difference parameter characterizes the consistency characteristics of the stability of the laser power and the powder feed rate, and the cumulative difference parameter characterizes the matching characteristics of the laser power and the powder feed rate. Therefore, the matching difference parameter and the cumulative difference parameter are combined to determine the process difference parameters during each layer of processing.

[0081] The method for obtaining the process difference parameter is: determine the range value of the maximum fluctuation range of the cumulative difference parameter as the first process parameter. In the embodiment of the present invention, the first process parameter can also be understood as the range of the maximum cumulative difference parameter and the minimum cumulative difference parameter in the current processing layer. The maximum value of the cumulative difference parameter in the current layer processing process is used as the second process parameter; the positive correlation mapping value of the matching difference parameter is used as the third process parameter; according to the first process parameter, the second process parameter and the third process parameter, the process difference parameter in each layer processing process is determined; wherein the first process parameter is negatively correlated with the process difference parameter, and the second process parameter and the third process parameter are both positively correlated with the process difference parameter.

[0082] In some embodiments, taking the i-th processing layer as an example, the process difference parameter of the i-th layer The calculation formula is: ;in, is the first process parameter of the i-th layer; is the second process parameter of the i-th layer; is the third process parameter of the i-th layer; exp is an exponential function with a natural constant as the base.

[0083] The larger the calculated process difference parameter is, the larger the matching characteristic deviation of the process control parameters in the processing of the i-th layer is, that is, up to the current processing moment of the i-th layer, its feedback deviation may be more affected by the cumulative impact of matching.

[0084] Step S220 , comparing process difference parameters of each processed layer with other processed layers, and selecting a comparison layer of each processed layer.

[0085] Aiming at the consistency characteristics and matching characteristics of each layer in the process of cemented carbide additive machining control, the process difference parameters of the production control process are calculated, and the cumulative difference parameters obtained through analysis reflect the characteristics of the influence of the matching accumulation on the process control feedback of the current layer. Furthermore, combined with different layers in the production process, although the layer thickness settings of different layers are different, the matching characteristics of the laser energy and powder feed amount in the machining process between different layers should be consistent, and for layers with similar effects on feedback deviation due to unstable characteristics, the more accurate the confidence analysis of the feedback for production control is, the more consistent the machining matching characteristics are.

[0086] Take any processing layer in the cemented carbide additive production control process as the target layer, and determine the confidence parameters of the target layer and each other processing layer according to the difference in process difference parameters between the target layer and each other processing layer; take the confidence parameter as the numerator and the process difference parameter of the target layer as the denominator, and use the ratio composed of the numerator and the denominator as the confidence coefficient of the target layer and each other processing layer. Screen out the processing layer whose confidence coefficient is less than or equal to the preset screening threshold as the comparison layer of the target layer. In an embodiment of the present invention, the confidence parameter of the target layer and each other processing layer is the absolute value of the difference between the process difference parameter of the target layer and each other processing layer; the preset screening threshold value is 0.1, and in other embodiments, the implementer can adjust the value according to the actual situation.

[0087] Step S230, determining the process control influence coefficient of each processing layer in combination with the matching difference of the laser power and the powder feeding speed between each processing layer and the corresponding comparison layer, and the process difference parameters.

[0088] If the matching consistency difference between the comparison layer and the target layer obtained through the above screening is greater, then based on the consistency analysis of the matching characteristics of the process control parameters in the cemented carbide additive processing process using the LENS technology, the processing of the laser energy and the powder feed amount is more likely to have staged cumulative protrusions or fractures during the processing of the target layer; therefore, the process control influence coefficient is obtained based on the matching characteristics between the target layer and the comparison layer and the cumulative impact of the feedback of each layer, specifically:

[0089] All the cumulative difference parameters corresponding to the target layer and each comparison layer are respectively composed of the sequence of the elements arranged in the corresponding difference sequence as the cumulative difference parameter sequence of the target layer and each comparison layer. It can be understood that the cumulative difference parameter sequence of the target layer and the corresponding comparison layer is respectively composed of the sequence of processing time. The sequence of processing time here can also be understood as the sequence of acquisition time. The acquisition time and processing time are consistent during the processing process.

[0090] Then, the process control influence coefficient H of the target layer is calculated based on the matching feature data sequence and the feedback confidence level in the comparison layer. More specifically, the cumulative difference parameter sequence of the target layer and each comparison layer is matched to obtain the sequence distance parameter. The sequence distance parameter is weighted with the proportion of the process difference parameter of the comparison layer of the target layer as the weight to obtain the influence base value of the target layer and each comparison layer. The process control influence coefficient of the target layer is determined by combining the cumulative difference parameter of the target layer and the influence base value of the target layer and the comparison layer.

[0091] As a preferred embodiment of the present invention, a dynamic time warping (DTW) algorithm is used to match the cumulative difference parameter sequence of the target layer and each comparison layer to obtain the DTW distance between the two sequences, which is recorded as the sequence distance parameter of the target layer and each comparison layer. It should be noted that the target layer and each comparison layer have a corresponding sequence distance parameter, that is, there are as many sequence distance parameters as there are comparison layers corresponding to the target layer.

[0092] Therefore, the corresponding proportion of the process difference parameters of the target layer and the comparison layer is used as the weight to weight the sequence distance parameters, and the basic impact value of the target layer and each comparison layer is obtained. In fact, it is an analysis of the target layer and any comparison layer. It can be understood that any comparison layer of the target layer is taken as the target comparison layer, and the analysis of the target layer and the target comparison layer is taken as an example. The proportion of the process difference parameters of the target layer and the target comparison layer is used as the weight to weight the sequence distance parameters of the target layer and the target comparison layer, and the basic impact value of the target layer and the target comparison layer is obtained.

[0093] As a preferred embodiment of the present invention, a method for obtaining the proportion of the process difference parameters of the target comparison layer of the target layer is: using the process difference parameters of the target comparison layer of the target layer as the numerator, and the sum of the process difference parameters of all comparison layers of the target layer as the denominator, and the ratio formed by the numerator and the denominator is the proportion of the process difference parameters of the target comparison layer of the target layer.

[0094] As a preferred embodiment of the present invention, the process control influence coefficient of the target layer is determined in combination with the process difference parameters of the target layer, and the influence base values ​​of the target layer and the comparison layer. Specifically, the process difference parameters of the target layer are used as weighted weights, and the mean of the influence base values ​​of the target layer and all the comparison layers are weighted to obtain the influence base values ​​of the target layer and the comparison layer.

[0095] The calculation formula of the process control influence coefficient H is: ; Where p is the process difference parameter of the target layer; n is the number of comparison layers corresponding to the target layer; is the process difference parameter of the kth comparison layer of the target layer; is the process difference parameter of the vth comparison layer of the target layer; is the cumulative difference parameter sequence of the target layer; is the cumulative difference parameter sequence of the kth comparison layer of the target layer; is the sequence distance parameter of the cumulative difference parameter sequence between the target layer and the kth comparison layer; is the proportion of process difference parameters of the kth comparison layer of the target layer; is the influence base value of the kth comparison layer of the target layer; It is the average of the impact base values ​​of the target layer and all comparison layers.

[0096] The larger the calculated process control influence coefficient is, the greater the consistency analysis based on the matching features between the target layer and the comparison layer, and the current matching difference degree analysis of the target layer. When the target layer is processed according to the set layer thickness at the current moment, the real-time monitoring feedback signal is greatly affected by the cumulative matching.

[0097] Step S300, through the process control influence coefficient, the feedback error of the laser power and the powder feeding speed collected by the PID controller is corrected, and the laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder are controlled according to the corrected feedback error.

[0098] When it comes to cemented carbide additive production, LENS technology is used to process parts, considering that its processing dimensional accuracy mainly depends on the stability control between laser power and powder feeding speed; combined with the matching consistency analysis between laser energy and powder feeding amount processed according to the set layer thickness between different layers in the processing process, the process control influence coefficient of the processing process is obtained, and the process control influence coefficient accurately reflects the characteristics of the real-time monitoring feedback signal being affected by the cumulative influence of matching; further, the feedback signal of the cemented carbide additive production control process is adjusted according to the obtained process control influence coefficient, so as to accurately control the production stability and improve the dimensional accuracy of cemented carbide additive processing products.

[0099] In the process of processing and producing cemented carbide additives using LENS technology, in order to ensure the accuracy and quality of production and molding, the laser power and powder feeding speed are collected in real time by sensors to provide feedback for the processing system, so as to timely adjust the laser power and powder feeding speed and realize closed-loop control. In an embodiment of the present invention, the closed-loop controller adopts a PID controller. For the control of laser power and powder feeding speed, the feedback data includes the real-time collected laser power s, powder feeding speed f and the process control influence coefficient obtained by the analysis of step S200; the initial feedback error of the laser power and powder feeding speed collected by the PID controller is corrected by the process control influence coefficient to obtain the corrected feedback error. It should be noted that the initial feedback error can be directly obtained by the PID controller, and its calculation method is the difference between the actual collected data and the set data. For example, taking the laser power in the embodiment of the present invention as an example, the initial feedback error of the laser power is the difference between the actual laser power collected by the power sensor and the set laser power.

[0100] The method of correcting the feedback error by the process control influence coefficient is:

[0101] Compare the normalized process control influence coefficient with the preset judgment threshold. When the normalized process control influence coefficient is greater than the preset judgment threshold, the initial feedback error is increased based on the initial feedback error of the laser power and powder feeding speed collected by the PID controller. In an embodiment of the present invention, the value of the preset judgment threshold is 0.5, and in other embodiments, the implementer can adjust the value according to the actual situation. Among them, the increase coefficient when increasing the initial feedback error is: W=h+0.5; h is the normalized process control influence coefficient; 0.5 is the preset judgment threshold; the increase coefficient W obtained according to the process control influence coefficient is multiplied by the initial feedback error to obtain the corrected feedback error. When the normalized process control influence coefficient is less than or equal to the preset judgment threshold, the initial feedback error is kept unchanged.

[0102] In some embodiments, the adjustment factor is W=T(h)+0.5. That is, when the normalized process control influence coefficient is less than or equal to the preset judgment threshold, T (h) = 0.5, at this time W = 0.5 + 0.5 = 1, the adjustment coefficient at this time is used as the weight, multiplied by the initial feedback error, and the initial feedback error is not changed, that is, the initial feedback error is kept unchanged.

[0103] The corrected feedback error is used as the feedback error of the PID controller, and the corrected laser power and powder feeding speed in the cemented carbide additive processing process are output through the PID controller.

[0104] See also Figure 4 , which shows a system block diagram of a production control system for cemented carbide additives provided by an embodiment of the present invention, the system includes the following modules:

[0105] The data acquisition module is used to collect the laser power during each layer processing and the powder feeding speed when adding metal powder during the cemented carbide additive processing;

[0106] The control analysis module is used to determine the process difference parameters in each processing layer according to the matching difference and feature consistency of laser power and powder feeding speed; compare the process difference parameters of each processing layer with other processing layers, and screen out the comparison layer of each processing layer; combine the matching difference of laser power and powder feeding speed and process difference parameters between each processing layer and the corresponding comparison layer to determine the process control influence coefficient of each processing layer;

[0107] The correction module is used to correct the feedback errors of the laser power and powder feeding speed collected by the PID controller through the process control influence coefficient, and control the laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder according to the corrected feedback error.

[0108] Optionally, the transmission medium may be a wired link, such as but not limited to coaxial cable, optical fiber, and digital subscriber line, or a wireless link, such as but not limited to Wireless Fidelity (WIFI), Bluetooth, and mobile device network.

[0109] It should be noted that the device provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the computer device can be divided into different functional modules to complete all or part of the functions described above.

[0110] Figure 5 is a schematic diagram of the structure of a computer device provided by an embodiment of the present invention. Figure 5 As shown, the computer device 400 includes: a memory 410, a processor 420, and a computer program 430 stored in the memory 410 and running on the processor 420, wherein when the processor 420 executes the computer program 430, the computer device can execute any one of the production control methods for cemented carbide additives introduced above.

[0111] In addition, an embodiment of the present invention also protects a device, which may include a memory and a processor, wherein the memory stores an executable program code, and the processor is used to call and execute the executable program code to execute a production control method for cemented carbide additives provided by an embodiment of the present invention.

[0112] The embodiment of the present invention can divide the functional modules of the device according to the above method example. For example, each functional module can be corresponded, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0113] In the case of dividing each module according to each function, the device may also include a signal uploading module, a determining module, an adjusting module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module, which will not be repeated here.

[0114] It should be understood that the device provided in the embodiment of the present invention is used to execute the above-mentioned production control method for cemented carbide additives, and thus can achieve the same effect as the above-mentioned implementation method.

[0115] In the case of an integrated unit, the device may include a processing module and a storage module. When the device is applied to a device, the processing module may be used to control and manage the actions of the device. The storage module may be used to support the device to execute mutual program codes, etc. The processing module may be a processor or a controller, which may implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of the present invention. The processor may also be a combination that implements a computing function, such as a combination of one or more microprocessors, a combination of digital signal processing (DSP) and a microprocessor, etc. The storage module may be a memory.

[0116] In addition, the device provided in an embodiment of the present invention may specifically be a chip, a component or a module, and the chip may include a connected processor and a memory; wherein the memory is used to store instructions, and when the processor calls and executes the instructions, the chip can execute a production control method for cemented carbide additives provided in the above embodiment.

[0117] An embodiment of the present invention also provides a computer-readable storage medium, in which a computer program code is stored. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement a production control method for cemented carbide additives provided in the above embodiment.

[0118] An embodiment of the present invention further provides a computer program product. When the computer program product is run on a computer, the computer is enabled to execute the above-mentioned related steps to implement a production control method for cemented carbide additives provided in the above embodiment.

[0119] Among them, the device, computer-readable storage medium, computer program product or chip provided in the embodiments of the present invention are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding methods provided above, and will not be repeated here. Through the description of the above implementation methods, technicians in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In the embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways.

[0120] The device embodiments described above are merely illustrative. For example, the division of modules or units is only a logical function division. There may be other divisions in actual implementation. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection of devices or units, which may be electrical, mechanical or other forms.

[0121] It should also be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or terminal device including the element.

[0122] It should be noted that the sequence of the above embodiments of the present invention is only for description and does not represent the advantages and disadvantages of the embodiments. The processes depicted in the accompanying drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0123] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

[0124] The above contents are only specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered within the protection scope of the present invention.

Claims

1. A production control method for cemented carbide additives, characterized in that: The method comprises the following steps: During the cemented carbide additive manufacturing process, the laser power during each layer processing and the powder feeding speed when adding metal powder are collected; According to the matching difference and characteristic consistency of laser power and powder feeding speed, the process difference parameters of each processing layer are determined; the process difference parameters of each processing layer are compared with other processing layers, and the comparison layer of each processing layer is screened out; the process control influence coefficient of each processing layer is determined by combining the matching difference and process difference parameters of laser power and powder feeding speed between each processing layer and the corresponding comparison layer; The feedback errors of laser power and powder feeding speed collected by the PID controller are corrected through the process control influence coefficient. The laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder are controlled according to the corrected feedback errors. Wherein, according to the matching difference and characteristic consistency of laser power and powder feeding speed, the process difference parameters in each layer processing process are determined, including: analyzing the characteristic consistency between laser power and powder feeding speed in each layer processing process, and determining the matching difference parameters between energy and powder feeding amount; analyzing the matching difference between laser power and powder feeding speed in each layer processing process, and determining the cumulative difference parameters of metal powder melting at the current moment; combining the matching difference parameters and the cumulative difference parameters, determining the process difference parameters in each layer processing process; Among them, comparing the process difference parameters of each processing layer with other processing layers and screening out the comparison layer of each processing layer includes: taking any processing layer as the target layer, and determining the confidence parameters of the target layer and each other processing layer according to the difference between the process difference parameters of the target layer and each other processing layer; taking the confidence parameter as the numerator and the process difference parameter of the target layer as the denominator, and taking the ratio composed of the numerator and the denominator as the confidence coefficient of the target layer and each other processing layer; and screening out the processing layer with a confidence coefficient less than or equal to a preset screening threshold as the comparison layer of the target layer.

2. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The analysis of the characteristic consistency between the laser power and the powder feeding speed during each layer processing determines the matching difference parameters between the energy and the powder feeding amount, including: Construct the laser power sequence and powder feeding speed sequence according to the order of processing time; The correlation coefficient between the laser power sequence and the powder feeding speed sequence is determined as a matching difference parameter between energy and powder feeding amount.

3. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The analysis of the matching difference between the laser power and the powder feeding speed during each layer processing to determine the cumulative difference parameters of the metal powder melting at the current moment includes: Standardizing the laser power sequence and the powder feeding speed sequence respectively to obtain a standard power sequence and a standard speed sequence; Calculating the absolute value of the difference between the elements at the same position in the standard power sequence and the standard speed sequence to form a difference sequence; wherein each element in the difference sequence corresponds to a moment; Taking any element in the difference sequence as the target element, the sum of the difference values ​​between the target element and each element before the target element is calculated as the cumulative difference parameter of the metal powder melting at the time corresponding to the target element.

4. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The combining the matching difference parameter and the cumulative difference parameter to determine the process difference parameter in each layer processing process includes: Determine a range value of a maximum fluctuation range of a cumulative difference parameter as a first process parameter; The maximum value of the accumulated difference parameter in the current layer processing process is used as the second process parameter; Using a positive correlation mapping value of the matching difference parameter as the third process parameter; According to the first process parameter, the second process parameter and the third process parameter, the process difference parameter in each layer processing process is determined; wherein the first process parameter is negatively correlated with the process difference parameter, and the second process parameter and the third process parameter are both positively correlated with the process difference parameter.

5. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The process control influence coefficient of each processing layer is determined by combining the matching difference of laser power and powder feeding speed between each processing layer and the corresponding comparison layer, and the process difference parameters, including: Taking any processed layer as the target layer, the target layer and the corresponding comparison layer are constructed according to the order of processing time. Match the cumulative difference parameter sequence of the target layer and each comparison layer to obtain the sequence distance parameter; The sequence distance parameter is weighted by taking the proportion of the process difference parameter of the target layer and the comparison layer as the weight to obtain the impact base value of the target layer and each comparison layer; The process control influence coefficient of the target layer is determined by combining the process difference parameters of the target layer, the target layer and the influence base values ​​of each comparison layer.

6. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The feedback errors of the laser power and the powder feeding speed collected by the PID controller are corrected by the process control influence coefficient, including: Compare the normalized process control influence coefficient with the preset judgment threshold. When the normalized process control influence coefficient is greater than the preset judgment threshold, the initial feedback error is increased based on the initial feedback errors of laser power and powder feeding speed collected by the PID controller; when the normalized process control influence coefficient is less than or equal to the preset judgment threshold, the initial feedback error is kept unchanged.

7. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: The method of controlling the laser power in the cemented carbide additive processing process and the powder feeding speed when adding metal powder according to the corrected feedback error includes: The corrected feedback error is used as the feedback error of the PID controller, and the corrected laser power and powder feeding speed in the cemented carbide additive processing process are output through the PID controller.

8. The production control method for cemented carbide additive manufacturing according to claim 1, characterized in that: After collecting the laser power during each layer processing and the powder feeding speed when adding metal powder during the cemented carbide additive processing, the method includes: The collected laser power and powder feeding speed are subjected to denoising by using a Wiener filter to obtain the denoised laser power and powder feeding speed.

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