Method and adjusting device for adjusting irradiation in manufacturing process for additive manufacturing of objects

Abstract

The invention relates to a method for adjusting irradiation in a manufacturing process for additive manufacturing of an object (2), in which a construction material is cured layer by layer in a construction field (8) in the form of an object layer (O), which corresponds to a cross-section of the object (2) to be manufactured, by irradiating the construction material. The invention further relates to an adjusting device, a control device and a manufacturing device.

Description

Technical Field

[0001] The invention relates to a method and a regulating device for regulating irradiation in a production process for additively producing an object, a control device for a production device for additively producing an object, and an additive production device for additively producing at least one object in an additive production process. Background Art

[0002] Additive manufacturing processes are becoming more and more important in the production of prototypes and also in mass production. In general, an "additive manufacturing process" can be understood as a manufacturing process in which a manufactured product ("object") is constructed by accumulating materials ("building materials"), usually based on digital 3D design data. Here, this construction is usually carried out layer by layer. As a synonym for additive manufacturing, the term "3D printing" is also often used. The production of models, samples and prototypes using additive manufacturing processes is often called "rapid prototyping", mold production is called "rapid tooling", and the flexible production of series components is called "rapid manufacturing". As mentioned at the beginning, the key point is the selective curing of the building material, wherein in various manufacturing processes, this curing can be carried out by means of irradiation with radiation energy (such as electromagnetic radiation, in particular light and / or thermal radiation), but if necessary, it can also be carried out with particle radiation (such as electron radiation).

[0003] Examples of methods that work by irradiation are "selective laser sintering" or "selective laser melting". Here, thin layers of a mostly powdered building material are repeatedly applied in a superimposed manner, and in each layer, the building material is selectively solidified by spatially limited irradiation of a location that should belong to the object to be produced after production is completed in a "welding process" in such a way that the powder particles of the building material are partially or completely melted by means of the energy introduced locally at this location by the radiation. During cooling, these powder particles then bond to each other and solidify to form a solid. In most cases, the energy beam is guided along a solidification path over the building field, and the remelting or solidification of the building material in the respective layer is correspondingly carried out in the form of a "welding path" or "weld bead", so that in the end there are a plurality of such layers formed by welding paths in the object. In this way, objects with very high quality and fracture strength can now be produced.

[0004] During manufacturing, it may happen that the energy input by the energy beam is absorbed unevenly by the object. This manifests itself as the presence of areas of the object layer with uneven heat distribution. Sometimes, it may be desirable to cure selected areas with different energy inputs, but this is usually undesirable, especially in the case of uniform or regularly contoured surfaces. Summary of the invention

[0005] The object of the present invention is to provide a method and a device for regulating the irradiation in a manufacturing process for additively manufactured objects, which overcome the disadvantages of the prior art and in particular allow to improve the quality of the objects and the uniform quality of the manufactured objects. Preferably, the object of the present invention is to increase the stability of the manufacturing process and in particular to prevent manufacturing interruptions or problems with the application of building material at locations with increased heat generation or increased thermal radiation.

[0006] This object is achieved by a method according to claim 1 , a regulating device according to claim 11 , a control device according to claim 13 and a production device according to claim 14 .

[0007] The method according to the invention is used to regulate irradiation in a manufacturing process for additively manufacturing an object. Here, by irradiating a building material, the building material is solidified layer by layer in the form of object layers within a building field, the object layers corresponding to the cross-section of the object to be manufactured. The method comprises the following steps:

[0008] - determining several shape regions corresponding to one another in shape and / or size in the object layer to be solidified,

[0009] - selecting several reference areas from the several shape areas, wherein at least the remaining shape areas are defined as (or regarded as) correction areas,

[0010] - determining a number of target thermal maps which define the desired thermal distribution of the correction region or of a number of groups of correction regions,

[0011] - curing a number of selected reference areas and recording spatially resolved thermal data of the number of reference areas as they cure,

[0012] - generating a number of correction factor modules for the correction area from the thermal data and the target thermal map, wherein each correction factor module specifies a spatially resolved correction factor for an irradiance value or a spatially resolved corrected irradiance value, and wherein one correction factor module is assigned to each correction area,

[0013] - solidifying at least the correction regions based on the correction factor modules respectively assigned to the correction regions.

[0014] The method advantageously regulates the irradiation of the manufacturing process by correcting the irradiation. The correction here concerns the energy introduced into the area. The correction factor module can here particularly influence the irradiation intensity and / or the irradiation duration. If it is found by means of the thermal data that a certain area (reference area) absorbs too much or too little heat during its curing, for example it is irradiated too strongly or too weakly, or it releases heat too quickly or too slowly after curing, then the irradiation of other areas (correction areas) can be adjusted accordingly with the aid of the correction factor module, i.e. the energy input can be optimized. This achieves that the amount of heat during the production of the component is The heat absorbed or dissipated by the component or by a component region) is similar or adapted in a position-specific manner. A similar amount of heat, in particular a constant amount of heat, advantageously leads to a reduction in mechanical stresses in the component to a minimum and / or to a uniform (in particular an ideal or minimum) porosity of the component. Furthermore, adapted amounts of heat are advantageous so that different component regions with different properties can be constructed. The different properties can be, for example, mechanical strength, porosity, microstructure, crystal structure or crystal phases.

[0015] In this embodiment of the method according to the invention, optimization is no longer possible for the reference region. Since the object is built up layer by layer, it is not necessarily a serious problem if a layer is cured at a slightly higher or lower temperature. However, it is also possible to specifically determine "sacrificial objects" which are subsequently removed and which then contain the reference region.

[0016] Within the scope of the method, several "shape regions" are determined. These shape regions are regions of the object to be manufactured and / or of several objects to be manufactured that correspond to one another in shape and / or size. Preferably, the shape and size of the shape regions are at least similar.

[0017] The feature that two shape regions correspond to each other in shape means that they are identical or at least similar in terms of their shapes. This may be the geometric shape of the shape region. For example, both shape regions are polygonal and have the same shape (i.e., they have the same number of sides and the same angle between two consecutive sides). Alternatively, both shape regions are polygonal and have similar shapes (i.e., these polygons are congruent in a portion of their respective perimeters, or these polygons have the same number of sides, wherein the angles between the sides deviate from each other within a certain interval).

[0018] The feature that two shape regions correspond to each other in size means that they are identical or at least similar in terms of their size. Here, the size of a shape region may be its area, in particular its geometric area. For example, if the areas of two shape regions are identical, they have the same size, or if the areas of two shape regions differ within a certain interval, they have similar sizes. Two shape regions may correspond in shape but not in size, or vice versa. However, it is also possible that the shape regions correspond in shape and size, i.e. they are identical or at least similar in terms of their shape and / or size.

[0019] As mentioned at the beginning, shape areas are determined in the object layer. Here, object layers of different objects can be determined as shape areas. In addition, it is particularly feasible to determine the object layers of the same object as shape areas. In this case, it should be noted that not all objects must be manufactured in the same manufacturing process. The thermal data of the reference area in one production process and the correction factor module can also be used in other production processes. When determining the shape area in the object layer, parts of the object layer can also be determined as shape areas. In this case, parts of different object layers (i.e., object layers in different objects) can be determined as shape areas. It is also feasible to determine several parts of the same object layer and, if necessary, parts of other object layers as shape areas at the same time. In one example, these partial areas can be areas of the same object, such as the sharp corners of a star.

[0020] It should also be noted that, while the shape regions must be determined at the beginning of the method in order to be able to select the reference regions, other shape regions may still be determined at a later time, after the shape regions have solidified.

[0021] It should be particularly noted that the shape regions do not necessarily have to be determined on the same layer (even though this is a preferred embodiment). It may happen that the same objects are staggered in height or that the same shape regions appear at different heights in one object.

[0022] Groups of regions of different shapes can also be given. The method can then be carried out for each group by selecting reference regions for each group and creating correction factor modules for the respective group from the thermal data of these reference regions.

[0023] It should be noted that it is not necessary that all regions that are similar in shape and / or size must be assigned to shape regions. For example, if there are many identical objects, a portion of the objects can simply be ignored in the method. However, for a better understanding, it is still conceivable that several identical objects should be formed and the same layers of these objects represent a set of shape regions.

[0024] It should also be noted that not all areas that are similar in shape and / or size must be assigned to a group of shape areas. For example, the shape areas of one layer can be assigned to one group of shape areas, and the shape areas of another layer that are identical to these shape areas can be assigned to another group of shape areas.

[0025] At least one reference area is selected from the determined shape area. The reference area is the area where thermal data is measured. In a simple example, it can be imagined that at least one reference area is cured and then (or during) its thermal distribution is measured, for example, by photographing it with an infrared camera, and then a correction factor module for correcting the correction area is determined therefrom.

[0026] "Reference area" and "calibration area" are two shape areas. A shape area is always a calibration area and / or a reference area. Preferably, no other areas are considered shape areas (even if they are similar in shape and / or size) because these areas are not considered in this method. The shape area whose thermal data is measured is the reference area, and the shape area whose curing is corrected is the calibration area. The shape area whose curing is corrected and whose thermal data is measured at the same time is both a reference area and a calibration area.

[0027] Therefore, the shape area can be both a correction area and a reference area, for example in such a case: a first reference area is selected, a correction factor module is determined from its thermal data, thereby correcting the correction area, and then this correction area is defined as a new reference area, so that further correction factor modules can be determined using its thermal data for further improved correction. Therefore, it is not necessary to select all reference areas at the beginning, but a reference area must be selected before the first correction area is corrected, and at the latest the last reference area should be selected before the last correction area is corrected.

[0028] However, it should be pointed out that the determination of the shape regions and the selection of the reference regions do not necessarily have to be completed when the object series is produced. If a new (same or similar) object series is to be produced some time later, the previously determined correction factor model can be used. It is also possible to select the reference regions again in the new series in order to determine whether the "old" correction factor model can be applied.

[0029] In order to determine the correction factor module, not only the thermal data of the reference area (the so-called potential "actual" state) is required, but also information about the ideal state, in particular information about the ideal state of the correction area. According to the present invention, at least one correction area is defined, and the ideal state of the correction area (the so-called "target" state to be achieved) is represented or determined by a (two-dimensional) target heat map. The target heat map is preferably represented as a non-uniform value distribution. Further preferably, the target heat map is two-dimensional, and these values ​​(for clarity, these values ​​of the target heat map are also referred to as "target heat values" below) are specified in a position-specific manner in the target heat map. This means that the correspondence between a target heat value and a certain position of a certain object layer has been given or can be reconstructed. There is also such a statement below that the target heat map is position-specific, or a position-specific target heat map is provided or exists. However, a uniform distribution of target heat values ​​in the target heat map is also feasible. The target heat map can be composed of a single value (target heat value) in particular.

[0030] The target calorific value is preferably a scalar value representing the amount of heat. The amount of heat, in particular when expressed as a scalar value, can be an integral under a thermal radiation curve or a thermal radiation spectrum, or a temperature. In addition, the target calorific value can be an absolute value or a relative value, wherein a relative target calorific value can involve a change compared to another target calorific value, or involve a predetermined target value (such as a calibration value). The absolute calorific value can, for example, be an absolute temperature or an amount of heat or energy in J / mm 2 . A relative thermal value is, for example, a temperature difference. In particular, the target thermal map can consist of so-called "gray values". A gray value is an indicator of thermal radiation (infrared radiation), which can be associated with a temperature, for example based on a calibration. The gray value can originate from an electrical signal, for example when thermal radiation is recorded with a CCD or CMOS camera, and can be associated with an amount of heat and / or a temperature, for example based on a calibration. For example, a gray value can correspond to an absolute or relative temperature, or to an absolute or relative value of an amount of heat, for example as a scalar value of an integral under a thermal radiation curve or a thermal radiation spectrum.

[0031] Preferably, a target heat map is determined for the correction area. This means that each correction area can be assigned a separate target heat map. Alternatively, a group of correction areas or all correction areas can be assigned a target heat map. In the case of the same objects, the correction areas of all objects can be assigned a unique target heat map. In the two-dimensional case of the target heat map, the same target heat map can exist for the same object. If the target heat map of the same object consists of a unique value (target heat value), this value can be the same for all the same objects. This value can be, for example, just a unique target temperature or a unique target heat. In addition, different objects can also be assigned different target heat maps. As mentioned above, the target heat value of the target heat map can be position-specific. A position-specific target heat map can be determined for the correction area in this way so that the correspondence between a target heat value of the target heat map and a position in the correction area has been given or can be reconstructed.

[0032] The target thermal values ​​can be distributed in the location-specific target thermal map in such a way that their distribution takes into account specific areas in the correction area. It is preferably possible to define areas within a correction area that are corrected differently than other areas of the correction area. For example, it can be advantageous if edge areas or small structures within the correction area are corrected differently than large and / or central surfaces.

[0033] As mentioned above, all of the above (shape area, reference area, target heat map) can be determined at the beginning of the method.

[0034] However, for the part of curing the reference area of ​​a layer and recording the thermal data, it is basically only necessary to know the reference area to be cured. This does not necessarily have to be done before the first calibration. As mentioned above, it is entirely possible to cure one reference area first and use its thermal data for calibration, and then cure other reference areas (also calibrated if necessary) and record more thermal data.

[0035] Thermal data is spatially resolved. This means that in a reference area, multiple thermal values ​​are measured at different positions and these values ​​are assigned to these positions. Preferred in this regard is a grayscale image, which is recorded using an infrared camera. The grayscale image recorded using an infrared camera corresponds to the thermal distribution and / or temperature; that is, one (each) position in the grayscale image reflects the amount of heat and / or the temperature of the corresponding position in the reference area. As mentioned above, the heat and temperature can be recorded or mapped as absolute or relative values. For example, an absolute temperature or a relative temperature or an absolute or relative value can be mapped in a grayscale image, for example as a scalar value of an integral under a thermal radiation curve or a thermal radiation spectrum. For example, the amount of heat can be mapped with a grayscale value.

[0036] The thermal data are measured when the reference area is being cured. This means (directly) after or during curing. Recording during curing gives more accurate values, since the area that solidifies first is recorded before it cools down. It can therefore be summarized that the thermal data essentially reflects the thermal distribution of the reference area.

[0037] If there are now thermal data (actual state) of at least one reference area and a target thermal map, the correction factor module can be calculated. This can be done simply by reducing the heat input in the correction area for those parts of the reference area that are overheated (the thermal data of these parts are higher than the corresponding thermal value in the target thermal map); and increasing the heat input for those parts of the reference area that are too cold (the thermal data of these parts are lower than the corresponding thermal value in the target thermal map). A suitable calculation method for the correction factor module can be easily determined by experiment.

[0038] The correction factor module here specifies spatially resolved correction factors for the irradiance values, ie factors by which predetermined irradiance values ​​are calculated (eg multiplied) to obtain corrected irradiance values. Alternatively, the correction factor module also specifies already spatially resolved corrected irradiance values.

[0039] Each correction area must be assigned a correction factor module, which allows the correction to be performed.

[0040] The correction areas are then cured based on the correction factor modules respectively assigned to them.

[0041] The regulating device according to the invention is used for regulating the irradiation in a manufacturing process for additively manufacturing an object. Here, by irradiating the building material, the building material is solidified layer by layer in the building field in the form of object layers, corresponding to the cross section of the object to be manufactured. The regulating device comprises the following components:

[0042] - Predetermined units, designed for

[0043] i) determining a plurality of shape regions corresponding to each other in shape and / or size in the object layer to be solidified,

[0044] ii) selecting a number of reference regions from the plurality of shape regions, wherein the remaining shape regions are defined as correction regions,

[0045] iii) determining a number of target thermal maps which set the desired thermal distribution of the calibration area or groups of calibration areas,

[0046] - a sensor unit designed to record spatially resolved thermal data of the several reference areas while they are being cured,

[0047] a correction module unit, designed to generate a number of correction factor modules for the correction area from the thermal data and the target thermal map, wherein each correction factor module specifies a spatially resolved correction factor for the irradiance value or a spatially resolved corrected irradiance value, and wherein one correction factor module is assigned to each correction area,

[0048] A control data unit designed to generate and output control data for curing at least the correction regions based on the correction factor modules respectively assigned to the correction regions.

[0049] The regulating device is preferably designed to carry out the method according to the invention. The functions of the individual components of the device have been described above.

[0050] A predetermined unit can have a plurality of different subunits which perform different tasks. These subunits can be assigned to the predetermined unit only according to their determined or selected functions.

[0051] The sensor unit is preferably an infrared camera, but may also be another thermal sensor. It is not absolutely necessary that the sensor unit can specify an absolute temperature (for example, if the goal of the method is only to homogenize the heat input), but it is advantageous if the sensor unit is calibrated, i.e., a specific temperature is assigned to a specific gray tone of the grayscale image of the infrared camera, for example.

[0052] The correction module unit may be a simple calculation unit, but may also be designed for generating a control instruction portion for irradiation based on the number of correction factor modules in order to additively manufacture an object.

[0053] The control data unit is designed to provide the control device with control data generated for additive manufacturing of the object.

[0054] The control device of the manufacturing device for additively manufacturing an object according to the invention comprises the regulating device according to the invention. Alternatively or additionally, the control device is also designed to control the manufacturing device according to the method according to the invention.

[0055] The manufacturing device according to the invention is used for additive manufacturing of at least one object in an additive manufacturing process. In principle, manufacturing devices for additive manufacturing are known and include at least one irradiation device in order to solidify the building material layer by layer by irradiation with at least one energy beam. The manufacturing device according to the invention additionally includes a control device according to the invention.

[0056] The invention can be implemented in particular in the form of a computer unit with suitable software. The computer unit can, for example, have one or more cooperating microprocessors or similar devices for this purpose. In particular, it can be implemented in the form of suitable software program segments (Programmabschnitten) in the computer unit. The advantage of the implementation in the form of software is that even existing computer units can be simply transformed by software or firmware updates so that they work in the manner of the invention. In this regard, the task is also solved by a corresponding computer program product, which has a computer program that can be directly loaded into the storage device of the computer unit, and has a program segment so that when the program is executed in the computer unit, all steps of the method according to the invention are performed. In addition to the computer program, such a computer program product can include documentation and / or additional components, as well as hardware components such as hardware keys (dongles, etc.) for the use of the software.

[0057] For transmission to a computer unit and / or storage at or in a computer unit, a computer-readable medium can be used, such as a memory stick, a hard disk or other portable or permanently mounted data carrier, on which program sections of a computer program that can be read and executed by the computer unit are stored.

[0058] Other particularly advantageous designs and improvements of the invention are derived from the dependent claims and the following description, wherein claims of one claim category may also be improved similarly to claims and description parts of another claim category, and in particular, individual features of different embodiments or variants may also be combined into new embodiments or variants.

[0059] Preferably, the reference region and the correction region are shaped regions of different objects. Alternatively or additionally, the reference region and the correction region are located in the same object, wherein the reference regions of directly superimposed layers preferably do not overlap, so that the thermal data of the reference region are not distorted by the underlying uncorrected layers.

[0060] Preferably, in one embodiment of the method, a plurality of groups of shape regions are determined in different layers, and the method steps are performed for each group of shape regions. Preferably, a shape region group is determined in each of S superimposed layers, so that preferably there are a plurality of shape region stacks, which are formed by superimposed shape regions of different shape region groups. In the case of identical objects, the shape region stacks may be object layers, but may also be regions in the same object.

[0061] Preferably, in addition to the thermal data, other data can also be recorded during the curing of the reference area, in particular data on the gas flow or oxygen concentration.

[0062] As described above, it is feasible to determine other shaped regions (correction regions and / or reference regions) during or after curing a certain region, in particular based on the observed process progression (Prozessverlaufs). It can be advantageous here to perform corrections only when a process deviation or irregularity is recognized. For this purpose, it is preferred to first select a reference region from the determined shaped regions, cure it, record the thermal data, and compare it with the target thermal map. If the thermal data is within the determined range and consistent with the target thermal Figure 1 map, no correction is made, but the next shaped region is selected as the reference region. This process continues until the thermal data is no longer within the determined range, i.e., deviates from the target thermal map. Then, the subsequently cured shaped region can be corrected as the correction region. In particular, several shaped regions can be determined continuously, i.e., the next shaped region is determined after curing a reference region. If it is found during curing a region that a correction is required. Then similar (uncured) regions are searched for in the object to be cured, and these regions represent a group of shaped regions. The cured region is the reference region of this group of shaped regions.

[0063] Preferably, multiple shaped regions are selected from N objects in each group of shaped regions (group of shaped regions), in particular N stacks of shaped regions, and M reference regions are selected (alternately or in turn) from the selected shaped regions in each layer, where M < N. In these groups, M can be different, so there are basically M values (i = 1, 2,..., N) of N. i values (i = 1, 2,..., N).

[0064] Preferably, the selected shaped regions, in particular the stacks of shaped regions, correspond to an object layer of an object. Alternatively or additionally, an object is preferably divided into several stacks of shaped regions.

[0065] Preferably, for the current layer (i.e., in particular for multiple object layers located in this layer), multiple reference regions are selected from the shaped regions of this layer, and the thermal data of these reference regions is recorded. It is also possible to alternatively or additionally provide the thermal data of the reference regions of several layers below the current layer. Basically, even if the old thermal data is not from the current manufacturing process, it can be taken into account. However, it is preferred to always (at least partially) consider the thermal data in the current production process, because there may be systematic differences in the production process, for example due to different external factors. Then, a correction factor module is generated for the correction region of the current layer from the above thermal data and the relevant target thermal map.

[0066] That is, thermal data from different reference areas are used here. These thermal data can come from different reference areas of the same layer or from different layers. In this case, it is preferred to calculate a (preferably weighted) average value from these thermal data. Alternatively, it is preferred to first calculate a plurality of correction factor modules for different thermal data and then calculate an average value, preferably a weighted average value, from these correction factor modules.

[0067] Preferably, the target thermal map of the correction area may depend on the thermal data of the reference area. This may be the case, for example, if only a homogenization of the thermal distribution is to be achieved. It may then be possible, for example, to select a value of the thermal data, such as a minimum value, a maximum value or an average value, and the target thermal map may be this selected value or a predetermined value distribution based on this value.

[0068] According to a preferred embodiment of the method, a correction function f is used to obtain n reference regions RB. i Thermal data WD(RB i ) and the target heat map SW(KB) of the correction area KB determine the correction factor module KFM for the correction area KB according to: KFM(KB)=f(WD(RB 1 ),WD(RB 2 ),...WD(RB n ), SW(KB)). The correction factor module may be or include the correction function, or instructions for correction using the correction function. For ease of understanding, it is conceivable that the correction factor module is defined by the correction function. When generating the correction factor module, the correction function is preferably adjusted so that when the thermal data and the target thermal map under consideration are input into the correction function, a corresponding correction factor for the irradiation is obtained.

[0069] It is preferred that different correction functions f (i.e., therefore also different correction factor modules) are used for different correction areas (at different positions, e.g., in different rows of the build field). These correction functions can be completely position-dependent here. It is particularly advantageous to use different correction functions for different correction areas when different areas are corrected in different ways from each other. It is feasible that correction areas located at different positions of the build field are corrected in different ways due to their different positions on the build field. This can be related, for example, to the gas flow direction or gas distribution and / or temperature distribution and / or heat distribution or heat dissipation in the component. It is also feasible that different correction areas are located at different positions in an object layer (in this case, an object layer is divided into a plurality of correction areas), and different correction areas are corrected in different ways due to their different positions in the object layer. In this case, different correction functions f can be used for different correction areas, so that different correction factor modules are determined for different correction areas (i.e., different correction areas are corrected separately).

[0070] Therefore, it is preferred that different target thermal maps are assigned to the correction areas, in particular in different rows on the build field. Alternatively or additionally, different correction factor modules are used for these different correction areas. It is preferred that the assignment of the target thermal map to the correction areas and / or the use of the correction factor modules for the correction areas depends on the gas flow direction and / or the gas distribution and / or the temperature distribution of the environment and / or the heat distribution or heat dissipation in the object.

[0071] Alternatively or additionally, it is preferred that the correction function f additionally depends on the thermal data of a correction region, which correction region has been additionally (e.g. afterwards) determined as a reference region. It is feasible here to determine a correction factor module for the correction region based on the thermal data in the reference region and from the target thermal map of the correction region, and to cure the correction region according to the correction factor module. When curing the correction factor module, the thermal data can be recorded and can be used to determine the correction factor module for another correction region. This means that the correction region of another correction region is determined as a reference region.

[0072] Alternatively or additionally, it is preferred that the thermal data of different reference areas are weighted differently in the correction function. The weighting of the thermal data in the correction function can be performed by weighting factors, for example, weighting factors can be assigned to these thermal data according to the reference area of ​​the thermal data. The correction function can depend on these weighting factors and / or these thermal data or their values ​​can be corrected (multiplied) by weighting factors. It is feasible that weighting factors are assigned to thermal data in correction areas at different positions on the build field according to the position of the reference area corresponding to the thermal data on the build field. This can be related to the gas flow direction or gas distribution and / or temperature distribution and / or heat distribution or heat dissipation in the component, for example. It is also feasible to assign weighting factors to the thermal data according to the curing order of the reference area corresponding to the thermal data.

[0073] For example, it can be assumed that the reference region RB of the object 1 1 The correction area KB of the corresponding objects 2 and 3 (of the same shape and / or size) 2 and KB 3 In the simple case, the correction area KB 2 and KB 3 The correction factor module (KFM) may be the same and depends on the reference region RB 1 The thermal data (WD) in and a common target heat map (SW). The result is:

[0074] KFM(KB 2 )=KFM(KB 3 )=f(WD(RB 1 ),SW).

[0075] The common target heat map can be a unique value or a heat distribution. 2 and KB 3 There are different target heatmaps (SW(KB 2 ) and SW(KB 3 )), you may get different correction factor modules (KFM (KB 2 ) and KFM(KB 3 )):

[0076] KFM(KB 2 )=f(WD(RB 1 ),SW(KB 2 )) and KFM(KB 3 )=f(WD(RB 1 ),SW(KB 3 )).

[0077] It should be noted that there can be a position dependency with x,y (building field) as well as a position dependency with height z (ie layer). Thus, it may apply that:

[0078] f→f(x,y,z), WD→WD(x,y,z), SW→SW(x,y,z) and KBM→KBM(x,y,z).

[0079] Preferably, in one embodiment of the method, the shape areas of a group of shape areas are located in different layers, wherein in particular the reference areas of these shape areas are located in different layers, and a number of correction factor modules are generated for the correction areas of the current layer based on the thermal data of the reference areas of the same group of shape areas of the next layer. This opens up the possibility, for example, of positioning the objects at different heights, treating the lowest object as a test object, and collecting data about some object layers from the manufacture of these object layers before the manufacture of the remaining objects. For example, if there are three objects, each of which is offset by one object layer relative to one another, an object layer of the lowest object can be manufactured as a reference layer and the corresponding object layer of the second lowest object (which is a correction area and at the same time a reference area) can be cured with the corrected irradiation values. The other object layers of the two objects can now be cured, and in particular the influence of the correction on the subsequent object layers can be checked before the first object layer of the third object is corrected.

[0080] Preferably, several objects are arranged at different heights. It is further preferred that a correction factor module is generated for a reference region and / or a correction region depending on the height of the correction region. For example, the thermal balance of a layer directly on the build plate is different from that of a layer on a support structure or a powder layer. This can be taken into account by taking the height into account.

[0081] Preferably, the correction factor module is generated for the correction region according to the curing order of the correction region. Alternatively or additionally, the correction factor module is generated for the correction region according to the position of the correction region (such as the position (x, y, z) in the build chamber and / or the position relative to the direction of the gas flow). Alternatively or additionally, the correction factor module is generated for the correction region according to the support structure of the correction region (such as whether there is a support structure, the size / length of the support structure relative to the object). Alternatively or additionally, the correction factor module is generated for the correction region according to the time interval between two consecutive exposures of the relevant object.

[0082] According to a preferred embodiment of the method, the correction factor module is determined from thermal data in a plurality of reference areas or from other correction factor modules, preferably by averaging, which is preferably weighted.

[0083] For example, if the shape regions of objects 1 and 2 in one layer are reference regions RB 1 and RB 2 , and the corresponding shape area of ​​object 3 is the correction area KB 3 , then preferably, in the correction area KB 3 When generating the correction factor module (KFM), two reference regions RB 1 and RB 2 The hot data WD(RB 1 ) and WD(RB 2 ) are weighted differently. The correction factor module is the thermal data WD(RB 1 ) and WD(RB 2 ) and the corresponding weighting factor k 1 and k 2 The correction function of :

[0084] KFM(KB 3 )=f(k 1 ,k 2 ,WD(RB 1 ),WD(RB 2 ),SW).

[0085] In particular, the correction factor module can be a correction function of the weighted average of the thermal data:

[0086] KFM(KB 3 )=f((k 1 WD(RB 1 )+k 2 WD(RB 2 )) / (k 1 -k 2 ),SW).

[0087] In one example, k 2 Can be greater than k 1 , because in the curing correction area KB 3 When the environmental conditions (such as temperature conditions) are related to the curing reference area RB 2 It is also possible to use the reference area RB 1 The correction factor module is generated for the region of object 2 in the layer using the thermal data in RB, and the thermal data in the same region is recorded simultaneously when object 2 is cured. Therefore, this region of object 2 may be both a correction region and a reference region. In this case, the thermal data in this correction / reference region of object 2 is not as good as that in the reference region RB of object 1. 1 The thermal data in RB are more meaningful because the corrected process values ​​were used when solidifying the shape area of ​​object 2, for which reason the reference area RB 1The hot data in the larger weight (i.e., k 1 Greater than k 2 ).

[0088] It is also possible to first determine the correction factor module for the correction area separately from the thermal data of the reference area and then average them. For the previous example, this could be, for example:

[0089] KFM1(KB 3 )=f(WD(RB 1 ),SW) and KFM2(KB 3 )=f(WD(RB 2 ),SW)

[0090] KFM1(KB 3 )=(k 1 ·KFM1(KB 3 )+k 2 ·KFM1(KB 3 )) / (k 1 +k 2 ).

[0091] It is further possible to take into account changes in the order in the layers when generating the correction factor module. As mentioned above, it is possible to change the exposure order in the layers and to select a region of a different object in each layer as a reference region.

[0092] Taking into account the change in sequence may also mean that the correction factors (or the corrected irradiance values) of the correction factor module depend on the time interval between two consecutive exposures of the same object (in particular two consecutive object layers of the same object).

[0093] For example, consider two layers A and B of three objects, in each of which a shape region group is determined, wherein the shape regions of the two groups are superimposed object layers. 1A is the correction area KB in the lower layer A 2A and KB 3A In the next layer B, the shape area of ​​object 2 is selected, which is located at KB 2A As the correction area KB for the other two objects 1B and KB 3B Reference area RB 2B , which are also located above the above areas. The curing sequence may be: RB 1A KB 2A KB 3A , apply a new layer of build material, RB 2B KB 3B and KB 1B .

[0094] Therefore, in KB 3A With KB 3B There is an exposure interval (RB 2B exposure time) plus the coating interval, and at RB 1A With KB 1B There are four exposure intervals (KB) between the exposures. 2A KB 3A , RB 2B and KB 3B exposure time) plus the coating interval. At the respective curing time points, KB 3B The temperature is higher than KB 1B , because KB 1B Is in KB 3B The exposure was made after a time interval about four times longer. 1B RB below 1A KB 3B KB below 3A Maybe it could dissipate more heat.

[0095] Therefore, in this case, the correction factor module is preferably generated in such a way that the time elapsed for the solidification of the relevant underlying object layer is additionally taken into account for the correction area. This may have an impact on the irradiation intensity and / or the scanning speed. Therefore, in the above example, the correction factor module is generated in such a way that the resulting KB 3B The corrected irradiation value of KB has a smaller irradiation intensity and / or a higher scanning speed than the corrected irradiation value of the correction factor module without considering the irradiation sequence. 1B The corrected irradiance value is compared with KB 3B The corrected irradiation value of the correction factor module has a greater irradiation intensity and / or a lower scanning speed. In this way, it is possible to compensate for thermal effects that occur due to the irradiation sequence.

[0096] In one example of a further preferred embodiment, the height of the object layer or its surroundings is taken into account. For example, if three reference areas are compared, one of which is directly located on the building platform, another is located on a support structure or an uncured powder layer and a third is located on a cured layer, it is possible to select or take into account by a weighting factor the data of the reference area for the correction factor module of the correction area, the environment of which is most similar to the environment of the correction area. For example, if the correction area is located on a support structure, it is possible to preferably select the second reference area.

[0097] In an example of a further preferred embodiment, the position in the build chamber is particularly taken into account. Certain properties of an object, such as its porosity, can depend on its position in the build chamber or its position relative to the gas flow direction. Preferably, two or more reference areas are selected at different positions, wherein these positions have systematic differences in the expected thermal data, in particular at the positions where the expected thermal data differences are the largest. This is, for example, the first and last build row, or the object closest to the gas inlet and the object farthest from the gas inlet. The correction factor module is then preferably determined from the weights of the thermal data of the reference areas, wherein the weights depend on the position of the relevant correction area relative to the reference areas. Here, the respective next reference area particularly receives the highest weight.

[0098] Preferably, when curing a correction area (i.e. directly after or during curing), the correction area is selected as a reference area to generate a correction factor module, the thermal data of this reference area is recorded, and these thermal data are used to generate several correction factor modules for curing other correction areas. In this way, iterative correction can be achieved. Since the corrected irradiation parameters are used to cure the correction area, the thermal data of the correction area can serve as a measure of the correction quality, and these thermal data are used to create improved correction factor modules. Therefore, the relevant correction area is also a reference area at the same time.

[0099] It is possible that within a shape region there is a special region which must be corrected systematically differently than other regions of the shape region (“normal regions”). This can be, for example, an edge at which the thermal data are distorted, i.e. the edge in the grayscale image passes precisely through pixels whose grayscale values ​​are systematically distorted here by the cooler surrounding material.

[0100] For this purpose, it is preferred to generate a correction factor module based on different correction functions. For example, a correction function F can be applied to the inner area of ​​an object and another correction function g can be applied to its edge. Preferably, the correction factor module is generated according to the following steps:

[0101] - dividing the correction areas into normal areas, in which the thermal data are within a predetermined value range around the value of the target temperature map at the corresponding position, and special areas, in which the thermal data are outside this value range;

[0102] The correction factor module is generated such that a first correction function is used for the normal regions and a second correction function is used for the special regions, wherein the first correction function and the second correction function are different from each other.

[0103] "Several correction regions" shall include the correction regions to which the correction factor module shall be applied. However, since these correction regions are all shape regions (ie all identical or at least similar), it is also possible to use basically any shape region for this purpose.

[0104] The division of the correction area can take place in such a way that it is basically determined where the correction is normal (normal area) and where the correction is not normal. Special areas can now strictly be any areas where the thermal data lies outside the value range. However, in order to compensate for outliers in the data, it is also possible to determine in advance "potential special areas" which completely become special areas if most of their area lies outside the value range. Potential special areas can be edge areas, closed areas with less than a predetermined area or structures with acute angles less than a predetermined degree.

[0105] The correction factor module can then be generated, for example, in such a way that for the normal area the correction function f of the correction factor module of the reference area from which the thermal data originate (the reference area being the correction area before curing) is used. It is possible to determine the correction function g for a specific area individually, in particular by modifying other correction functions f.

[0106] For the correction area corrected using the correction factor module, the standard area is then corrected based on the corresponding correction function f, and the special area is corrected based on the corresponding correction function g. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] The present invention will be described in more detail again below by way of example in conjunction with the accompanying drawings. In this regard, identical components are provided with identical reference numerals in different drawings. These drawings are generally not drawn to scale. The accompanying drawings show:

[0108] Figure 1 A schematic, partially sectional view of an exemplary embodiment of a device for additive manufacturing is shown;

[0109] Figure 2 The arrangement of objects in the layer is shown by a top view;

[0110] Figure 3 Three layers are shown with an object layer, a reference region, and a correction region;

[0111] Figure 4 A shape region within an object is shown with a variable reference region R;

[0112] Figure 5 The top view shows the arrangement of the objects and the changes of the reference area within an object and, if necessary, also between objects;

[0113] Figure 6 A block diagram of the method as a conditioning method and alternatively as a training method is shown;

[0114] Figure 7 Reference and correction regions are shown in the object at different locations. DETAILED DESCRIPTION

[0115] The following embodiments will be described with reference to a device 1 for additively manufacturing a component in the form of a selective laser sintering device or a laser melting device, wherein it is once again explicitly pointed out that the present invention is not limited to selective laser sintering devices or laser melting devices. Therefore, without limiting its generality, the device is referred to as a "manufacturing device" 1 in the following text.

[0116] Figure 1 Such a manufacturing device 1 is schematically shown. The device has a processing chamber 3 or a processing chamber 3 with a chamber wall 4, in which the manufacturing process is basically carried out. In the processing chamber 3, there is a container 5 open to the top with a container wall 6. The top opening of the container 5 forms a corresponding current working plane 7. The area of ​​this working plane 7 located within the opening of the container 5 can be used to build the object 2 and is therefore called a building field 8.

[0117] The container 5 has a base plate 11 which is movable in a vertical direction V and which is arranged on a carrier 10. The base plate 11 closes the container 5 downwards and thus forms its bottom. The base plate 11 can be formed integrally with the carrier 10, but it can also be a plate formed separately from the carrier 10 and can be fixed to the carrier 10 or simply supported thereon. Depending on the specific building material (i.e., for example, the powder used) and the type of manufacturing process, a building platform 12 can be mounted on the base plate 11 as a building base, on which the object 2 is built. In principle, however, the object 2 can also be built on the base plate 11 itself, which then constitutes the building base.

[0118] The basic construction of object 2 is carried out as follows, namely first a layer of building material 13 is applied to building platform 12; then, as explained below, a laser beam 22 is used as an energy beam to selectively cure building material 13 at points that should form parts of object 2 to be manufactured; then substrate 11 is lowered with the aid of carrier 10, thereby lowering building platform 12, and a new layer of building material 13 is applied and selectively cured, and so on. Figure 1An object 2 built in a container on a building platform 12 is shown in an intermediate state, below a working plane 7. The object already has a plurality of cured layers, which are surrounded by a still uncured building material 13. Various materials can be used as building material 13, preferably powders, in particular metal powders, plastic powders, ceramic powders, sand, filled or mixed powders, or also pasty materials, and optionally mixtures of a plurality of materials.

[0119] Fresh building material 15 is located in a storage container 14 of the production device 1. By means of a coater 16 movable in a horizontal direction H, the building material can be applied in the form of a thin layer in the working plane 7 or in the building field 8.

[0120] Optionally, an additional radiation heating device 17 is provided in the process chamber 3. This radiation heating device can be used, for example, to heat the applied building material 13 so that the irradiation device for selective curing does not need to introduce too much energy. This means that, for example, with the aid of the radiation heating device 17, a certain amount of basic energy can already be introduced into the building material 13, which of course is still lower than the energy required to melt or sinter the building material 13. For example, infrared radiators or VCSEL radiators can be used as radiation heating devices 17.

[0121] In order to perform selective curing, the manufacturing device 1 has an irradiation device 20, or more precisely, an irradiation device 20 with a laser 21. The laser 21 generates a laser beam 22, which is deflected via a deflection device 23 so as to scan the corresponding layer to be selectively cured along an irradiation path or trajectory set according to the irradiation strategy and selectively introduce energy. Further, the laser beam 22 is focused onto the working plane 7 in a suitable manner by a focusing device 24. Here, the irradiation device 20 is preferably located outside the processing chamber 3, and the laser beam 22 is guided into the processing chamber 3 via a coupling window 25 installed in the chamber wall 4 at the top of the processing chamber 3.

[0122] For example, the irradiation device 20 may include not one but a plurality of lasers. Preferably, it may be a gas laser or a solid laser or any other type of laser, such as a laser diode, in particular a VCSEL (Vertical Cavity Surface Emitting Laser) or a VECSEL (Vertical External Cavity Surface Emitting Laser) or a series of these lasers. Particularly preferably, within the scope of the present invention, one or more non-polarized single-mode lasers may be used, such as a 3kW fiber laser with a wavelength of 1070nm.

[0123] The manufacturing is monitored with a sensor assembly 18. The sensor assembly may, for example, comprise a radiation sensor (such as a thermal imaging camera) and measure spatially resolved thermal data of several areas (reference areas) of the component layer B.

[0124] The control device 30 is used to control the units of the production device 1 and comprises a control unit 29 which actuates the components of the irradiation device 20 , namely here the laser 21 , the deflection device 23 and the focusing device 24 , and transmits corresponding control data PS to these components.

[0125] The control unit 29 also controls the radiation heating device 17 by means of suitable heating control data HS, controls the coater 16 by means of coating control data ST, and controls the movement of the carrier 10 by means of carrier control data TS, thereby controlling the layer thickness.

[0126] The control device 30 can be connected to a terminal 40 with a display etc. via a bus 60 or another data connection, for example. Via the terminal 40, an operator can control the control device 30 and thus the entire laser sintering device 1, for example, by transmitting process control data PS.

[0127] The control device 30 comprises a regulating device 31 according to the invention for regulating the irradiation. The regulating device 31 comprises a presetting unit 32 , a sensor unit 18 , a correction module unit 33 and a control data unit 34 .

[0128] The presetting unit 32 is designed to pre-set some areas or target values ​​required for correction. Everything can be fixedly pre-set at the beginning of the method, but it can also be additionally pre-set during the method. The pre-setting unit has the following tasks:

[0129] - determining a plurality of shape areas corresponding to one another in shape and / or size in the object layer O to be solidified,

[0130] - selecting a number of reference regions R from the plurality of shape regions, wherein the remaining shape regions are defined as correction regions K, and

[0131] - Determination of several target thermal maps S which set the desired thermal distribution of the correction region K or several groups of correction regions K.

[0132] The sensor unit 18 is designed to record spatially resolved thermal data W of the reference regions R during the curing. It can record them in the form of a film or a number of images, for example, during the curing of the component layer. The thermal data of the respective just-cured partial regions can then be summarized from these individual images.

[0133] The correction module unit 33 is used to generate several correction factor modules F for the correction area K from the thermal data W and the target thermal map S, wherein each correction factor module F specifies a spatially resolved correction factor for the irradiance value or a spatially resolved corrected irradiance value, and each correction area K is assigned a correction factor module F.

[0134] The control data unit 34 is used to generate and output control data for curing at least the correction region K based on the correction factor modules F respectively assigned to the correction region.

[0135] It should also be pointed out here again that the present invention is not limited to such a manufacturing device 1. It can be applied to other methods for generating or additively manufacturing three-dimensional objects by layer-by-layer coating and selective curing of building materials, wherein an energy beam for curing is emitted to the building material to be cured. Therefore, the irradiation device can not only be a laser (as described herein), but it is also possible to use any device that can selectively apply energy in the form of wave radiation or particle radiation to or into the building material. For example, it is possible to use other light sources, electron beams, etc. instead of lasers.

[0136] even though Figure 1 Only a single object 2 is shown in the figure, preferably, a plurality of objects are produced simultaneously in the processing chamber 3 or container 5. To this end, the building material is scanned layer by layer by the energy beam 22 at locations corresponding to the cross-section of the object in each layer.

[0137] Figure 2 The arrangement of the objects 2 in the layers on the build field 8 is shown in a top view. A total of 16 identical objects 2 are manufactured. In the layer S1 shown on the left, 16 identical shape areas can be seen. The shape area of ​​the object 2 in the lower right corner is selected here as the reference area R, which has been cured. The shaded part is intended to represent the thermal distribution, which is recorded in the form of thermal data W. The remaining shape areas are correction areas, and their irradiation is corrected using these thermal data.

[0138] In the layer S2 shown on the right, the reference region R is located in the object 2 above the object 2 of the layer S1 on the left. In this way, the layer is solidified on the already corrected and therefore thermally adjusted layer, so that the thermal distortion is smaller than if only the object 2 in the lower right corner was used as a reference.

[0139] Figure 3 Three layers are shown with an object layer O, a reference region R and a correction region K. Here, the reference region is located in the bottom row and, starting from the bottom left, the reference region of each layer S1, S2, S3 is shifted one position to the right. The purpose here is to show the thermal distortion of the object layer O due to the wrong heat input.

[0140] In the left layer, the reference region R is not irradiated correctly, for example the temperature is too high, which can possibly be corrected in the correction region K. In the next layer S2 (middle layer), there is excess heat intrusion from the lower layer S1 into the now solidified object layer O in the lower left corner (indicated by thin shading). It may therefore be sensible to select another reference region R, i.e., for example next to it on the right.

[0141] In the right image, there is still a small thermal irritation in the lower left corner. Therefore, a reference region R in another object (next to its right) is selected. In theory, in the next layer, it might be possible to select a reference region from the lower left object 2 again, so that one ends up with three "sacrificial objects" and the rest of the objects are made in the most optimal way.

[0142] Figure 4 The shape regions within an object 2 are shown with varying reference regions R. A symmetrical object 2 is shown here with four identical shape regions. The dashed cross in the middle is only for visual separation of the shape regions. Figure 3 The difference is that it is now possible to select different shape regions of the same object 2 as reference regions R in each layer. Figure 3 As suggested, we restart after three layers, so the downward arrow shape will never be a reference region. But in practice, it is reasonable to choose a reference region R in turn.

[0143] Figure 5 The top view shows the arrangement of the objects and the variation of the reference area within an object 2 and, if necessary, also between objects 2 . Figure 4 The shape of is produced four times here, wherein the reference region R is always changing. The right figure shows that the reference region R does not have to be selected in the same object O.

[0144] Figure 6 A block diagram of a method as a regulating method and alternatively as a training method is shown.

[0145] In step I, the reference regions R are cured and spatially resolved thermal data W of the reference regions are recorded as they are cured (ie after or during curing). The thermal data W can be represented here, for example, as a grayscale image.

[0146] In step II, a target thermal map S is determined, which is intended to apply to all shape regions of the object O. The target thermal map defines the ideal thermal distribution of the correction region K.

[0147] In step III, a correction factor module F is generated for the correction region K from the thermal data W and the target thermal map S. The correction factor module F specifies spatially resolved correction factors for the irradiance values ​​and is assigned to each correction region K.

[0148] Now, the method is divided into two possible links.

[0149] In step IV, the correction region K of the further object 2 is corrected based on the correction factor module F so that its quality is optimized.

[0150] In an alternative process, in step V, the machine learning model M is trained with the thermal data, the target thermal map and the correction factor model F. In this case, the thermal data W of the correction regions produced in step IV can also be taken in (these correction regions may then additionally be reference regions R).

[0151] In step IV, the correction region K of the other object 2 is corrected based on the thermal data and the trained model M, thereby optimizing its quality.

[0152] Figure 7 Reference areas R and correction areas K are shown in an object 2 at different positions. An object 2 is shown on the left, in which the reference area R (lower) is located on the building platform 12. The downward heat dissipation here is very good, and the thermal data of this reference area R may not be representative for other areas. In this object 2, a reference area R (upper) located on the solidified area is also shown. The middle component 2 has a shape area that is a reference area R and also a correction area K. The relevant object layer O is located on a spacer (Abstandshaltern). If this structure is compared with the object next to it on the left, it may be possible to use the upper reference area R there for correction. It may be best to use the reference area R of the middle object O for correcting the correction area K of the object 2 on the right, because the structure with the spacer corresponds.

[0153] It may also be feasible to take all reference regions R into consideration for the correction of the correction region K, wherein the thermal data of the reference regions or the weights of the correction factor modules based on them are weighted differently, and wherein preferably the thermal data or the correction factor module of the reference region R of the middle object O is assigned a greater weight than the thermal data or the correction factor modules of other reference regions.

[0154] Finally, it is pointed out again that the invention described in detail above is only an embodiment, and those skilled in the art can modify it in various ways without departing from the scope of the invention. In addition, the use of the indefinite article "a" or "an" does not exclude the possibility that there may be multiple related features. Similarly, the term "unit" does not exclude that it is composed of several subcomponents that act together, and these subcomponents may also be spatially dispersed when necessary. The term "several" should be understood as "at least one". Regardless of the grammatical gender of a particular term, both male and female are included.

[0155] Reference numerals list

[0156] 1 Manufacturing equipment / Laser sintering equipment

[0157] 2 Objects

[0158] 3 Processing room / processing cavity

[0159] 4 Cavity wall

[0160] 5. Container

[0161] 6 container wall

[0162] 7 Work Plane

[0163] 8. Build the Field

[0164] 10 Carrier

[0165] 11 base plate

[0166] 12 Build Platform

[0167] 13 building materials (in container 5)

[0168] 14 Storage Containers

[0169] 15 Construction Materials (in storage container 14)

[0170] 16 Coating Machine

[0171] 17 Radiant heating device

[0172] 18 Sensor unit

[0173] 20 Irradiation device

[0174] 21 Laser

[0175] 22 Laser Beam

[0176] 23 Deflector / Scanner

[0177] 24 Focusing Equipment

[0178] 25 Coupling window

[0179] 29 Control Unit

[0180] 30 Control Equipment

[0181] 31 Adjustment device

[0182] 32 scheduled units

[0183] 33 Correction module unit

[0184] 34 Control Data Unit

[0185] 40 Terminal

[0186] 60 Bus

[0187] F Correction Factor Module

[0188] H Horizontal direction

[0189] HS Heating Control Data

[0190] K Correction Area

[0191] KD Processing Room Control Dataset

[0192] M Machine Learning Model

[0193] O Object Layer

[0194] PS Process Control Data

[0195] R Reference area

[0196] S Target Heatmap

[0197] S1, S2, S3 layers

[0198] SD Processing Room Sensor Dataset

[0199] ST coating control data

[0200] TS Carrier Control Data

[0201] V vertical direction

[0202] W Thermal data.

Claims

1. A method for regulating irradiation in a manufacturing process for additively manufacturing an object (2), wherein: By irradiating the building material, the building material is solidified layer by layer in the building field (8) in the form of an object layer (O), the object layer (O) corresponding to the cross section of the object (2) to be manufactured, the method comprising the following steps: - determining a plurality of shape regions corresponding to one another in shape and / or size in the object layer (O) to be solidified, - selecting a number of reference areas (R) from a plurality of said shape areas, wherein at least the remaining shape areas are defined as correction areas (K), - determining a number of target thermal maps (S) which define the desired thermal distribution of the calibration zone (K) or of a number of groups of calibration zones (K), - curing the selected reference regions (R) and recording spatially resolved thermal data (W) of the reference regions (R) as they cure, - generating a number of correction factor modules (F) for the correction area (K) from the thermal data (W) and the target thermal map (S), wherein each correction factor module (F) specifies a spatially resolved correction factor for an irradiance value or a spatially resolved corrected irradiance value, and one correction factor module (F) is assigned to each correction area (K), - solidifying at least said correction area (K) based on said correction factor modules (F) respectively assigned to said correction area (K).

2. The method according to claim 1 , wherein a plurality of groups of shape regions are determined in different layers (S1, S2, S3) and the method steps are performed for each group of shape regions, preferably wherein a group of shape regions is determined in each of S superimposed layers (S1, S2, S3) so that there are a plurality of shape region stacks formed by superimposed shape regions of different shape region groups, Preferably, a plurality of shape regions in N objects (2) are selected from each group of shape regions, in particular N shape region stacks, and M reference regions (R) are selected from the selected shape regions in each layer (S1, S2, S3), wherein M <N, Preferably, the selected shape regions, in particular the shape region stacks, correspond to object layers (O) of an object (2), and / or an object (2) is divided into a plurality of shape region stacks.

3. A method according to any one of the preceding claims, wherein for a current layer (S1, S2, S3), a plurality of reference regions (R) are selected from the shape region of the layer (S1, S2, S3), and thermal data (W) of the reference regions (R) are recorded, and / or thermal data (W) of reference regions (R) of several layers (S1, S2, S3) below the current layer (S1, S2, S3) are provided, and a correction factor module (F) is generated for the correction region (K) of the current layer (S1, S2, S3) from the thermal data (W) and the associated target thermal map (S), Preferably, for this purpose, an average value, preferably a weighted average value, is calculated from the thermal data (W), or a plurality of correction factor modules (F) are first calculated for different thermal data (W) and then an average value, preferably a weighted average value, is calculated from the correction factor modules (F).

4. The method according to claim 1 , wherein the correction function f is used to obtain n reference regions (R) RB i Thermal data (W) WD (RB i ) and the target heat map (S) SW (KB) of the correction area (K) KB determine the correction factor module (F) KFM for the correction area (K) KB according to: KFM (KB) = f (WD (RB1), WD (RB2), ... WD (RB n ),SW(KB)), Preferably, wherein - using different correction functions f for different correction areas (K), and / or the correction function f additionally depends on the thermal data of a correction region (K) which has additionally been determined as a reference region (R), and / or - said thermal data (W) of different reference regions (R) are weighted differently in the correction function.

5. The method according to any of the preceding claims, wherein shape areas of a group of shape areas are located in different layers (S1, S2, S3), wherein in particular reference areas (R) of the shape areas are located in different layers (S1, S2, S3), and a number of correction factor modules (F) are generated for the correction area (K) of the current layer (S1, S2, S3) based on thermal data (W) of reference areas (R) of the same group of shape areas of the lower layer (S1, S2, S3), Preferably, the plurality of objects (2) are arranged at different heights, preferably, a correction factor module (F) is generated for the correction region (K) according to the height of the reference region (R) and / or the correction region (K).

6. The method according to any of the preceding claims, wherein the correction factor module (F) is generated for the correction area (K) according to the following factors: - the sequence of curing of the correction zones (K), and / or - the position of said correction zone (K), and / or - a supporting structure of said correction zone (K), and / or - The time interval between two consecutive exposures of the object of interest.

7. The method according to any of the preceding claims, wherein the correction factor module (F) is determined from other correction factor modules (F), preferably by averaging, the averaging preferably being weighted.

8. A method according to any one of the preceding claims, wherein when curing a correction region (K), the correction region (F) is selected as a reference region to generate a correction factor module (F), thermal data (W) of the reference region (R) is recorded and the thermal data (W) is used to generate several correction factor modules (F) to cure other correction regions (K).

9. The method according to claim 1 , wherein different target heat maps (S) are assigned to the correction regions (K), in particular in different rows on the build field (8), and / or wherein different correction factor modules (F) are used for the correction regions (K), Preferably, the assignment of the target thermal map (S) to the correction area (K) and / or the use of the correction factor module (F) for the correction area (K) depends on the gas flow direction and / or the gas distribution and / or the temperature distribution of the environment and / or the heat distribution or heat dissipation in the object.

10. The method according to any of the preceding claims, wherein the correction factor module (F) is generated based on different correction functions and based on thermal data (W) of a reference region (R), the reference region being a cured correction region (K), wherein the correction factor module (F) is preferably generated according to the following steps: - dividing a plurality of calibration areas (K) into a plurality of normal areas and a plurality of special areas, wherein in the normal areas, the thermal data (W) is located within a set value range around a value of the target thermal map (S) at a corresponding position, and in the special areas, the thermal data (W) is located outside the value range, - the correction factor module (F) is generated in such a way that a first correction function is used for the normal regions and a second correction function is used for the special regions, wherein the first correction function and the second correction function are different from each other.

11. A device (31) for regulating irradiation in a manufacturing process for additively manufacturing an object (2), wherein by irradiating a building material, the building material is solidified layer by layer in a building field (8) in the form of an object layer (O), the object layer (O) corresponding to a cross section of the object (2) to be manufactured, the device (31) comprising: - a predetermined unit (32) designed for i) determining a plurality of shape areas corresponding to one another in shape and / or size in the object layer (O) to be solidified, ii) selecting a number of reference regions (R) from the plurality of said shape regions, wherein the remaining shape regions are defined as correction regions (K), iii) determining a number of target thermal maps (S) which define a desired thermal distribution of a calibration region (K) or a number of groups of calibration regions (K), - a sensor unit (18) designed to record spatially resolved thermal data (W) of said several reference regions (R) during their curing, a correction module unit (33) designed to generate a number of correction factor modules (F) for the correction area (K) from the thermal data (W) and the target thermal map (S), wherein each correction factor module (F) specifies a spatially resolved correction factor for an irradiance value or a spatially resolved corrected irradiance value, and one correction factor module (F) is assigned to each correction area (K), A control data unit (34) designed to generate and output control data for solidifying at least the correction region (K) based on the correction factor modules (F) respectively assigned to the correction region (K).

12. The regulating device (31) according to claim 11 comprises a machine learning model (M), which has been trained according to the method according to claim 10.

13. A control device (30) for a manufacturing apparatus (1) for additively manufacturing an object (2), wherein the control device (30) comprises an adjustment device (31) according to claim 11 or 12, and / or is configured to control the manufacturing apparatus (1) according to a method according to any one of claims 1 to 10.

14. A manufacturing device (1) for additively manufacturing at least one object (2) in an additive manufacturing process, comprising at least: - irradiation means for curing the building material layer by layer by irradiation with at least one energy beam, and - A control device (30) according to claim 13.

15. A computer program product comprising instructions, which, when a computer executes the program, cause the computer to perform the steps of the method according to any one of claims 1 to 10.

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