WO2024032919A1

WO2024032919A1 - Device and method for calibrating a production system based on optical interaction

Info

Publication number: WO2024032919A1
Application number: PCT/EP2022/083435
Authority: WO
Inventors: Andreas Redler
Original assignee: Dmg Mori Additive Gmbh
Priority date: 2022-08-09
Filing date: 2022-11-28
Publication date: 2024-02-15
Also published as: DE102022120064A1

Abstract

The present invention relates to a method and a device for calibrating a production system (1) based on optical interaction, in particular a production system for selective laser melting (SLM), in which, by means of a conversion body (29) integrated into the production system (1), a processing light beam (14') of the production system (1) can be absorbed and converted into a detectable and preferably visible calibration light (32). The present invention also relates to a method and a device which, by selectively displacing the processing light beam (14') along said conversion body (29) and subsequently detecting the thus generated calibration light (32), allow a specific adaptation of the device elements required for moving the processing light beam (14').

Description

Device and method for calibrating a manufacturing system based on optical interaction

The present invention relates to a method and a device for calibrating a manufacturing system based on optical interaction, in particular a manufacturing system for selective laser melting (SLM), in which a processing light beam from the manufacturing system is absorbed by means of conversion material and converted into a detectable and preferably visible calibration light can be converted. In addition, the present invention relates to a method and a device which enables calibration of the production system by selectively moving the processing light beam along the conversion material and detecting the calibration light generated in this way.

Background of the invention

Due to increasingly complex work processes and the resulting requirement to be able to produce as precisely, automatically and on a large scale as possible, the production and processing of workpieces based on optical interaction processes has become established.

Manufacturing systems known from the prior art and based on optical interaction (optical manufacturing systems), such as laser-induced and/or manufacturing systems based on additive manufacturing steps, such as selective laser melting, usually include one or more high-performance systems operating in the infrared range. Intensity light sources, which are coupled to a plurality of finely adjusted optical elements (lenses, mirrors, filters, etc.) that can be controlled automatically via a computer system and thus make it possible to plastically impact a workpiece or workpiece by generating a compressed processing light beam focused on a specific production point a material to take effect. By way of example, a manufacturing system using the selective laser melting process has at least one laser light source, which can use software-supported optics to focus a bundled laser beam onto powdery layers of materials to be processed and thus create an extremely effective, three-dimensional manufacturing process through local, layer-by-layer fusions.

Despite constant further development of such manufacturing systems, the problem still occurs in most such systems that, due to different external and internal influences, such as thermal expansion or mechanical displacements of individual manufacturing components contained in the manufacturing system, the light path of the processing light beam is particularly independent of any settings of the optical elements can be changed, which can sometimes result in noticeable deviations between the target position of the processing light beam to be controlled and an actual position that is actually present. Accordingly, it is critical for existing optical manufacturing systems to produce the most precise possible analysis of existing light path deviations and, if necessary, a correction of the above-mentioned position discrepancies, which is able to both identify any changes in the light beam being processed and to correct the resulting misalignment of the light path .

As a reference for such a calibration method, for example, US 2021 016394 A1 describes the use of a so-called scanning field plate, on which a predefined geometric pattern is melted and analyzed using an external measuring machine to determine any light beam misses. In addition, the above-mentioned method provides, in addition to the pattern generation, to apply a series of measurement coordinates to the scanning field plate and to include said positioning of the measurement coordinates together with the analysis results of the previously described melt pattern in a calibration data set used to readjust optical elements. Although the previously used methods from the prior art were able to prove themselves due to sufficient accuracy for recalibrating the previously described elements, the use of these methods, in particular the use of scanning field plates, has always been characterized by a number of failures underestimated disadvantages: For example, the plastic deformations of the respective calibration element that are usually required for calibration require a constant exchange of calibration materials to be used, so that the methods according to the prior art are usually associated with high material costs. In addition, locating the point of impact of the processing light beam, which is usually in the micrometer range, forces a generally long-lasting analysis process, which can only be carried out by externally stored devices specially designed for this purpose and thus equally prevents an automated adjustment mechanism that can be carried out specifically within the production machine.

In this respect, it is an object of the present invention to provide, in particular, a calibration method and a device for identifying and adjusting any light path misalignments, which can overcome the previously described shortcomings of the prior art and primarily enable a more material-saving and therefore more cost-effective adaptation of the manufacturing system based on optical interaction. In addition, it is an object of the present invention to carry out such identification and adjustment steps equally automatically and in particular within the corresponding manufacturing system to be calibrated, so that a much more efficient, more precise and, among other things, accelerated correction of the latter can be made possible. Detailed description of the invention

To solve the above-mentioned problem, the features of the independent claims are suggested. The dependent claims relate to preferred embodiments of the present invention.

The claimed method and the claimed device for calibrating the optical manufacturing system can at least, in a first aspect of the present invention, include the use and provision of a light-converting medium, hereinafter referred to as a “conversion body”, which is preferably used for calibrating one in one processing light beam used in an optical production system, can be introduced into a respective production system and set up to absorb the light of the processing light beam (in particular a bundled light beam with an infrared wavelength and thus an invisible laser) by hitting certain points on the conversion body and for subsequent identification. and adjustment processes to convert or emit a detectable and preferably visible light. Contrary to the prior art, the basis of the present invention thus forms a calibration process which is preferably based on the conversion of the processing light beam into a detectable light signal, which means that neither plastic deformations/destructions on a calibration material nor any externally stored ones are observed for the analysis of any light path deviations within a production system to be corrected Measuring machines are required. Accordingly, the present invention can be used in particular to carry out the calibration of the corresponding light path within the production facility without the necessary exchange of calibration elements, so that material costs are saved as well as a calibration process that can be carried out exclusively within the production facility (ie competent in situ) and is enabled to be automated can be. According to the invention, through the use of suitable sensors within the manufacturing machine in combination with a conversion material arranged in a predetermined pattern on a carrier material or substrate, the position of the laser beam (light beam) can be directly detected and evaluated as soon as the beam passes over the conversion medium emotional. This type of position detection also applies advantageously to rays that strike at an angle of inclination.

For this purpose, a calibration method according to the present invention may comprise at least one of the following steps:

1) positioning the conversion body at a calibration position within a manufacturing system based on optical interactions;

2) Moving the processing light beam on the conversion body;

3) detecting a detectable calibration light signal emitted by the conversion body;

4) determining a current position (actual position) of the processing light beam by analyzing the captured calibration light signal;

5) Comparing the determined actual position with a reference position (target position) of the processing light beam predefined within the production system; and

6) Calibrate the optical manufacturing system based on the differences determined between the compared actual position and the target position.

As already mentioned, the calibration method described above is preferably designed to be carried out completely within the production system to be adjusted, so that any changes caused by the exchange Waiting times that arise or relocating calibration materials can be effectively avoided. The claimed method is generally not limited to a specific type of manufacturing system, but can preferably be used for any type of manufacturing system based on optical interactions. In this respect, the method claimed herein can initially be used preferably for any production system which is at least capable of plastically acting on a predefined workpiece or a material required to generate the workpiece by focusing a light beam generated within the corresponding production system and thus on an at least two-dimensional body to create.

In a particularly preferred exemplary embodiment, the optical manufacturing system applicable to the method can also comprise for this purpose at least one radiation source set up to generate the light beam, such as a laser or high-energy diodes, which are used to focus the generated light beam on the corresponding material, optically can be coupled with a series of selectively adjustable optical elements, such as (converging or scattering) lenses, mirrors or filters, and thus enables the production system to target and focus the light generated at least along a predefined working plane located within the production system procedure. In a further preferred exemplary embodiment, the latter working plane can preferably also be positioned within an installation space that is decoupled from the location of the optical elements and is preferably set up for the production of the respective workpiece, for example a process chamber arranged in the production system, so that the optical elements themselves during the production process can be effectively protected against any emissions (e.g. smoke, dust, sparks, etc.). In this respect, it should be emphasized that even manufacturing systems for additive manufacturing, such as 3D printers or SLM systems based on optical interactions, can preferably be effectively calibrated using the above-mentioned method. The claimed method itself can preferably be started with an initial initiation phase in which, in a preferred exemplary embodiment of the present invention, particularly required system settings and/or calibration elements are adjusted into the production system to be adjusted and the subsequent calibration can thus be prepared as efficiently as possible.

Here, as described above, a first step of the aforementioned initiation phase can preferably initially provide for positioning of the conversion body required centrally for the calibration process at a predefined calibration position within the respective production system to be adjusted, the position at which the latter conversion body can preferably be defined as the calibration position also illuminated by the processing light beam of the production system and should therefore be analyzed for the further process and used to adjust the production system. In a particularly preferred exemplary embodiment, the corresponding calibration position can be arranged, in particular at least in the aforementioned working plane, but in further exemplary embodiments at least at a point within the used installation space that can be reached by the processing light beam by controlling the optical elements of the production system, so that it is preferred This makes it possible to illuminate said conversion body without the addition of additional aids (and thus potentially additional sources of error that need to be included).

For this purpose, the said conversion body can, for example, preferably, in a first exemplary embodiment of the present invention, be introduced into a locking device which is set up for releasably fixing the conversion body and stationed within the installation space, preferably in the working plane of the production system, so that irradiation of the conversion body for the subsequent calibration process preferably by the same as the conventional manufacturing process, but in a further preferred embodiment at least partially coaxial with the The light path used for the manufacturing process can be done. Such a positioning of the body not only offers the above-mentioned advantage of the redundancy of further required calibration materials, but can also be used to generate the highest possible precision in the subsequent calibration phase due to the minimum width of the processing light beam generated by the focus point.

Further variants of the above-mentioned first exemplary embodiment can also result in particular from the reuse of already existing elements of the production system: For example, it can equally be possible for devices of the optical production system that are already used for production to be used as a locking device, in a particularly preferred exemplary embodiment, However, it can even be designed as the actual conversion body to be positioned on the working plane, whereby the installation of further mechanisms within the production system can be avoided and the efficiency of the claimed calibration method can be further increased. In this respect, in a further representation of the above-mentioned embodiment, the locking device set up to fix the conversion body can, for example, preferably also be used as a holding mechanism that already exists within the installation space and is usually configured for positioning and fixing the respective workpieces/materials, such as one conventional in additive manufacturing systems occurring base plate, so that said holding mechanism in the present invention preferably assumes a double role and can therefore be used both to lock any workpieces and the conversion body used for calibration. In a further form of the exemplary embodiment, however, it may also be possible for said holding mechanism itself to be designed as a conversion body, which in particular generates the advantage that the claimed calibration method completely dispenses with the import of external calibration materials and is therefore designed completely in situ can be. In order to be able to allow efficient positioning or provision of the conversion body within the installation space even in the case of non-existent or potentially incompatible holding devices, the conversion body can also preferably, alternatively or in addition to the above-mentioned properties, also be designed to be movable in particular, whereby the conversion body can preferably be made possible to move along a predefined transport path for precise placement at the respective calibration position. In this respect, in a second exemplary embodiment of the present invention, the positioning of the conversion body within a respective installation space can also include at least the additional step of moving the conversion body along at least one axis and at least from a first position (henceforth called “first travel position”) to a second (movement -) position and back, whereby the second travel position can be identified in a preferred case as the desired calibration position of the manufacturing system.

To implement the last-mentioned method step, for this purpose, controllable transport devices that are configured specifically for the transport of the locking device and/or the conversion body and are equally integrated within the installation space, for example a rail system or a lifting work platform that can be moved along at least one axis, can also be provided, so that it In particular, the production system is made possible not only to carry out the method step described above, preferably fully automatically, but also to selectively move the conversion body used out of or into a potential processing zone, for example to enable a production step to be carried out in the meantime. In this respect, it can be seen that with the above-mentioned exemplary embodiment, any removal of the conversion body from the production plant, in particular to protect against potential emissions occurring during the manufacturing process, is no longer necessary, so that in this case the conversion body is preferably firmly attached to the respective installation space can be designed to be portable. As an alternative to the previously described embodiment of the transport device set up to move the conversion body, the latter can, in a particularly preferred example, also, similar to the first mentioned embodiment, in particular again as one already existing in the production plant or at least a part of one already in the production plant existing facility, so that the corresponding installation space can be used equally effectively. For example, in the case of a manufacturing system based on additive manufacturing, the locking device (and thus the respective conversion body) can be used, for example, to position the conversion body, preferably on movable manufacturing elements used for the enrichment of material, such as coaters or material nozzles used for powder melting processes Manufacturing system can be attached, so that by appropriately moving the manufacturing element, an equally simple and efficient position adjustment and thus a dynamic introduction of the conversion body into the light path of the processing light beam can be achieved. In a further variant, it may also be possible again for these movable production elements, such as the above-mentioned coater, to be used as conversion bodies themselves, which not only avoids any additional attachment processes that need to be carried out, but also further minimizes the materials required for calibration can.

Accordingly, it should be noted that the above-mentioned method step for positioning the conversion body in a respective production system to be adjusted can include a plurality of process steps that improve or simplify the calibration process, so that an extremely effective calibration is made possible compared to the prior art.

The present invention can also be used as a second process step within the initiation phase, especially after the above-mentioned introduction of the conversion body into the corresponding production system the setting of any existing manufacturing facilities in the manufacturing plant to initiate the subsequent one

Provide calibration process.

In this respect, in a second preferred process step, at least the processing light of the radiation source integrated within the optical production system can be adapted for the same calibration process.

Radiation sources that are set up especially for optical manufacturing processes (and thus the light beams emanating from them) usually have an extremely high power density, which, when the conversion body is irradiated during the calibration process to be described, leads to the destruction of important materials existing on the conversion body and thus the Calibration accuracy can visibly decrease. Accordingly, an extremely preferred method step can at least include reducing the power emitted by the radiation source per unit of time, whereby said conversion body can be effectively protected during the entire calibration process.

For this purpose, in a first exemplary embodiment, the radiation source can preferably be equipped with an adjustment mechanism, which allows the former, for example by receiving an initiation signal from the production system, to set the power of the radiation source at the beginning of the calibration process to a predefined one for the irradiation of the conversion body to minimize the value to be used. As an alternative to this process, it may also be possible, particularly in cases in which the radiation source may not be suitable for adjusting its power on its own (for example in the case of a laser source), for an opto-mechanical device specifically intended for the light beam of the radiation source Power filter, such as an absorption filter designed for the wavelength of the processing light beam, can be introduced into the beam path of the radiation source and thus externally modifies the power density reaching the conversion body. In an extremely In a preferred embodiment, especially in the case of a laser light source used, for example a CW laser, the production system can also be set up to activate a pulse operation of the laser light source, which is preferably set up for the calibration process and is preferably adjustable, whereby the outgoing power, in particular by adjusting the Pulse lengths defining light radiation can be adjusted effectively and preferably continuously, even without additional elements being introduced. The latter can preferably be done by using preferred laser light modulations, such as quality modulation (Q-switch) or various mode coupling methods, for example modulation methods based on acousto-optical (AOM) or electro-optical modulators (EOM), and so, depending on the laser light source used, as much as possible enable precise adjustment of the laser light to be used.

Furthermore, if at least the conversion body is arranged in the intended calibration position and preferably all other preparations required to initiate the calibration process have been made, the present invention can, in a next step, preferably initiate a calibration phase intended for identifying optical shifts and corresponding adjustment of the processing light beam.

As already described, the calibration method provided for this purpose can preferably use at least the properties of the conversion body present in the production system, which is set up to absorb the light of the processing light beam of the production system during the irradiation at predefined points of the conversion body and preferably into a detectable, preferably visible, calibration light convert and emit.

For this purpose, the conversion body itself, in a particularly preferred exemplary embodiment, can preferably initially be made of an inert material, for example glass or anodized aluminum Substrate provided and designed as any three-dimensional body, which can comprise an application consisting of at least one conversion material that interacts with the processing light beam to produce the above-mentioned optical conversion properties. The light beam, which is preferably a laser beam, is converted by the conversion material from its infrared wavelength, which is invisible to the human eye, into visible light in order to be able to carry out direct position detection. More precisely, the conversion material in question can, for example, preferably be a polymer made of optically active materials, such as lithium niobate (LiNb03), potassium dihydrogen phosphate (KH2P04), barium borate (BA(BO2)2), YAG (Y3AI5012), a mixture of rare earths such as neodymium ( Nd) or yttrium (Y), or other elements fulfilling the above property, which can be explicitly designed to carry out the previously described conversion process upon exposure to the processing light beam and thus to provide the calibration light required for the calibration, preferably through purely quantum optical effects generate.

In this respect, in a particularly preferred exemplary embodiment, the conversion material applied to the conversion plate can also be set up in particular in such a way that the aforementioned calibration light can be generated, for example, by means of preferred frequency doubling of the absorbed light beam of the radiation source used, so that an accurate and in particular dependent on the processing light Definition of the calibration light is made possible. In addition, the described three-dimensional shape of the conversion material can generate the advantage that a conversion of the processing light can take place by the sole impact of the processing light beam on the conversion material and the present calibration process can therefore be carried out in particular independently of any angles of irradiation or orientation of the last-mentioned light beam, which the

Calibration process further simplified. Preferably, the conversion body can be designed as a flat, preferably plate-shaped plate, for example in the same size and/or shape as a workpiece originally to be processed in the respective production system, so that the conversion body can be effectively integrated into the production system of the respective production system to be adjusted. In a further exemplary embodiment, an already existing manufacturing device (or an element) of the manufacturing system, such as a base plate set up to fix a workpiece or a movable coater, can assume the function of a conversion body, which can be achieved, for example, by applying the previously described conversion material to a predefined surface of the respective Manufacturing facility is generated. The latter in particular results in an extremely effective calibration procedure.

Based on this basis, the claimed calibration method can initially, in a first step of the calibration method, provide for the identification of a misalignment of the processed light beam of the optical manufacturing system to be adjusted, by moving the processed light beam, preferably by controlling the optical elements, along a surface wetted with the conversion material of the conversion body and, based on this process, an explicit difference between an impact position (target position) originally intended by the optical production system and an actual impact position (actual position) of the machine being processed, which is generated by the misalignment and deviates from the target position Light beam on the conversion body can be determined.

For this purpose, in a first step of the latter identification process, a calibration trajectory responsible for the movement of the processing light beam can preferably first be created or at least selected from a plurality of possible calibration trajectories, preferably using a predetermined database within the optical production system, so that the method of processing light beam on the surface of the conversion body at least along said predefined Calibration trajectory can be done. The latter process step not only has the advantage that the respective method of the processing light beam can be completely determined based on the predefined travel path and can therefore be repeated consistently even in iterative processes, but the creation of a calibration trajectory can also be used to define a plurality of "target" values to be compared. Positions” can be used.

In a particularly preferred example, for example, each point P of the selected calibration trajectory (for example named T) can be defined at least by a temporal component t and a spatial component x or a temporal t and a speed-indicating component v, whereby the travel path T(P(x,t)) or T(P(v,t)) to be carried out by the processing light beam is completely defined at any time. In this respect, by creating the above-mentioned calibration trajectory and then reading out the resulting spatial-temporal travel coordinates of the trajectory, it is possible to make an exact statement about the intended position (target position) of the moving light beam of the production system at any given time obtained so that, after equivalent identification of any actual positions, a simple analysis of existing misalignments can be made possible.

The latter identification of actual positions to be used can also preferably be carried out by means of the above-mentioned conversion of the processing light by the conversion body. More specifically, for this purpose, the conversion of the processing light beam into a detectable light can preferably be carried out in a particularly spatially-dependent manner, so that, for example, by irradiating only areas of the conversion body capable of conversion at predefined positions and subsequent detection of the calibration light generated by the conversion , at least one actually occurring impact position (actual position) of the processing light beam on the conversion body can be verified. For this purpose, in a particularly preferred example and in order to fulfill the above-mentioned properties, the conversion body can, for example, be designed in such a way that, during the irradiation of the conversion body by the processing light beam, the processing light is converted into the detectable light only at certain, predefined positions of the conversion body can be done.

In this respect, for this purpose, in a preferred exemplary embodiment of the present invention, the application of the conversion material to the conversion body can preferably only be spatially limited. In a particularly preferred exemplary embodiment, this spatial restriction can also be designed in such a way that the conversion body can only provide individual application structures made of conversion material (hereinafter also referred to as “conversion structures”), which are only present at specific, i.e. predefined positions, which in particular results in the effect is generated so that the above-mentioned calibration light is generated only when the processed light beam hits the positions defined by the conversion structures and can therefore be used as an effective and position-specific detection signal.

Based on these principles, a corresponding calibration phase of the present invention can preferably be designed in such a way that the processing light beam can initially be moved along a predefined travel path on the conversion body, preferably by using the aforementioned calibration trajectory. If the processing light beam then hits at least part of a conversion structure positioned on the conversion body along its travel path, the processing light can then be absorbed by the conversion materials located within the conversion structure and converted into the detectable calibration light. Since the conversion structure is only placed at predefined positions on the conversion body, in a next step, by detecting the Conversion structure outgoing calibration light, verified that the current actual position of the processing light beam must be at one of the corresponding, predefined positions of the conversion structure, so that, preferably by detecting a plurality of calibration light emissions, the actual travel path of the processing light beam and thus the on The actual positions of the processing light beam that actually occur during this travel path can be effectively reconstructed.

Accordingly, it can be seen that through the above-mentioned simple structuring of the conversion body using individual position-specific conversion structures, an extremely efficient detection system can be created, which, based on the purely optical conversion and detection processes, is also more material-saving than the prior art as well as accelerated calibration procedures are permitted.

The actual detection of the calibration light emanating from the conversion material can also preferably be achieved by a sensor and in particular a photodiode or a photodiode array. Furthermore, an optical sensor device integrated into the production system can be present, such as a one- or two-dimensional CCD sensor, a cMOS sensor, so that the calibration process can also be carried out completely in situ, that is, exclusively within the production system and in particular autonomously.

For the final identification of any misalignments of the processing light beam, as already described above, the actual positions of the light beam determined by the above detection process can, in a next step, preferably be compared with the target positions provided within the optical production system. More specifically, for this purpose, as a result of the reconstruction of the actual travel path of the processing light beam made possible by means of signal detection, selected positions can be taken from the reconstructed travel path, defined as actual positions and are contrasted with the target positions stored within the calibration trajectory used and actually intended at the time of a respective actual position, so that the present identification process determines an explicit spatial difference between said actual and target positions of the processing light beam and preferably for one subsequent adjustment of the optical production system can continue to be used.

Accordingly, the method claimed here can also provide, in a subsequent step, for a recalibration of the respective optical production system, preferably on the basis of the previously identified differences between the determined actual and target position.

For this purpose, in a particularly preferred exemplary embodiment, for example, the above-mentioned identified differences between the actual and target positions of the processing light beam can be fed as corresponding difference data into an adjustment device which is specifically set up for adjusting the production system and is also integrated into the production system , preferably based on information obtained from these differences (for example: distance between the positions, relative displacement coordinates, position in the coordinate system of the manufacturing system) can carry out a change in the control parameters of the optical manufacturing system used to control the processing light beam. In this respect, it may be possible, for example, using the above-mentioned adjustment device, to modify the control of at least one of the optical elements of the production system in such a way that the actual positions are brought closer to the corresponding target positions and thus the production system is aware of any unwanted modifications to the processing light beam can be adjusted.

Which control parameters can be changed by the adjustment device depending on the information received or, in general, which consequences can be drawn from the information received, can preferably be done by reading out parameter-dependent parameters stored in the adjustment device Process decisions are defined. For example, in a first preferred embodiment, the adjustment device can contain an internal data library with regard to possible solutions to position discrepancies that occur with certain light beam modifications, which the adjustment device can check to find potentially useful parameter changes and, if necessary, use as a basis for adapting the above-mentioned control parameters. In a second extremely preferred exemplary embodiment, it may also be possible for a corresponding modification of existing control parameters to be carried out, preferably automatically, and by a calibration program used by the adjustment device and preferably based on artificial intelligence or machine learning, whereby, in particular in the case of complex calibration problems, an extremely individual and correspondingly efficient parameter adjustment can be made possible. For this purpose, the calibration program mentioned can, for example, preferably be set up to extract the aforementioned information based on the identified difference between the actual and target position of the processing light beam and a potential parameter change accordingly based on the information extracted and a previous training of the contained artificial intelligence, for example with regard to to carry out optical effects resulting from various parameter changes.

In this respect, it can be seen that the claimed calibration method, especially due to the extremely material-friendly and precise process steps, offers a much more efficient method approach compared to the state of the art, which, in addition to further advantages, such as a completely possible in situ procession, dynamically feasible analysis steps or a purely optical detection process, can be applied to a large number of different manufacturing systems based on optical interactions. In addition, the claimed calibration method, due to which individually adaptable process steps, a wide variety of adaptation options that can be applied to a respective system.

In particular, the claimed calibration method can be designed to be completely automated. For this purpose, the optical manufacturing system can preferably additionally comprise, for example, at least one central control device, which can preferably be connected in terms of signals to individual manufacturing devices or elements, such as the optical elements, the radiation source or a device that gives the conversion body position (for example the locking device), and is set up accordingly to regulate the above-mentioned method centrally and automatically by means of signal exchange between the above-mentioned production facilities and the control device. More specifically, the central control device can preferably be set up to check the process status of a respective method step by requesting and receiving a status signal to be sent by a responsible manufacturing facility and, based on the signals thus received, to initiate a subsequent method step by controlling further manufacturing facilities or to continue existing method steps . According to this circumstance, a completely automatable calibration process can be generated, since each process step of the claimed method can preferably only be carried out within the production system and thus in the control area of the above-mentioned control device.

In addition, to further improve the calibration precision, the present method can also preferably be carried out iteratively, so that after a respective change in the control parameters by the adjustment device, a new start of the calibration method can be initiated if, for example, the light beam modifications resulting from the adjustment are not the desired improvement of the processing light beam can be achieved. Accordingly, the claimed method can preferably also provide to repeat the calibration process preferably so often until at least the determined spatial difference between at least one identified actual position and the corresponding target position falls below a predefined limit or at least a predefined number of process iterations have been carried out. In this respect, it is possible to use the above-mentioned method to improve the accuracy of the processing light beam in a potentially unlimited manner, since each iteration of the calibration process can achieve an improved approximation of the desired precision of the optical manufacturing system.

In a further preferred exemplary embodiment, it may also be possible that the detection process carried out by the optical sensor device and required for detecting the calibration light can be carried out in particular continuously during the process of the processing light beam, so that a calibration of the production system is preferably carried out in real time and with an increased Number of calibration information is possible. Thus, in this preferred exemplary embodiment, the optical sensor device can preferably be set up to first detect the calibration light generated by the conversion of the processing light as a calibration light signal, which is preferably dependent on the intensity or on the amount of the detected calibration light, whereby, by means of the above-mentioned continuous determination type , a time course of the detected calibration light quantity/calibration light signal generated during the process of the processing light beam can be generated. Accordingly, the above-mentioned process step has the advantage that by constantly detecting the calibration light emitted by the conversion structures, a time-dependent signal structure can be generated, which generates both additional information for identifying any actual/target positions as well as the precision of the Detection of any calibration light emission can be further increased. For example, the sensor device can be set up to use the previously described generated signal curve to generate an additional process step for verifying existing calibration light emissions by searching the signal curve mentioned by the sensor device, preferably in real time, for any signal patterns indicating calibration light emission. Accordingly, this process step can preferably provide for identifying, in particular, those signal intervals as emission events that have actually occurred, which can show a comparatively strong calibration light signal value or one that preferably exceeds a specified signal limit value, so that, through an explicit comparison of existing signal values, any resulting from external influences and thus to Signal detection resulting in incorrect adjustments can be effectively eliminated.

A further advantage of the generated signal curve can also be seen in further improving the identification of the exact impact positions of the processing light beam on the respective conversion structure, in particular by making it possible to analyze an exact point in time of a respective detected calibration light emission. In this respect, it may be possible, for example, that due to the predefined beam width of the light beam traveling on the conversion body, the said light can strike at several points of a conversion structure (for example when passing through a conversion structure), so that an emission occurs for several intended positions of the light beam of the calibration light to be detected, thus making it more difficult to determine the exact position of the processing light.

In order to avoid this, however, the optical sensor device can in particular preferably be set up to search the signal curve correspondingly generated by the last-mentioned calibration light emission, preferably for a signal maximum, and to select an impact position on the conversion structure to be used for identifying the actual positions, preferably at least for the time of this signal maximum to determine. This is based on this Process step in particular ensures that by moving a finitely wide light beam on a predefined conversion structure, a signal maximum is generated at a point of the largest structure exposure area, so that by determining the signal maximum, preferably the center of the exposed conversion structure or at least the position in which the processing light beam the largest area of the conversion structure exposed can be identified.

The previously mentioned reconstruction of the actual travel path of the processing light beam by means of the plurality of detected calibration light signals can also preferably be made possible by using a wide variety of geometric analysis mechanisms, such as dynamic regression algorithms and / or compensation calculations based on fit functions, which can preferably be set up when receiving the A plurality of calibration light signals and comparison of the latter with the predefined positions of the conversion structures to simulate the actual movement of the processing light beam. More precisely, for this purpose, for example, the calibration light signals continuously determined by the optical sensor device during the movement of the processing light beam can be collected and passed on to the above-mentioned analysis mechanisms after the travel path has ended, so that due to the large amount of existing data/information generated in this way, an exceedingly precise identification of the actual travel path of the processing light beam can be made possible.

Accordingly, the above-mentioned process steps can be used to further improve the detection of the actual and target positions to be identified by supporting the determination of the respective impact positions of the processed light beam on the conversion structures and the reconstruction mechanism based thereon by a time-dependent analysis method that is dependent on dynamic signal structures becomes. To further improve the above-mentioned process, it may also be possible to adapt the conversion structures applied to the conversion body specifically to the previously described calibration method. Thus, in an extremely preferred exemplary embodiment, the at least one conversion structure located on the conversion body can, for example, be provided with a predefined, geometric pattern, whereby in particular the aforementioned reconstruction of the actual travel path of the processing beam can be further specified.

According to these principles, the pattern of the at least one conversion structure can, for example, include a plurality of geometries filled with the conversion material and designed as a line structure, so that the potentially impact positions on the conversion structure to be taken into account (and thus the inaccuracies to be taken into account for the reconstruction), in particular due to the so preferably small structural area can be reduced. In addition, in a particularly preferred exemplary embodiment, the line structures mentioned can, for example, only be present in orientations that are parallel and/or orthogonal to one another, so that when a calibration light signal corresponding to this line structure is detected, the potential impact positions can be limited to only one-dimensional coordinates . In a further, particularly preferred exemplary embodiment, however, it may also be possible for each line structure of the at least one conversion structure to be designed with different widths or with another predefined geometric figure, such as a circular shape, a triangular shape, a trapezoidal shape, etc , so that by passing through the processing light beam on each line structure, a line structure-specific signal structure generated on the optical sensor device is generated and these can therefore also be used for improved identification of any actual/target positions. Furthermore, on the technical side of the present inventions, any additional device properties to be installed in the optical manufacturing system may also be possible.

For example, the conversion body or the locking device fixing the conversion body within the optical production system can be designed to be movable at least vertically, but in a preferred exemplary embodiment at least perpendicular to the focal plane of the processing light beam, so that the calibration position is equally above and / or below the corresponding working level of the optical production system can be defined. Accordingly, the above-mentioned property can generate the advantage that the calibration method described above can be carried out using a focused light beam (calibration position in the focal plane/working plane), but in desired cases also with defocused optics (calibration position below/above the focal plane/working plane). can be operated, so that additional effects, such as error analysis that is equally dependent on the z-position of the processing light beam, can be made possible.

In addition, in order to use a particularly efficient calibration method, the positioning of the optical sensor device can preferably be adapted to the respective optical production system to be adjusted. For this purpose, in a first preferred exemplary embodiment, the optical sensor device can, for example, be positioned in a free area of the installation space, that is to say independent of the light path of the radiation source, so that the calibration light emitted by the conversion body preferably impinges directly on the integrated sensor of the optical sensor device and thus can generate a particularly strong calibration light signal. In a further exemplary embodiment, it may also be possible for the optical sensor device to be preferably attached to a position adjacent to the light path of the processing light beam, whereby it In particular, it is made possible for the optical sensor device of the calibration light to use at least part of the optical elements integrated in the optical production system for its own detection of the calibration light and thus the light path of the calibration light can be at least partially aligned coaxially with the light path of the processing light beam. In this respect, the last exemplary embodiment can be used to create an extremely efficient and space-saving integration of the optical sensor device into the production system to be adjusted.

In order to be able to detect the calibration light signal to be detected by the optical sensor device even more precisely, the present invention can also include the introduction of at least one optical filter device, preferably into the light path of the optical sensor device. The optical filter device can preferably provide at least one optical filter element, such as a long-pass filter, a short-pass filter or a band-pass filter, and can therefore at least be set up to transmit light within a predefined wavelength range, preferably in the wavelength range of the emitted calibration light, and to absorb light outside this wavelength range. whereby any interference signals for the optical sensor device caused, for example, by external light sources can be effectively minimized. In a particularly preferred exemplary embodiment, it may also be possible for said filter device to preferably be designed to be integrated in a manufacturing device that already exists within the respective manufacturing plant, so that in this case too, a design that is as space-saving and cost-efficient as possible is made possible. In preferred exemplary embodiments, the filter device mentioned can be, for example, as an optical element of the optical production system wetted with an optical filter glass, but in further examples also, for example, as a protective glass of the installation space positioned in the light path of the processing light beam and provided with one of the above-mentioned filter elements or as a Filter turrets that already exist in the production plant can be designed. Short description of the characters

Figure 1: shows an embodiment of an optical manufacturing system set up to use the claimed calibration method with an optical sensor device integrated in the scanning head of the manufacturing system;

Figure 2A: shows a schematic representation of the claimed calibration method;

Figure 2B: shows an exemplary top view of a portion of a conversion plate with an applied conversion structure;

Figure 2C: shows an exemplary course of the calibration light signal detected by the sensor device of the claimed invention;

Figure 3: shows a further embodiment of the optical production system shown in Figure 1 with the optical sensor device integrated in the installation space of the production system;

Figure 4: shows an exemplary calibration method according to the present invention carried out by the production system of the embodiments of Figures 1 and 3.

Detailed description of preferred embodiments

Exemplary embodiments of the present invention are described in detail below using exemplary figures. The features of the exemplary embodiments can be combined in whole or in part and the present invention is not limited to the exemplary embodiments described.

Figure 1 shows a schematic embodiment of a manufacturing system 1 based on optical interactions, specifically a manufacturing system for selective laser melting of the present invention, in which a material to be processed is applied in layers on a movable base plate 16 and locally remelted by means of focused laser irradiation in such a way that by continuous application , exposing and fusing additional material layers 24, a three-dimensional workpiece 26 can be generated (additive manufacturing).

For this purpose, the manufacturing plant 1 provides at least one (laser) light source 4, which generates a light beam LS modified to interact with the material layers 24 via a control system 6 coupled to the manufacturing plant 1, and this light beam LS with the aid of various devices in a scanning head 2 integrated optical elements L _e , such as focus or scatter lenses LI, L2, L3, mirrors 13A, optical filters, etc., are focused via a light path onto the material layer 24 to be processed. In particular, galvanometer scanners are used as deflection mirrors. In this case, the scan head 2 itself is present as an independent, rigid housing, in which the latter optical elements L _e are aligned so that they can be controlled manually and/or automatically and thus, depending on their current orientation and the optical properties assigned to them (e.g. focus lengths or filter frequencies ) generate a light beam that can be positioned three-dimensionally and is designed to process the material layers 24. In order to ensure suitable protection of the above-described optical elements L _e from possible process emissions, the scan head 2 in the present embodiment is initially designed as a closed or lockable system in which the light beam processing the material only passes through an exit hole provided with a scan head glass 3 can be led out of the scan head 2. In further embodiments, however, it may also be possible to design the optical elements L _e as a free-standing device system or to integrate the latter at least partially in other units of the production system 1, such as the light source 4. In this case, the representation of the light source 4 only serves visual purposes, so that the latter can be designed to be integrated into the scan head 2 or other elements of the production system 1.

Due to the above-mentioned working distances of the optical elements L _e implemented in the scan head 2, the light path used to produce the workpiece 26 also leads through the scan head glass 3 into a process chamber 12 which is spaced from the scan head 2 by a free space 5, which in this case is called The installation space to be used is used and in which the various material layers 24 to be processed are applied to a movable base plate 16 and are focused on a working plane AE by the producing light beam to produce the workpiece 26. The exact manufacturing process, as described above, provides for an iterative coating and exposure process: To produce any three-dimensional workpiece 26, the material to be processed is first applied in powder form in a thin layer 24 to a base plate 16 and by at least a vertical process the base plate 16 is positioned at a processing height corresponding to the light path by means of controllable lifting devices 20 (eg pneumatic, electrical or mechanical cylinder or scissor lifting devices). In order to guarantee a material layer 24 that is as uniform and in particular dense as possible, the corresponding powdery material 18 in this exemplary embodiment is previously coated with at least one layer parallel to the one being processed Material layer 24 movable roller or alternatively with other devices such as integrated silicone lips, brought to a predefined layer height and excess material removed from the base plate 16, so that in particular consistent material conditions can be guaranteed within each iteration process.

The processed powdery material layer 24 is then locally remelted using the above-mentioned light beam focused through the light path and forms a solid material layer after solidification. The base plate 16 is then lowered by a predefined layer thickness of the material layer 24 and a new material layer 24 is applied to the base plate 16, so that a fused, three-dimensional material shape (the workpiece) 26 can be formed by repetitive processing and adding new material layers 24.

In order to enable the atmospheric conditions suitable for the above-mentioned SLM manufacturing process, the process chamber 12 of the manufacturing plant 1 is also designed to be completely closable and equipped with any regulatory elements, such as pressure regulators or for importing or exporting the required processing chemicals (e.g. argon, neon, etc. ) equipped valves, equipped processing housing is designed, which in particular completely encloses the above-mentioned base plate 16, through integration into the process chamber structure 11 (ie at least the process chamber outer wall), and can thus provide an installation space that is sealed off from external influences. In order to equally enable the light path to come into contact with the different material layers 24, a protective glass 10 is also introduced into the process chamber housing 11, which, due to its optical properties, is at least set up to protect both from the light source 4 and through the scanning head 2 to allow the controlled light beam into the process chamber 12 as well as the elements of the production system 1 mounted in the scan head 2 or otherwise before any during the to shield the process emissions 28 (powder residues, smoke, sparks, etc.) that occur during production.

However, as already described, in optical manufacturing systems such as the SLM system 1 shown in FIG Light beam can be unintentionally modified, so that the light path of the actually occurring processing light beam 14 'and thus the resulting impact position (actual position IP) on the material layer 24 differs from the light path or the impact position (target position SP) of the originally intended Light beam 14 can deviate and thus cause inaccuracies within the manufacturing process. In this respect, it is of great importance for existing optical manufacturing systems to have a method or a possibility which makes it possible to identify the above-mentioned misalignment of the processing light beam and, in a preferred case, to correct it at the same time.

Figure 2A shows a first schematic representation of the operation of the claimed calibration method. In the present invention, a particularly extremely precise and non-invasive calibration process is made possible in that detection of the potential misalignment of the processing light beam 14 'can only be generated by a purely optical identification mechanism. More specifically, for this purpose, the present invention provides for a so-called conversion body 29 coated with a conversion material to be positioned in the installation space of the production plant 1, which is capable of being exposed to light by means of the conversion material, which is usually in the infrared range (and therefore difficult to identify). ) Processing light of the manufacturing plant 1, the processing light into a detectable, preferably visible calibration light 32 and so, by detecting the emanating from the conversion material Calibration light 32 to enable a position determination of the processing light beam 14 '.

Figure 2A shows the basic principle of the identification and calibration process to be generated in a schematic minimal system. In the present invention, in order to precisely determine the actual position of the processing light beam 14 ', the conversion body 29 used, in this case designed as a rectilinearly aligned, plate-shaped plate, is provided with so-called conversion structures, which are only at predefined positions, shown here as a line pattern of vertical and horizontal line structures 34 & 34 ', are applied to the substrate 33 of the conversion body 29 and to achieve the previously described conversion process, contain the above-mentioned conversion materials. If a processing light beam 14 ', preferably focused on this conversion body 29, now moves along and illuminates one of the predefined positions of the applied conversion structures, the aforementioned calibration light 32 can be generated at this point, so that an optical, non-invasive and in particular spatially-dependent detection signal can be created whenever the processing light beam 14 'travels over a predefined position of the conversion body 29. Accordingly, it is possible by targeted movement of the processing light beam 14 'on the conversion body 29 and time-coordinated detection of the calibration light 32 generated when the light beam 14' hits a predetermined conversion pattern by a sensor device S (shown here as a sensor device S and a that Calibration light 32 collecting lens system L _s ), to generate a signal pattern defined by detecting the calibration light 32, which is characteristic of the respective actual travel path of the processing light beam and is therefore used to reconstruct this travel path (and thus to identify any actual positions IP). can.

For this purpose, Figures 2B and 2C show an exemplary detection and analysis step of the aforementioned sensor device S for identification any actual positions IP of the processing light beam 14 'to be used for the calibration process. 2B shows an exemplary schematic top view of a conversion body, which is provided with a conversion structure designed as a vertical and horizontal line pattern 34 & 34 'and along which the processing light beam 14' is moved along an actual travel path TV. In addition, KT describes the travel path of the processing light beam 14 'that was originally intended and predetermined by a calibration trajectory KT.

In particular, the shape of the conversion structure shown here only serves visual purposes and can also be present in other embodiments in a different configuration, for example with different geometries (e.g. spatially defined circular or cuboid shapes), sizes or orientations. 2C shows an exemplary, schematic and time-dependent course of a detection signal correspondingly generated at the sensor device S, also called a calibration light signal KS, which is generated at the sensor device S during the movement of the processing light beam 14 'along the travel path TV of FIG. 2B.

As can be seen, the travel path TV is designed such that the processing light beam 14 'over a plurality of areas affected by conversion structures, for example shown at positions M2, M4 and M5, and free areas (see, for example, positions M1 and M3). of the conversion body 29 moves, so that the temporal signal curve of the sensor device S forms as a signal pattern with a plurality of signal peaks. More precisely, at each point in time at which the processing light beam 14 'travels over a line structure 34 &34' of the conversion structure, due to the above-mentioned conversion of the processing light, a calibration light 32 is generated, which is recorded by the sensor device S and thus as a characteristic increased Calibration light signal KS is inserted into the signal curve (see, for example, those with conversion structures Positions M2, M4 and M5, which can be found as signal peaks in the time course of the sensor device S).

According to the above-mentioned circumstance, an extremely efficient identification of existing actual positions of the processing light beam 14 'can now be made possible in the present invention by evaluating the characteristic signal pattern shown in FIG The travel path TV used by the processing light beam 14 'can be reconstructed. More precisely, the geometric analysis mechanism can provide for this purpose to examine the individual values of the time-dependent signal curve, but also other information (e.g. different distances between the individual signal peaks, widths of the signal pattern taken or, for example, the orientation of the original calibration trajectory KT) and by comparison This information with the predefined positions of the individual conversion structures (for example using geometric regression methods) to create an exact replica of the travel path TV actually used by the processing light beam 14 '.

In this respect, it is possible to use the above-mentioned method to identify the actually existing travel path TV of the processing light beam 14 ' solely through optical interaction and detection mechanisms, so that in a subsequent step this can be compared with the originally intended calibration trajectory KT and thus for the final adjustment of the optical Manufacturing plant 1 can continue to be used.

For this purpose, Figure 1 also shows a first embodiment of the above-mentioned method, as it can be practiced in the optical manufacturing system 1 and thus in particular in an SLM system.

The conversion body 29 shown is again plate-shaped and provided with the conversion line structures 34 already shown in FIG. 2B Structure shown, which in the present case was placed within the process chamber 12 on the movable base plate 16 and, by means of the controllable lifting device 20 in at least the vertical direction, is present at a calibration position KP located on the working or focal plane AE of the production system 1. In further exemplary embodiments, however, it may also be possible for the scanning field plate 29 to be stationed below or above the focal plane of the optical manufacturing system 1 by means of the method of the base plate 16, so that calibration can also be implemented when the light is not focused. Likewise, the general shape of the conversion body 29 can also deviate from the geometry shown, so that the conversion body 29 can not necessarily be designed as a plate, but in other embodiments also as any three-dimensional shape provided with the conversion structures. Furthermore, it is also possible that even one of the illustrated elements of the production system 1, such as the base plate 16, can be provided with the conversion structures and thus used as a functional conversion body 29.

If the processing light beam 14 'is now moved on the optical conversion body 29, which in the case shown is preferably carried out, analogously to the previously mentioned processing method, by selective control of the optical elements L _e , then by converting the processing light on the conversion structure, the calibration light 32 is generated, which is detected by the sensor device S in the case shown for the calibration method already mentioned above. In the present exemplary embodiment, the sensor device S itself is positioned within the scanning head 2, in particular behind a wavelength-specific mirror device 13A, which is also used for the manufacturing process and is preferably coordinated with the calibration light 32, such as an interference mirror or a wavelength-dependent prism, which in particular is set up to transmit light with a wavelength corresponding to the calibration light 32, but to reflect light outside of this wavelength. In this respect, the construction described above enables extremely effective and space-saving integration the sensor device S can be provided, which can not only use existing optical elements (e.g. L3) of the production system 1 for the detection of the calibration light 32 due to the light path used partly coaxially with the processing light beam 14 ', but also by means of the filtering capability of the mirror device 13A, any interference signals potentially arriving at the sensor device S are effectively prevented. In order to be able to further improve the above-mentioned signal precision, in the present case other elements located within the light path of the production system 1, such as the protective glass 10 or the exit glass 3, can also be provided with a filter function (e.g. by applying a wavelength-specific filter coating) , so that in particular a detection mechanism generated via a plurality of filter processes can be generated.

3 also shows a further embodiment of the production system already shown in FIG. 1, wherein, in contrast to the exemplary embodiment shown in FIG Installation space of the manufacturing device 1 shown were introduced. Accordingly, the positioning of the sensor device S shown in FIG. 3 makes it possible in particular to detect the calibration light 32 independently of other optical elements and thus in particular directly.

Figure 4 also shows an exemplary sequence of an exemplary embodiment of the claimed calibration method, shown as a flow chart, as it can be carried out in one of the production plants 1 of Figures 1 or 3.

Here, the claimed method can be initiated in particular with an initiation phase preceding the actual identification of misalignments of the processing light beam 14 ' and the adjustment of the production system 1, in which the system to be adjusted can first be set up for the subsequent calibration. In this respect, in a first step Sl, the conversion body 29 to be used for the calibration can first be positioned in the installation space, in the case shown on the movable base plate 16 of the production system 1, so that the former is exposed by the processing light beam 14 'and thus the initiation of the calibration process is made possible.

It is then possible, in a second step S2, to adjust the height of the conversion body 29 positioned in the base plate 16, whereby the conversion body 29 in a preferred case moves into the focal plane/working plane AE of the processing light beam 14 ', but also in other cases can be aligned below or above this level.

Furthermore, in a further step, the settings used in the production system must be adapted to the calibration process. Accordingly, in a third step S3, the method can at least provide for the laser used in the production system, as radiation source 4, to be converted into an adjustable pulse operation and thus to effectively throttle the power of the processing light beam to protect the conversion plate.

If all the necessary settings have been made within the initiation phase, the claimed calibration method can then move on to the so-called calibration phase, in which, preferably automated and coordinated as an in situ process, a misalignment of the processing light beam 14 'is identified and, based on this, the corresponding optical Manufacturing plant 1 is readjusted. An automation of the calibration process can be realized in particular by using a control device set up centrally within the manufacturing system 1, which preferably has signal connections to the individual manufacturing devices located in the optical manufacturing system 1 (e.g. the optical elements L _e or LS, the movable lifting device 20 or the Radiation source 4) check the status of the calibration process to be carried out and use selective Can guide the control of the above-mentioned production facilities. For example, for this purpose the control device can receive continuous information (e.g. in the form of status signals) from the manufacturing facilities currently used during the calibration process and, in response, by creating and sending control signals (e.g. NC-based signals) to the respective manufacturing facilities to be used. initiate subsequent procedural steps. The process steps themselves (e.g. defining the calibration trajectory KT to be processed, setting the radiation source 4, etc.) can preferably be present or stored as predefined process instructions in a memory, which is also integrated in the production system, and by connecting the memory to the control device, to the latter be passed on.

In a first step of the calibration phase S4, the processing light beam 14 ', in this case designed as a pulsed laser beam, is then moved along a predefined calibration trajectory KT, whereby when the processing light beam 14 'impacts on a conversion structure applied to the conversion body 29, the Light from the radiation source 4 is converted into a detectable, preferably visible calibration light.

This converted calibration light can subsequently, in a second step of the calibration phase S5, be detected by the sensor device integrated in the production system 1 and used according to the method described in FIGS. 2A to 2C to identify the travel path actually used by the processing light beam 14 ' . Specifically, in a third step of the calibration phase S6, the actual path of the processing light beam 14 'is reconstructed by evaluating the characteristic signal pattern detected in the optical sensor device S.

Following this process, in a fourth step of the calibration phase S7, one or more actual positions IP can be determined in which one predefined number of position points can be taken from the reconstructed travel path.

In order to identify a potential misalignment of the processing light beam based on this, the calibration process can then provide, in a fifth step of the calibration process S8, to compare the previously determined actual positions IP of the processing light beam 14 'with originally intended target positions SP, whereby explicit, spatial differences can be generated between the two positions. The target positions SP to be compared are preferably taken from the calibration trajectory KT and compared with the actual positions IP corresponding to the same point in time.

In the sixth step of the calibration method S9, the determined difference between the detected actual position IP and the target position SP can also be used to correct the misalignment of the processing light beam 14 'by recalibrating the optical manufacturing system 1. For this purpose, the determined differences are preferably fed as difference data into an adjustment device integrated in the production system 1, which is carried out using the included adjustment mechanism, such as the use of predefined decision-making processes based on different difference data or the use of an artificial intelligence/a program based on machine learning, which is used for Method of the processing light beam 14 'used control parameters of the manufacturing plant 1, for example by changing the control of the optical elements L _e , and thus reduces the difference between the actual and target position IP and SP.

In a final step of the calibration method S10, a final assessment method must also be used, in which the accuracy of the current processing light beam 14 'is evaluated with regard to the previously carried out calibration. For this purpose, this step can, for example, provide for the difference between the determined actual and target positions IP and SP investigate and, depending on the result (e.g. a difference greater than a predefined limit), force a new iteration of the previously described calibration phase. In this respect, this last step enables a continuous approach to the desired accuracy of the production system 1 and thus, potentially, the misalignment of the processing light beam 14 'to be found can be completely corrected.

Claims

Patent claims

1. Method for calibrating a manufacturing system (1) based on optical interaction, in particular an SLM system, comprising at least one optical radiation source (4) for generating a light beam (14 '), in particular a laser beam, designed for the production of a workpiece (26). , and at least one adjustable optical element (L _e ), which is designed to selectively direct the light beam (14') generated by the radiation source (4) to a position in the area of a working plane (AE) of the production system for producing the workpiece (26). (1) and a construction space comprising the working plane (AE) in which workpiece materials (24) to be exposed by the light beam (14 ') can be introduced to produce the workpiece (26), the method comprising the steps:

(54) moving the light beam (14') of the radiation source (4) on a conversion body (29), the conversion body (29) being set up to be irradiated by the light beam (14) of the radiation source (4) at predefined locations of the conversion body ( 29), converting the light from the radiation source (4) into a detectable, in particular visible, calibration light (32) and emitting the detectable calibration light (32);

(55) detecting the detectable calibration light (32) emitted by the conversion body (29) by a sensor device (S) integrated into the production system (1);

Determining at least one actual position (IP) of the light beam (14') emanating from the radiation source (4) based on the calibration light (32) detected by the sensor device (S);

(S8) comparing at least one determined actual position (IP) with at least one target position (SP) of the light beam (14') predefined within the production system (1); (S9) Calibrating the optical manufacturing system (1) based on at least the determined actual position (IP) and/or the target position (SP) of the light beam (14') of the radiation source (4).

2. The method according to claim 1, wherein the conversion body (29) for converting the light beam (14 ') of the radiation source (4) into detectable calibration light (32) comprises at least one conversion structure equipped with a conversion material, the conversion structure being on a substrate (33 ) of the conversion body (29) is applied with a predefined pattern and the conversion material is set up to convert and emit the light from the radiation source (4) into the detectable, in particular visible, calibration light (32).

3. The method according to claim 2, with the steps:

Moving the light beam (14') of the radiation source (4) at least partially on the conversion structure of the conversion body (29); and

Detecting the calibration light (32) emitted by the conversion structure in the event that the light beam (14') of the radiation source (4) impinges on at least part of the conversion structure (34; 34').

4. The method according to at least one of the preceding claims, wherein the optical radiation source (4) is a laser radiation source and the method further comprises:

- (S3) Activating an adjustable pulse operation of the optical radiation source (4) to adjust the strength of the light beam (14') generated by the optical radiation source (4).

5. The method according to at least one of the preceding claims further comprising: - (S10) Repeating the method until a difference between the at least one determined actual position (IP) and the target position (SP) of the optical light beam (14 ') falls below a predefined limit value.

6. The method according to at least one of the preceding claims further comprising:

- Adjusting the calibration light (32) detected by the optical sensor device (S) by an optical filter device integrated into the production system (1), the optical filter device being set up to transmit light within a predefined wavelength range and to absorb light outside the predefined wavelength range.

7. The method according to at least one of the preceding claims, wherein the conversion body (29) is detachably and/or movably attached in the installation space (12) of the production system (1) and wherein the method further comprises:

Moving the conversion body (29) along at least one axis from a first travel position for accommodating the conversion body (29) within the installation space (12) to at least a second travel position for introducing the conversion body (29) into the beam path of the radiation source (4) and back, wherein the second travel position is preferably a calibration position (KP) of the conversion body (29) used to calibrate the production system (1).

8. The method according to at least one of the preceding claims, wherein the movement of the light beam (14 ') on the conversion body (29) takes place according to a predefined calibration trajectory (KT); where each position within the calibration trajectory (KT) is defined at least by a temporal and a spatial or by a temporal and a velocity component; and wherein the target position (SP) to be compared is taken from the coordinates of the calibration trajectory (KT).

9. The method according to at least one of the preceding claims, wherein the detection of the calibration light (32) by the sensor device (S) takes place continuously during the movement of the light beam (14 '), such that a time course of a detected calibration light signal (KS) is generated becomes; wherein in order to determine the actual position (IP) of the light beam (14') emitted by the radiation source (4), at least one signal maximum is identified from the time profile of the detected calibration light signal (KS).

10. The method according to at least one of the preceding claims, wherein the light path of the calibration light signal (KS) is at least partially arranged coaxially to the light beam (14 ') of the radiation source (4) or the calibration light signal (KS) is independent of the light path of the radiation source (4) is detected within the installation space (12).

11. The method according to at least claim 2, wherein the conversion structure applied to the conversion body (29) comprises a plurality of geometries filled with the conversion material and designed as a line structure; and the line structures of the geometries are preferably designed to have different widths.

12. The method according to at least one of the preceding claims, wherein the conversion body (29) is designed to be at least vertically movable during the movement of the light beam (14 '), so that the calibration position (KP) of the conversion body (29) is above and / or below that of Working level (AE) of the manufacturing plant (1) can be moved.

13. The method according to at least one of the preceding claims, wherein the calibration of the optical manufacturing system (1) is carried out by a calibration program based on machine learning; wherein the calibration program is set up to obtain the differences between the actual position (IP) and the target position (SP) of the light radiation (14 ') emanating from the radiation source (4) and the optical manufacturing system (1), based on a prior training of the calibration program to calibrate.

14. Device for calibrating a manufacturing system (1) based on optical interactions, in particular an SLM system, comprising the manufacturing system based on optical interactions

- at least one optical radiation source (4) for generating a light beam (14') set up for the production of a workpiece (26),

- at least one adjustable optical element (L _e ) which is designed to selectively direct the light beam (14') generated by the radiation source (4) to a position within a working plane (AE) of the production system (1) for producing the workpiece (26). to focus,

- a construction space (12) comprising the working plane (AE), in which workpiece materials (24) to be exposed by the light beam (14 ') can be introduced to produce the workpiece (26), and - a conversion body (29) at a calibration position (KP) within the installation space (12) of the production system (1), the conversion body (29) being set up to be irradiated by the light beam (14') of the radiation source (4) at predefined locations the conversion body (29), converting the light from the radiation source (4) into a detectable, in particular visible, calibration light (32) and emitting the detectable calibration light (32); wherein the device for calibrating the manufacturing system (1) based on optical interaction is set up to carry out at least the method according to claim 1.

15. Computer-implemented method which, when applied to a computing unit that can be controlled by the device according to claim 14, causes the device according to claim 14 to carry out at least the method steps according to claim 1.