Method for the additive manufacture of a component, control system for controlling a method for the additive manufacture of a component, and manufacturing system

Abstract

The invention relates to a method for the additive manufacture of a component (104) on the basis of process parameters, having the steps of: detecting state changes relating to the additive manufacture using an event-based sensor (122, 124), wherein a state change is characterized by a signal property lying above a threshold; generating event-based data which represents the state changes; and setting at least one of the process parameters on the basis of the event-based data such that the additive manufacture is controlled in a process-parallel manner.

Description

[0001] Method for additive manufacturing of a component, control system for controlling a method for additive manufacturing of a component and manufacturing system

[0002] The invention relates to a method for additive manufacturing of a component based on process parameters, a control system for controlling a method for additive manufacturing of a component based on process parameters and a manufacturing system for additive manufacturing of a component.

[0003] Processes for the additive manufacturing of components are generally known. A manufacturing system designed to carry out the process for the additive manufacturing of components implements the process parameters so that the component is produced. A process parameter can be, for example, a laser power, a powder grain size, or a supplied shielding gas. It is known that such process parameters can be adjusted during the production of a component. Such adjustment can also be based on measured values ​​recorded during the production of the component. For example, German patent application 10 2021 104 440.5 describes the use of a light field camera for this purpose.

[0004] A problem with known control systems is that the recording of measured values ​​and the resulting control or regulation of production takes place with a time delay, because, among other things, the volume of data to be processed is so high that no process-parallel evaluation and adjustment of the process parameters is possible.

[0005] It is an industry requirement to control and regulate the additive manufacturing of components in real time to ensure high component quality. Furthermore, simple system technology and simple data processing are required to ensure the cost-effectiveness of such control systems. Furthermore, such control systems generally require ease of use and, preferably, availability as a retrofit solution.

[0006] It is therefore an object of the invention to provide a method for additively manufacturing a component based on process parameters, a control system for controlling a method for additively manufacturing a component based on process parameters, and a manufacturing system for additively manufacturing a component that reduce or eliminate one or more of the aforementioned disadvantages. It is further an object of the invention to provide a solution that enables real-time control and / or real-time regulation of a method for additively manufacturing a component.

[0007] This object is achieved by a method and a control system according to the features of the independent patent claims. Further advantageous embodiments of these aspects are specified in the respective dependent patent claims. The features listed individually in the patent claims and the description can be combined with one another in any technologically expedient manner, with further embodiments of the invention being demonstrated.

[0008] According to a first aspect, the object mentioned at the outset is achieved by a method for the additive manufacturing of a component, preferably within a process space, based on process parameters, comprising the steps of: detecting state changes relating to the additive manufacturing, in particular within the process space, with an event-based sensor, wherein a state change is characterized by a signal property lying above a threshold value, generating event-based data representing the state changes, and setting at least one of the process parameters based on the event-based data, so that the additive manufacturing is controlled in parallel with the process.

[0009] The invention is based, among other things, on the finding that process-parallel control of additive manufacturing of a component is essentially not possible with the previously common complete acquisition of a monitoring field, since the high data volume does not allow subsequent evaluation and process-parallel adjustment of process parameters, or only allows it to a limited extent, as this is too time-consuming. With the usual complete acquisition, all pixels of a sensor, for example, a camera, are repeatedly output at a fixed time interval, the so-called frame rate, e.g., at 60 fps, which generates the high data volume.

[0010] The inventors have discovered that process-parallel control of additive manufacturing is possible if only an aspect subject to change is recorded within the sensor's detection range. This is the focus of event-based aspect detection, which essentially consists in processing only state changes and not those states that are subject to no or only minor change. This approach results in a reduced volume of measurement data without any significant loss of information. For example, each pixel of the event-based sensor, independent of the other pixels of the sensor, only outputs data when a state change is detected, thereby reducing the data volume. Furthermore, the time intervals between the recorded state changes can vary.Real-time data analysis of high-resolution images is enabled, allowing a multitude of quality- and / or process-critical influencing variables to be monitored simultaneously in real time. Based on this information, real-time adjustment of process parameters is possible. In particular, it is possible to capture high-resolution images during additive manufacturing without the risk that real-time adjustment of process parameters is no longer possible due to a correspondingly high data volume. Such recording of state changes is possible, among other things, with so-called event camera technology, also known as event-based camera technology.

[0011] The process involves the additive manufacturing of a component based on process parameters. Additive manufacturing refers, in particular, to the process steps for shaping the component. This can include, for example, exposing a powder bed to a laser beam, creating a powder bed surface with a coater, or applying a binder.

[0012] Process parameters are understood to mean any parameters related to the additive manufacturing of the component. Depending on the respective additive manufacturing process, different process parameters are the focus of process-parallel adjustment, whereby an applied energy, an inserted material, and / or ambient conditions can often be a process parameter.

[0013] The method comprises the step of detecting state changes relating to additive manufacturing using an event-based sensor, wherein a state change is characterized by a signal property exceeding a threshold value. In particular, the event-based sensor essentially exclusively detects state changes and not those sections of additive manufacturing that do not involve state changes. A state change is characterized by a signal property exceeding a threshold value, wherein a signal property can be a signal intensity and / or a change in a signal intensity.

[0014] An event-based sensor is, in particular, a sensor that always enables signal acquisition by all signal acquisition units, for example, pixels, but only generates an output by the signal acquisition units that detect a change. From a sensor technology perspective, the state change is characterized by a signal property that exceeds a threshold, in particular a signal intensity or a change in signal intensity. For example, the brightness of a melt pool can be monitored, and a state change is only detected or output if the brightness changes by a predetermined difference, whereby this difference can be defined by the threshold.

[0015] The threshold value can be adjusted depending on the processing situation or other parameters. For example, the threshold values ​​for exposing a powder bed can differ from those for creating a powder layer. Furthermore, the event-based sensor can have recording sections, for example, pixels or pixel areas, that have different threshold values. These recording sections can be distributed, for example, as a pattern. Furthermore, the threshold value can be distributed with a gradient across the recording section(s).It may be preferred that the event-based sensor has a first detection section and a second detection section, wherein the first detection section has a first threshold value and the second detection section has a second threshold value different from the first threshold value, so that different sections of the monitoring area can be monitored using different threshold values. Such an event-based sensor allows, for example, the melt pool to be monitored with a first threshold value and the section surrounding the melt pool to be monitored with a second threshold value.

[0016] The event-based sensor is preferably an optical event-based sensor, which can be designed in particular to detect radiation. Furthermore, the event-based sensor can be an acoustic event-based sensor, which can be designed in particular to detect sound waves.

[0017] The method further comprises the step of generating event-based data representing the state changes. These data represent, in particular, only those state changes that can be defined according to the previous description such that they are characterized by a signal property that lies above a threshold value. It can be ensured that only relevant state changes are represented by the data. The event-based data can be generated by the event-based sensor and / or by a control device described below and / or by an additional device.

[0018] In particular, insignificant state changes or aspects of additive manufacturing that are not subject to change at a given acquisition time, such as a non-changing section of a powder bed, are not represented in the data, thus keeping the data volume low. The event-based data can, for example, have one bit per change per signal acquisition unit, such as a pixel.

[0019] The method further comprises the step of adjusting at least one of the process parameters based on the event-based data so that the additive manufacturing is controlled in parallel with the process. It is particularly preferred that the at least one process parameter is adjusted such that the additive manufacturing is controlled in parallel with the process. Adjusting the at least one process parameter particularly relates to changing the process parameter, but can also include keeping the process parameter constant.

[0020] According to a preferred embodiment of the method, it is provided that it comprises the steps of identifying and / or classifying at least one condition characteristic during the production of the component based on the event-based data, and generating a data set based on a result of the identification and / or classification, wherein the data set characterizes the at least one process parameter to be adjusted. A condition characteristic can be, for example, a component condition, a process instability, a process characteristic, and / or a defect.

[0021] According to a further embodiment of the method, the state characteristic relates to a powder bed, a melt pool or a joined material.

[0022] A condition characteristic of the melt pool can be, for example: a melt pool fluctuation, in particular an oscillation of the melt, a geometric formation, in particular in the course of a scan vector, an extension and / or dimension and / or shape of the melt pool, in particular laterally in an XY plane, a penetration depth in the melt pool, also called keyhole formation, as well as a melt pool depth, a bulging and / or wavy shape of the melt pool, for example an elevation in the z-direction, a position of the melt pool in the XY plane, a gloss value of the melt pool, a temperature distribution in the melt pool and in adjacent areas, in particular in the powder bed, on the generated component, a support structure and / or a build platform, a radiation emission, in particular spectral, of the melt pool, which can also be an intensity, moving splashes and / or smoke leaving the melt pool, in particular dimensions, speeds, trajectories,Temperatures and / or emissions of the spatter or smoke, a movement of powder particles, since powder particles adjacent to the melt pool can be drawn into the melt, a heat shimmer in the area of ​​the melt pool, a plasma above the melt pool and in the keyhole, in particular a dimension, a shape, a dynamic, a radiation emission spectrum and / or a temperature, a metal vapor cloud above the melt pool and in the keyhole, in particular a dimension, a shape, a dynamic, a radiation emission spectrum and / or a temperature.

[0023] The condition characteristic relating to the joined material and the powder bed can be, for example: a position, a dimension and / or a shape of the joined and / or wetted surfaces, a material compaction due to melting, in particular a sinking of the exposed surface due to compaction of the material during melting, a weld bead, in particular a dimension, a spacing and / or a regularity of the weld flakes, a slag and / or a tarnish color, a gloss value of the weld seam, a sinking process of binder between the particles, a gloss and / or a color change of particles due to wetting with binders including drying, adhering and / or sintered particles on joined and / or obstructed tracks and / or surfaces, a shrinkage of the solidifying material and / or upon cooling of the solidified material, residual stresses of the joined volume, for example indirectly via shrinkage,a topography of the powder bed, the joined and / or wetted traces and / or surfaces, the component surface, in particular in DED, splashes and / or smoke deposits on a surrounding powder bed and exposure surfaces, the melt beads and the resulting surfaces of a joined material or the build platform, a temperature, a layer thickness, a powder distribution, artifacts in the layer application, a plasma and / or metal vapor cloud, a gas flow, changes and / or movements in the powder bed, foreign bodies, exposure surfaces, in particular a position, a dimension and / or a scaling factor, a scan field offset, a scanner trajectory, in particular a path and / or a speed, a blown-away powder, a powder feed, a wire feed and / or a nozzle.

[0024] A preferred embodiment of the method is characterized in that the at least one set process parameter is or comprises a process energy, a property of a starting material, a property of a coater, a property of the powder bed and / or a protective gas atmosphere.

[0025] The following describes the adjusted process parameters in response to a specific condition characteristic. However, this relationship is not mandatory, and the process parameters can also be adjusted independently of the described condition characteristic.

[0026] In response to a melt pool fluctuation, the following process parameter(s) can be adjusted: spatial and temporal energy input, in particular an adjustment of a laser power, a pulse width, a pulse duration, a pulse shape, a scan speed, a beam shape, a beam width, a focus position, a wobble and / or a micro-movement of the laser during the vector-wise scan, a focus position, which is only summarized below as spatial and temporal energy input; preheating of the powder bed and / or the powder material; partial and / or local re-exposure and / or energy input; stabilization by switching on an additional energy source, for example a laser or a UV lamp.

[0027] In response to a geometric formation, the following process parameter(s) can be adjusted: spatial and temporal energy input; preheating of the powder bed or powder material; re-exposure and / or energy input; on / off delays, jump delays of the scanner or generally of a scanner parameter; adjustment of the sky writing.

[0028] In response to a penetration depth centrally in the melt pool, the following process parameter(s) can be adjusted: spatial and temporal energy input; preheating of the powder bed and / or the powder material.

[0029] In response to a bulging and / or wobble of the melt pool, the following process parameter(s) can be adjusted: spatial and temporal energy input, scanning strategy and / or temporal sequence of the exposure vectors; re-exposure and / or energy input; preheating of the powder bed and / or the powder material.

[0030] In response to a position of the melt pool in the XY plane, the following process parameter(s) can be set: on / off delays and / or jump delays of the scanner and / or general scanner parameters; a scan field correction, for example, mapping in the construction plane; XY offset for correcting a weld seam width, in particular for generating dimensional accuracy of the generated surfaces or components.

[0031] In response to a gloss value of the melt pool, the following process parameter(s) can be set: spatial and temporal energy input; preheating of the powder bed and / or the powder material. In response to a temperature distribution in the melt pool and adjacent areas, for example, the following process parameter(s) can be set: spatial and temporal energy input; a scanning strategy, a temporal sequence of the exposure vectors; re-exposure and / or energy input; preheating of the powder bed and / or the powder material; active cooling of the component, the powder bed, the build chamber and / or system components, in particular the reduction of the temperature of an inert gas; pausing or aborting individual components as well as the build job.

[0032] In response to a radiation emission from the melt pool, the following process parameter(s) can be adjusted: spatial and temporal energy input, a scanning strategy, temporal sequence of the exposure vectors; re-exposure and / or energy input; preheating of the powder bed and / or the powder material; change of the powder.

[0033] In response to moving spatter and / or smoke, the following process parameter(s) can be adjusted: spatial and temporal energy input; scanning strategy, spatial and temporal sequence of the exposure vectors; direction of exposure of the vectors; re-exposure and / or energy input, for example to remove elevations on exposed welds; adjustment of the inert gas flow; preheating of the powder bed and / or the powder material.

[0034] In response to the movement of powder particles, the following process parameter(s) can be adjusted: spatial and temporal energy input; reduction of the kinetic energy in electron beam melting; pre-consolidation of the particles with a defocused beam, in particular before exposure; control of the heating and / or cooling rate; multiple exposure, for example successive introduction of energy, and / or lower power to stretch the energy input over time; pre-heating of the powder bed and / or powder material.

[0035] In response to heat shimmer in the area of ​​the melt pool, the following process parameter(s) can be adjusted: spatial and temporal energy input, preheating of the powder bed and / or the powder material.

[0036] In response to a plasma above the melt pool and in the keyhole, the following process parameter(s) can be adjusted: spatial and temporal energy input; scanning strategy, temporal sequence of the exposure vectors; re-exposure and / or energy input; preheating of the powder bed and / or the powder material; change of the powder.

[0037] In response to a metal vapor cloud above the melt pool and in the keyhole, the following process parameter(s) can be adjusted: spatial and temporal energy input; scanning strategy, temporal sequence of the exposure vectors; repetition of the exposure; preheating of the powder bed and / or the powder material; changing the powder.

[0038] In response to a position, a dimension and / or a shape of the joined and / or wetted surfaces, the following process parameter(s) can be set: on / off delays, jump delays of the scanner, in particular scanner parameters; scan field correction, in particular mapping in the build plane; XY offset for correcting a weld seam width; adaptation of the scanner control signal; spatial and temporal energy input; scan strategy, temporal sequence of the exposure vectors; repetition of the exposure; preheating of the powder bed and / or the powder material.

[0039] In response to material compaction by melting, the following process parameter(s) can be adjusted: Control of the powder layer thickness and / or lowering of the build platform; Adjustment of the alignment and / or orientation of the coater and / or layer-applying element, in particular the rubber lip, the steel blade and / or the brush; Partial or complete replacement of the layer-applying element; Cleaning, reworking and / or post-processing of the layer-applying element; Dosing factor of the powder feed; Spatial and temporal energy input; Scanning strategy, temporal sequence of the exposure vectors; Re-exposure; Preheating of powder bed and / or powder material.

[0040] In response to a property of a weld bead, in particular a dimension of spacing and regularity of weld flakes and / or slag and / or annealing color, the following process parameter(s) can be adjusted, for example: spatial and temporal energy input; scanning strategy, temporal sequence of the exposure vectors; re-exposure; preheating of the powder bed and / or the powder material.

[0041] In response to a weld seam gloss value, the following process parameter(s) can be adjusted: spatial and temporal energy input; scanning strategy, temporal sequence of exposure vectors; re-exposure; preheating of the powder bed and / or the powder material.

[0042] In response to the binder sinking between the powder particles, the following process parameter(s) can be adjusted: binder dosing factor; homogeneity and cadence of the binder droplet; spatial and temporal sequence of the printing strategy; cleaning of the print head; viscosity of the binder; preheating of the powder bed and / or powder material.

[0043] In response to a gloss and / or color change of the particles due to wetting with binder, including drying, the following process parameter(s) can be adjusted: binder dosing factor; homogeneity and cadence of the binder droplet; spatial and temporal sequence of the printing strategy; cleaning of the print head; viscosity of the binder; preheating of the powder bed and / or powder material; drying temperature and / or drying time.

[0044] In response to adhering and / or sintered particles on joined and / or obstructed tracks and / or surfaces, the following process parameter(s) can be adjusted: binder dosing factor; homogeneity and cadence of the binder droplet; spatial and temporal sequence of the printing strategy; cleaning of the print head; viscosity of the binder; preheating of the powder bed and / or powder material; drying temperature and / or drying time; spatial and temporal energy input; scanning strategy, temporal sequence of the exposure vectors; re-exposure.

[0045] In response to shrinkage of the solidifying material and cooling of the solidified material, the following process parameter(s) can be adjusted: exposure with defocused beam; multiple exposure; spatial and temporal energy input; preheating of powder bed and / or powder material.

[0046] In response to residual stress in the joined volume, the following process parameter(s) can be adjusted: exposure with adjusted performance parameters, for example pre-exposure, control of the heating and / or cooling rate, heat treatment; spatial and temporal energy input; scanning strategy, temporal sequence of the exposure vectors; heating of the powder bed and / or powder material and / or the component; switching on an additional energy source; adjustment of the connection and / or the support.

[0047] In response to the topography of the powder bed, the joined and / or wetted traces and / or areas, the component surface, splashes or smoke, and the like, the following process parameter(s) can be adjusted: binder dosing factor; homogeneity and rate of binder droplets; spatial and temporal sequence of the printing strategy; cleaning of the print head; binder viscosity; preheating of the powder bed and / or powder material; drying temperature and / or drying time; spatial and temporal energy input; scanning strategy; temporal sequence of the exposure vectors; adjustment of the layer application parameters; re-application of the powder layer; regulation of the powder layer thickness and / or lowering of the build platform; adjustment of the alignment and / or orientation of the coater and / or the layer-applying element; partial or complete replacement of the layer-applying element;Cleaning or reworking and / or post-processing of the layer-applying element; dosing factor for powder delivery; re-exposure; adjustment of the inert gas flow; leveling of the build platform. In response to a temperature, the following process parameter(s) can be adjusted: spatial and temporal energy input; scanning strategy; temporal sequence of exposure vectors; re-exposure and / or energy input; preheating of the powder bed and / or powder material; active cooling of the component, powder bed, build chamber, and / or system elements; pausing or aborting individual components as well as the build job.

[0048] In response to a layer thickness, the following process parameter(s) can be adjusted: renewed powder layer application; adjustment of layer application parameters, e.g. an application speed and / or a layer thickness; control of the powder layer thickness and / or lowering of the build platform; adjustment of an alignment and / or orientation of the coater and / or layer-applying element, e.g. a rubber lip, steel blade, brush; partial or complete replacement of the layer-applying element, e.g. by means of automatic blade change; cleaning or reworking and / or post-processing of the layer-applying element; dosing factor of the powder feed.

[0049] In response to powder distribution, the following process parameter(s) can be adjusted: renewed powder layer application; adjustment of the layer application parameters, e.g. application speed, layer thickness; control of the powder layer thickness and / or lowering of the build platform; adjustment of the alignment and / or orientation of the coater and / or layer-applying element; partial or complete replacement of the layer-applying element; cleaning or reworking and / or post-processing of the layer-applying element; dosing factor of the powder feed; interruption or termination of production.

[0050] In response to artifacts in the layer application, the following process parameter(s) can be adjusted: adjustment of the layer application parameters; regulation of the powder layer thickness and / or lowering of the build platform; adjustment of the alignment and / or orientation of the coater and / or layer applying element; partial or complete replacement of the layer applying element; cleaning or reworking and / or post-processing of the layer applying element;

[0051] Dosing factor of powder feed; interruption or termination of production.

[0052] In response to the plasma and / or metal vapor cloud, the following process parameter(s) can be adjusted: spatial and temporal energy input; adjustment of the inert gas flow, for example, by adjusting the intensity through power control of the circulation pump, or by controlling the direction through controllable guide vanes, nozzles, and outlets.

[0053] In response to a gas flow, the following process parameter(s) can be adjusted: Adjustment of the inert gas flow, for example by an intensity through power control of the circulation pump, a direction through controllable guide vanes, nozzles, outlets.

[0054] In response to changes and / or movements in the powder and / or powder bed, the following process parameter(s) can be adjusted: Adjustment of the inert gas flow; re-application of the powder layer; adjustment of the layer application parameters; control of the powder layer thickness and / or lowering of the build platform; adjustment of the alignment and / or orientation of the coater and / or layer application element; partial or complete replacement of the layer application element; cleaning or reworking and / or post-processing of the layer application element; dosing factor of the powder feed; pausing or aborting individual components as well as the build job.

[0055] In response to foreign bodies, the following process parameter(s) can be set: pausing or aborting individual components as well as the entire build job; actively removing the foreign body, e.g., using a suction unit or a gripper arm; interrupting or terminating production.

[0056] In response to exposure areas, in particular their position, dimension and / or scaling factor, the following process parameter(s) can be set: on / off delays, jump delays of the scanner; scan field correction; XY offset for correcting the weld seam width, in particular for generating dimensional accuracy of the generated areas and / or components; focus position.

[0057] In response to a scan field offset, the following process parameter(s) can be set: on / off delays, jump delays of the scanner; scan field correction; XY offset for correcting the weld seam width, in particular to ensure dimensional accuracy of the generated surfaces and / or components; focus position.

[0058] In response to a scanner trajectory, in particular a path and / or a speed, the following process parameter(s) can be adjusted: on / off delays, jump delays of the scanner; adaptation of the scanner control signal; overshoot; scan field correction, in particular mapping in the build plane.

[0059] In response to powder blown away, the following process parameter(s) can be adjusted: re-application of powder layer; adjustment of the inert gas flow.

[0060] In response to powder feeding, wire feeding and / or nozzle feeding, the following process parameter(s) can be adjusted: renewed powder application, in particular powder layer application; adjustment of the layer application parameters; cleaning or reworking and / or post-processing of the layer-applying element; dosing factor of the powder feed; cleaning of the print head and / or nozzle.

[0061] In a further preferred embodiment of the method, the threshold value is adjusted based on a manufacturing situation. By adjusting the threshold value, for example, a sensitivity, the data volume can be reduced or controlled while taking into account the phenomenon to be detected. For example, the threshold value can be increased in the case of high fluctuations in the intensity of the melt pool, so that minor changes in the surroundings of the melt pool are masked out.

[0062] A phenomenon can be the image of a physical event on the sensor. These can be characterized by: the magnitude of the change in intensity, the number of pixels simultaneously emitting a signal, in particular the size of the phenomenon, the temporal sequence on a pixel, especially slow or fast phenomena, the temporal sequence across multiple pixels, especially high-frequency, large-area fluctuations, melt pools, high-frequency or short-term, small-area state changes, and flying splashes. The states can be derived and classified from the characteristics of the phenomena emitted by the sensor.

[0063] It is preferred that the threshold be adjusted depending on spatial aspects and / or a temporal sequence. A spatial dependency can occur, for example, depending on the expected phenomenon, such as with an on-axis arrangement of the event-based sensor and detection of the melt pool. Furthermore, the threshold can be determined depending on a process step; for example, a different threshold may be considered when exposing the melt pool than when using a coater to create another powder layer.

[0064] In a further preferred embodiment of the method, the state changes are detected with a first event-based sensor and a second event-based sensor, wherein the state changes are preferably detected three-dimensionally, so that the event-based data characterize the state changes three-dimensionally to enable a more precise adjustment of the at least one process parameter. Furthermore, it is preferred that the first event-based sensor has a first threshold value and the second event-based sensor has a second threshold value different from the first threshold value in order to detect different state changes.

[0065] In a further preferred embodiment of the method, it is provided that the state changes are detected with an additional sensor, in particular a light field camera, an RGB camera, a monochrome camera or a photodiode, so that the event-based data are expanded by additional data in order to detect the state changes in particular using quotient pyrometric methods.

[0066] The additional sensor can be used to supplement the data generated by the event-based sensor with contextual information. For example, the movement of a spatter in the vicinity of a melt pool detected by the event-based sensor can be linked to location information. The additional sensor can also capture a scene from a different perspective, e.g., off-axis and / or on-axis, and / or a background image that is not subject to change. When using a light-field camera and / or a stereo configuration, this can be 3D videometric information. For example, the topography of the build plane, e.g., of the powder bed and printed areas, the size and direction of flight of a spatter, or an overall state of the process can be described in more detail.

[0067] Furthermore, the additional sensor enables simplified characterization of the states detected with the event-based sensor by adding context information. Context information may, for example, indicate no change in a signal property or a change below the threshold value, so these would not be detected with the event-based sensor.

[0068] A combination with a light-field camera is particularly preferred, since the data from the light-field camera representing the three-dimensional information can be advantageously combined with the data from the event-based sensor. For example, the event-based sensor can be used to capture rapid state changes between two frames of the light-field camera.

[0069] The additional sensor can be designed as a separate sensor or as a sensor unit combined with the event-based sensor.

[0070] A preferred development of the method is further characterized in that it comprises the steps of: detecting state changes in a fast operation, wherein the state changes in the fast operation are detected in such a way that they are represented with a first data set having a first data volume, and detecting state changes in a normal operation, wherein the state changes in the normal operation are detected in such a way that they are represented with a second data set having a second data volume, wherein the first data volume is smaller than the second data volume, so that the at least one process parameter can be set in a fast operation parallel to the process in data-intensive manufacturing situations.

[0071] The ability to set fast mode reduces the level of detail and resolution, thus reducing the data volume and allowing the initial data set to be processed more quickly, enabling process-parallel production control. Furthermore, the phenomena to be observed can be narrowed down in fast mode. For example, the threshold value described above can be higher in fast mode than in normal mode.

[0072] It is preferred that the detection of the state changes and the generation of the event-based data during and after setting up a printing process and each layer generation, during and after the printing process of each layer generation, during and after the

[0073] Printing process of each layer creation, during and after

[0074] Post-processing of each layer creation in the printing process, during and after the application of a new powder layer and / or after the production of the component.

[0075] For example, this can occur when leveling the build platform and / or positioning the workpiece, when setting up the layer-applying element, when creating an initial powder layer and / or layer to complete a build job, for example during an interruption, during exposure by, for example, a process laser, an electron beam and / or directed radiation, during introduction of the binder, during introduction of an additive, during the recording of each printed layer and / or the printed workpiece, during lowering of the build platform and / or repositioning of the workpiece.

[0076] Furthermore, this can be done in-line during subtractive machining, such as contour milling or recessing, in-line during powder removal, and / or in-line during the introduction of non-powder elements, such as an RFID chip. Furthermore, this can be done before and after lowering the build platform and / or repositioning the workpiece, in-line during the conveying of the powder material, in-line during the powder layer application, and / or after the powder application.

[0077] Furthermore, this can be done either during the cooling process or during the unpacking of the workpiece from the powder bed. Furthermore, it can be a 3D scan of the printed workpiece after relative movement to the event-based sensor.

[0078] According to a further aspect, the object mentioned at the outset is achieved by a control system for controlling a method for the additive manufacturing of a component based on process parameters, comprising an event-based sensor which can be arranged and is designed to detect changes in state relating to the additive manufacturing, in particular within a process space, wherein a change in state is characterized by a signal property which lies above a threshold value, and a control device which is designed to set at least one process parameter based on the event-based data representing the changes in state, so that the additive manufacturing can be controlled in parallel with the process.

[0079] An event-based sensor only generates data when it detects a change in state. The event-based sensor can, for example, have a large number of individual pixels. The pixels are designed to receive light. The pixel measures the brightness signal, which often first passes through an amplifier circuit and then reaches a comparator, where the brightness signal is compared with a previous value. If the brightness signal increases or decreases, a change in state can be detected, for example, if the change exceeds a threshold that defines a change. Instead of a matrix of pixel values, as with conventional image sensors, a data stream is sent, preferably of event values, which uses the pixel coordinates, the time of the event, and the light polarity for each pixel that has detected a change.It enables the control system to control additive manufacturing exclusively based on state changes.

[0080] In a preferred embodiment of the control system, it is provided that the control device is configured to identify and / or classify at least one state characteristic during the production of the component based on the event-based data and to generate a data set based on a result of the identification and / or classification, and the data set characterizes the at least one process parameter to be adjusted.

[0081] It is further preferred that the control device is configured to adjust the threshold value based on a manufacturing situation.

[0082] In a further preferred embodiment of the control system, it is provided that it comprises a second event-based sensor, wherein the control device is configured such that the event-based data characterize the state changes three-dimensionally to enable a more precise adjustment of the at least one process parameter. It is particularly preferred that the first event-based sensor has a first threshold value and the second event-based sensor has a second threshold value different from the first threshold value in order to detect various state changes.

[0083] It is further preferred that the control system comprises an additional sensor, in particular a light field camera, an RGB camera, a monochrome camera or a photodiode, which can be arranged and is designed to detect changes in state, wherein the control device is designed to expand the event-based data and additional data in order to detect the change in state in particular using quotient pyrometric methods.

[0084] In a further preferred embodiment of the control system, it is provided that the first event-based sensor, the second event-based sensor and / or the additional sensor can be arranged and designed to detect state changes in a fast mode, wherein the state changes in the fast mode can be detected in such a way that they can be represented with a first data set having a first data volume, and to detect state changes in a normal mode, wherein the state changes in the normal mode can be detected in such a way that they can be represented with a second data set having a second data volume, wherein the first data volume is smaller than the second data volume. It is further preferred that the control system comprises an optical unit. The optical unit can in particular be arranged and designed to vary a monitored area, the so-called field-off view.This can be particularly advantageous for monitoring specific states, sub-aspects, and / or events during ongoing process operations. The optical unit can, for example, comprise a camera lens, a lens configuration, a mirror, a filter, a plenoptic lens array, MEMS mirrors, and / or light field lenses.

[0085] In a further preferred embodiment of the control system, it is provided that it has a lighting unit, which can be arranged and configured, in particular, to illuminate a monitored area. The lighting unit can have one, two, or more lighting elements. The lighting unit can, in particular, be configured to provide continuous, pulsed, diffuse, directed, patterned, homogeneous, spectrally dispersed, monochrome, polychrome, on-axis, and off-axis illumination. Furthermore, it can be coherent, incoherent, polarized, and / or unpolarized.

[0086] The lighting unit can be designed, for example, as or comprise an LED, a laser diode, a thermal radiator, a black body radiator, a halogen, an OLED, a plasma, and / or a gas radiator. Furthermore, the lighting unit can be designed for passive illumination.

[0087] It is further preferred that a monitored area can be adjusted, for example via a MEMS, a shutter, optical apertures, optical filters, moving mirrors and / or polarization.

[0088] According to a further aspect, the object mentioned at the outset is achieved by a manufacturing system for the additive manufacturing of a component, comprising a process space in which the component can be additively manufactured based on process parameters, a process unit which can be adjusted with at least one process parameter and which acts within the process space, a control system which is coupled to the process unit by means of signals according to one of the embodiments described above, wherein the event-based sensor is arranged such that changes in state relating to the additive manufacturing can be detected within the process space.

[0089] The process space can, for example, be the build space of an additive manufacturing machine. It can also be the workspace of a robot.

[0090] The process unit is, in particular, a unit for carrying out additive manufacturing. This can be a laser or a coating unit, as explained in more detail below.

[0091] In a preferred embodiment of the manufacturing system, the process unit for beam-based manufacturing is designed with a beam path, and the event-based sensor is arranged within the beam path. Such a process unit can be, for example, a laser unit.

[0092] A preferred development of the manufacturing system is further characterized in that the process unit comprises: an exposure unit, in particular a laser unit, which is arranged and configured to expose a powder bed in the process chamber with a high-energy beam in order to selectively solidify powder of the powder bed. Furthermore, the process unit can comprise a coating unit, which is arranged and configured to produce a flat powder bed surface of the powder bed. It is further preferred that the exposure unit and / or the coating unit can be adjusted, in particular controlled and / or regulated, using the at least one process parameter.

[0093] In a further preferred embodiment of the manufacturing system, the event-based sensor is arranged on the coating unit.

[0094] Furthermore, it is preferred that the event-based sensor be arranged on a movable handling unit. The handling unit can be, for example, a robot, a tripod, a gantry, or a linear unit.

[0095] For further advantages, design variants, and details of the individual aspects and their possible refinements, please refer to the description of the additional aspects, the corresponding features, and refinements. Preferred embodiments are illustrated by way of example in the accompanying figures. They show:

[0096] Figure 1 : a schematic, two-dimensional view of an exemplary

[0097] Embodiment of a manufacturing system;

[0098] Figure 2: a schematic, two-dimensional plan view of the manufacturing system shown in Figure 1;

[0099] Figure 3: a schematic representation of a process; and

[0100] Figure 4: a schematic representation of another method.

[0101] In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals.

[0102] The manufacturing system 100 shown in Figures 1 and 2 is designed for the additive manufacturing of a component 104. In particular, the manufacturing system 100 is designed for powder-bed-based additive manufacturing. For this purpose, the manufacturing system 100 comprises a process chamber 102 provided as a build space, in which a powder 132 is arranged. The process chamber 102 is bounded at the bottom by a table 114, wherein the table 114 can be moved back and forth by a vertically movable lowering unit 116.

[0103] This arrangement allows the component 104 to be built up layer by layering a first powder layer and selectively solidifying it with the exposure unit 108. Subsequently, the table 114 can be lowered, and a new powder layer can be applied by the coating unit 110, which can be moved back and forth in the direction of movement 112. This new layer can then be solidified again with the exposure unit 108. The processing chamber 102 is bounded laterally by, among other things, the frame 118.

[0104] The manufacturing system 100 comprises a process unit 106. The process unit 106 comprises the exposure unit 108 and the coating unit 110. Furthermore, the manufacturing system 100 comprises a control system 120. The control system 120 is configured to control the method for additively manufacturing the component 104 based on process parameters. The control system 120 comprises a first event-based sensor 122 and a second event-based sensor 124, which are arranged and configured to detect state changes relating to the additive manufacturing process, wherein a state change is characterized by a signal property above a threshold value, in particular a signal intensity and / or a change in a signal intensity.

[0105] Furthermore, the control system 120 comprises a control device 128 which is configured to adjust at least one process parameter based on the event-based data representing the state changes, so that the additive manufacturing can be controlled in parallel with the process.

[0106] The manufacturing system 100 further comprises a lighting unit 130 with which the process space 102, in particular a powder bed surface, can be illuminated.

[0107] The method shown in Figure 3 is intended for the additive manufacturing of a component based on process parameters. In step 200, state changes relating to additive manufacturing are detected using an event-based sensor 122, 124, wherein a state change is characterized by a signal property exceeding a threshold value. In step 202, the event-based data representing the state changes are generated. In step 204, at least one of the process parameters is adjusted based on the event-based data, so that additive manufacturing is controlled in parallel with the process.

[0108] The method shown in Figure 4 is designed for the additive manufacturing of a component based on process parameters. In step 300, the state changes relating to additive manufacturing are detected using an event-based sensor. In step 302, the event-based data representing the state changes are generated. In step 304, at least one state characteristic is identified during the manufacturing of component 104 based on the event-based data. In step 306, this state characteristic is classified.

[0109] In step 308, a data set is generated based on a result of the classification, wherein the data set characterizes the at least one process parameter to be adjusted. The method described above, the control system 120, and the manufacturing system 100 have the advantage that a process-parallel adjustment of process parameters is generated even in complex monitoring situations. This further enables process-parallel control and / or regulation of the additive manufacturing of the component.

[0110] REFERENCE SYMBOL

[0111] 100 manufacturing system

[0112] 102 Process room

[0113] 104 Component 106 Process unit

[0114] 108 exposure unit

[0115] 110 Coating unit

[0116] 112 Direction of movement

[0117] 114 Table 116 Lowering unit

[0118] 118 frame

[0119] 120 Control system

[0120] 122 first event-based sensor

[0121] 124 second event-based sensor 126 additional sensor

[0122] 128 Control device

[0123] 130 lighting unit

[0124] 132 powder

Claims

CLAIMS Method for the additive manufacturing of a component (104) based on process parameters, comprising the steps: detecting changes in state relating to additive manufacturing with an event-based sensor (122, 124), wherein a change in state is characterized by a signal property that is above a threshold value; Generating event-based data representing the state changes; and Adjusting at least one of the process parameters based on the event-based data so that the additive manufacturing is controlled in parallel. The method according to claim 1, comprising the steps: Identifying and / or classifying at least one condition feature during the manufacture of the component (104) based on the event-based data, and Generating a data set based on a result of the identification and / or classification, wherein the data set characterizes the at least one process parameter to be adjusted. Method according to one of the preceding claims, wherein the state feature relates to a powder bed (132), a melt pool, or a joined material. Method according to one of the preceding claims, wherein the at least one adjusted process parameter is or comprises a process energy, a property of a starting material, a property of a coater, a property of the powder bed (132), and / or a protective gas atmosphere. Method according to one of the preceding claims, wherein the threshold value is adjusted based on a manufacturing situation. Method according to one of the preceding claims, wherein the state changes are detected with a first event-based sensor (122) and a second event-based sensor (124), - wherein the state changes are preferably recorded three-dimensionally, so that the event-based data characterise the state changes three-dimensionally in order to enable a more precise adjustment of the at least one process parameter, and / or - wherein preferably the first event-based sensor (122) has a first threshold value and the second event-based sensor (124) has a second threshold value different from the first threshold value in order to detect various state changes. The method according to one of the preceding claims, wherein the state changes are detected with an additional sensor (126), so that the event-based data are expanded with additional data, in particular to detect the state changes using quotient pyrometric methods. The method according to one of the preceding claims, comprising the steps: Detecting state changes in a fast mode, wherein the state changes in the fast mode are detected in such a way that they are represented with a first data set having a first data volume; and Detecting state changes in normal operation, wherein the state changes in normal operation are detected in such a way that they are represented with a second data set having a second data volume; - wherein the first data volume is smaller than the second data volume, so that the at least one process parameter in data-intensive manufacturing situations can be adjusted in parallel with the process in rapid operation. A control system (120) for controlling a method for the additive manufacturing of a component (104) based on process parameters, comprising an event-based sensor (122) that can be arranged and is designed to detect state changes relating to the additive manufacturing, wherein a state change is characterized by a signal property that lies above a threshold value; and a control device (128) that is configured to adjust at least one process parameter based on the event-based data representing the state changes, such that the additive manufacturing can be controlled in parallel with the process.The control system (120) according to the preceding claim, wherein the control device (128) is configured to identify and / or classify at least one state feature during the production of the component (104) based on the event-based data, and to generate a data set based on a result of the identification and / or classification, and the data set characterizes the at least one process parameter to be adjusted. The control system (120) according to one of the preceding claims, wherein the control device (128) is configured to adapt the threshold value based on a production situation. The control system (120) according to one of the preceding claims, comprising a second event-based sensor (124). - wherein the control device (128) is configured such that the event-based data represent the state changes characterize three-dimensionally to enable a more precise adjustment of at least one process parameter, - wherein preferably the first event-based sensor (122) has a first threshold value and the second event-based sensor (124) has a second threshold value different from the first threshold value in order to detect various state changes. The control system (120) according to one of the preceding claims, comprising an additional sensor (126), in particular a light-field camera, an RGB camera, a monochrome camera, or a photodiode, which can be arranged and is designed to detect state changes. - wherein the control device (128) is configured to expand the event-based data with additional data, in particular to detect the state changes using quotient pyrometric methods. The control system (120) according to any one of the preceding claims, wherein the first event-based sensor (122), the second event-based sensor (124), and / or the additional sensor (126) are arranged and configured to detect state changes in a rapid mode, wherein the state changes in the rapid mode are detectable in such a way that they can be represented with a first data set having a first data volume, and to detect state changes in a normal mode, wherein the state changes in the normal mode are detectable in such a way that they can be represented with a second data set having a second data volume; - wherein the first data volume is smaller than the second data volume. Manufacturing system (100) for additive manufacturing of a component (104), comprising a process chamber (102) in which the component (104) can be additively manufactured based on process parameters, a process unit (106) which can be adjusted with at least one process parameter and acts within the process chamber, a control system according to one of the preceding claims 9-14 which is coupled to the process unit (106) by means of signals, - wherein the event-based sensor (122, 124) is arranged such that changes in state relating to additive manufacturing can be detected within the process space (102). The manufacturing system (100) according to the preceding claim, wherein the process unit (106) is configured for beam-based manufacturing with a beam path, and the event-based sensor (122, 124) is arranged within the beam path. The manufacturing system (100) according to one of the preceding claims, wherein the process unit comprises: an exposure unit (108) arranged and configured to expose a powder bed (132) in the process space (102) with a high-energy beam in order to selectively solidify powder of the powder bed, and / or a coating unit (110) arranged and configured to produce a flat powder bed surface of the powder bed (132). - wherein the exposure unit (108) and / or the coating unit (110) can be adjusted with the at least one process parameter. The manufacturing system (100) according to any one of the preceding claims, wherein the event-based sensor (122, 124) is arranged on the coating unit (110). The manufacturing system (100) according to any one of the preceding claims, wherein the event-based sensor (122, 124) is arranged on a movable handling unit.

Images