EP3703890A1

EP3703890A1 - Method for measuring a base element of a construction cylinder arrangement, with deflection of a measuring laser beam by a scanner optical system

Info

Publication number: EP3703890A1
Application number: EP18789392.0A
Authority: EP
Inventors: Markus Pieger; Frederik SCHAAL; Simon DAMBACH; Valentin BLICKLE
Original assignee: Trumpf Laser und Systemtechnik GmbH
Current assignee: Trumpf Laser und Systemtechnik GmbH
Priority date: 2017-11-03
Filing date: 2018-10-17
Publication date: 2020-09-09
Also published as: CN111295259B; US20200263978A1; US11628621B2; WO2019086250A1; CN111295259A; DE102017219559A1

Abstract

The invention relates to a method for measuring a base element (13), particularly a substrate (13a) or a preform (13b), of a construction cylinder arrangement (11), the construction cylinder arrangement (11) being arranged on a machine (1) for the additive manufacturing of three-dimensional objects (2) by sintering or melting a powdery material (6) using a high-energy beam (16), in which the base element (13) can be moved by means of a piston (12) in the substantially cylindrical base body (14) of the construction cylinder arrangement (11), a measurement pattern (50) is produced from laser light that illuminates at least part of the base element (13), for measuring the base element (13), and sites of incidence (A1, A2) of the laser light are observed and evaluated with a camera (21), resulting in the determination of measuring data about the base element (13), comprising position information and/or orientation information and/or information about the three-dimensional shape of at least part of the surface (01-03) of the base element (13). Said method is characterised in that the measurement pattern (50) is produced from laser light by deflection of a laser beam (24) of a measuring laser (23) by a scanner optical system (19) such that differently deflected laser beams (24a) are produced and the deflected laser beams (24a) are oriented at least towards the part of the base element (13), and in that the camera (21) is arranged in a laterally offset manner in relation to the deflected laser beams (24a). The invention provides a method for measuring a base element, which is simple, can be used in a flexible manner, and only requires a small amount of space in the processing chamber.

Description

Method for measuring a base element of a construction cylinder arrangement, with deflection of a measuring laser beam by a scanner optics

The invention relates to a method for measuring a base element, in particular a substrate or a preform, a construction cylinder arrangement,

wherein the construction cylinder arrangement is arranged on a machine for producing three-dimensional objects in layers by sintering or melting powdered material with a high-energy beam, wherein the base element in a substantially cylindrical

Base body of the construction cylinder arrangement is movable with a piston, in particular wherein the piston has an upper piston part, on which the base member is arranged, and a lower piston part, opposite to the upper piston part by means of at least two, preferably three , Adjusting elements is alignable, wherein for measuring the base element, a measurement pattern of laser light is generated, which illuminates at least a part of the base element, and locations of the laser light are observed and evaluated with a camera and thus survey data on the base element, comprising position information and / or orientation information and / or

Information about the three-dimensional shape of at least a part of the surface of the base member to be determined.

Such a method has become known from WO 2016/207258 A1.

By layering three-dimensional objects by means of sintering or melting with a high energy beam, in particular a laser beam or electron beam, object geometries can be fabricated with the

conventional techniques (for example, based on a casting process or milling a solid body) are not accessible.

In this case, a thin layer of powdered material is applied to a base element, usually a substrate (also called a construction platform) or a preform in a structural cylinder (also called a construction chamber) and then heated at selected locations with a high-energy beam until the powdered material melts or sinters , Subsequently, the

Lowered base element via an associated piston part in the structural cylinder by a layer thickness of the powder, applied another layer of the powdery material and again at selected locations through the

High energy beam heated, and so on. The building cylinder is attached to an Anschiuss a process chamber.

For a good manufacturing accuracy, the base element must be aligned in the construction cylinder. In particular, by preheating the powdery material may cause deformation, in particular a tilting of the Base element in the construction cylinder or come relative to the rest of the process chamber.

From WO 2016/207258 A1, a construction cylinder arrangement has become known, in which a substrate is fastened to an upper piston part, which is detachably fastened to a central piston part. The middle Kolbentei! is in turn arranged on a lower piston part and aligned with respect to this by means of three Stelleiementen. Furthermore, a measuring device is provided, wherein three laser diodes each generate a laser line at an oblique angle at different locations on a gap between a reference surface, such as a process chamber bottom, and the substrate, and wherein a camera system detects the various locations individually. In this case, the beam path of a camera is directed by a scanner optics of the processing laser beam, wherein the scanning position of the camera is switched by means of the scanner optics. The scanner optics are arranged centrally above the substrate.

With the measuring device, an offset of laser line parts can be detected at the gap, and thereby determines a tilt of the substrate and corrected by means of the adjusting elements. The arrangement of the three

However, laser diodes require a relatively large amount of space in the process chamber. The laser diodes must be specially aligned for the type of construction cylinder used, whereby this procedure is complicated and inflexible in the establishment. Also, the information available with the laser diodes is limited.

From DE 10 2016 106 403 A1 a method for calibrating a scanning system of a laser sintering or laser melting system has become known, in which a line pattern is generated by a scanning system on a surface in the plane of a construction field. Object of the invention

The invention has for its object to provide a simple and flexible method for measuring a base element, which manages with less space in the process chamber.

Brief description of the invention

This object is achieved by a method of the type mentioned, which is characterized

in that the measuring pattern is generated from laser light by deflecting a laser beam of a measuring laser from a scanner optics, so that differently deflected laser beams are generated, and the deflected laser beams are directed at least to the part of the base element,

and that the camera is laterally offset from the deflected laser beams.

In the present invention, a scanner optics is used to direct a laser beam in rapid succession in different directions and thus to produce differently deflected laser beams. These

differently deflected laser beams can be used to measure the base element, such as in a frame

Triangulation.

Depending on the application or measurement task, different measurement patterns can be generated by means of the scanner optics, wherein only the activation of the scanner optics needs to be changed (reprogrammed). In particular, no structural changes to the hardware are required to change the measurement pattern. An adaptation of the measuring pattern to a

(Expected) geometry of a base element, such as a preform, is easily possible, for example via inputs to the control software. It can be flexible Survey data are determined to base elements, in particular

Positions, such as altitudes, or tilting be measured, or even three-dimensional structures (such as preforms, or

Layer measurements). The obtained survey data can be used to correct the position and / or orientation of the base member prior to commencing fabrication of a three-dimensional object, and / or a subsequent process of layering a three-dimensional object to the found position, orientation and / or shape of the base member adapt.

In addition, only a single measuring laser is required for generating the measuring pattern, even if laser beams deflected at different points of the base element (approximately at three points distributed in the peripheral area in the edge region of the base element) are required. With the

Scanner optics, the desired locations can be illuminated in rapid succession. Meanwhile, the exposure of the camera for an integral image capture done; Alternatively, a separate image recording with the camera can be made for different locations (or for respective partial measurements).

The measurement pattern may be limited to the base element or a part thereof, or also additional parts of a reference structure (which is stationary in the machine, and in particular does not move with the piston) illuminate.

The measuring laser can be arranged in the process chamber or preferably outside the process chamber, so that little or no space is required in the process chamber for this purpose; likewise, the scanner optics can be arranged inside or preferably outside the process chamber. Due to the lateral offset of the camera (or the picture-capturing

Camera lens) with respect to the respective deflected laser beam is achieved that a shift of the impact location of the deflected laser beam in the beam propagation direction to a shift in the image of the

Impact in the image plane of the camera leads. As a result, the local height of the base element (measured mostly vertically, essentially along the deflected laser beam) can be determined.

Typically, for a given measurement pattern, a target image ("calibrated zero position") is stored in an evaluation device, and from the

Deviations of a measured image of the camera to the target image, the measurement information on the base element (such as a tilt or altitude) is determined. To improve the measurement accuracy (in particular repeatability), several measurements can be performed and an average measurement result can be determined.

The measuring laser is typically a separate laser used only for the measurement of the base element. Alternatively, a pilot laser or a processing laser can be used as measuring laser. Preferably, the measuring laser is power stabilized (for example, to a maximum of 5% power fluctuation or better) in order to achieve a good measurement resolution. The measuring laser can have a reduced coherence (for example, with 10 nm bandwidth or better, i.e. even higher bandwidth), which is a reduction in the so-called

causes laser speckle and thereby also improves the measurement resolution. The laser wavelength of the measuring laser can be visible

Spectral range, for example, in the red spectral range (around 650 nm).

Within the scope of the invention, high measurement resolutions (position resolutions) are possible. Typically, the camera and measuring laser are set up so that a measuring resolution of 100 μm or better, preferably 50 μm or better, particularly preferably 15 μm or better, is achieved. The measurements are reliable, robust and fast (no artifacts due to powder application, no iterative coating needed); the measurements do not require any

Coatings or powder wear (such as by oxidation).

Preferred variants of the invention

In a preferred variant of the method according to the invention, the measurement of the base element also determines at least a tilting of the base element relative to a reference structure. As a result, a common in preheating the powdery material type of

Deformation are detected, whereby a corresponding correction is made possible. The reference structure is stationary in the machine, such as the bottom of a process chamber. Note that the reference structure does not necessarily need to be illuminated by the measurement pattern.

An advantageous development of this variant provides that the measurement pattern illuminates at least part of the base element in three

includes different zones. This allows easy determination of the tilt (i.e., two tilt angles) without further assumptions. One measuring point is sufficient for each zone; usually, however, several measuring points per zone are evaluated. As an alternative to this variant, it is also possible, for example, to lay two lines over the base element and to determine their distance from respective nominal lines; however, the measurement pattern can also comprise more than two lines. It is also possible, instead of lines, to use line trains or more complex, e.g. curved to insert patterns.

It is preferred if the locations of at least two, preferably three, of the zones substantially correspond to the locations of actuating elements with which the base element can be tilted relative to the reference structure.

As a result, the control (or the software) for the location elements is special easy.

It is likewise preferred if the measurement pattern in each of the three zones comprises a plurality of laser points, in particular one laser line in each case. Multiple laser points can reduce noise by averaging. In addition, speckle patterns are reduced by moving a laser spot along a line. General is for the determination of a single

Measurement information about the base element the use of multiple

Laser points or a laser line (traversing laser point) preferred.

In a preferred variant, at least one three-dimensional determination of at least one part of a surface of the base element, in particular of the preform, is performed by the measurement. By means of the scanner optics it is also possible to scan the surface of a base element and thus to determine or check its shape. Bad base elements can be detected and sorted out. Likewise, it is possible to make corrections for the subsequent layered application of material, and to grow for example in material supernatants only later with powdered material, or prematurely with powdery material returns in material

To grow material.

An advantageous development for this purpose provides that the measurement pattern comprises a line-by-line scanning of at least the part of the surface of the base element, wherein during the line-by-line scanning a plurality of

Single shots to be made with the camera. By doing so, even larger parts of the surface can be detected easily. From the individual images (images) can then be combined a total measurement or total information.

Also preferred is a variant in which at least a determination of the height position of the base element with respect to a by the measurement Reference structure is done. Thus, the altitude can be corrected if necessary (for example via a method of the piston in the body) to ensure a correct focus position of the processing laser. Note that the measurement pattern does not necessarily have to illuminate the reference structure.

In an advantageous variant, a comparison of the observed with the camera impact locations of the laser light on the base element with expected points of incidence of the Laseriichts on the

Base member,

in particular wherein the measurement pattern exclusively illuminates the base element and / or only points of incidence of the laser light are evaluated on the base element. In this particularly simple variant, no reference structure needs to be illuminated. This also allows one

particularly reliable measurement of the base element; any

Dirt or errors in the reference structure are irrelevant.

Variants for the multiple use of machine components

In a particularly preferred variant it is provided that the machine further comprises a processing laser, and that after the measurement of the base element then for the production of layers of at least one three-dimensional object on the base member at least parts of

Layers of powdered material on the base element with

Processing patterns are illuminated from laser light, the

Processing patterns are generated by a laser beam of the

Processing laser is deflected by said scanner optics. This duplicates the scanner optics (for triangulation measurement and for editing). The method is characterized particularly cost effective; the machine for layered production can be made particularly compact. Also preferred is a variant in which it is provided that after the measurement of the base element then for the production of layers

At least one three-dimensional object on the base element layers of powdered material are applied to the base member, wherein the layers of powdered material prior to application of the

High-energy beam with the said camera to be visually checked.

As a result, the camera is used twice (as a powder image camera and

Triangulationskamera). The method is characterized particularly cost effective; The machine for layered production can be particularly compact

be formed.

Method with calibration via a measurement sequence and a reference measurement sequence with traversing base element

In a preferred variant of the method according to the invention, it is provided

in that the measurement pattern comprises at least one triangulation point, that points of incidence of the at least one in a measurement sequence

Triangulation point at different travel positions of the

Base element in the body are observed with the camera and associated Meßsequenzdaten be obtained, wherein the triangulation point is generated by a deflected laser beam which is directed at a fixed angle during the measuring sequence to the base member,

that the measurement sequence data are compared with reference measurement sequence data from a reference measurement sequence, wherein in the context of the reference measurement sequence locations of the at least one triangulation point at different movement positions of a reference base element in the base body were observed with the camera and the associated

Reference triangulation point was generated by a deflected laser beam which, under a reference angle fixed during the reference measurement sequence to the reference Basic element was addressed,

and that from the comparison of the measurement sequence data and the reference measurement sequence data correction information for the measurement of the

Base element is derived.

With the correction information in particular a pointing instability or drift of the measuring laser or the associated scanner optics can be compensated in the measuring system, which leads to errors such as in the position determination in a triangulation. The correction factor may, for example, be a height offset in the region of a (particular) triangulation point; By means of a precise traversing mechanism of the piston, such a height offset can be compensated. The trajectory of the build platform is usually a very precisely adjustable axis. Due to the specified procedure, their precision (in particular in the case of the height variation in the reference measurement) can also be used for the calibration of a machine for the layered production of three-dimensional objects or their measuring system. The measurement sequence and the reference measurement sequence are usually (at least slightly) exposed to different locations on the base element, whereby an averaging of measurements independent of speckle effects is achieved. This can also improve the precision of the calibration or the associated layer-wise production of a three-dimensional object. Typically, at least five, preferably at least ten

Measure measuring points (positioning positions) for each measuring sequence or reference measuring sequence.

The reference measurement sequence is typically performed once upon commissioning of a machine for the layered production of three-dimensional objects; the measurement sequence is typically executed at the beginning of a new construction job. In most cases, the measurement sequence and the reference measurement sequence apply the same measurement pattern or at least similar measurement patterns; the measurement patterns can also be different. The comparison of Reference measurement sequence data and the measurement sequence data takes place

typically via parameters derived from the reference measurement sequence data and / or the measurement sequence data.

Typically, the correction information is used to determine the position or orientation of the base member and readjust, if necessary, to effect the most accurate, subsequent production of the three-dimensional object.

In the simplest case, directly desired survey data about the base element can be obtained with the measurement sequence data or a part thereof and the correction information. However, it is also possible, after receiving the correction information, to promptly carry out a further measurement according to the invention of the base element, for example using a different measurement pattern, and to continue to use the correction information for this measurement.

Preferred is a development of the above variant, in which that the

Measuring pattern comprises at least three, preferably at least four triangulation points,

preferably wherein the triangulation points are formed as corner points of the measuring pattern, to which straight sections of the measuring pattern adjoin,

particularly preferred wherein the triangulation points are formed as vertices of a rectangular measuring pattern. By means of three or more triangulation points, an orientation of the base element can be determined, for example a tilt with respect to two axes. If desired, five or even more triangulation points may be provided. The determination of vertices of a measurement pattern is particularly simple and reliable over the extrapolation of straight sections by means of automatic image analysis software possible. When using a rectangular measuring pattern ("square"), the determination of the position of the Corner points further simplified, since the edges along the pixel axis of the camera sensor can be oriented.

Particularly preferred is a development that provides that from the

Measurement sequence data and the reference measurement sequence data each one or more curve parameters, in particular hyperbola parameters are determined, each describing a curve, in particular hyperbolic curve (91, 92), which in each case the observed impact locations as a function of the movement position of the base member in the main body anfittet. By fitting curves and using curve parameters, the speckle error is easily extracted from the measurement data. The determination of the correction information about the curve parameters can be increased with

Accuracy done. As fitted curves are particularly suitable

Hyperbola curves, since the geometry of the optics yields such a curve. However, it is also possible to match other curve types in a good approximation, for example based on a polynomial function.

Preferably, it is provided in this development that the

Correction information from an offset of the curves of the measurement sequence data and the reference measurement sequence data is determined. This procedure is particularly simple, and can be used particularly well when the measurable travel of the base element in the base body (in the z direction) is relatively small (eg with a travel of less than 4 cm or a travel of less than 1/12 the mean distance to the camera entrance pupil), and / or if there are no significant differences from

Reference angles of the laser beam at the reference measurement sequence and the angle of the laser beam in the measurement sequence are to be expected.

Alternatively, it is advantageously provided in the above development that the respective fitted curve is a hyperbolic curve and the curve parameters are hyperbola parameters, and that of the one or more Hyperbola parameters one position (ZP ^m , zp ^R ) of a pole of each hyperbola is determined, and the correction information from a comparison of the determined positions (ZP ^M , ZP ^r ) of the poles of the

Hyperbolic curves of the measurement sequence data and the reference measurement sequence data is determined. In general, the position (x) of a

Triangulationpunkts on an image plane of the camera as a function of the set position (z) of the base element according to a

Hyperbolic curve, with x = Po / (Pi + z) + P2, with Po, Ρι, P2: Hyperbolic parameter. The hyperbolic curve always has a pole at the height of the entrance pupil of the

Camera lens; The position of the pole is in particular independent of the set angle of incidence of the laser beam on the base element. The parameter P1 describes the position of this pole. Therefore, by comparing the positions of the poles from the hyperbolic curves of the reference measurement sequence and the measurement sequence, a calibration can be made which also includes angular errors of the laser system (ie, a deviation between the

Reference angle and the angle of the measuring sequence). For example, in the case of the reference measurement sequence, the pole / entrance pupil was at the travel position zp ^R (corresponding to parameter P1 of the hyperbolic curve of the reference measurement sequence), and a desired position (relative to the fixed camera) of the reference base element or its surface at the Reference measurement sequence at the set travel position ZB ^r received, and was further for the measurement sequence, the pole / entrance pupil at the travel position zp ^M (corresponding parameter P1 of the hyperbola of the measurement sequence) obtained, so by setting a position ZB ^M according to

For example, ^M = (ZP ^M -ZP ^R ) + ZB ^R

the base element or its surface are obtained at the identical position (relative to the fixed camera) as in the reference measurement sequence with respect to the reference base element. In this procedure, a very accurate calibration is possible; Typically, the measurement sequence and the reference measurement sequence are used to measure a relatively large travel path in order to obtain the To determine hyperbola parameters with high accuracy (eg over a travel of at least 4 cm or over a travel of more than 1/12 of the average distance to the camera entrance pupil).

In an advantageous development of the fixed angle is inclined to a direction of travel of the base member in the body. This ensures that during the measurement sequence, the triangulation point moves noticeably relative to the surface of the base member, resulting in an averaging that reduces speckle errors. Typically, the angle is 5 ° or more to the travel direction. Similarly, the reference angle for the reference measurement sequence should be selected obliquely to the direction of travel of the base member in the main body.

Also advantageous is a development in which the base element and the reference base element are of identical construction. This minimizes the

Correction variables, and contributes to a higher manufacturing accuracy.

Machines according to the invention for the layered production of three-dimensional objects

The scope of the present invention also includes a machine for the layered production of three-dimensional objects by sintering or

Melting of powdered material with a high-energy jet, with a Bauzyiinder arrangement having a substantially cylindrical base body and a movable body in the piston, on which a base member, in particular a substrate or a preform is arranged, in particular wherein the piston is an upper piston part on which the base element is arranged, and has a lower piston part, with respect to which the upper piston part can be aligned by means of at least two, preferably three, actuating elements,

and with a measuring system for measuring the base element by means of Laser light comprising survey data on the base element

Position information and / or orientation information and / or

Information about the three-dimensional shape of at least part of the surface of the base element determines

characterized in that the measuring system for measuring the

Base element comprises

- a scanner optics,

a measuring laser coupled to the scanner optics,

- A control device which is adapted to deflect a laser beam generated by the measuring laser by means of the scanner optics so that

differently deflected laser beams are generated in accordance with a programmed measurement pattern, and the deflected laser beams are directed at least to a portion of the base member,

a camera capable of observing the locations of incidence of the laser beams deflected by the scanner optics and arranged laterally offset from any deflected laser beam emitted by the laser beam

Scanner optics could be aimed at the base element,

and an evaluation device, which is set up to evaluate, from the laterally offset camera, the points of incidence of the laser light of the measurement pattern generated by the scanner optics, and from this the

To determine survey data about the base element. With the

According to the invention, a compact construction is possible; in particular, little or no space is required in the process chamber for the measuring system. The measuring system is simple, in particular with regard to the installation, and can be used flexibly for different types of structural cylinder arrangements and basic elements (substrates or Preferoms). Preferably, the camera is arranged so that it is also laterally offset from possible laser beams, which are directed by the scanner optics on a reference structure surrounding the base member. Typical survey data

(Measurement information) is data about a tilt of the base element, data about the elevation of the base element or data about the three-dimensional shape of at least a part of the surface of the

Base member. The machine according to the invention is suitable for carrying out a method according to the invention, above.

Preferred is an embodiment of the machine according to the invention, which provides that the machine as a high-energy beam source a

Processing laser includes, and that the processing laser is also coupled to said scanner optics. As a result, the scanner optics can be used twice, which is inexpensive and very compact.

An advantageous development of this embodiment provides that a beam splitter is arranged in the beam path in front of the scanner optics, and the measuring laser and the processing laser are each aligned with the beam splitter. By means of the beam splitter (typically a semitransparent mirror, arranged at a 45 ° angle to the input and output beams) can be done in a simple manner, the coupling of measuring laser and processing laser on the same scanner optics. The beam splitter and the scanner optics as well as the measuring laser and the processing laser are typically located outside the process chamber.

Also preferred is an embodiment in which the machine further comprises a test device which is adapted to read and evaluate recordings of the said camera from a layer of pulverulent material applied to the base element before processing with the high-energy beam. This dual use of the camera, which is inexpensive and very compact.

A development of this embodiment provides that the scanner optics or one of the scanner optics downstream focusing optics or a group of scanner optics, which includes the scanner optics, or a group of focusing optics, which are nachgeiagert this group of scanner optics, is arranged above the base element, in particular centrally above the base element

Base element is arranged, and the camera is arranged in the horizontal direction next to the base element. By the arrangement over the

Base element (ie in the vertical direction above the base member, and with respect to the horizontal direction in alignment with the base member), in particular (at least substantially) centrally above the base element, all parts of the base element for deflected laser beams are easily accessible with the scanner optics and the focusing optics; Beam expansions of a deflected laser beam are minimized, which also allows a good spatial resolution. By arranging the scanner optics or the focusing optics above the base element and the arrangement of the camera next to the

Base element (and in the vertical direction above the base member, usually at a similar height as the scanner optics) they are spaced apart in the horizontal direction, and the camera is easily arranged in a straight line offset from all possible deflected laser beams, which from the scanner optics to the base element could be directed.

Horizontally next to the base element is usually sufficient space for the camera in the process chamber; Alternatively, the camera can also be arranged outside the process chamber behind a window.

In the context of the invention, the measuring system for measuring the

Base element also comprise a plurality of scanner optics, which are each coupled to the measuring laser or alternatively to a plurality of measuring laser, and which are controlled by the control device to generate the measurement pattern. In this case, more complex patterns are possible, and possibly can

Shading can be avoided or minimized, especially when measuring the surface of preforms. If desired, a plurality of cameras can also be provided, which are each arranged offset laterally with respect to all possible deflected laser beams that could be directed onto the base element by respectively associated scanner optics; This also shading can be avoided or minimized. Preferably, the group of these scanner optics or a group of

Focusing optics, which are downstream of this group of scanner optics, arranged above the base element, in particular centrally above the

Base element arranged.

Also advantageous is an embodiment in which the camera is designed as a camera with geschafteter optics. This will be in the shots

Distortions, especially in falling lines avoided. Alternatively, for example, any distortions can be calculated out with software from the images of the camera.

Furthermore, within the scope of the present invention, the use of a machine according to the invention specified above falls within one

according to the invention, the above-mentioned method.

Further advantages of the invention will become apparent from the description and the drawings. Likewise, according to the invention, the above-mentioned features and those which are still further developed can each be used individually for themselves or for a plurality of combinations of any kind. The embodiments shown and described are not to be understood as an exhaustive list, but rather have exemplary character for the

Description of the invention.

Detailed description of the invention and drawing

The invention is illustrated in the drawing and will be explained in more detail with reference to embodiments. Show it:

Fig. 1 is a schematic view of an embodiment of a

Inventive machine for the layered production of three-dimensional objects, for carrying out the

inventive method;

FIG. 2 shows a schematic longitudinal section of a construction cylinder arrangement for the invention; FIG.

Fig. 3 is an illustration of a triangulation measurement for the invention;

Fig. 4 is a schematic plan view of a base member, on the one

Measuring pattern is directed, without tilting and tilting of the base member, according to the inventive method;

Fig. 5 is a schematic side view of line by line scanning a preform, in the context of the invention;

Fig. 6 is a schematic overview for the detection of a

Triangulation point of a measuring pattern, at different traversing positions of a Basiseiements, for the invention;

7 shows a schematic overview of a measuring pattern for four

Triangulation points, for the invention; 8 shows a schematic overview of the image recognition in the measurement pattern of FIG. 7, for the invention;

9 is a schematic diagram illustrating a set of

Reference measurement sequence data, for the invention; a schematic diagram illustrating a set of measurement sequence data and a fit curve of the reference measurement sequence data of Figure 9, for calibration over a cam offset, for the invention; a schematic diagram illustrating the calibration over the offset of poles, based on fitted hyperbolic curves as shown in Fig. 10 and Fig. 11.

Fig. 1 shows a schematic view from the side of a

Embodiment of a machine 1 according to the invention for the layered production of a three-dimensional object 2 (or more

three-dimensional objects), also called 3D printing machine.

The machine 1 comprises a gas-tight process chamber 3, which can be filled and / or rinsed in an unspecified manner with an inert gas (protective gas), for example nitrogen or a noble gas such as argon.

Connected to the process chamber 3 is a powder cylinder arrangement 4 with a powder cylinder (storage cylinder) 5 for a powdery material 6 (shown dotted), from which the three-dimensional object 2 is manufactured here by sintering or melting. The powdery material 6 may consist, for example, of metal particles having an average particle size (D50) of 25-100 μm; in other applications can also plastic particles or ceramic particles of similar size. By stepping up a powder piston 7 with a first lifting device (powder lifting device) 8, a small amount of the powdery material 6 is raised above the level of the bottom 9 of the process chamber 3, so that with a motor-operated slide 10, this small amount to a Construction cylinder arrangement 11 can be spent.

The also connected to the process chamber 3 Bauzylinder- arrangement 11 has the piston 12, on the upper side

Base element 13, here a substrate 13a, is arranged. On the base element 13, the three-dimensional object 2 is constructed. The base member 13 is vertically movable with the piston 12 in a base body 14. The piston 12 is designed in several parts and provided with adjusting elements in order to be able to correct a tilting of the base element 13 in the construction cylinder arrangement 11 (not shown in detail, but see FIG. 2).

In each case before the production of a new layer of the three-dimensional object 2, the piston 12 is lowered by one step with a second lifting device (lifting device) 15, and a small amount of the powdered material 6 is coated with the slider 10 into the construction cylinder arrangement 11. The applied layer of the powdery material 6 is checked with a camera 21 and a test device 28 connected to it (operating an image evaluation software); If necessary, the applied layer can be corrected with the slider 10 and / or with further powdered material 6. In particular, a damaged slider 10 can be detected on the basis of a faulty powder application and exchanged in the sequence in order to correct the applied layer. The camera 21 is preferably provided with a geschifteten optics (not shown in detail). The camera 21 is arranged here behind a window 21 a outside the process chamber 3. Then, the newly applied powder layer from above with a

High-energy beam 16, here a machining laser beam 16a, from a high-energy beam source 17, here a processing laser 17a, at locations that are provided for local solidification (melting, sintering) of the powdery material 6, locally illuminated and thereby locally strongly heated.

The processing laser beam 16a is passed through a beam splitter 18 via a scanner optics 19, comprising one or more mirrors, which are pivotable about at least two axes as a whole, via a focusing optics 29 and through a window 20. The scanner optics 19 and the focusing optics 29 are located centrally above the base element 13. By means of the scanner optics 19, the processing laser beam 16a can scan the base element 13 or the uppermost powder layer thereon in accordance with the intended shape of the three-dimensional object 2

( "Edit pattern").

Thereafter, further layers are made until the three-dimensional object 2 is completed. Excess powdery material 6 can be painted with the slider 10 in a collecting container 6a.

The machine 1 according to the invention has a measuring system 22 for

Measuring the base element 13, in particular before the beginning of the

Manufacturing process to detect any deformations (such as tilting) on the base member 13 and correct if necessary.

The measuring system 22 here includes its own measuring laser 23, whose

Laser beam 24 via the beam splitter 18 in the also used by the processing laser beam 16a scanner optics 19 and the beam path

can be coupled, so that deflected by the scanner optics 19 laser beams 24a of the measuring laser 23 can be directed at least to parts of the base member 13 according to a measurement pattern. The deflected laser beams 24a extend in a vertical direction downwards or at a small angle (usually <30 °, preferably <20 °) from the vertical. The

Scanner optics 19 are connected to a control device 25 in which one or more measurement patterns or corresponding control commands for controlling the scanner optics 19 for the measurement of the base element 13 are programmed.

The measuring system 22 also includes here the camera 21, which also for

Powder bed test is used. With the camera 21, the surface of the base member 13 can be accommodated, so that the actual

Locations of the deflected laser beams 24a of the measuring laser 23 can be detected according to the measurement pattern. The camera 21 is connected to a

Evaluation device 26 is connected, with which the observed impact locations are evaluated and converted into survey data on the Basisiseiement 13, such as a tilt of the base element. This attacks the

The evaluation device typically returns to reference information ("target images"), which can then be used to correct the position or orientation of the base element 13, if necessary also iteratively.

The camera 21 is offset from the base element 13 in the horizontal direction, cf. Offset 27 (here drawn between the edge of the

Base members 13 and the center of the camera lens of the camera 21; Note that in practice the camera lens is usually much smaller than the offset 27). This ensures that the camera 21 at an angle (usually> 20 °) looks at the deflected laser beams 24a.

2 shows a construction cylinder arrangement 11, as can be used in the machine of FIG. 1, in a schematic

Longitudinal section. In the approximately cylindrical base body 14, the piston 12 along the vertically extending cylinder axis with the second lifting device 15 is movable.

The piston 12 has an upper piston part 12 a, on which the

Base element 13, here a substrate 13a, arranged and fixed on the upper side. The upper piston part 12 has a powder seal 30, with which a gap is closed to the main body 14, so that powdered material can not penetrate further or only in very small quantities down into the Bauzylinder- assembly 11. The upper piston part 12a has

typically via a heater, with which the base member 13 and thereon located powdery material can be heated (not shown).

The upper piston part 12a is arranged on a middle piston part 12b, wherein a ceramic insulation plate 31 is arranged between the upper piston part 12a and the middle piston part 12b.

The middle piston part 12b is supported by three adjusting elements 32 on a lower piston part 12c. The adjusting elements 32 may be formed, for example, as piezo actuators. The adjusting elements 32 allow the setting of a tilting of the central piston part 12b (and thus also the upper piston part 12a) relative to the lower piston part 12c with respect to two horizontal axes. The lower piston part 12c has a gas seal 33, which seals the gap to the base body 14 and prevents the penetration of atmospheric oxygen into the interior of the construction cylinder arrangement 11 during the production of a three-dimensional object.

Typically, the lower piston part 12c has a cooling (not shown in detail). Fig. 3 illustrates the principle of the measurement of a base element, such as the determination of the local height of a portion of the base member, in the context of the invention. Preferably, the measurement of the base element takes place in

Frame of the invention by means of triangulation. In this case, a measurement pattern is projected onto the base element, wherein the desired position of the measurement pattern (or the laser beam impingement points) on the base element due to the Scanneroptik- control and the (target) geometry of the base element is known, and from the deviation of the actual instantaneous measurement pattern (or the laser beam impact points) on the base member, observed by a laterally offset camera, a position or orientation information is obtained.

The laser beam 24 of the measuring laser 23 is deflected at the scanner optics 19, cf. the deflected laser beam 24a. The deflected laser beam 24a has an angle β with respect to the vertical, which is parallel to a z-axis;

typically, β is in a range of +/- 30 ° or less, or even +/- 20 ° or less.

The deflected laser beam 24a hits an impact location A1 on a

Surface 01 of the base element. A camera, with the camera lens 40 laterally offset in the horizontal x direction, observes the impact location A1. The impact location A1 is imaged as a projection location P1 on a camera sensor 41 or a corresponding image plane.

Is the surface of the base member in the vertical z-direction to the

Height difference dz deeper, cf. the surface O2, however, the camera detects the impact A2, which hits the camera sensor 41 at the projection location P2. The projection locations P1 and P2 differ around the

Projection offset dp in the x-direction. The projection location P1 on the camera sensor 41 can be used as a reference variable for which the altitude z1 of the impact location A1 is known. By means of the projection offset dp of the projection location P2 with respect to the projection location P1, the altitude z2 of the impact location A2 can then be easily determined (with knowledge of the angle β and the focal length f0 of the camera lens 40) using the laws of geometric optics. If desired, the horizontal position x2 of the impact location A2 can be determined accordingly also in the case of a known horizontal position x1 of the impact location A1.

To determine the tilt of a base member 3, includes

Measuring pattern 50 is typically an illumination of the base member 13 in three different zones 51a, 51b, 51c, as can be seen in the plan view of the base member 13 in Fig. 4. In this case, the measuring pattern 50 comprises in each zone 51a, 51b, 51c a laser line 52a, 52b, 52c (shown in solid lines); Each laser line 52a, 52b, 52c consists of a plurality of laser spots (not resolved in FIG. 4). The laser lines 52a-52c are here generated by a measuring laser and a scanner optics centrally above the base element 13 (not shown).

In the case of tilting of the base member 13, such as the upper in Fig. 4 section down into the plane, the move

Laser lines on the surface of the base element, cf. the dashed laser lines 53a, 53b, 53c, which can be easily detected with a laterally offset camera (not shown). For each of the zones 51a, 51b, 51c, a separate local altitude of the base element 13 can be determined; this will typically be altitude information of the various

Laser points of a respective laser line averaged. From the three local

Altitudes results in the tilt of the base member thirteenth

Preferably, adjusting elements (not shown) for adjusting the

Orientation of the base member 13 against a stationary Reference structure 54, which is approximately part of the bottom of the process chamber, respectively directly below the zones 51 a, 51 b, 51 c.

Fig. 5 schematically illustrates the measurement of a base member 13 formed as a preform 13b. The preform 13b already has a complex three-dimensional shape on which the actual three-dimensional object to be produced in layers (not shown) is to be built up. Before the production of the three-dimensional object begins, the surface (contour) 03 of the preform 13b can be scanned with deflected laser beams 24a which are generated from the laser beam 24 of a measuring laser with the scanner optics 19 (limited by possible shading). In Fig. 5 is the

Scanning a line of the preform 13b indicated in an angular range σ; the entire survey includes more lines in front of and behind the

Drawing plane of FIG. 5, for each of which a separate image acquisition takes place.

The inventive method can also be used to a

To calibrate the measuring system. 6 illustrates, by way of example, a simple measurement setup (see upper sub-image) with a base element 13 that can be moved along a (in this case, vertical) travel direction (z-direction). A deflected laser beam 24a of a measuring laser generates on the base element 13 a so-called triangulation point 60, corresponding to a point of incidence of the laser beam 24a on the surface of the base element 13. The camera 21, comprising here an objective 61, which simultaneously forms an entrance pupil of the camera 21, and A CMOS sensor 62 detects an image 63 of the triangulation point on the CMOS sensor 62. Depending on the travel position z of the base element 13, another impact location, also called position signal x, of the image 63 of the triangulation point on the CMOS sensor 62 results The position signal x obeys a hyperbolic curve as a function of the movement position z of the base element 13, with x = Po / (Pi + z) + P2, with Po, P1, P2: hyperbola parameter. The position signal x diverges on the CMOS sensor 62 when the base element 13 is the height of the entrance pupil or here of the lens 61, regardless of the angle of the laser beam 24a relative to the vertical or the direction of travel (z-direction). This can be used for calibration (see Fig. 11). By way of example, FIG. 6 shows three different movement positions of the base element 13, which are referred to here as

Construction platform is formed; in the sub-images from top to bottom, the base member 13 is moved upward. In the context of the invention, position signals x at different travel positions z of a reference base element or the base element are measured both in a reference measurement sequence and in later measurement sequences in individual construction jobs.

Note that in FIG. 6 the laser beam is parallel to the (vertical)

Moving direction of the base member 13 is directed, which represents a possible design. But is preferred that the laser beam 24a obliquely to

Traversing direction z runs, ie with an angle ß> 0 °, as shown in Fig. 3, preferably with ß> 5 °. Then speckle errors can be minimized.

FIG. 7 shows by way of example a measurement pattern 50 in the form of the edges of a rectangle, on which four triangulation points 60 are formed at the corners of one of the rectangles; typically all tracing points 60 are considered separately within (reference) measurement sequences. The straight sections of the rectangle are clearly recognizable by image recognition software, cf. Fig. 8, in which the recognized straight sections are marked in bold, so that the position of the vertices or triangulation points 60 can be easily determined by extrapolation.

9 illustrates the raw data (shown as circles) of a reference measurement sequence, in which the position signal (x), ie the location of the image of a triangulation point (plotted upward), as a function of

Movement position (z) of the reference base element (applied to the right) is shown. The individual measuring points lie on a fitted one

Hyperbolic curve 91, which is drawn through. By the fitted Hyperbolic curve 91 (or another fitted curve, such as one

Polynomial curve), the behavior of the reference primitive is described and speckle errors are averaged out.

The location (with respect to z) of a pole (ZP ^r ) of the hyperbola curve which determines the location of the hyperbola curve can also be determined from the fitted hyperbolic curve 91

Input pupil of the camera represents. The pole is outside the measured range, and is calculated by calculation from the

Hyperbola parameter Pi of the fitted hyperbola determines (see Fig. 1 1 this).

FIG. 10 shows the raw data of a measurement sequence (shown as circles), again with position signal x (upwards) against the

Movement position (z) of the base element (to the right). Again, a hyperbolic curve 92 (or other curve) may be fitted to these measurement points. In addition, the hyperbolic curve 91 of the reference measurement sequence is shown again.

If it is ensured that, for the reference measurement sequence and the measurement sequence, the reference angle and the angle at which the respective laser beam was directed to the reference base element were practically identical, an offset 93 of the fitted curves 91, 92 to a height difference from the reference base element used in the reference measurement sequence and the base element used in the

Measurement sequence was used, be closed directly. Such a height difference can be, for example, from manufacturing tolerances of building platforms, or by thermal expansion, or simply by

give different types of construction platforms. This determined

Height difference can be used for setting the travel position of the

Base element in the subsequent layer-wise production of a three-dimensional object as a correction term are taken into account. In the present case, under the boundary conditions of the measurement sequence (see hyperbolic curve 92) the traversing position z may be set lower by the offset 93 to obtain the positions of the surface of the base member (opposite to the camera) in accordance with the boundary conditions of the reference measuring sequence. The offset 93 can be determined relatively accurately even with comparatively small travel paths in the z direction.

If equality of reference angle and angle can not or should not be assumed to be certain, especially for a higher one

Calibration accuracy, the position of the pole (zp) can also be determined for the fitted hyperbola 92 of the measurement points of the measurement sequence. The pole is again outside the measured range of Fig. 10, and is determined by calculation from the hyperbola parameter Pi of the fitted hyperbola 92 (see Fig. 11).

FIG. 11 schematically shows the hyperbolic curve 91 of the reference measurement sequence and the hyperbolic curve 92 of the measurement sequence in a larger range, in particular also in the region of the pole positions. The position of the

Poles of the reference measurement sequence and measurement sequence are independent of the respective existing reference angle and angle of the laser beam in the reference measurement sequence and the measurement sequence, and corresponds to the (always the same) location of the entrance pupil of the camera, such as the lens. By comparing the pole positions can therefore also a

Calibration of the measuring system, regardless of interfering influences such as pointing instabilities of the laser. A desired z position of the

Surface of a base element, which was achieved in the reference measuring sequence (with a reference base element) at a movement position ZB ^r , wherein the pole in the reference measurement sequence at zp ^R and the pole in the

Measurement sequence was determined at ZP ^m , can be obtained (with the boundary conditions of the measurement sequence) by setting a travel position ZB ^M- ZP ^M + (ZB ^R -ZP ^R ) = ZB ^r + (zp ^M - zp ^R ). The difference 94 of the pole positions can thus be used as correction term 95. LIST OF REFERENCE NUMBERS

1 machine

2 three-dimensional object

3 process chamber

4 powder cylinder arrangement

5 powder cylinders

6 powdered material

6a collection container

7 powder pistons

8 first lifting device

9 floor

10 slides

11 construction cylinder arrangement

12 pistons of the construction cylinder arrangement

12a upper piston part

12b middle piston part

12c lower piston part

13 basic element

13a substrate

13b preform

14 basic body

15 second lifting device

16 high energy beam

16a machining laser beam

17 high-energy beam source

17a processing laser

18 beam splitters

19 Scanner optics 20 Scanner optics window

21 camera

21a Window of the camera

22 measuring system

23 measuring lasers

24 Laser beam of the measuring laser

24a deflected laser beam of the measuring laser

25 control device

26 evaluation device

27 offset

28 testing device

29 focusing optics

30 powder seal

31 insulation plate

32 control element

33 gas seal

40 camera lens

41 camera sensor

50 measurement patterns

51a-51c zones

52a-52c laser lines with untilted base element

53a-53c laser lines with tilted base element

54 Reference Structure

60 triangulation point

61 lens

62 CMOS sensor

63 Illustration of the triangulation point

91 hyperbolic curve (measurement sequence)

92 Hyperbolic Curve (Reference Measurement Sequence) 93 Offset

94 Difference of the pole positions 95 Correction term

A1, A2 places of arrival

dx horizontal offset

dp projection offset

dz height offset

fO focal length

01-03 Surface of the base element

P1. P2 projection locations

Po, Ρι; P2 hyperbolic parameters

x horizontal direction / position signal

x1, x2 horizontal layers

z vertical direction / travel direction

z1, z2 altitudes

For example, ^M desired z position of the base element in measurement sequence ZB ^R desired z position of the base element in reference measurement sequence

zp ^M z position of the pole in measurement sequence

zp ^R z position of the pole in reference measurement sequence

ß angle of the deflected laser beam with respect to the vertical σ angular range of the deflected laser beams of a scanning line

Claims

claims

1. A method for measuring a base member (13), in particular

a substrate (13a) or a preform (13b), a construction cylinder arrangement (11), wherein the construction cylinder arrangement (11) on a machine (1) for the layered production of three-dimensional objects (2) by sintering or melting of powdered material ( 6) with one

High energy beam (16) is arranged, wherein the base member (13) in a substantially cylindrical base body (14) of the structural cylinder assembly (11) with a piston (12) is movable, in particular wherein the piston (12) has an upper piston part (12a), on which the base element (13) is arranged, and a lower piston part (12c), with respect to which the upper piston part (12a) is alignable by means of at least two, preferably three, adjusting elements (32), wherein for measurement of the base member (13) a measurement pattern (50) of laser light is generated which illuminates at least a portion of the base member (13) and impact locations (A1, A2) of the laser light are observed and evaluated with a camera (21) and thus Surveying data on the base element (13), comprising position information and / or orientation information and / or information about the

three-dimensional shape of at least part of the surface (01 -03) of the base element (13), characterized in that the measurement pattern (50) is generated from laser light by a

Laser beam (24) of a measuring laser (23) is deflected by a scanner optics (19), so that different deflected laser beams (24a) are generated, and the deflected laser beams (24a) are directed at least to the part of the base member (13),

and that the camera (21) is laterally offset from the deflected laser beams (24a).

2. The method according to claim 1, characterized

that with the measurement of the base element (13) at least also a tilting of the base element (13) relative to a reference structure (54) is determined.

3. The method according to claim 2, characterized in that the

Measuring pattern (50) an illumination of at least a part of

Base element (13) in three different zones (51a-51c). 4. The method according to claim 3, characterized in that the locations of at least two, preferably three, of the zones (51a-51c) substantially correspond to the locations of control elements (32) with which the

Base element (13) relative to the reference structure (54) can be tilted.

5. The method according to any one of claims 3 or 4, characterized in that the measurement pattern (50) in the three zones (51a-51c) each have a plurality of laser points, in particular in each case a laser line (52a-52c, 53a-53b) comprises.

6. The method according to any one of the preceding claims, characterized

that with the survey at least a three-dimensional

Determination of at least a portion of a surface (01 -03) of the base member (13), in particular of the preform (13b) takes place.

7. The method according to claim 6, characterized in that the

Measuring pattern (50) comprises a line-by-line scanning of at least the part of the surface (O1-O3) of the base element (13), wherein during the line-by-line scanning a plurality of individual images are made with the camera (21).

8. The method according to any one of the preceding claims, characterized

characterized in that at least a determination of the altitude (z1, z2) of the base member (13) relative to a reference structure (54) is effected by the measurement.

9. The method according to any one of the preceding claims, characterized

in

in that, for measuring the base element (13), a comparison of the impact locations (A2) of the laser light observed on the base element (13) with expected locations of incidence (A1) of the laser light on the base element (13) takes place with the camera (21),

in particular, wherein the measuring pattern (50) exclusively the

Base element (13) illuminated and / or only impact locations (A1, A2) of the laser light on the base element (13) are evaluated.

10. The method according to any one of the preceding claims, characterized

characterized in that the machine (1) continues to have a

Processing laser (17a) comprises, and that after the measurement of the base member (13) then for the production of layers at least a three-dimensional object (2) on the base element (13) at least parts of layers of powdered material (6) on the base element (13) are illuminated with laser light processing patterns, the processing patterns being produced by a laser beam (16a) of the processing laser (16a) 17a) is deflected by said scanner optics (19).

11. The method according to any one of the preceding claims, characterized

characterized in that after the measurement of the base element (13) then for the production of layers of at least one three-dimensional object (2) on the base element (13) layers of powdered material (6) are applied to the base member (13), wherein the layers of powder Material (6) prior to application of the high energy beam (16) with said camera (21) are checked visually.

12. The method according to any one of the preceding claims, characterized

in

the measurement pattern (50) comprises at least one triangulation point (60),

in a measuring sequence, impact locations (A1, A2) of the at least one triangulation point (60) at different displacement positions (z) of the base element (13) in the base body (14) are observed with the camera (21) and associated measurement sequence data are obtained, the triangulation point (60) is generated by a deflected laser beam (24a) which is directed onto the base element (13) under a fixed angle (β) during the measurement sequence,

in that the measurement sequence data are compared with reference measurement sequence data from a reference measurement sequence, wherein in the context of the reference measurement sequence also locations of arrival of the at least one triangulation point (60) with different movement positions (z) a reference base element in the base body (14) were observed with the camera (21) and the associated reference measurement sequence data were obtained, wherein the triangulation point (60) was generated by a deflected laser beam (24a) under one during the reference measurement sequence fixed reference angle was directed to the reference base element,

and that correction information for the measurement of the base element (13) is derived from the comparison of the measurement sequence data and the reference measurement sequence data.

13. The method according to claim 12, characterized

the measurement pattern (50) comprises at least three, preferably at least four triangulation points (60),

preferably wherein the triangulation points (60) are formed as corner points of the measuring pattern (50), against which straight sections of the measuring pattern (50) adjoin,

particularly preferably wherein the triangulation points (60) are formed as corner points of a rectangular measuring pattern (50).

14. The method according to claim 12 or 13, characterized in that from the measurement sequence data and the reference measurement sequence data in each case one or more curve parameters, in particular hyperbola parameters (Po, Pi) are determined, each having a curve, in particular

Hyperbolic curve (91, 92), describe which each of the observed impact locations (A1, A2) as a function of the position (z) of the

Base element (13) in the base body (14) anfittet.

15. The method according to claim 14, characterized in that the

Correction information from an offset (93) of the curves of

Measurement sequence data and the reference measurement sequence data is determined.

16. The method according to claim 14, characterized in that the respective fitted curve is a hyperbolic curve (91, 92) and the

Curve parameter are hyperbola parameters (Po, Ρι, P2), and that from the one or more hyperbolic parameters (Po, P1, P2) one position (zp ^M , zp ^R ) of a pole of the respective hyperbolic curve (91,

92), and the correction information is determined from a comparison of the determined positions (zp ^M , ZP ^r ) of the poles of the hyperbolic curves (91, 92) of the measurement sequence data and the reference measurement sequence data.

17. The method according to any one of claims 12 to 16, characterized

characterized in that the fixed angle (ß) obliquely to a

Traversing (z) of the base member (13) in the base body (14) extends.

18. Machine (1) for the layered production of three-dimensional objects (2) by sintering or melting of pulverulent material (6) with a high-energy beam (16),

with a construction cylinder arrangement (11) having a substantially cylindrical base body (14) and a piston (12) movable in the base body (14), on which a base element (13), in particular a substrate (13a) or a preform (13b) , is arranged

in particular, wherein the piston (12) has an upper piston part (12a) on which the base element (13) is arranged, and a lower piston part (12c), with respect to which the upper piston part (12a) by means of at least two, preferably three, Stelleiementen (32) is alignable,

and with a measuring system (22) for measuring the base element (13) by means of laser light, the surveying data on the base element (13) comprising position information and / or orientation information and / or information about the three-dimensional shape of at least part of the surface (O1-O3) of the base element (13), characterized in that the measuring system (22) for measuring the base element (13)

a scanner optics (19),

a measuring laser (23) coupled to the scanner optics (19),

a control device (25) which is adapted to deflect a laser beam (24) generated by the measuring laser (23) by means of the scanner optics (19) in such a way that differently deflected laser beams (24a) are generated in accordance with a programmed measuring pattern (50), and the deflected laser beams (24a) at least on a part of

Be directed base element (13),

- A camera (21), with the place of impact (A1, A2) of the

Scanner optics (19) deflected laser beams (24a) can be observed, and the laterally offset from all possible deflected laser beams (24a) is arranged, which could be directed by the scanner optics (19) on the base member (19),

- And an evaluation device (26) which is adapted to evaluated by the laterally offset camera (21) observed impact locations (A1, A2) of the laser light generated by the scanner optics (19) measurement pattern (50) and from there the survey data on the base element (13).

19. Machine (1) according to claim 18, characterized in that the

Machine (1) as a high-energy beam source (17) comprises a processing laser (17a), and that the processing laser (17a) is also coupled to said scanner optics (19).

20. Machine (1) according to claim 19, characterized in that in

Beam path in front of the scanner optics (19) a beam splitter (18) arranged is, and the measuring laser (23) and the processing laser (17a) each aligned with the beam splitter (18).

21. Machine (1) according to one of claims 18 to 20, characterized

characterized in that the machine (1) further comprises a testing device

(28) adapted to take pictures of said camera (21) from a layer of pulverulent material (6) applied to the base element (13) before being processed with the camera

High energy beam (16) read out and evaluate.

22. Machine (1) according to any one of claims 18 to 21, characterized

in that the scanner optics (19) or one of the scanner optics (19) has a downstream focusing optic (29), or a group of

Scanner optics, which includes the scanner optics (19), or a group of focusing optics, the group of scanner optics

are arranged downstream, is arranged above the base element (13), in particular centrally above the base element (13) is arranged, and the camera (21) in the horizontal direction next to the base element (13) is arranged.

23. Machine (1) according to one of claims 18 to 22, characterized

characterized in that the camera (21) is designed as a camera (21) with geshifteter optics. 24. Use of a machine (1) according to any one of claims 18 to 23 in a method according to one of claims 1 to 17.