Method for specifying the position and / or orientation of a device head

Description

[0001] The present invention relates to a method for specifying a position and / or orientation of a device head. State of the art

[0002] The automation of measurement and assembly tasks using robots is increasingly taking hold in the construction industry. Robots have so far been used primarily in automated assembly lines, which are characterized by fixed positions and constant conditions. In contrast to assembly lines, construction sites are spatially complex measurement environments that are constantly changing as construction progresses. For assembly tasks on the construction site, such as drilling holes, creating slots, and installing installation equipment, accuracies in the millimeter range are required. This accuracies in the millimeter range cannot be achieved by conventional on-board sensor systems, such as LiDAR sensors, which severely limits the possible applications of these on-board sensor systems for measurement and assembly tasks using robots on construction sites.

[0003] To achieve the required accuracy in the millimeter range, available state-of-the-art devices on construction sites use external sensor devices that are not connected to the device head on the robot. External sensor devices are designed, for example, as total stations; the disadvantage of these external sensor devices is that prior to use, referencing must be established between the external sensor device and the measuring environment. Furthermore, total stations are only suitable for determining position and not orientation. Alternatively, active or passive target objects can be positioned in the measuring environment of the construction site, whose positions and / or orientations are determined in advance, whereby the position and / or orientation of the device head is determined using the known positions and / or orientations of the target objects.Disadvantages of the target objects are that before using the device, the target objects must be positioned in the measurement environment of the construction site.

[0004] DE 10 2018 202 322 A1 discloses a method and a device for specifying a position and / or orientation of a device head in a measurement environment, wherein the device head is attached to a robot arm and can be moved within the measurement environment. The device comprises an on-board sensor device, a camera device, and a control device communicatively connected to the on-board sensor device and the camera device. The control device determines deviations between target positions and actual positions and generates corresponding control commands to correct the position and / or orientation of the device head in the measurement environment.

[0005] WO 2015 / 162334 A1 discloses another method and device for specifying a position and / or orientation of a device head in a measurement environment, wherein the device head is attached to a robot arm and can be moved within the measurement environment. The device comprises an on-board sensor device, a distance measuring device, and a control device communicatively connected to the distance measuring device and the on-board sensor device. A known reference object is used to determine the accuracy of the position and / or orientation. Description of the invention

[0006] The object of the present invention is to provide a method with which the position and / or orientation of a device head can be determined with the required accuracy in the millimeter range.

[0007] This object is achieved according to the invention in the method mentioned at the outset by the features of independent claim 1. Advantageous further developments are specified in the dependent claims.

[0008] The method according to the invention for specifying a position and / or orientation of a device head connected to a robot arm mounted on a work platform in a measuring environment by means of a distance measuring device and a control device is characterized by a sequence of a first, second, third and fourth step, which is carried out N times, N ≥ 1, where: ▪ In the first step of the sequence, the device head is positioned in the measuring environment in a measuring position and pose data for the measuring position are determined by the control device, whereby the pose data for the measuring position of the first sequence are determined by means of the on-board sensor device and the pose data for the measuring positions of further sequences are determined by means of the on-board sensor device and a further on-board sensor device, ▪ In the second step of the sequence, the distance measuring sensors carry out a distance measurement to surfaces of the measuring environment and transmit their measured distance values ​​to the control device,▪ In the third step, corresponding estimated distance values ​​are determined from the geometric model of the measurement environment and the pose data for the measurement position to the measured distance values ​​and ▪ In the fourth step, the deviations between the measured distance values ​​and the corresponding estimated distance values ​​are calculated and stored as error values, , and after the Nth sequence of the first to fourth steps, an error minimization (compensation calculation) for the position and / or orientation of the device head is carried out using the error values ​​of the first to Nth sequence and the position and / or orientation of the device head is specified by the control device.

[0009] The idea of ​​the present invention is to first determine the position and / or orientation of the device head using a known on-board sensor device and then to specify this position and / or orientation of the device head using a distance measuring device connected to the device head, a geometric model of the measurement environment, and known standard methods for compensation calculations (e.g., the method of least methods). For example, a LiDAR sensor device is used as the on-board sensor device. This LiDAR sensor device is connected to the device head and can determine the position and / or orientation of the device head with an accuracy in the centimeter range. The distance measuring device comprises at least one distance measuring sensor, with multiple distance measuring sensors increasing the accuracy or reducing the number of sequences of the first to fourth steps.

[0010] The device head is arranged in N different measuring positions, and in each measuring position, the sequence of steps one to four is carried out. In the first step of the sequence, the device head is arranged in a measuring position in the measuring environment, with pose data being determined for the measuring position by the control device. In the second step of the sequence, the distance measuring sensors carry out distance measurements to surfaces in the measuring environment and transmit their measured distance values ​​to the control device. In the third step, corresponding estimated distance values ​​are determined from the geometric model of the measuring environment and the pose data for the measured distance values. The deviations between the measured distance values ​​and the corresponding estimated distance values ​​are calculated in the fourth step of the sequence and stored as error values.After the Nth sequence of the first to fourth steps, an error minimization (compensation calculation) for the position and / or orientation of the device head is carried out using the error values ​​of the first to Nth sequence, and the position and / or orientation of the device head is specified by the control device.

[0011] First, the first sequence of the first to fourth steps is carried out in a first measuring position, wherein the first measuring position corresponds to the position and / or orientation of the device head determined by means of the on-board sensor device, and the position and / or orientation of the device head determined by means of the on-board sensor device is used as first pose data for the first sequence. The first measuring position in which the first sequence of the first to fourth steps is carried out corresponds to the position and / or orientation of the device head that is to be specified using the method according to the invention. The specification is carried out, among other things, using the error values ​​of the first sequence, wherein the specification is carried out when the sequence of the first to fourth steps has been carried out N times. The number of error values ​​determined in a sequence can be increased by increasing the number of distance measuring sensors.

[0012] According to the invention, the sequence of the first to fourth steps is carried out twice in a first measuring position and a second measuring position, wherein the first measuring position corresponds to the position and / or orientation of the device head determined by means of the first on-board sensor device, the second measuring position is different from the first measuring position, and the movement of the device head from the first measuring position to the second measuring position is recorded by the further on-board sensor device in the form of first movement data. The first measuring position in which the first sequence of the first to fourth steps is carried out corresponds to the position and / or orientation of the device head that is to be specified using the method according to the invention. The larger the number N of sequences, the more error values ​​can be used in the error minimization (compensation calculation).

[0013] Preferably, the second pose data for the second measurement position are determined from the first pose data of the first measurement position and the first motion data. The second pose data for the second measurement position are required in the third step of the sequence of the first to fourth steps in order to determine estimated distance values ​​corresponding to the measured distance values ​​in the geometric model of the measurement environment.

[0014] Alternatively, the second pose data for the second measurement position are determined from optimized first pose data and the first movement data, wherein the optimized first pose data are determined from the position and / or orientation of the device head determined by the on-board sensor device by error minimization (compensation calculation) using the error values ​​of the first sequence. The aim of the method according to the invention is to more precisely specify the position and / or orientation of the device head determined by the on-board sensor device.

[0015] In a further alternative variant, the sequence of the first to fourth steps is performed at least three times, with the movement of the device head from one measuring position to a new measuring position being recorded by the additional on-board sensor device in the form of movement data. The first measuring position in which the first sequence of the first to fourth steps is performed corresponds to the position and / or orientation of the device head that is to be specified using the method according to the invention.The device head is moved from the first measuring position to a second measuring position, wherein the movement of the device head from the first to the second measuring position is detected by the further on-board sensor device as first movement data, and the device head is moved from the second measuring position to a third measuring position, wherein the movement from the second to the third measuring position is detected by the further on-board sensor device as second movement data.

[0016] Preferably, the pose data for the new measurement position are determined from the first pose data of the first measurement position and the motion data. The pose data for the new measurement position are required in the third step of the sequence of the first to fourth steps to determine estimated distance values ​​corresponding to the measured distance values ​​in the geometric model of the measurement environment.

[0017] Alternatively, the pose data for the new measurement position are determined from optimized first pose data and the movement data. The optimized first pose data are determined from the position and / or orientation of the device head determined by the on-board sensor device through error minimization (compensation calculation) using the error values ​​of the sequences performed in the first to fourth steps. The additional on-board sensor device, which is connected to the device head, records the movement of the device head between all measurement positions.

[0018] In a further development of the method, an error measure is determined after the Nth sequence of the first to fourth steps as part of the error minimization (compensation calculation). This error measure evaluates the quality or accuracy with which the position and / or orientation of the device head is specified.

[0019] Preferably, the error measure is compared with a maximum error. If the error measure is greater than the maximum error, the device head is moved to a new measuring position, and the sequence of steps one through four is repeated for the new measuring position. The sequence of steps one through four is repeated until the position and / or orientation of the device head has been precisely determined with the required quality or accuracy. Examples of implementation

[0020] Embodiments of the invention are described below with reference to the drawings. These are not necessarily intended to represent the embodiments to scale; rather, where useful for explanation, the drawings are schematic and / or slightly distorted. With regard to additions to the teachings immediately apparent from the drawings, reference is made to the relevant prior art. It should be noted that numerous modifications and changes to the form and detail of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, the drawings and the claims can be essential for the further development of the invention, both individually and in any combination.The general concept of the invention is not limited to the exact form or detail of the preferred embodiment shown and described below, nor is it limited to an object that would be limited compared to the object claimed in the claims. For given dimensioning ranges, values ​​within the stated limits are also intended to be disclosed as limit values ​​and can be used and claimed as desired. For the sake of simplicity, the same reference numerals are used below for identical or similar parts or parts with identical or similar functions.

[0021] They show: FIG. 1 shows a device head whose position and / or orientation is to be specified in a measurement environment; FIG. 2 shows a geometric model of the measurement environment in which the position and / or orientation of the device head is to be specified; and FIGS. 3A-C show the device head of the FIG. 1 in a first measuring position ( FIG. 3A), a second measuring position ( FIG. 3B ) and a third measuring position ( FIG. 3C ).

[0022] FIG. 1 shows a device head 10, the position and / or orientation of which in a measuring environment 11 to be determined with millimeter-level accuracy. The term "device head" encompasses all processing heads, assembly heads, and measuring heads designed for performing processing, assembly, or measuring tasks. The device head 10 can be designed, for example, as a grinding head, welding head, drilling head, or detector head.

[0023] In the embodiment, the device head 10 is equipped with a robot arm 12 connected to a work platform 13The robot arm 12 is designed as a multi-axis robot arm with several rotation axes, and the work platform 13 is adjustable in one plane via motor-driven wheels mounted on two axes. The robot arm 12 consists of several rigid links connected by rotary or sliding joints, whereby the rotary or sliding joints can be adjusted by controlled drives. The required number of rotary or sliding joints depends on the type of device head 10 and the intended application.

[0024] By combining the robot arm 12 with the work platform 13, the spatial area of ​​the device head 10 can be enlarged. The work platform 13 enables the device head 10 mounted on the robot arm 12 to be positioned at least roughly in the measurement environment 11, with the rough positioning taking place in two dimensions in the plane. Instead of the motor-adjustable work platform 13, the robot arm 12 can be mounted on a manually adjustable work platform. A motor-adjustable work platform 13 allows operator-free positioning of the device head 10, whereas a manually adjustable work platform 13 must be adjusted by the operator. Instead of the adjustable work platform 13, the robot arm 12 can be connected to a stand that allows the robot arm 12 to stand securely; the stand can be adjusted by the operator to enlarge the spatial area.In principle, the device head 10 can also be used without a robot arm and / or work platform. The number of degrees of freedom of the device head 10 can vary greatly and depends on the type of device head 10 and the intended application. The device head 10 can be adjustable in one or more translational directions, in one or more rotational directions, or in a combination of translational and rotational directions.

[0025] The position and / or orientation of the device head 10 is determined by means of an on-board sensor device 14 determined and then using a device 15 to specify the position and / or orientation of the device head 10. The device 15 comprises a distance measuring device 16 and a control device 17,which is communicatively connected to the on-board sensor device 14 and the distance measuring device 16. The on-board sensor device 14 serves to determine the position and / or orientation of the device head 10; a LiDAR sensor device, for example, can be used as the on-board sensor device 14. The distance measuring device 16 comprises a number of M, M ≥ 1 distance measuring sensors. 18 whose measuring directions differ from one another. In the exemplary embodiment, the distance measuring device 16 has three distance measuring sensors 18 arranged at right angles to one another. The distance measuring device 16 is connected to the device head 10 and serves to precisely determine the position and / or orientation of the device head 10, which was determined by the on-board sensor device 14.

[0026] In order to specify the position and / or orientation of the device head 10, the device head 10 is arranged in various measuring positions in which the distance measuring sensors 18 of the distance measuring device 16 perform a distance measurement. The movement of the device head 10 from one measuring position to a new measuring position is recorded by another on-board sensor device. 19 , which is connected to the device head 10, in the form of movement data; the further on-board sensor device 19 is designed, for example, as an acceleration sensor.

[0027] The measuring environment 11 is in a geometric model 21 pictured, which is in FIG. 2is shown. The geometric model 21 depicts the objects of the measuring environment 11 that form boundary surfaces, and enables the distances between the device head 10 and the boundary surfaces to be estimated. The distances are estimated in the directions that correspond to the measuring directions of the distance measuring sensors 18. A design model of the measuring environment 11 produced with CAD support, for example, can be used as the geometric model 21. Alternatively, the measuring environment 11 can be scanned using a laser scanner, and a geometric model of the measuring environment 11 is created from the scan data. The geometric model 21 can depict the measuring environment 11 completely or only partially. For the present application, the surfaces of the measuring environment 11 that are used as a reflection surface or scattering surface for a distance measurement are relevant.The estimated distance values, which are compared with the measured distance values, are determined from the geometry model 21 using known ray tracing methods.

[0028] The method according to the invention for specifying the position and / or orientation of the device head 10 is characterized by a sequence of a first, second, third, and fourth step, which is carried out (N times). The device head 10 is arranged in N, N ≥ 1 different measuring positions, and in each measuring position, the sequence of the first to fourth steps is carried out. In the exemplary embodiment, the sequence of the first, second, third, and fourth steps is carried out three times. The device head 10 is arranged in the measuring environment 11 in three measuring positions, which as the first measuring position MP1 ( FIG. 3A ), second measuring position MP2 ( FIG. 3B ) and third measuring position MP3 ( FIG. 3C ) are referred to.

[0029] In the first step of the first sequence, the device head 10 is in the first measuring position MP 1 ( FIG. 3A ). The first measurement position MP 1 corresponds to the position and / or orientation of the device head 10, which is to be specified by the device 15. For the first measurement position MP 1, first pose data are determined, wherein the position and / or orientation of the device head 10, which was determined by the on-board sensor device 14, is used as the first pose data. In the second step of the first sequence, the distance measuring sensors 18 perform a distance measurement and transmit their measured distance values. d m_ j1for j = 1 ... M to the control device 17; in the exemplary embodiment, the three distance measuring sensors 18 determine three measured distance values ​​d m_ 11, d m_ 21, d m_ 31. For the first measuring position MP 1, in the third step of the first sequence, corresponding estimated distance values ​​are determined from the geometric model 21 for the measured distance values ​​d m_ j1 d e_ j1 for j = 1 ... M; in the exemplary embodiment, three estimated distance values ​​d e_ 11, d e_ 21, d e_ 31 are determined. In the fourth step of the first sequence, the deviations Δ j1 for j = 1 ... M between the measured distance values ​​d m_ j1 and the corresponding estimated distance values ​​d e_ j1 are calculated and stored as error values; the first sequence provides three error values ​​Δ 11 , Δ 21 , Δ 31 in the exemplary embodiment.

[0030] After completion of the first sequence of the first to fourth steps, the device head 10 is moved in the first step of the second sequence from the first measuring position MP 1 to the second measuring position MP 2 ( FIG. 3B ). The movement of the device head 10 from the first measuring position MP 1 to the second measuring position MP 2 is recorded by the further on-board sensor device 19 in the form of first movement data.

[0031] The second pose data of the second measurement position MP 2 can be determined from the first pose data of the first measurement position MP 1 and the first motion data. Alternatively, the second pose data of the second measurement position MP 2 can be determined from optimized first pose data and the first motion data. For this purpose, a compensation calculation for the position and / or orientation of the device head 10, referred to as error minimization, is performed using the error values ​​Δ 11 , Δ 21 , Δ 31 of the first sequence. The result of this compensation calculation yields the optimized first pose data.

[0032] In the second step of the second sequence, the distance measuring sensors 18 carry out a distance measurement and transmit their measured distance values d m_ j2for j = 1 ... M to the control device 17; in the exemplary embodiment, the three distance measuring sensors 18 determine three measured distance values ​​d m_ 12, d m_ 22, d m_ 32. For the second measuring position MP 2, in the third step of the second sequence, corresponding estimated distance values ​​are determined from the geometric model 21 for the measured distance values ​​d m_ j2 d e_ j2 for j = 1 ... M; in the exemplary embodiment, three estimated distance values ​​d e_ 12, d e_ 22, d e_ 32 are determined. In the fourth step of the second sequence, the deviations Δ j2 for j = 1 ... M between the measured distance values ​​d m_ j2, j = 1 ... M and the corresponding estimated distance values ​​d e_ j2, j = 1 ... M are calculated and stored as error values; the second sequence provides three error values ​​Δ 12 , Δ 22 , Δ 32 in the exemplary embodiment.

[0033] After completion of the second sequence of the first to fourth steps, the device head 10 is moved in the first step of the third sequence from the second measuring position MP 2 to the third measuring position MP 3 ( FIG. 3C ). The movement of the device head 10 from the second measuring position MP 1 to the third measuring position MP 3 is recorded by the further on-board sensor device 19 in the form of second movement data.

[0034] The third pose data of the third measurement position MP 3 can be determined from the first pose data of the first measurement position MP 1 and the first and second motion data. Alternatively, the third pose data of the third measurement position MP 3 can be determined from optimized first pose data and the first and second motion data. For this purpose, a compensation calculation for the position and / or orientation of the device head 10 (error minimization) is performed using the error values ​​Δ 11 , Δ 21 , Δ 31 of the first sequence and Δ 12 , Δ 22 , Δ 32 of the second sequence, and the result of this compensation calculation yields the optimized first pose data.

[0035] In the second step of the third sequence, the distance measuring sensors 18 carry out a distance measurement and transmit their measured distance values d m_ j3for j = 1 ... M to the control device 17; in the exemplary embodiment, the three distance measuring sensors 18 determine three measured distance values ​​d m_ 13, d m_ 23, d m_ 33. For the third measuring position MP 3, in the third step of the third sequence, corresponding estimated distance values ​​are determined from the geometric model 21 for the measured distance values ​​d m_ j3 d e_ j3 for j = 1 ... M; in the exemplary embodiment, three estimated distance values ​​d e_ 13, d e_ 23, d e_ 33 are determined. In the fourth step of the third sequence, the deviations Δ j3 for j = 1 ... M between the measured distance values ​​d m_ j3 and the corresponding estimated distance values ​​d e_ j3 are calculated and stored as error values; the third sequence provides three error values ​​Δ 13 , Δ 23 , Δ 33 in the exemplary embodiment.

[0036] After completion of the third sequence of the first, second, third, and fourth steps, the control device 17 performs a compensation calculation for the position and / or orientation of the device head 10 (error minimization) using the error values ​​of the first sequence Δ 11 , Δ 21 , Δ 31 , the error values ​​of the second sequence Δ 12 , Δ 22 , Δ 32 , and the error values ​​of the third sequence Δ 13 , Δ 23 , Δ 33 . The compensation calculation is carried out, for example, using the least squares method. The result of the compensation calculation is the more precise position and / or orientation of the device head 10.

[0037] In a further development of the method, after the Nth sequence of the first to fourth steps, an error measure δ is determined by the control device 17 as part of the adjustment calculation, which indicates the quality or accuracy with which the position and / or orientation of the device head 10 is specified. The error measure δ is compared with a maximum error δ max , which indicates the permissible inaccuracy. If the error measure δ is greater than the maximum error δ max , the device head 10 is moved from the third measuring position MP 3 to a new measuring position in which the sequence of the first to fourth steps is carried out again; the new measuring position is referred to as the fourth measuring position MP 4. The movement of the device head 10 from the third measuring position MP 3 to the fourth measuring position MP 4 is recorded in the form of third movement data by the further on-board sensor device 19.

[0038] In a further development of the method according to the invention, the quality of the error values ​​Δ ji determined in the sequences can be evaluated by the control device 17 using suitable calculation methods, and error values ​​of poor quality can be given less weight or ignored in the adjustment calculation (error minimization), which is performed after completion of the last sequence of the first to fourth steps. Significant deviations between the measured distance values ​​and the corresponding estimated distance values ​​can occur if the distance measuring sensors 18 are directed toward edges in the measurement environment 11, since even small angular deviations can lead to large changes in the measured distance values.

Claims

1. Method for setting more precisely a position and / or orientation of a device head (10), which is connected to a robot arm (12) mounted on a working platform (13), in a measuring environment (11) by means of a distance measuring device (15), which comprises a number of M, M ≥ 1 distance measuring sensors (18) and which is connected to the device head (10), and a control device (17), which is connected in a communicating manner to the distance measuring device (16) and at least two on-board sensor devices (14, 19), wherein the position and / or orientation of the device head (10) is determined by means of a first on-board sensor device (14) and transmitted to the control device (16) and a geometry model (21) of the measuring environment (11) is stored in the control device (16), characterized by a sequence of a first, second, third and fourth step, which is carried out N times, N ≥ 1, wherein: ▪ in the first step of the sequence, the device head (10) is arranged in a measuring position (MP1, MP2, MP3) in the measuring environment (11), and pose data are determined for the measuring position (MP1, MP2, MP3), wherein the pose data for the measuring position (MP1) of the first sequence are determined by means of the first on-board sensor device (14) and the pose data for the measuring positions (MP2, MP3) of further sequences are determined by means of the first on-board sensor device (14) and a further on-board sensor device (19), ▪ in the second step of the sequence, the distance measuring sensors (18) carry out a distance measurement in relation to surfaces of the measuring environment (11) and transmit their measured distance values (dm_j1, dm_j2, dm_j3) to the control device (17), ▪ in the third step of the sequence, the geometry model (21) and the pose data for the measuring position (MP1, MP2, MP3) are used to determine estimated distance values (de_j1, de_j2, de_j3) corresponding to the measured distance values (dm_j1, dm_j2, dm_j3), and ▪ in the fourth step of the sequence, the deviations (Δj1, Δj2, Δj3) between the measured distance values (dm_j1, dm_j2, dm_j3) and the corresponding estimated distance values (de_j1, de_j2, de_j3) are calculated and stored as error values (Δj1, Δj2, Δj3), and after the Nth sequence of the first to fourth steps, the error values (Δj1, Δj2, Δj3) are used to carry out an error minimization for the position and / or orientation of the device head (10) and the position and / or orientation of the device head (10) is set more precisely by the control device (17).

2. Method according to Claim 1, characterized in that the first sequence of the first to fourth steps is carried out in a first measuring position (MP1), wherein the first measuring position (MP1) corresponds to the position and / or orientation of the device head (10) that was determined by means of the first on-board sensor device (14), and the position and / or orientation of the device head (10) that was determined by means of the first on-board sensor device (14) is used as first pose data for the first sequence.

3. Method according to Claim 1, characterized in that the sequence of the first to fourth steps is carried out twice in a first measuring position (MP1) and a second measuring position (MP2), wherein the first measuring position (MP1) corresponds to the position and / or orientation of the device head (10) that was determined by means of the first on-board sensor device (14), the second measuring position (MP2) is different from the first measuring position (MP1) and the movement of the device head (10) from the first measuring position (MP1) into the second measuring position (MP2) is recorded by the further on-board sensor device (19) in the form of first movement data.

4. Method according to Claim 3, characterized in that the second pose data for the second measuring position (MP2) are determined from the first pose data of the first measuring position (MP1) and the first movement data.

5. Method according to Claim 3, characterized in that the second pose data for the second measuring position (MP2) are determined from optimized first pose data and the first movement data, wherein the optimized first pose data are determined from the position and / or orientation of the device head (10) that was determined by means of the first on-board sensor device (14), by error minimization by means of the error values (Δj1) of the first sequence.

6. Method according to Claim 1, characterized in that the sequence of the first to fourth steps is carried out at least three times, wherein the movement of the device head (10) from one measuring position (MP1, MP2) into a new measuring position (MP2, MP3) is recorded by the further on-board sensor device (19) in the form of movement data.

7. Method according to Claim 6, characterized in that the pose data for the new measuring position (MP2, MP3) are determined from the first pose data of the first measuring position (MP1) and the movement data.

8. Method according to Claim 6, characterized in that the pose data for the new measuring position (MP2, MP3) are determined from optimized first pose data and the movement data, wherein the optimized first pose data are determined from the position and / or orientation of the device head (10) that was determined by means of the first on-board sensor device (14), by error minimization by means of the error values (Δj1, Δj2) of the sequences of the first to fourth steps carried out.

9. Method according to Claim 1, characterized in that, after the Nth sequence of the first to fourth steps, an error measure (δ) is determined within the error minimization.

10. Method according to Claim 9, characterized in that the error measure (δ) is compared with a maximum error (δmax), wherein, in the event that the error measure (δ) is greater than the maximum error (δmax), the device head (10) is moved into a new measuring position (MP4) and the sequence of the first to fourth steps is carried out for the new measuring position (MP4).