Device and method for producing a reference plane

Abstract

The invention relates to a device and a method for generating a reference plane, for which a radiation transmitter (118) is provided. The radiation transmitter is designed, for example, as a rotating laser and is configured to rotate a measuring beam (121) in a plane at relatively constant angular velocities in two directions of rotation. A signal generator is configured to detect at least one predetermined angle value associated with a direction of the measuring beam (121). Furthermore, computing and evaluation units of the radiation transmitter (118) and a radiation receiver (130) have timers which operate synchronously except for a temporally constant but unknown phase shift. This makes it possible to determine a position of a radiation receiver (130) with respect to a reference direction linked to the radiation transmitter (118) with relatively little complexity.

Description

[0001]Device and method for generating a reference plane The invention relates to a device for generating a reference plane according to the preamble of claim 1. The invention further relates to a method for generating a reference plane. Such a device and a method for generating a reference plane are known from EP 2 781 879 A1. This previously known device has a radiation transmitter designed as a rotating laser, which is configured to emit a measuring beam that is rotatable about an axis of rotation over an angular range and pivotable about at least one axis relative to a reference plane into a reference plane. A radiation receiver is provided to detect the measuring beam at a setup position, wherein the radiation receiver has a receiver data processing unit that is configured to emit a detection signal after detection of a passage of the measuring beam.Furthermore, the aforementioned device is equipped with a central data processing unit configured to receive detection signals from the or at least one radiation receiver and, based on the detection signals, to determine the direction of the installation position of the respective radiation receiver with respect to a reference direction. For this purpose, different rotation angle ranges are distinguished by code patterns assigned to each rotation angle range. Further devices for generating a reference plane are known from EP 2 000 767 A2, DE 10 2011 054 224 A1, US 6 693 706 B2, and DE 10 2010 061 725 A1. DE 103 01 971 A1 discloses a position-determining device with which a horizontal reference plane and an inclined reference plane can be generated simultaneously.For this purpose, the position-determining device comprises a rotating laser device to which at least two fan-shaped, diverging laser beams can be emitted while the laser beams rotate about a given axis. At least two fan-shaped laser beams diverge in a plane that is not the horizontal plane. One of the fan-shaped laser beams differs from the or another laser beam in terms of inclination angle. Furthermore, an optical sensor with at least one light-receiving segment for receiving the laser beams is provided. The optical sensor has a detection means for determining a relative position of itself with respect to the laser device based on a state in which the laser beams are received in the or a light-receiving segment.WO 2016 / 016290 A1 discloses a tracking method and a tracking system for determining the position of a mobile measuring station relative to a base station in an interior space. The base station projects a pattern of light points onto a wall, while a camera of the mobile measuring station captures images of the wall. The position of the mobile measuring station is calculated based on the image coordinates of at least three light points that are part of the pattern and the associated emission directions and distances from the wall. The invention is based on the object of specifying a device and a method of the type mentioned above, which is characterized by a relatively simple structure for determining the installation position of a radiation receiver with a relatively high angular resolution. This object is achieved in a device for generating a reference plane of the type mentioned above with the characterizing features of claim 1.This object is achieved in a method for generating a reference plane with the features of claim 6. Because the measuring beam rotates in two directions of rotation in a device and a method according to the invention, time differences in the time systems of the receiver data processing unit and the central data processing unit can be eliminated, and the directions of installation positions of the or each radiation receiver in question can be determined relatively accurately. Further expedient embodiments of the invention are the subject of the dependent claims. Further expedient embodiments and advantages of the invention will become apparent from the following explanation of exemplary embodiments with reference to the figures of the drawing. They show: Fig.1 shows a schematic perspective view of an embodiment of an exemplary device for generating a reference plane by means of a measuring beam with a rotating laser as the radiation source and with two radiation receivers, Fig. 2 shows a block diagram of essential components of the rotating laser and a radiation receiver in the embodiment according to Fig. 1, Fig. 3 shows a clear illustration of the conditions when arranging a radiation receiver in relation to a polar coordinate system of a rotating laser with an installation axis at an angular distance from a laser sensor axis in the embodiment according to Fig. 1, Fig. 4 shows a further clear illustration of the conditions according to Fig. 3 over an angular range of less than 180 degrees with indicated opposite directions of rotation of the measuring beam and Fig.5 is a graphical representation of an exemplary embodiment of the temporal relationships between the rotating laser and a radiation receiver during revolutions of the measuring beam. Fig. 1 is a schematic perspective view of an embodiment of an exemplary device for generating a reference plane according to the invention. The illustration according to Fig. 1 shows a building site 103 with, for example, a horizontal installation plane 106 and with a construction plane 115 to be measured, which is inclined relative to the installation plane along an X-axis 109 and a Y-axis 112. Advantageously, but not necessarily, the X-axis 109 and the Y-axis 112 are aligned at right angles to one another for ease of use.The exemplary embodiment explained below has a rotating laser 118 as a radiation transmitter, which is configured to rotate a measuring beam 121 about a rotation axis over an angular range and to pivot it relative to a reference plane, for example the installation plane 106, about at least one axis, but preferably about two axes such as the X-axis 109 and the Y-axis 112, into a reference plane, such as a plane parallel to the build plane 115. The rotating laser 118 is rotatable in the illustration according to Fig. 1 and preferably also pivotable for rough alignment and adjustable in height on a swivel-legged tripod 124. The tripod 124 is arranged in the illustration according to Fig. 1 such that its plumb line base 127 lies in the transition area between the build plane 115 and the installation plane 106. Furthermore, the exemplary embodiment according to Fig.1 has two radiation receivers 130, each configured to detect the measuring beam 121 at a respective installation position. In the exemplary embodiment according to Fig. 1, the radiation receivers 130 are releasably and firmly held by a receiver holder 133, while the receiver holder 133 is in turn mounted so as to be displaceable in the longitudinal direction of a support rod 136 and is rotatable together with the support rod 136. The support rods 136, in turn, are installed in the subsoil 103, for example, in the installation plane 106 in the illustration according to Fig. 1, essentially upright and secured against unintentional tilting or even falling over. Fig. 2 shows a block diagram of essential components of the rotating laser 118 and a radiation receiver 130 of the exemplary embodiment according to Fig. 2.The rotating laser 118 has an operating unit 203, which is configured with a laser light module 206 for generating the measuring beam 121 and with a rotation module 209 for rotating the measuring beam 121 in two directions of rotation, namely clockwise and counterclockwise, over a predetermined angular range, expediently over an angular range of 360 degrees. The rotation module 209 is configured to generate rotation direction identifiers associated with the respective direction of rotation. Furthermore, the operating unit 203 is configured with an inclination sensor module 212 having a number of inclination sensors for detecting the effective inclination of the measuring beam 121 relative to a reference plane. In the first embodiment of an operating unit 203 shown in Fig. 2, a signal module 215 is provided, which is configured to generate rotation angle-dependent signals.In a first embodiment, the signal module 215 is designed as an angle measuring module configured to directly detect the respective angle of rotation of the measuring beam 121 relative to a reference direction inherent in the rotation module 209 during the rotation of the measuring beam 121. In a second embodiment, the signal module 215 is designed as a pulse signal generator configured to generate at least one pulse signal as an index mark per revolution of the measuring beam 121. In particular, it is advantageous in the second embodiment that the rotation module 209 provides a relatively high degree of synchronization in both directions of rotation, i.e., a temporally constant and expediently also an identical angular velocity in both directions of rotation.The operating unit 203 is connected for bidirectional data exchange to a computing and evaluation unit 218 of the rotating laser 118 as a central data processing device, which in this exemplary embodiment is in turn connected to a timer 221. The timer 221 of the rotating laser 118 is configured to generate time stamps on a predetermined time scale explained in more detail below and to feed them to the computing and evaluation unit 218 of the rotating laser 118. Furthermore, an inclination adjustment unit 224 for receiving adjustment signals from the computing and evaluation unit 218 of the rotating laser 118 is connected to the computing and evaluation unit 218 of the rotating laser 118. The inclination adjustment unit 224 is configured to adjust the inclination of the measuring beam 121 with respect to at least one axis, but preferably about two axes such as the X-axis 109 and the Y-axis 112.Furthermore, the computing and evaluation unit 218 of the rotating laser 118 is connected to a communication unit 227 of the rotating laser 118 via a bidirectional data connection. The communication unit 227 of the rotating laser 118 is, as explained in more detail below, configured to exchange data with the radiation receiver 130 via a preferably wireless communication connection 230. The radiation receiver 130, in turn, has a laser sensor unit 233 configured to detect the passages of the measuring beam 121. The laser sensor unit 233 is connected to a computing and evaluation unit 236 of the radiation receiver 130, which is configured, among other things, to receive output signals from the laser sensor unit 233 and to store them together with time stamps that can be generated by a timer 239 connected to the computing and evaluation unit 236.Certain data from the computing and evaluation unit 236 of the radiation receiver 130 can be fed to a display unit 242 for visual recording by a user of a device according to the invention. The radiation receiver 130 is further equipped with a communication unit 245, which is configured to exchange data with the computing and evaluation unit 236 of the radiation receiver 130 and to feed the data to the communication connection 230. According to the invention, the timers 221, 239 are synchronous in the sense that they have the same time period with a periodic time clock or the same time increments with a linearly advancing time scale, but run with a certain, but temporally constant, phase shift relative to one another.In this respect, the time stamps generated by the timers 221, 239 are comparable with each other and can be traced back to a common time system if this phase shift, which is generally initially unknown and can be determined as explained in more detail below, is known. Fig. 3 shows in a descriptive representation the conditions when arranging a radiation receiver 130 in relation to a rotating laser 118 in a coordinate system determined by the X-axis 109 and the Y-axis 112 with a setup axis 303 as a connecting line between the rotating laser 118 and the radiation receiver 130 and with the radiation sensor axis of the radiation receiver 130 at an angular distance from the Y-axis 112. Furthermore, in the representation according to Fig. 3, a reference plane 306 is shown, delimited by an outer circle running through the radiation receiver 130, in which reference plane the measuring beam 121, which in the representation according to Fig. 3 momentarily coincides with the setup axis 303, runs.From Fig. 3 it can be seen that the installation axis 303 of the radiation receiver 130 has a deviation angle 309 with respect to the X-axis 109 and thus also to the Y-axis 112, which deviation angle is different from 90 degrees or 0 degrees, the exact value of which is initially unknown when the measuring beam 121 passes through the radiation receiver 130, also due to an unknown phase shift in the case of uncoupled, freely running timers 221, 239, even with the same clock time or the same time scale between the time stamps of the timers 221, 239. Fig. 4 shows in a larger, clear representation the conditions according to Fig. 3 over an angular range of less than 180 degrees. From the representation according to Fig.4 it can be seen that in the case of an angle measurement according to the first embodiment with an angle measuring module as signal module 215, with a first direction of rotation R of the measuring beam 121 in a clockwise direction, i.e. in a so-called right-hand direction, a right-hand transit time stamp can be generated at a predetermined first position 403 and at a predetermined second position 406 on the time scale of the timer 221 of the rotating laser 109, or with a first direction of rotation L of the measuring beam 121 counterclockwise, i.e. in a so-called left-hand direction, a left-hand transit time stamp can be generated at the predetermined first position 403 and at the predetermined second position 406 on the time scale of the timer 221 of the rotating laser 109.Accordingly, when the direction of rotation of the measuring beam 121 is reversed from the first direction of rotation L, R, two left-hand transit time stamps can be generated at the aforementioned predetermined positions 403, 406 of the rotating laser 118 in a second direction of rotation L of the measuring beam 121, i.e., counterclockwise or in the left direction, or two right-hand transit time stamps can be generated at the aforementioned predetermined positions 403, 406 of the rotating laser 118 in a second direction of rotation R of the measuring beam 121, i.e., clockwise or in the right direction. In the aforementioned first embodiment with an angle measuring module as the signal module 215, the predetermined positions 403, 406 are determined by predetermined angle values ​​of the measuring beam 121.In the aforementioned second embodiment with a pulse signal generator as the signal module 215, with constant, but not necessarily equal, angular velocities of the measuring beam 121 in each of the rotational directions L, R, the predetermined positions 403, 406 are determined by predetermined times with respect to the pulse signal during a pass of the measuring beam 121. When the measuring beam 121 passes through the radiation receiver 130, a receiver time stamp generated by the timer 239 of the radiation receiver 130 can be generated at a set-up position 409 of the radiation receiver 130, which can be fed to the computing and evaluation unit 218 of the rotating laser 118 via the communication connection 230. Fig. 5 shows in a graphic manner the temporal relationships of the rotating laser 118 and a radiation receiver 130 during revolutions of the measuring beam 121 in an exemplary embodiment.5 shows a time axis 503 for the time values ​​t of the timer 221 of the rotating laser 118 in dimensionless units. Furthermore, an angle scale 506 of the rotating laser 118 is shown in dimensionless units, on which the angular position α is also shown in dimensionless units for the case where the rotating laser 118 is equipped with an angle measuring module for explicit angle measurements according to the first embodiment of the exemplary embodiment explained above. Furthermore, FIG. 5 shows a time line 509 for the direction of rotation R of the measuring beam 121 and a time line 512 for the direction of rotation L of the measuring beam 121. Furthermore, the graphic according to FIG. 5 shows a time axis 515 for the time t of the timer 239 of a radiation receiver 130 in dimensionless units.The following explains the sequence of a measurement for determining the direction of the installation position 409 of a radiation receiver 130 with respect to a reference direction of the rotating laser 118 when the measuring beam 121 rotates in the direction of rotation R, i.e., in the clockwise direction, using a purely exemplary configuration for the first embodiment with an angle measuring module as the signal module 215. When the measuring beam 121 rotates in the direction of rotation R, a first clockwise time stamp is recorded at the first position 403 at a time t. 1R , in the diagram according to Fig. 5 with t 1R = 18. In the further course, a receiver time stamp t ER , in the diagram according to Fig. 5 with t ER = 516. Next, the rotating laser 118 records a second clockwise time stamp t at the second position 406. 2R, in the diagram according to Fig. 5 with t 2R = 50. Since for the first version with an angle measuring module as signal module 215 the positions 403, 406 are known in their angular positions α1, α2, the difference between the clockwise running time stamps t 1R , t 2R assuming a constant angular velocity during the direction of rotation R, at least between the positions 403, 406, a right-hand angular velocity ω R determine, in the diagram according to Fig. 5 with ω R = 1.25. For a rotation direction L of the measuring beam 121 in the left direction, the following conditions prevail for the first embodiment with an angle measuring module as the signal module 215. When the measuring beam 121 rotates in the rotation direction L, a first left-hand transit time stamp is recorded at the second position 406 at a time t 2L , in the diagram according to Fig. 5 with t 2L= 170. In the further course, a receiver time stamp t EL , in the diagram according to Fig. 5 with t EL = 696. Next, the rotating laser 118 records a second left-hand travel time stamp t 1L , in the diagram according to Fig. 5 with t 1L = 218. Since for the first version with an angle measuring module as signal module 215 the positions 403, 406 are known in their angular positions α1, α2, the difference between the left-hand travel time stamps t 2L , t 1L assuming a constant angular velocity at least between the positions 403, 406 during the direction of rotation L, a counterclockwise angular velocity ω L determine, in the diagram according to Fig. 5 with ω L= 0.83. The following is a purely exemplary configuration for the second embodiment with a pulse signal generator as signal module 215, which explains the sequence of a measurement for determining the direction of the installation position 409 of a radiation receiver 130 with respect to a reference direction of the rotating laser 118 when the measuring beam 121 rotates clockwise in the direction of rotation R, i.e., in the right direction. When the measuring beam 121 rotates in the direction of rotation R at a constant angular velocity, a receiver time stamp t is recorded at a radiation receiver 130 at the installation position 409. ER , in the diagram according to Fig. 5 with t ER = 516. Next, the rotating laser 118 records a clockwise time stamp t 0R , in the diagram according to Fig. 5 with t 0R= 34. With a counterclockwise rotation direction L of the measuring beam 121 in the left direction, the following conditions prevail for the second embodiment with a pulse signal generator as signal module 215. When the measuring beam 121 rotates in the rotation direction L at a constant angular velocity, a receiver time stamp t is recorded at a radiation receiver 130 at the installation position 409. EL , in the diagram according to Fig. 5 with t EL = 696. Next, the rotating laser 118 records a left-hand travel time stamp t 0L , in the diagram according to Fig. 5 with t 0L = 193. Since the position of the index mark is known for the second version with a pulse signal generator as signal module 215, the angular speeds in both directions of rotation R, L are constant, but not necessarily the same, from the differences between the clockwise running time stamp t 0R and the recipient timestamp tER or the left-hand transit time stamp t 0L and the recipient timestamp t ELDetermine the position of the radiation receiver 130 relative to the index mark. Exemplary procedures for a method according to the invention for determining the direction of the installation position of a radiation receiver 130 are explained below with reference to the above-explained explanations of the exemplary embodiment according to the invention. In the first procedure with the first embodiment of the above-explained exemplary embodiment with explicit angle measurement, the initial steps include determining the exit angle of the measuring beam 121 in values ​​from the angle measuring module 215 and determining the direction of the sensor axes of the inclination sensors of the inclination sensor module 212. In a next step, the radiation receiver 130 is brought to an installation position 409 in the construction field 103.Subsequently, the rotating laser 118 is initially aligned relatively roughly and then finely in a known automated catching process with the radiation receiver 130 until the reference plane 306 hits the laser sensor unit 233 of the radiation receiver 130. Thus, with each pass of the measuring beam 121, the radiation receiver 130 transmits a pass signal provided with a time stamp from the timer 239 of the radiation receiver 130 depending on the respective direction of rotation L, R at times t. EL , t EROn the rotating laser 118 side, time stamps of the rotating laser 118 are recorded at two predetermined angular positions, for example, at the first position 403 and at the second position 406 according to Fig. 4. The aforementioned steps occur with a first rotation direction of the rotating laser 118, for example, a clockwise rotation in the direction of rotation R. Subsequently, the rotation direction of the rotating laser 118 is reversed to a second rotation direction, for example, a counterclockwise rotation in the direction of rotation L, and it is expedient to wait until the measuring beam 121 is again moving at a constant angular velocity. Subsequently, time stamps are recorded at the predetermined positions 403, 406, and the time stamp is recorded when the measuring beam 121 passes through the radiation receiver 130.On this basis, the direction of the installation position 409 of the radiation receiver 130 with respect to a reference direction of the rotating laser 118 is determined as follows. In a first step, the angular velocities when the measuring beam 121 is moved counterclockwise in the direction of rotation L or when the measuring beam 121 is rotated clockwise in the direction of rotation R are determined according to equations (1.1) and (1.2) as follows: (1.1) ωL = (α2 - α1) / (t1L - t2L) (1.2) ω. R = (α2- α1) / (t 2R - t 1R ) with ω L : Angular velocity when moving the measuring beam 121 counterclockwise in the direction of rotation L ω R : Angular velocity when moving the measuring beam 121 clockwise in the direction of rotation R α1: Angle at the first position 403 α2: Angle at the second position 406 t 1L: Time stamp of the rotating laser 118 at the first position 403 when rotating counterclockwise in the direction of rotation L t 1R : Time stamp of the rotating laser 118 at the first position 403 when rotating clockwise in the direction of rotation R t 2L : Time stamp of the rotating laser 118 at the second position 406 when rotating counterclockwise in the direction of rotation L t 2R : Time stamp of the rotating laser 118 at the second position 406 when rotating clockwise in the direction of rotation R The time stamp at the radiation receiver 130 at the times t EL , t ER In the directions of rotation L, R, the time stamps t 1L , t 1R , t 2L , t 2R of the rotating laser 118 has an initially unknown but constant phase shift or time offset ΔT, whereby when using the times t 1L and t 1R the following relationship applies: (1.2) (t ER - ΔT - t 1R ) ∙ ωR = (t 1L - (t EL - ΔT)) ∙ ω L Solving equation (1.2) for ΔT gives: (1.3) ΔT = ((t ER - t 1R ) ∙ ω R + (t EL - t 1L ) ∙ ω L ) / (ω L + ω R ) Using an alternative time point t 2L and t 2R the following relationship applies: (1.4) (t 2R - (t ER - ΔT)) ∙ ω R = (t EL - ΔT - t 2L ) ∙ ω L Solving equation (1.4) for ΔT gives: (1.5) ΔT = ((t ER - t 2R ) ∙ ω R + (t EL - t 2L ) ∙ ω L ) / (ω L + ω R) To reduce the influence of errors, it is advisable to calculate the average value for the phase shift ΔT from equations (1.3) and (1.5). The angular position ε of the radiation receiver 130 with respect to the angle measuring system of the rotating laser 118 is determined according to one of the following equations: (1.6) ε = (t ER - ΔT - t 1R ) ∙ ω R + α1(1.7) ε = (t 2R - t ER + ΔT) ∙ ω R - α2(1.8) ε = (t 1L - t EL + ΔT) ∙ ω L + α1(1.9) ε = (t EL - ΔT + t 2L ) ∙ ω L- α2. To reduce error influences, it is also expedient to determine the angular position ε of the radiation receiver 130 by calculating the mean value from at least two of equations (1.6) to (1.9), particularly preferably from all equations (1.6) to (1.9). The method according to the invention for determining the direction of the installation position 409 of a radiation receiver 130 with respect to a reference direction of the rotating laser 118 with the second embodiment of the above-described exemplary embodiment having a pulse signal generator as the signal module 215 proceeds as follows in a further procedure. First, as in the method explained above, the rotating laser 118 is aligned so that the measuring beam 121 hits the laser sensor unit 233 of the radiation receiver 130 and, with each passage of the measuring beam 121 in the two rotational directions L, R, the latter receives a value determined by the timer 239 of the radiation receiver 130 at times t EL , t ERcertain time stamp to the rotating laser 118. At a relatively constant angular velocity in one direction of rotation, for example counterclockwise in the direction of rotation L, an index mark is set at an index angular position α0 which is predetermined in time and with respect to the relative angular value determined by the position of the index mark, but with respect to the absolute angular value in the coordinate system of the rotating laser 118, initially fundamentally, that is to say in the case of a lack of determination of the angular value during assembly, undetermined, which in the second embodiment is determined by the pulse signal generated by the pulse signal generator at time t 0Lis determined, the detection of a time stamp generated by the timer 221 of the rotating laser 118. Subsequently, the direction of rotation is reversed, for example, clockwise in the direction of rotation R, and a wait is made until the angular velocity of the rotating laser 118 is constant in the new direction of rotation. With a relatively constant angular velocity in this new direction of rotation, for example, clockwise in the direction of rotation R, the index mark is set at the predetermined index angular position α0, which in the second embodiment is determined by the pulse signal generated by the pulse signal generator at time t 0Ris determined by capturing a time stamp generated by the timer 221 of the rotating laser 118. On this basis, in the second embodiment, the direction of the installation position 409 of the radiation receiver 130 is calculated as follows. In a first step, the angular velocity during a counterclockwise rotation of the measuring beam 121 in the direction of rotation L is determined according to equation (2.1) as follows: (2.1) ω L = 2π / τ L with, unless already explained above, τ L : Cycle time when moving the measuring beam 121 clockwise in the direction of rotation L over the index mark. Subsequently, in a second step following the first step, the angular velocity when moving the measuring beam 121 clockwise in the direction of rotation R is determined according to equation (2.2) as follows: (2.2) ω R = 2π / τ R with, unless already explained above, τ R: Cycle time when moving the measuring beam 121 counterclockwise in the direction of rotation R over the index mark Due to the fact that, as in the first embodiment, different time differences in the directions of rotation L, R with different angular velocities ω L , ω R correspond to the same angle differences, results from the relationship (2.3) (t ER - ΔT - t 0R ) ∙ ω R = (t 0L - (t EL - ΔT)) ∙ ω L for the initially unknown phase shift ΔT (2.4) ΔT = ((t ER - t 0R ) ∙ ω R + (t EL - t 0L ) ∙ ω L ) / (ω L + ω R ) and for the angular position ε of the radiation receiver 130 with respect to the position of the rotating laser 118 in the direction of rotation L (2.5) ε = (t 0L - t EL + ΔT) ∙ ω L + α0and for the direction of rotation R (2.6) ε = (t ER - ΔT - t 0R ) ∙ ω R+ α0. In the second embodiment, for determining the angular position ε of the radiation receiver 130, it is expedient to calculate the average of the two equations (2.5) and (2.6) to reduce the influence of errors. This results in a relatively accurate determination of the direction of the installation position 409 of a radiation receiver 130 with respect to a reference direction of the rotating laser 118, with synchronized timers 221, 239 of the rotating laser 118 and the radiation receiver 130, using signals that are easy to process in terms of data technology in the form of time stamps of the timers 221, 239, eliminating any constant phase shifts that may exist between the timers 221, 239, without latencies in the communication link 230 playing any role.This provides a relatively simple structure for a computational correction of the coordinate system of the rotating laser 118 to the coordinate system of the radiation receiver 130, given knowledge of the obtained angular position ε. In a further development of a device and a method according to the invention, the phase shift between the timers 221, 239 is determined from the above-explained determination of the actual angular position of the radiation receiver 130, assuming that the angular velocities ω. L , ω Rover the entire orbit and the value of the phase shift are constant over time, to determine the angular position of the radiation receiver 130 at each installation position 409 of the radiation receiver 130, without latencies in the communication link 230 playing any role. Once the determination of the time difference Δt, i.e. a phase shift, between the two timers 221, 239 has been completed, the direction of the installation position of a radiation receiver 130 can be determined at any desired position. For this purpose, the radiation receiver 118 sends one of its previously explained time stamps t EL , t ERto the rotating laser 118 as soon as a measuring beam 118 has been detected. Using one of the aforementioned calculation rules (1.6) to (1.9) for determining the angle value ε, a direct determination of the direction of the installation position of the radiation receiver 130 is thus possible. Only the respective direction of rotation L, R of the rotating laser 118 and thus the corresponding selection of the calculation rule must be taken into account, namely equation (1.8) or equation (1.9) for the counterclockwise direction of rotation L in the left direction, otherwise equation (1.6) or equation (1.7) for the clockwise direction of rotation R in the right direction. The values ​​for the previously explained quantities α1, α2, t, which are to be considered constant in this case, 1L , t 2L , t 1R and t 2Rcan be adopted unchanged, namely as used to determine the time difference Δt. In the first version with the signal module 215 designed as an angle measuring module, the previously determined angular velocity ω L , ω R between the angular positions α1 and α2 is assumed to be constant over the entire rotation range of the rotating laser 118. To reduce inaccuracies, it is also expedient here to alternate the direction of rotation L, R of the rotating laser 118 and thus use both directions of rotation L, R with averaging to determine the angular position ε. In the second embodiment with the signal module 215 designed as a pulse signal generator, the respective angular velocity ω is determined L , ω R necessarily on the basis of a complete revolution of the measuring beam 121 with the assumption of a correspondingly constant angular velocity ω L , ω ROnce the radiation receiver position 409 has been at least roughly determined, the measuring beam 121 is expediently emitted only in a relatively small angular range in which the radiation receiver position 409 and thus the radiation receiver 130 are located. This largely avoids interference with other optical systems in the construction area 103.

Claims

CLAIMS 1. Device for generating a reference plane (306) with a radiation transmitter (118) which is configured to emit a measuring beam (121) rotatable about an axis of rotation over an angular range and pivotable about at least one axis (109, 112) relative to a reference plane into a reference plane (306), with at least one radiation receiver (130) which is configured to detect the measuring beam (121) at a set-up position (409), and which has a receiver data processing unit (236) which is configured to emit a detection signal after detection of a passage of the measuring beam (121), and with a central data processing unit (218) which is configured to receive detection signals from the or at least one radiation receiver (130) and, on the basis of the detection signals, to determine the direction of the set-up position (409) of the radiation receiver in question (130) with respect to a reference direction,characterized in that the radiation transmitter (118) is designed to rotate the measuring beam (121) in two directions of rotation (L, R) and to feed the central data processing unit (218) a direction of rotation identifier assigned to the respective direction of rotation (L, R), and in that the central data processing unit (218) is designed to, on the basis of the data obtained in the two directions of rotation (L, R), Detection signals to determine the direction of the setup position (409) of at least one radiation receiver (130) with respect to the reference direction.

2. Device according to claim 1, characterized in that the central data processing unit (218) and the receiver data processing unit (236) each have a timer (221, 239) that are synchronized except for a temporally constant phase shift.

3. Device according to claim 2, characterized in that each timer (221, 239) is configured to generate its own time stamp. 4.Device according to claim 3, characterized in that the timer (221) assigned to the radiation transmitter (118) is configured to feed the associated time stamps to the central data processing unit (218) during a revolution at two predetermined angular values ​​(α1, α2) assigned to two beam directions of the measuring beam (121), and in that the timer (239) assigned to the receiver data processing unit (236) is configured to feed its time stamp generated during this revolution of the measuring beam (121) to the receiver data processing unit (236).

5. Device according to claim 4, characterized in that a signal module (215) designed as an angle measuring module is present, which is configured to determine angle values ​​(α1, α2) in the coordinate system of the radiation transmitter (118) at the two predetermined beam directions.Device according to claim 3, characterized in that the beam rotation unit (209) has an angular velocity in each of the two directions of rotation (L, R) that is sufficiently constant for a predetermined accuracy for determining the direction of the setup position (409) of the at least one radiation receiver (130), in that the timer (221) assigned to the radiation transmitter (118) is configured to feed the associated time stamps to the central data processing unit (218) at two predetermined times during a revolution of the measuring beam (121), and in that the timer (233) assigned to the receiver data processing unit (236) is configured to feed its time stamp generated during this revolution of the measuring beam (121) to the receiver data processing unit (236).Device according to claim 6, characterized in that a signal module (215) designed as a pulse signal generator is provided, which is designed to generate at least one pulse signal as an index mark per revolution of the measuring beam (121).

8. A method for generating a reference plane (306) comprising - providing a device according to one of claims 1 to 7, - moving the measuring beam (121) in a first rotational direction (L, R) and obtaining detection signals from at least one radiation receiver (130) as the measuring beam (121) passes through, - feeding the detection signals into the central data processing unit (218), - moving the measuring beam (121) in a second rotational direction (R, L) opposite to the first rotational direction (L, R), - feeding the detection signals of the radiation receiver (130) into the central data processing unit (218), and - determining the direction of the setup position (409) of a radiation receiver (130) with respect to a reference direction. 9.Method according to claim 8, insofar as a device according to claim 4 or according to claim 5 is provided, characterized in that time stamps of the timer (221) assigned to the radiation transmitter (118) are obtained at two predetermined beam directions of the measuring beam (121).

10. Method according to claim 8, insofar as a device according to claim 6 or according to claim 7 is provided, characterized in that, at a constant angular velocity in each of the two directions of rotation (L, R), time stamps of the timer (221) associated with the radiation transmitter (118) are obtained at two predetermined times.

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