Method for ascertaining a profile section, 2d laser scanner and system

Abstract

The invention relates to a method for ascertaining a profile section of an object and / or a space by means of a 2D laser scanner having a laser distance measuring device, comprising the following method steps: • detecting distance measurement values and distance measurement directions which can be assigned to one another by means of the laser distance measuring device in a measurement plane radially swept through by a laser beam of the laser distance measuring device; • ascertaining a profile section from the distance measurement values and the distance measurement directions; • ascertaining an angle of inclination of the measurement plane relative to a reference plane; • correcting the profile section using the angle of inclination of the measurement plane. According to the invention, the angle of inclination of the measurement plane is ascertained using the laser distance measuring device. Furthermore, a 2D laser scanner and a system are proposed.

Description

Technical Field

[0001] This invention relates to a method for determining the profile of an object and / or space using a 2D laser scanner with a laser rangefinder. Furthermore, this invention relates to a 2D laser scanner. Background Technology

[0002] A laser rangefinder is known from DE 10 2009 027 668 A1, in which a laser beam can be rotated within a measuring plane by means of a mirror in order to measure a plurality of angle-dependent distances within said measuring plane. These distances are measured between a laser diode emitting the laser beam in the laser rangefinder and a surrounding wall. Summary of the Invention

[0003] This invention is based on a method for determining the contour profile of an object and / or space using a 2D laser scanner equipped with a laser rangefinder, and a 2D laser scanner. The 2D laser scanner includes at least one laser rangefinder, wherein the 2D laser scanner is configured to detect mutually compatible, especially compatible, distance measurements and distance measurement directions in a measurement plane at least partially radially swept by the laser beam of the laser rangefinder. The 2D laser scanner is used to measure the object and / or space, particularly in the case of generating a two-dimensional contour profile. Such 2D laser scanners are used by architects, space or building planners, real estate agents, or craftspeople to determine the shape and / or size of spaces and / or objects (e.g., swimming pools). The 2D laser scanner is particularly applicable to measurement tasks, such as those found especially in the field of crafts. For example, the 2D laser scanner is used in interior decoration of buildings or generally in construction projects.

[0004] The 2D laser scanner includes a laser rangefinder for non-contact distance measurement. Furthermore, the laser rangefinder includes at least one laser source, particularly a laser diode, for generating laser radiation. The laser rangefinder is configured to emit time-modulated laser radiation in the form of a laser beam along the distance measurement direction toward a target object from which the distance relative to the laser rangefinder is to be determined. The laser radiation reflected or scattered by the target object, i.e., the reflected laser radiation, is at least partially detected by the laser rangefinder, particularly by its receiving mechanism, and used to determine the distance measurement value to be measured along the distance measurement direction. The receiving mechanism is configured to detect the reflected laser radiation. The light propagation time is determined by phase comparison between the emitted laser radiation and the laser radiation reflected from the surface of the target object, and the desired distance measurement value between the laser rangefinder, i.e., the 2D laser scanner, and the target object is determined by the speed of light. Alternatively, the light propagation time can also be determined from time-of-flight measurements. The basic scheme for non-contact distance measurement using lasers is known to those skilled in the art. The concepts of “laser radiation” and “laser beam” are used as synonyms here. “At least partially swept” means that during the period when the emitted laser beam moves from one distance measurement direction (measurement position) to the next distance measurement direction (measurement position) in the measurement plane, only a segment of the plane (e.g., within an angular range of 180°) is swept and / or the laser beam is temporarily interrupted.

[0005] The 2D laser scanner is configured to orient the laser beam emitted by the laser ranging device in different spatial directions, thereby obtaining distance measurements along different spatial directions, i.e., the distance measurement directions. The 2D laser scanner is particularly configured to allow the laser beam of the laser ranging device to sweep across the measurement plane, at least partially radially, from the centrally located laser ranging device. This can be achieved, for example, by rotating the laser ranging device about a rotation axis perpendicular to the emission direction of the laser beam. Here, the zero point of the distance measurement can advantageously be located on the rotation axis and thus at the center of the rotational motion. Alternatively, it is conceivable to use beam-guiding optical elements, such as diffraction elements, mirrors, reflectors, or similar devices, to achieve, in a technically simple manner, the emission of the laser beam in different spatial directions, wherein the laser beam of the laser ranging device also sweeps across the measurement plane, at least partially radially, from the centrally located optical element. In particular, the 2D laser scanner can include a drive mechanism for orienting the laser ranging device or the beam-guiding optical element, especially for rotating it about the rotation axis. The drive mechanism can be set, for example, by an electric motor or, alternatively, by using a spring that can be tightened, as in a sand clock, such that the spring is pre-tensioned and then relaxed in a defined manner. This drive mechanism enables particularly easy and automated detection of distance measurements along different distance measurement directions. The distance measurement direction is detected in three-dimensional space, especially in the measurement plane swept by a laser beam, which is emitted towards the target object, during the corresponding distance measurement performed by means of a sensor or by a control device, such as the drive mechanism. In this sense, the distance measurement direction is also detected by means of a laser rangefinder, or when using a laser rangefinder, because the given orientation of the laser rangefinder defines the current distance measurement direction at that moment. The detection of the distance measurement direction can be achieved, for example, by detecting the distance measurement angle, such as the rotation angle of the laser rangefinder relative to the aforementioned axis of rotation. Thus, with respect to a 2D laser scanner, the distance measurement direction is defined by the distance measurement angle. By directing the laser beam, particularly due to the orientation of the laser rangefinder, distance measurements can be performed in different distance measurement directions, i.e., different spatial directions, without changing the position of the 2D laser scanner itself. This correspondingly accelerates the measurement of the object and / or space, as well as the creation of the profile, compared to performing multiple individual measurements, because the 2D laser scanner only needs to be positioned once (especially as centrally as possible in space) and subsequently, different distance measurements can be performed without changing its position.

[0006] In this way, during the 2D laser scanning, the laser rangefinder identifies mutually dependent or associated distance measurements and distance measurement directions, especially distance measurement angles, within a measurement plane at least partially radially swept by the laser beam of the laser rangefinder. "Mutually dependent / associated" here means that the associated distance measurement direction, especially the associated distance measurement angle, is detected and processed, and at least temporarily stored, for each detected distance measurement by means of the 2D laser scanner. The detected distance measurements and distance measurement directions are initially represented as a profile profile in the abstract form of a 2D point cloud. Here, "profile profile" means that the data set includes mutually dependent distance measurements and distance measurement directions within a measurement plane at least partially radially swept by the laser beam of the laser rangefinder during the 2D laser scanning, thus obtaining a spatial profile—a profile profile—as an imaginary intersection of the space and the measurement plane. Next, the profile can be further processed, for example by means of a computing unit, especially an analysis unit, and / or output to the user of the 2D laser scanner using an output device (internal or external to the device), such as a screen. Furthermore, various analyses can be conceived using the profile, such as area calculations, angle calculations, and the generation of planar diagrams. Different types of analyses using such profiles are known to those skilled in the art.

[0007] When measuring a typical space, the surfaces targeted for detecting the laser distance measurements are mostly vertical walls or horizontal ceilings and floors. For simplicity, the following discussion (without limiting generality) focuses solely on measuring vertical walls, where the measurement plane of the 2D laser scanner is oriented almost horizontally. It should be noted that the same applies without problem to measurements with an almost vertically oriented measurement plane. Ideally, the profile resulting from measurements of vertical walls should include the distance measurement value and the distance measurement direction in a (ideally) horizontal plane. In this case, the horizontal plane is the reference plane. If this is not the case, i.e., the measurement plane has an angle of inclination relative to the horizontal plane, a distorted profile is produced, which is less suitable for further analysis. The method according to the invention allows for the correction of the profile initially detected after the 2D laser scan with respect to the angle of inclination of the measurement plane relative to the horizontal plane (or generally, relative to the reference plane) by mathematically projecting the detected distance measurement value and distance measurement direction onto the (ideal) horizontal plane (or reference plane). Here, the correction refers to the conversion of the detected distance measurement value by means of trigonometric functions and with the use of tilt angle, wherein the distance measurement value is projected onto the (ideal) horizontal plane (commonly referred to as: reference plane).

[0008] In one embodiment of the 2D laser scanner, the 2D laser scanner has a computing unit configured to execute the method for determining a contour profile according to the invention. The computing unit specifically refers to a computer device, particularly a processor device.

[0009] In another aspect of the invention, a system comprising a 2D laser scanner and a computing unit implemented externally to the 2D laser scanner is proposed. The 2D laser scanner is configured to detect mutually compatible or associated distance measurements and distance measurement directions, particularly distance measurement angles, in a measurement plane at least partially radially swept by a laser beam from the laser rangefinder, using a laser ranging device. The computing unit, for example in the form of a smart device, such as a tablet computer, smartphone, etc., is configured to implement the method of the invention for determining a profile. In this embodiment, the correction is implemented according to the method of the invention on a computing unit external to the 2D laser scanner, wherein, when using the data communication interface of the 2D laser scanner, the required profile and possible other information (e.g., tilt angle or data for determining the tilt angle) are provided, particularly transmitted, to the external computing unit. "Data communication interface" can, for example, refer to a Bluetooth interface, Bluetooth Low Energy interface, WiFi data communication interface, or a similar interface. "External computing unit" can, for example, refer to a smartphone, cloud, computer, tablet computer, or a similar device.

[0010] The method for determining the contour profile of an object and / or space according to the present invention begins with a method comprising the following steps:

[0011] • Using the laser ranging device, mutually dependent or associated distance measurements and distance measurement directions are detected in a measurement plane at least partially radially swept by the laser beam of the laser ranging device;

[0012] • The profile profile is determined from the distance measurements and the distance measurement direction;

[0013] • Determine the angle of inclination of the measuring plane relative to a reference plane, especially a horizontal or vertical plane;

[0014] • Correct the profile profile when using the tilt angle of the measuring plane.

[0015] Correcting the profile profile requires knowing the tilt angle of the measuring plane relative to the reference plane. According to the present invention, the tilt angle of the measuring plane is determined when using a laser rangefinder. Here, the reference plane represents a horizontal or vertical plane depending on the orientation of the measuring plane.

[0016] In methods known in the prior art, such as those from US 8,699,005 B2, the tilt angle is known to be determined using an accelerometer or inertial sensor, which detects the orientation of the laser rangefinder and thereby the orientation of the measurement plane. This requires the integration of additional, particularly precise, and therefore expensive sensors into the 2D laser scanner. The proposed method allows for the elimination of additional sensors while still detecting the tilt angle in a simple manner, by means of which the detected profile can be corrected.

[0017] In one embodiment of the method, the tilt angle of the measuring plane is determined, particularly in an additional calibration measurement. For example, in one embodiment of the method, it is possible to determine the tilt angle of the measuring plane during the calibration measurement.

[0018] • By means of the laser rangefinder, multiple distance measurements are detected in two different, especially non-collinear and non-parallel, distance measurement directions, in addition to the distance measurements in the measurement plane, at angles that increase and / or decrease (rotation) relative to the measurement plane (that is, when the distance measurement directions projected onto the measurement plane are the same, i.e., when the distance measurement angle remains unchanged).

[0019] • Wherein, a minimum value of the plurality of distance measurements is determined, and wherein, by means of the minimum value and the distance measurement value in the measurement plane, the angular deviation (depending on the direction) is determined for the corresponding distance measurement direction.

[0020] • The tilt angle of the measuring plane relative to the reference plane is calculated from the two angular deviations and the angular distance between the two distance measuring directions (the difference between the corresponding distance measuring directions).

[0021] Specifically, it is conceivable that the calibration measurement is initiated using the input device of the 2D laser scanner, subsequently triggering a sequence of multiple distance measurements. Then, during the measurement sequence, these multiple individual distance measurements are performed "lateral" to the measurement plane (always originating from the center of the laser rangefinder, only by a (rotational) angle). Then, at least one minimum value among the multiple distance measurements is determined, which exists precisely for the case where the laser beam is in the reference plane. In this way, the angular deviation of the measurement plane along this direction can be determined simply by rotating the laser beam back to the surface to be measured during the calibration measurement.

[0022] In one embodiment of the method, the two different distance measurement directions are chosen orthogonally to each other. This allows for the description of a mathematically simple, computationally inexpensive, and therefore quickly implementable method.

[0023] In one embodiment of the method, the plurality of distance measurements are detected by increasing and / or decreasing angles relative to the measurement plane during manual or automatic tilting (or rotation) of the laser rangefinder, particularly a 2D laser scanner. Automatic tilting of the laser rangefinder can be achieved, for example, by means of a special (tilting) actuator. This actuator can be in the form of a motor. Alternatively or supplementary, manual tilting can be achieved by means of a mechanical rotation device. This illustrates a method that can be implemented in a structurally simple manner.

[0024] In one embodiment of the method, the tilt angle of the measuring plane is determined from the profile itself. In particular, it is conceivable that, in one embodiment of the method, the tilt angle is determined in a simulated manner to compensate for distortions in the profile caused by changes in the tilt angle. When the distortion of the profile is completely (at least within tolerance limits) eliminated and thus compensated, the simulated (changing) angle corresponds to the actual tilt angle of the measuring plane. Therefore, a design of the method can be described in this way, where it is not necessary to implement special structural pre-measures for the 2D laser scanner.

[0025] In one alternative or supplementary embodiment of the method, the tilt angle is determined by triangulation from two distance measurements along different, especially non-collinear or parallel distance measurement directions and the angular spacing between these directions. In particular, the tilt angle of the measuring plane can be calculated in this way from the alignment of the actually detected distance measurements with respect to predictable distance measurements according to a pre-given or pre-given angular spacing (e.g., pre-given by the step size of a stepper motor). This method can also be implemented without pre-emptive measures in the special structure of the 2D laser scanner.

[0026] In one embodiment of the method, the determined tilt angle of the measuring plane is refined or calibrated using sensors, particularly inertial sensors such as gravity sensors, acceleration sensors, or rotation rate sensors, tilt sensors, electro-optical levels, or sensors operating in an electrolytic manner. Such sensors, known to those skilled in the art, allow for simple, and especially small-scale, integration into the 2D laser scanner. Attached Figure Description

[0027] The invention is explained in detail in the following description with the aid of embodiments shown in the accompanying drawings. The drawings, description, and claims contain a large number of features in combination. Those skilled in the art will also suitably consider these features individually and generalize other meaningful combinations. The same reference numerals in the drawings denote the same elements.

[0028] in:

[0029] Figure 1 A perspective view of one design of the 2D laser scanner according to the present invention is shown.

[0030] Figure 2a b shows the order according to Figure 1 The design of the 2D laser scanner according to the present invention, together with a side view of the partially opened housing,

[0031] Figure 3 a and b illustrate a typical measurement scenario (a) and a profile (b) using a 2D laser scanner according to the invention.

[0032] Figure 4 A method diagram of one embodiment of the method according to the invention is shown.

[0033] Figure 5 A schematic diagram of the steps for determining the tilt angle is shown. Detailed Implementation

[0034] Figure 1 The illustration shows a system 100 consisting of a 2D laser scanner 10 and a computing unit 70 implemented externally to the 2D laser scanner 10. In particular, a perspective side view shows one embodiment of the 2D laser scanner 10 according to the invention.

[0035] The 2D laser scanner 10 has a housing 12 with an edge length ranging from 4 to 15 cm. The housing 12 encloses the mechanical components, as well as the optical and electronic components of the 2D laser scanner 10 (see especially). Figure 2a (b) and protect these components from mechanical damage and reduce the risk of contamination. An exit opening 14 is provided on the upper side of the 2D laser scanner 10, which is implemented in the form of a dome extending from the housing 12 with a transparent window.

[0036] Figure 2a and 2b The side view shows the above. Figure 1The same embodiment of the 2D laser scanner 10 shown herein, wherein a portion of the housing 12 is shown in the open state. The 2D laser scanner 10 includes a laser rangefinder 16. The laser rangefinder 16 includes a laser diode (not shown in detail here) for generating a laser beam 18 that can be emitted by the laser rangefinder 16. The laser beam 18 can exit from the housing 12 through an exit opening 14, particularly a window. The laser rangefinder 16 is used to perform non-contact laser ranging along a ranging direction 20, which is shown here, along with the laser beam 18, by arrows. The laser rangefinder 16 also includes a receiving device (not shown in detail here) for detecting from the target object 22 (in... Figure 2a , 2b The laser radiation reflected by the target object 22 (e.g., a wall) is not shown in detail here. The propagation time of light is determined by phase comparison between the emitted laser beam 18 and the laser radiation reflected by the target object 22, and the required distance measurement 24 between the laser rangefinder 16, that is, the 2D laser scanner 10, and the target object 22 is determined by the speed of light (see [reference]). Figure 3 b). The laser rangefinder 16 is rotatably supported about a rotation axis 26, which is oriented perpendicular to the ranging direction 20 of the laser rangefinder 16. The active rotation of the laser rangefinder 16 can be performed by means of a stepper motor 28. The stepper motor 28, in cooperation with the computing unit 30 of the 2D laser scanner 10, is configured to rotate the laser rangefinder 16 by a predetermined or pre-defined rotation angle 32 (see...). Figure 3 b) The distance measured in two consecutive steps (in) Figure 3 (as indicated by the corresponding arrows in b) further rotates between these points. Here, the zero point (or reference point or starting point) of the distance measurement is located on the rotation axis 26 and thus at the center of the rotational motion and the 2D laser scanner 10. In this way, the laser beam 18 emitted by the 2D laser scanner 10 can be directed in different ranging directions 20 (see...). Figure 3 (20a, 20b) in b) are oriented. Here, the laser beam 18 emitted by the 2D laser scanner 10 is directed in the radial direction (see... Figure 1 or Figure 3 b - The distance measurement is performed radially from the 2D laser scanner 10 and is emitted in a manner that at least partially sweeps across the measurement plane 34 (e.g., interrupted by a temporary shutdown of the laser diode).

[0037] In the form of an angle 36 measured about the distance of the axis of rotation 26 (see...) Figure 3a) During the corresponding distance measurement, the distance measurement angle corresponds to the rotation angle 32, and the distance measurement direction 20 of the laser beam 18 is detected in the measurement plane 34. Thus, the distance measurement direction 20 is defined relative to the 2D laser scanner 10 by the distance measurement angle 36. The zero point of the distance measurement angle 36 and / or the rotation angle 32 can be arbitrarily chosen in principle, as it depends only on the relative angular spacing 58 (see...). Figure 3 b).

[0038] The 2D laser scanner 10 is configured to automatically measure objects and / or space (see...). Figure 3 a) The method is as follows: In the measurement plane 34, the distance measurement values ​​24 along different directions and the corresponding distance measurement directions 20 are detected, and the profile section 38 is identified therein (see Figure 3 b).

[0039] The 2D laser scanner 10 also includes an operating element 40 for initiating the 2D laser scanning process. Furthermore, the 2D laser scanner 10 has a data communication interface (not shown in detail here), by means of which the detected profile 38 and other relevant information can be provided to an external computing unit 70, which is in the form of a smartphone. For this purpose, the external computing unit 70 also has a similar type of data communication interface (not shown in detail here), such as a Bluetooth data communication interface. Data transmission is... Figure 1 The external computing unit 70 is illustrated by radio symbol 42. It has a processor device with a storage unit (not shown in detail here), on which a computer program for performing corrections to the profile section 38 is provided. Therefore, the external computing unit 70 is configured to be used within the scope of the method according to the invention (see...). Figure 4 The correction is performed in step 1008 of the method. Furthermore, the external computing unit 70 is used here to output the profile 38 and / or any calculated parameters, such as area, to the user. Alternatively or supplementarily, it is conceivable that the computing unit 30 of the 2D laser scanner 10 itself is configured to correct the detected profile 38 according to the method of the invention.

[0040] Furthermore, the housing 12 of the 2D laser scanner 10 has a battery compartment. A battery compartment cover 44 closes the battery compartment flush with the surface of the housing 12. The battery compartment is used to receive batteries (not shown in detail here) or also to receive rechargeable batteries for powering the 2D laser scanner 10.

[0041] exist Figure 2a In b, besides Figure 1In addition to the features shown, the bracket of the laser rangefinder 16 can be seen, which houses the stepper motor 28 at its upper end. Furthermore, an actuator 48 in the form of a rotary device can be seen, which is used to tilt the measuring plane 34. This tilting or rotation of the measuring plane 34 (see [reference]) Figure 2a and 2b (At a glance), angle 56 (which is also, in particular, tilt angle 50) can be achieved between the measuring plane 34 and the reference plane 52, which is here chosen to be a reference plane extending in a horizontal line (this angle 56 is equal to zero in Figure 2, in... Figure 2b (not equal to zero), wherein the incident point of the laser beam 18 on the target object 22 changes, which in Figure 2b This is indicated by arrow 54. The direction indicated by arrow 54 is referred to in this document as "transverse to the measuring plane 34".

[0042] exist Figure 3 A typical measurement scenario is illustrated in section a. Here, the 2D laser scanner 10 is positioned at the center of space 2000. Distance measurements 24 relative to the wall surrounding the 2D laser scanner 10, which is the target object 22, are successively detected along different distance measurement directions 20, 20a, and 20b (see section a). Figure 3 b) In this way, the outline section 38 of the space 2000 is determined (see...) Figure 3 b). Here, the laser beams 18 are emitted radially by the 2D laser scanner 10, wherein the distance measurements are respectively located in the measurement plane 34. If the 2D laser scanner 10 is not leveled during the 2D laser scanning, that is, the measurement plane 34 is not parallel to the horizontal reference plane 52 (shown in shaded area here), but has an angle of inclination 50 relative to the horizontal reference plane, then, for example, in Figure 3 The distorted profile sections 38 and 38a shown in b. These distorted profile sections 38 and 38a are capable of performing the method 1000 according to the invention (see [reference]). Figure 4 The corrected profiles 38 and 38b are shown in the attached image. Figure 3 b.

[0043] Figure 4An embodiment of the method according to the invention for identifying, and in particular correcting, the contour profile 38 of an object, here in space 2000, is shown. First, in method steps 1002 and 1004, the contour profile 38 is detected by means of a 2D laser scanner 10, whereby: in method step 1002, distance measurements 24 and distance measurement directions 20 associated with each other are detected by means of the laser rangefinder 16 in a measurement plane 34 at least partially radially swept by the laser beam 18; and in method step 1004, the contour profile 38 is identified from these distance measurements 24 and the associated distance measurement directions 20 in the form of a filtered and smoothed point cloud (e.g., in…). Figure 3 The profile section 38a shown in b). Here, the individual points of the point cloud can also be connected by lines to obtain... Figure 3 Illustration of b - profile section 38a.

[0044] Then, in method step 1006, the tilt angle 50 of the measuring plane 34 relative to the reference plane 52, which is horizontal in this case, is determined. This can be done in different ways.

[0045] In the first embodiment of method step 1006, indicated herein by (a), the tilt angle 50 of the measurement plane 34 is determined in a separate calibration measurement. Here, in the following sub-method steps...

[0046] ·1006a.1:

[0047] Using the laser rangefinder 16, distances are measured in two mutually orthogonal directions 20, 20a, 20b (see...) Figure 3 a) - In addition to the distance measurement value 24 in the measuring plane - also at an angle 56 that increases and / or decreases relative to the measuring plane 34 (see Figure 5 Also see Figure 2b ) Detect multiple distance measurements 24a, 24b, 24c, and 24d.

[0048] ·1006a.2:

[0049] The minimum value of the plurality of distance measurements 24 (here, distance measurement 24b) is determined, and the angular deviation (depending on the direction) for the corresponding distance measurement directions 20, 20a, 20b is determined by using the minimum value and the distance measurements 24 in the measurement plane 34.

[0050] ·1006a.3:

[0051] The tilt angle 50 of the measuring plane 34 relative to the reference plane 52 is calculated from the two angular deviations and the angular distance 58 between the two distance measurement directions 20, 20a, and 20b.

[0052] Here, method step 1006a.1 is implemented using the actuator 48 shown in Figure 2.

[0053] exist Figure 5 The diagram schematically illustrates the measurement principle for distance measurement direction 20. Here, in addition to the distance measurement value 24 (solid arrow) in the measurement plane 34, multiple distance measurement values ​​24a, 24b, 24c, 24d (dashed arrows) are detected at angles 56a, 56b, 56c, 56d that increase and decrease relative to the measurement plane 34. The angular deviation 60 along this direction (e.g., distance measurement direction 20a9) is determined by means of trigonometric functions from the minimum distance measurement value 24b and the distance measurement value 24 in the measurement plane 34.

[0054] In the second embodiment of method step 1006, indicated herein by (b), the tilt angle 50 of the measuring plane 34 is determined by the profile sections 38, 38a themselves, wherein the tilt angle 50 is determined in a simulated manner for the following condition: the distortion of the profile sections 38, 38a caused by the change in tilt angle 50 is compensated for, thereby obtaining the desired (i.e., straight or without bends as expected according to typical wall orientation) profile sections 38, 38b.

[0055] In the third embodiment of method step 1006, indicated herein by (c), the tilt angle 50 of the measuring plane 34 is determined by the profile sections 38, 38a themselves through triangulation performed by two different, non-collinear or parallel distance measurement directions 20, 20a, 20b and the angular spacing 58 between these distance measurement directions 20, 20a, 20b.

[0056] Finally, in method step 1008, the distorted profiles 38, 38a are corrected using the determined tilt angle 50 of the measurement plane 34 by means of trigonometric functions and by converting the detected distance measurements 20, 20a, 20b using the tilt angle 50, wherein the distance measurements 20, 20a, 20b are projected onto the reference plane 52 in this manner.

Claims

1. A method for determining the profile of an object and / or space by means of a 2D laser scanner with a laser rangefinder, the method comprising the following steps: • Using the laser ranging device, distance measurements and distance directions that can be matched with each other are detected in the measurement plane radially swept by the laser beam of the laser ranging device. • The contour profile is determined from the distance measurement value and the distance measurement direction. • Determine the angle of inclination of the measuring plane relative to the reference plane. • Correct the profile profile using the tilt angle of the measuring plane. Its features are, Using the laser rangefinder, determine the tilt angle of the measuring plane. • The laser ranging device detects multiple distance measurements along two different and non-parallel distance measurement directions, in addition to the distance measurements in the measurement plane, at angles that increase and / or decrease relative to the measurement plane. • Wherein, the minimum value of the distance measurement is determined, and • The determination of the corresponding distance measurement direction, using the minimum value and the distance measurement value in the measurement plane, depends on the angular deviation of the direction. The tilt angle of the measuring plane relative to the reference plane is calculated by two angular deviations depending on the direction and the angular spacing between the two distance measurement directions.

2. The method according to claim 1, characterized in that, The reference plane is either horizontal or vertical.

3. The method according to claim 1, characterized in that, The tilt angle of the measurement plane is determined during calibration measurements.

4. The method according to claim 1, characterized in that, Two different distance measurement directions are chosen in a manner that is orthogonal to each other.

5. The method according to any one of claims 1 to 4, characterized in that, During the manual or automatic tilting of the laser rangefinder, multiple distance measurements are detected at angles that increase and / or decrease relative to the measurement plane.

6. The method according to any one of claims 1 to 4, characterized in that, During the manual or automatic tilting of the 2D laser scanner, multiple distance measurements are detected at angles that increase and / or decrease relative to the measurement plane.

7. The method according to any one of claims 1 to 4, characterized in that, The tilt angle of the measuring plane is determined from the profile section.

8. The method according to claim 7, characterized in that, The tilt angle is determined by simulation in the following case: the distortion of the profile caused by the change of the tilt angle is compensated.

9. The method according to claim 7, characterized in that, The tilt angle is determined by trigonometric calculations using two distance measurements along different and non-parallel distance measurement directions and the angular distance between these distance measurement directions.

10. The method according to any one of claims 1 to 4, characterized in that, When using sensors, refine or adjust the determined tilt angle of the measuring plane.

11. A 2D laser scanner comprising at least one laser ranging device, wherein the 2D laser scanner is configured to detect mutually compatible distance measurements and distance measurement directions in a measurement plane radially swept by a laser beam from the laser ranging device, characterized in that... A computing unit configured to perform the method according to any one of claims 1 to 10.

12. A system comprising a 2D laser scanner and a computing unit, wherein the 2D laser scanner includes at least one laser ranging device, wherein the 2D laser scanner is configured to detect distance measurements and distance measurement directions that are compatible with each other in a measurement plane radially swept by the laser beam of the laser ranging device by means of the laser ranging device, and wherein the computing unit is configured to perform the method according to any one of claims 1 to 10.

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