LASERSCANNER

Description

[0001] The invention relates to a laser scanner according to the preamble of claim 1.

[0002] The basic design of such laser scanners is disclosed, for example, in DE 101 50 436 B4. This document describes a 3D laser scanner that can be used to measure objects, such as buildings, crime scenes, production facilities, etc., with high precision. In such a scanner, the measurement beam emitted by a laser diode is deflected by a mechanical beam deflection system in such a way that a comprehensive, three-dimensional spatial measurement of the surrounding area is possible. The digitized measurement data is processed and stored by a computing unit, where it is available for further processing and visualization of the measured object.

[0003] This 3D measurement is performed by guiding the modulated laser light over the environment to be measured, whereby both the distance and reflectance values ​​can be measured point by point for different spatial directions. The arrangement of all measured spatial directions results in distance and reflectance images. The distance images represent the geometry of the environment, and the reflectance images represent its visual representation, analogous to the grayscale images of a video camera. Both images correspond pixel by pixel and are largely independent of environmental influences due to the independent, active illumination with laser light.

[0004] In the known solution, the beam deflection system is designed with a deflection mirror mounted in a rotating head – hereinafter referred to as the rotor – of the laser scanner. This is mounted on a housing of the scanner, rotating around a first axis, preferably a horizontal axis. The housing, in turn, can be pivoted by at least 180° around a rotation axis that runs perpendicular to the rotation axis, for example, in the vertical direction. As mentioned, with such a 3D laser scanner, the image information is captured in the form of 3D pixel clouds, which can then be converted into a grayscale image of the measurement object.

[0005] In many cases, a color image of the measurement object is desired. The color information can be scanned using a camera that is mounted, for example, on the housing of the laser scanner. Solutions are also known in which the color information of the measurement object is captured using a camera mounted in the beam path of a mirror arrangement. The disadvantage of this type of solution is that deflecting mirrors and any other optical elements present can cause color distortions in the camera image. Systems with a camera mounted on the housing of the laser scanner have the disadvantage that they require considerable installation space and, furthermore, parallax errors arise due to the different perspectives of the mounted camera and the actual laser scanner, which must be eliminated using a complex Z-buffer calculation.To overcome this disadvantage, DE 10 2012 105 027 A1 describes a laser scanner in which the color camera for capturing the color information of the measuring object is mounted on or in the measuring head / rotating head, so that the virtual optical centers of the camera and the measuring beam essentially coincide and thus a parallax error is avoided.

[0006] The concept of signal processing in laser scanners is explained in the applicant’s DE 198 51 307 A1.

[0007] Similar concepts can also be implemented with 2D laser scanners, where the laser scanner is not pivotable around a vertical axis but is mounted on a mobile platform.

[0008] DE 10 2014 109 432 A1 describes a laser scanner that is additionally equipped with a thermographic camera, so that the measurement result is a 3D scan (point cloud of the measuring object) with linked thermographic data.

[0009] Since complex measurement objects are measured from different locations, such laser scanners can be equipped with a navigation system that records the respective scanner location and orientation. As described in the applicant's DE 10 2016 102 607 A1, such navigation systems integrated into the laser scanner are designed to enable GNSS (e.g., GPS)-independent determination of the absolute position of the laser scanner or at least a relative position to a known location in the field. This enables the measurement of interior spaces. This navigation data is also stored in the laser scanner's internal memory for measurement signal processing.

[0010] Particularly when surveying military facilities, nuclear power plants, or safety-relevant manufacturing facilities, there is a requirement that the survey and evaluation take place within the facility, and that no data may be transmitted or transferred outside the facility. With conventional laser scanners, this means that the entire 3D survey must be completed and evaluated within the facility, and then the corresponding data must be deleted from the hard drive of the laser scanner's processing unit and other external computers. This represents a significant effort, as it is necessary to ensure that all data has been removed, and appropriate documentation must be provided to the facility operator.

[0011] In this regard, the document US 2014 / 0111618 A1 shows a laser scanner without a removable storage medium.

[0012] The "TX5 3D Laser Scanner User Guide" (Trimble) shows a generic laser scanner with removable storage for scan data, designed as an SD card, held in a slot in the housing. The storage can also store firmware updates and be used to install them.

[0013] A laser scanner comparable to the latter is shown in the document US 2014 / 0300906 A1.

[0014] In contrast, the invention is based on the object of creating a 2D or 3D laser scanner that enables reliable and simple removal of the registered and evaluated scan.

[0015] This object is achieved according to the invention by a laser scanner having the features of patent claim 1.

[0016] Advantageous further developments of the invention are the subject of the subclaims.

[0017] A laser scanner has a rotor rotatably mounted on a housing. A beam deflection system is arranged in the rotor to direct a measurement beam emitted by a transmitter, for example, a laser diode, onto a measurement object or a beam reflected by the transmitter onto a receiver. The laser scanner is designed with a processing unit for controlling the laser scanner and for data processing, which is provided with an internal data memory for storing measurement data. According to the disclosure, the data memory is removably held in a receptacle of the housing. The term "removable" is to be understood as meaning that the holder is designed for easy and quick changing or removal of the data memory without the need for complex disassembly of components.The computing unit is preferably designed so that the relevant measurement data (scan data and logging files) can only be stored on this data storage device.

[0018] In a variant not included in the invention, the operating system and the software for controlling the scanner can be stored on an internal memory, e.g., a flash memory. This is designed in such a way that no measurement data can be stored on it and is therefore write-protected.

[0019] According to the invention, the software and operating system required to control the laser scanner are also implemented on the internal data storage device, so that the laser scanner is no longer functional after the data storage device is removed.

[0020] By storing at least the measurement data recorded during the measurement process (3D pixel cloud and associated color information, logging files) on the internal data storage, the requirements mentioned above can be met very easily by removing the data storage and leaving it on site or even deleting it.

[0021] In cases where the laser scanner does not have to meet any of the above-mentioned safety-related requirements, the internal data storage (e.g., an internal SSD drive (SATADOM)) can also be permanently installed in a conventional manner, which is not typical of the type. In this case, an additional storage medium, such as an SD card, can be provided, particularly for copying the data. This SD card can then be inserted into an externally accessible slot in the housing in a conventional manner.

[0022] The use of a S ata D isc O n MModule as internal data storage has the advantage that it does not require its own power connection, as the power supply is provided via the SATA connection.

[0023] In a further development, the rotor is held between two housing parts, which are connected to each other by means of an intermediate housing part that tapers towards the latter - this is the typical structure of a 3D laser scanner.

[0024] In such laser scanners, the housing can be rotated about an axis of rotation arranged perpendicular to the axis of rotation of the rotor by means of a rotary drive.

[0025] In a further development, it is provided that the rotary drive has a backlash-free gear, which is preferably designed as a gear transmission, wherein an encoder is assigned to the rotation axis of the housing to detect the respective rotation angle of the laser scanner.

[0026] To enable measurements independent of an external power supply, laser scanners are often equipped with a rechargeable battery. These batteries are relatively heavy and must be moved via the aforementioned rotary drive. To reduce the moment of inertia, it is recommended that several batteries, for example two, be arranged symmetrically at a relatively short distance from the aforementioned axis of rotation. It is also preferred if these batteries are arranged as close as possible to the support of the laser scanner in order to minimize any tipping moment. Furthermore, these batteries are aerodynamically optimized with regard to their external geometry in order to minimize air resistance during pivoting around the vertical axis. In this way, measurement errors when measuring objects can be further reduced.

[0027] In one variant, it is preferred if the batteries are combined with a cover of the respective housing part to form a structural unit.

[0028] Operating the laser scanner is particularly easy thanks to a touchscreen display mounted on one of the housing sections. This touchscreen display is arranged in portrait format.

[0029] The measurement accuracy can be further improved if the laser scanner is operated according to the phase shift measurement principle with three measurement frequencies.

[0030] The removable internal data storage can be accessible, for example, when the battery is removed.

[0031] The applicant reserves the right to make independent patent claims relating to the arrangement of the batteries or the use of three measuring frequencies or the use of a backlash-free gear for the rotary drive, which may be pursued further in divisional applications.

[0032] Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. They show: Figure 1 a three-dimensional representation of an embodiment of a 3D laser scanner according to the invention; Figures 2 and 3 a rear view or a front view of the laser scanner according to Figure 1 ; Figure 4 a side view of the laser scanner; Figure 5 a section along the line AA in Figure 4 ; Figure 6 a section along the line BB in Figure 3 ; Figures 7 and 8 Views of the laser scanner according to Figure 1 with the housing covers removed and Figure 9 a detailed view of a recording of an internal data memory of the laser scanner according to Figure 1 .

[0033] Figure 1shows a three-dimensional representation of an embodiment of a 3D laser scanner 1. This has a measuring or rotating head, hereinafter referred to as rotor 2, which rotates around a horizontal rotation axis 4 (see also Figures 2, 3 ) is rotatably mounted on a housing 6 of the laser scanner 1. This housing 6 has - similar to the known solutions described above - two housing parts 8, 10, between which the rotor 2 extends. In the figure according to Figure 1 Below the rotor 2, the two housing parts 8, 10 are connected to each other via an intermediate housing part 12, which tapers towards the rotor 2 in a manner known per se in order to minimize shadowing during measurement.

[0034] The housing 6 is supported by an adjustable mounting flange 14 on a tripod or a movable platform, for example a handcart, as offered by the applicant under the trademark SCADDY ®<. In the illustrated embodiment, the Figure 1 right housing part 8 is designed with two handles 16, 18 to simplify handling.

[0035] On the other housing part 10 there is a touch display 20 arranged in portrait format, via which the laser scanner 1 can be operated and on which the measurement results can also be visually displayed.

[0036] As will be explained in more detail below, this housing part 10 contains a computing unit whose internal data memory is held in a holder so that it can be easily removed. This will be explained below with reference to Figure 9 The example of Figure 9The internal data storage (SATADOM) described in more detail can be secured in an appropriate manner so that accidental or unauthorized removal is made difficult.

[0037] In one embodiment of the invention, a slot 22 covered by a cover 23 is designed to accommodate an additional storage medium, e.g., an SD card 24, onto which measurement data can be copied. However, this variant does not comply with the aforementioned safety-related requirements and is not applicable to scanners that must meet these requirements.

[0038] The laser scanner 1 is switched on and off via a switch 25. The Figure 1 The laser scanner 1 shown is further designed for mains-independent operation with two batteries 26, 28, which are inserted flush into the respective housing parts 8, 10 and are arranged at a comparatively small distance from the fastening flange 14 in order to minimize a tilting moment.

[0039] In order to reduce the mass moment of inertia, the two batteries 26, 28 are also arranged at the shortest possible distance from a rotation axis 30 about which the entire laser scanner 1 can be rotated, so that when rotating or pivoting about the rotation axis 30 with the rotor 2 rotating about the rotation axis 4, the entire surrounding space can be measured.

[0040] In according to the representation Figure 1 Also visible are a power connection 32 and a LAN connection 34, so that the laser scanner 1 can also be operated with an external power supply and the measurement signals can be transmitted via the LAN connection 34 to a satellite computer located in the field for registration and / or evaluation of the scan.

[0041] Of course, this registration and evaluation can also be carried out on the laser scanner 1 itself.

[0042] The procedure for such registration and evaluation is explained in the applicant’s DE 10 2016 102 607 A1.

[0043] Figure 2 shows a rear view of the laser scanner according to Figure 1 Accordingly, a color camera 36 (strictly speaking, only a camera window is visible here) is incorporated in the rotor 2 to capture image / color information of the measurement object. In order to capture this image information with sufficient quality, the rotor 2 is designed with a lighting unit 38, via which the image field can be illuminated. In the illustrated embodiment, this lighting unit 38 has four LEDs arranged in the peripheral area of ​​the color camera 36 to ensure optimal illumination. Details of this lighting unit are explained in the applicant's parallel application with the file number DE 10 2017 114 617.2.

[0044] In the representation according to Figure 2one can also clearly see the integration of the two batteries 26, 28 into the housing parts 8, 10. The fastening of the housing 6 to the Figure 2 The fastening flange 14 (not shown) is fixed via three fastening pins 40 located on a pitch circle, of which Figure 2 only one is provided with a reference symbol.

[0045] According to the front view in Figure 3 The output or input of the laser optics is arranged on the rotor 2; this is covered by an obliquely positioned protective glass 42, as described in the aforementioned DE 101 50 436 B4.

[0046] As can be seen from the illustrations according to the Figures 1 to 3 As can be seen, the housing 6 of the laser scanner 1 is designed to have a smooth surface, for example without cooling fins or the like, so that the outer contour is also aerodynamically optimized and offers as little resistance as possible against wind or during the rotation / rotation of the laser scanner 1.

[0047] In the representations according to the Figures 2 and 3 Furthermore, a reference module 44 for distance measurement is shown.

[0048] Figure 4 shows a side view of the housing part 10, on which the touch display 20 is arranged. The battery 28 is arranged underneath.

[0049] The batteries 26, 28 are removably mounted on the housing parts 8, 10, allowing them to be charged via an external charging station. When connected to the power grid via the power connector 32, the batteries 26, 28 are charged via the laser scanner 1.

[0050] Figure 5 shows a section along the line AA in Figure 4 . In this illustration, one can clearly see the two batteries 26, 28, which are each designed as a battery block with a plurality of rechargeable batteries 46 and are inserted into a receptacle 48, 50 of the respective housing part 8, 10.

[0051] In the cut according to Figure 5 one can see the basic principle of a rotary drive 52, via which the housing 6 is driven to pivot about the rotation axis 30. The housing 6 is mounted via the housing intermediate part 12 on a downwardly projecting pot-shaped base 54, wherein the housing intermediate part 12 dips into the base 54 via a drive hub 56 and is guided there in the radial direction via a bearing arrangement 58 and a central axis 60.

[0052] The drive hub 56 is designed with external teeth 62 that mesh with a drive pinion 64 driven by a motor shaft of a motor 66 supported on the base 54. The drive pinion 64 and the external teeth 62 form a backlash-free gear transmission.

[0053] The respective angle of rotation of the housing 6 and thus the angle of rotation position of the color camera 36 and the laser beam is determined via a Figure 5The encoder 68, indicated by the arrow, senses the angle of rotation relative to the central axis 60. The backlash-free design of the gear train enables high measurement accuracy of the encoder 68 and thus an exact determination of the angle of rotation. Such encoders are usually arranged on the motor 66, so that the angle of rotation position of the housing 2 is only indirectly detected.

[0054] As mentioned, the applicant reserves the right to make its own claim on the provision of a backlash-free transmission, preferably a gear transmission, and on the determination of the angle of rotation by means of an encoder arranged on the axle.

[0055] In the representation according to Figure 5 The above-mentioned computing unit 70, which is housed in the housing part 10, is also visible, along with the control modules required to operate the laser scanner 1. As can be seen from the Figure 9As explained in more detail below, this computing unit 70 (CPU), in an embodiment not belonging to the invention, has an internal flash memory that is not accessible from the outside. The operating system and other software for operating the laser scanner 1 are stored on this flash memory. Writing data to the flash memory is not possible because of the write protection.

[0056] The scan data and the logging files are located on an internal data storage or drive that can be removed, further details are provided with Figure 9 explained.

[0057] As mentioned above, the SD card only serves to copy the data stored on the internal data storage or drive. However, this option with the additional SD card storage can be omitted. For applications with lower security requirements, the internal data storage or internal drive (SATADOM) can be omitted. In this case, however, the SD card option is implemented to simplify data processing on external computers and data backup.

[0058] In the Figure 5 The aforementioned rotor 2 is arranged in the upper area of ​​the laser scanner 1. A unit referred to as a laser radar measuring system 72 is arranged between the rotor and the computing unit 70, which is located opposite the computing unit 70 and is housed in the housing part 8. This laser radar measuring system 72 contains, among other things, at least one detector for detecting the signals reflected from the measurement object.

[0059] The image data captured by the color camera 36 is transmitted to the computing unit 70 via a removable slip ring assembly 74. The function of this slip ring assembly 74 is explained in the aforementioned DE 10 2012 105 027 A1. Accordingly, this slip ring assembly 74 is disengaged during distance measurement using the laser, so that friction during the distance measurement is minimal. To capture the image data, the slip ring assembly is then operatively engaged following the distance measurement, so that the image data captured by the color camera 36 is transmitted to the computing unit 70.

[0060] The reference number 69 in the illustration according to Figure 5 an inclination measuring device 69, via which an inclination of the laser scanner 1 can be detected, so that the measured values ​​can be corrected according to this inclination.

[0061] The beam guidance of the distance measuring system is determined by Figure 6 which shows a section along the line BB in Figure 3 shows.

[0062] This sectional view shows the actual color camera 36, ​​whose lens 80 is arranged approximately axially parallel to the rotation axis 4. The color camera 36 can, for example, be a chip camera in which the actual recording chip and the lens 80 are arranged on a circuit board. The light rays carrying the color information of the object to be measured enter the rotor 2 through a camera window 78 and are deflected by a camera mirror 76 toward the lens 80 of the color camera 36. The color information is then transmitted to the computing unit 70 via the described slip ring arrangement 74.

[0063] The rotor 2 is driven by a DC motor 82, which in turn is assigned an encoder for detecting the rotational angular position of the rotor 2. The basic structure of such a rotor drive is explained in DE 10 2012 105 027 A1.

[0064] The laser beam or laser beams used in a measurement system with multiple wavelengths / frequencies are each emitted via a commercially available laser diode, with the divergent beam of the laser diode being collimated via a collimator 84. This collimated beam then passes, in a conventional manner, via a channel of a mirror body onto a beam exit mirror 86, which is deflected by the latter toward a beam taper device 88, which is implemented as a Galilean telescope. The resulting laser beam / measurement beam is then deflected via a plane-inclined mirror 90 toward the object to be measured and exits the rotor 2 through the aforementioned protective glass 42.The beam reflected by the measuring object enters the rotor 2 through the protective glass 42 and is deflected by the plane inclined mirror 90 in the direction of the mirror body, which has a beam input mirror 92, via which the reflected beams are directed in the direction of the detector of the laser radar measuring system 72 (see . Figure 5 ). The basic structure of such a beam guide is known, so further explanations are unnecessary.

[0065] In the representation according to Figure 6 A focusing device 94 is also shown, which enables focusing with intensity adjustment in the close range. This focusing is accessible from the outside if, according to the Figures 7 and 8 a cover of the housing part 8 is removed.

[0066] Figure 7shows the housing part 10 with the cover removed, which also carries the touch display 20. When this cover is removed, the computing unit 70 (CPU), the DC motor 82 and also the slip ring arrangement 74 are accessible. In the illustration according to Figure 7 Furthermore, the battery 28 is removed so that the corresponding receptacle 48 with the electrical contacts 96 is visible.

[0067] Figure 8 shows the housing part 8 with the cover removed. This provides access to the focusing device 94 and the previously described beam guide (with the mirrors 86, 92 and the beam narrowing device 88). The laser radar measuring system 72 is arranged below this beam guide. In the illustration according to the Figures 7 and 8 Furthermore, the bearing 98, 100 of the rotor 2 is also visible.

[0068] As explained, the scan data and logging files generated during the survey are stored on an internal data storage device or drive (SSD, SATADOM) 104 of the computing unit 70. For this purpose, the laser scanner 1 is configured according to Figure 9 designed so that this internal data memory 104 can be removed, wherein in an embodiment not forming part of the invention, the operating system and program are stored on an internal flash memory and are not accessible from the outside or can be overwritten. The internal drive 104 is in the embodiment in Figure 9Accessible when the battery 28 is removed. A flap 102 is provided in the receptacle 48, which is, for example, latched or screwed. With the flap 102 open, the internal drive 104 containing the scan data and logging files can be removed. In the case of the embodiment not forming part of the invention, it is then impossible for the laser scanner 1 to contain any further data due to the write protection of the internal flash memory. This ensures that the acquired data remains in the system and does not leak out.

[0069] As explained at the beginning, the invention provides that the operating system and the program required for controlling the laser scanner 1 are also implemented on the removable data storage device / drive 104, so that the laser scanner 1 is "dead" after the removal of this drive 104 - a conclusion about previous measurements is then no longer possible.

[0070] Of course, the internal drive 104 can also be accommodated in the area of ​​the computing unit 70 in the housing part 10.

[0071] According to the disclosure, it can further be provided that the laser scanner is operated with three measuring frequencies, so that the measuring accuracy is significantly improved compared to conventional solutions with two measuring frequencies.

[0072] As mentioned above, the laser scanner is preferably equipped with a navigation unit that enables the position to be determined even when there is no GNSS / GPS signal.

[0073] As explained at the beginning, other essential features of the described laser scanner, in addition to the increased safety through the provision of a removable internal drive, are also seen in the backlash-free drive of the vertical rotation axis and the arrangement of the batteries as well as in the operation of the laser scanner with more than two measuring frequencies.

[0074] A laser scanner is disclosed in which scan data and logging files are stored only on an easily replaceable data storage device. List of reference symbols:

[0075] 1 Laser scanner 2 Rotor / rotating head 4 Rotation axis 6 Housing 8 Housing part 10 Housing part 12 Housing intermediate part 14 Mounting flange 16 Handle 18 Handle 20 Touch display 22 Slot 23 Cover 24 SD card 25 Switch 26 Battery 28 Battery 30 Rotation axis 32 Power connection 34 LAN connection 36 Color camera 38 Light unit 40 Mounting pin 42 Protective glass 44 Reference module 46 Battery 48 Mount 50 Mount 52 Rotary drive 54 Base 56 Drive hub 58 Bearing arrangement 60 Axis 62 External gearing 64 Drive pinion 66 Motor 68 Encoder 69 Inclinometer 70 Processing unit 72 Laser radar measuring system 74Slip ring assembly 76Camera mirror 78Camera window 80Lens 82DC motor 84Collimator 86Beam exit mirror 88Beam taper device 90Plane-inclined mirror 92Beam entrance mirror 94Focusing device 96Contact 98Bearing 100Bearing 102Flap 104Internal data storage / internal drive

Claims

1. Laser scanner (1) comprising a rotor (2) rotatably mounted on a housing (6), wherein optics are provided for directing a measuring beam emitted from an emitter onto a measuring object, or a beam reflected therefrom onto a detector, wherein a calculator unit (70) is provided for controlling the laser scanner and for data processing, the calculator unit having an internal data memory (104) on which the scan data processed by the calculator unit (70) are stored, wherein the data memory (104) is removably held in an accommodation of the housing (6), characterized in that an operating system and software for controlling the laser scanner are stored on the data memory (104), so that the scanner is no longer functional after removing the data memory (104).

2. The laser scanner according to claim 1, wherein the accommodation is accessible after removal of a cover or a functional component of the laser scanner (1).

3. The laser scanner according to claim 1 or 2, wherein the rotor (2) is held between two housing parts (8, 10) which are connected to one another by means of a housing intermediate part (12) tapering towards the rotor (2).

4. The laser scanner according to any of the preceding claims, wherein the housing (6) is rotatable about a pivot axis (30) arranged perpendicular to an axis of rotation (4) of the rotor (2) by means of a rotary drive.

5. The laser scanner according to claim 4, wherein the rotary drive comprises a play-free gear, preferably a gear train, and the angular position of the housing (6) can be detected via an encoder (68) arranged on an axis (60) of the housing (6).

6. The laser scanner according to any of the preceding claims, wherein an accumulator (26, 28) is held on each housing part (8, 10) and the housing parts (8, 10) and the accumulators (26, 28) are designed such that the rotating masses and outer geometries are approximately balanced with respect to the pivot axis, and that an overturning moment with respect to a support of the laser scanner is minimal.

7. The laser scanner according to claim 6, wherein the accumulators (26, 28) complement one another with a cover (23) of the respective housing part (8, 10) to form a structural unit.

8. The laser scanner according to any of the preceding claims, wherein a touch display (20) arranged in vertical format is located on a housing part (8).

9. The laser scanner according to any of the preceding claims, wherein the laser scanner is operated with three measuring frequencies according to the measuring principle of phase shift.

10. The laser scanner according to any of the preceding claims, wherein the outer surfaces of the housing (6) have a substantially smooth surface.

11. The laser scanner according to any of the preceding claims, wherein the removable internal data memory (104) is an SSD memory, in particular a SATADOM memory.