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EP-4303619-B1 - LASER SCANNER

EP4303619B1EP 4303619 B1EP4303619 B1EP 4303619B1EP-4303619-B1

Inventors

  • MARK, Simon
  • BEREUTER, KLAUS
  • MÜLLER, Benjamin
  • STEFFEN, ROMAN
  • Böckem, Burkhard
  • Dold, Jürgen
  • SCHEJA, JOCHEN
  • HEINZLE, Lukas
  • DUMOULIN, CHARLES LEOPOLD ELISABETH

Dates

Publication Date
20260506
Application Date
20161110

Claims (15)

  1. A laser scanner (1", 1‴) for optical measurement of an environment, comprising • an optical distance measuring device (10) for detecting distance measurement data, having ∘ a transmitter unit for emitting a distance measurement radiation (9, 9', 9") and ∘ a receiver unit for receiving returning parts (32) of the distance measurement radiation (9, 9', 9"), • a support (4, 4', 4"), • a beam steering unit (7) for the distance measurement radiation (9, 9', 9"), which is fixed to the support (4, 4', 4") such that it can rotate about a beam axis of rotation (6), and • an angle encoder for recording angle data with respect to a rotation of the beam steering unit (7) about the beam axis of rotation (6), wherein the laser scanner (1", 1‴) configured such that the distance measurement data and the angle data, hereafter designated as measurement data, are recorded as part of a measurement process, which comprises a scanning sensing by means of the distance measuring device (10) with • a defined progressive rotation of the beam steering unit (7) about the beam axis of rotation (6) and • a continuous emission of the distance measurement radiation (9, 9', 9") and a continuous reception of returning parts (32) of the distance measurement radiation (9, 9', 9"), characterized in that • the laser scanner (1", 1‴) has only a single, integrated control element (21), • the control element (21) has only a single active and a single inactive state, and can be switched by way of an external action in order to occupy the active or inactive state, • a set of defined measurement programs and/or actions of the laser scanner (1", 1‴) is stored, and • individual measurement programs and/or actions from the set of defined measurement programs and/or actions are triggered based on at least one element from the following group: ∘ change of state of the control element (21) from the inactive to the active state, ∘ change of state of the control element (21) from the active to the inactive state, ∘ switching of the control element (21) by means of a persistent external action during a defined time interval, ∘ a coded sequence of state changes of the control element (21) between the active and inactive state, and ∘ a coded sequence of temporally persistent external actions on the control element (21) over defined time intervals.
  2. The laser scanner (1", 1‴) as claimed in claim 1, characterized in that the set of defined measurement programs and/or actions of the laser scanner (1", 1‴) comprises activating the laser scanner (1", 1‴), as well as at least one element from the following group: • deactivation of the laser scanner (1", 1‴), • starting the measurement process, • interruption of the measurement process, • aborting the measurement process, and • restarting the measurement process.
  3. The laser scanner (1", 1‴) as claimed in claim 2, characterized in that a set of different settings for the measurement process is stored and/or can be defined and the set of defined measurement programs and/or actions of the laser scanner (1", 1‴) unit also comprises at least one element of the following group: • adjusting a setting from the set of settings for the measurement process, • starting the measurement process with a setting from the set of settings for the measurement process, and • restoring a default setting of the laser scanner (1", 1‴), in particular a default startup configuration of the laser scanner (1", 1‴).
  4. The laser scanner (1", 1‴) according to any one of claims 1 to 3, characterized in that the coded sequence of state changes of the control element (21) is defined by a definite number of state changes during a defined time interval between the active and inactive state.
  5. The laser scanner (1", 1‴) according to any one of the claims 1 to 4, characterized in that the coded sequence of temporally persistent external actions is defined by one or more differently defined time intervals for maintaining the external action.
  6. The laser scanner (1", 1‴) according to any one of the claims 1 to 5, characterized in that • the support (4, 4', 4") is fixed on a base (5, 5', 5") of the laser scanner (1", 1‴) in a manner rotationally about a support axis of rotation (3), in particular a slow axis of rotation, • the laser scanner (1", 1‴) comprises a further angle encoder for recording further angle data with respect to a rotation of the support (4, 4', 4") about the support axis of rotation (3), and • the laser scanner (1", 1‴) is configured such that the scanning sensing of the measurement process further comprises a defined progressive rotation of the support (4, 4', 4") about the support axis of rotation (3), and that the further angle data, forming part the measurement data, is also recorded in the course of the measurement process.
  7. The laser scanner (1", 1‴) according to claim 6, characterized in that with respect to a rotation of the support (4, 4', 4") about the support axis of rotation (3) the base is designed exclusively as passive element, in the sense that all active electronics required for the motorization of the rotation around the support axis of rotation (3) is arranged exclusively in the support (4, 4', 4") and co-rotates with the support (4, 4', 4") around the support axis of rotation (3).
  8. The laser scanner (1", 1‴) according to claim 7, characterized in that each of the following components is arranged entirely in the support (4, 4', 4") and co-rotates with the support (4, 4', 4") about the support axis of rotation (3): • an active drive element (55) for the rotation of the support (4, 4', 4") about the support axis of rotation (3), in particular a rotary motor with a drive shaft (56) coupled to the motor or an electrical coil element for a radial interaction with respect to the support axis of rotation between the electrical coil element and a passive magnetic element in the base (5, 5', 5"), and • a power supply unit for the active drive element.
  9. The laser scanner (1", 1‴) according to any one of claims 6 to 8, characterized in that during the measurement process the beam steering unit (7) rotates about the beam axis of rotation (6) with a rotation speed of at least 50 Hz, in particular of at least 100 Hz, and/or during the measurement process the base (5, 5', 5") rotates about the support axis of rotation (3) with a rotation speed of at least 0.01 Hz, in particular of at least 0.02 Hz.
  10. A measurement system for optical measurement and for imaging an environment, having • a laser scanner (1", 1‴) according to any one of claims 6 to 9, • a processing unit for processing portions of the measurement data into processed measurement data, and • a display (23) for displaying portions of the processed measurement data, which represent at least a partial region of the environment, wherein • the laser scanner (1", 1‴) further comprises a flat sensor (8) for acquiring flat sensor data, namely at least one color camera for recording image data, wherein the sensor (8) defines an optical axis (25) of the sensor (8) and a viewing direction of the sensor (8) along the optical axis (25), and • the laser scanner (1", 1‴) is configured such that the measurement process further comprises performing multiple read outs of the flat sensor (8) with respect to different viewing directions of the sensor (8), and that the read flat sensor data, forming part of the measurement data, are also recorded in the course of the measurement process, characterized in that • the processing unit is arranged on a computing device (19), particularly a tablet, separate to the laser scanner (1", 1‴), and • the laser scanner (1", 1‴) and the computing device (19) are configured in such a way that ∘ a transmission of the measurement data from the laser scanner (1", 1‴) to the computing device (19) takes place wirelessly, ∘ the transmission of the measurement data is carried out during the measurement process by means of a data streaming of parts of the measurement data which is started simultaneously with respect to the start of the measurement process, or at least almost simultaneously, ∘ an at least initial processing of the parts of the measurement data in terms of a linking of the surface sensor data with the distance measurement data and the first and second angle data takes place during the measurement process, and ∘ displaying of portions of the processed measurement data takes place during the measurement process and is progressively updated based on the processed measurement data, wherein a display (23) being integrated in the computing device (19) is provided for the displaying.
  11. The laser scanner (1", 1‴) according to any one of claims 6 to 9 characterized in that • the laser scanner (1", 1‴) comprises a status indicator (22) for an indication of a device status, in particular for the indication of a status of the measurement process, • the status indicator (22) is arranged on the support (4, 4', 4"), which means it co-rotates when the support (4, 4', 4") rotates about the support axis of rotation (3), • the status indicator (22) is designed in such a way that it appears substantially identical around its circumference with respect to the support axis of rotation (3) in all azimuthal directions, • so that irrespective of a rotational position of the support (4, 4', 4") about the support axis of rotation (3), for a user of the laser scanner (1", 1‴) the same information provided by the status indicator (22) is visible and readable from all horizontal user perspectives.
  12. The laser scanner (1", 1‴) according to claim 11, characterized in that • the status indicator (22) is implemented by means of continuous and interruption-free lighting means, which substantially completely surround the support (4, 4', 4") and the support axis of rotation (3), in particular wherein the lighting means are implemented as an LED ring, and/or • the status indicator (22) is designed by means of a fiber-optic ring with at least one coupling input for light, in particular by means of two or four coupling inputs, wherein with increasing distance from the coupling input position along the fiber-optic ring the ratio of radiation, namely the radial light extraction, to transmission of the light along the fiber-optic ring increases.
  13. The laser scanner (1", 1‴) according to any one of the preceding claims, characterized in that the control element (21) is arranged on the support (4, 4', 4").
  14. The laser scanner (1", 1‴) according to claim 13, characterized in that • the laser scanner (1", 1‴) further comprises a flat sensor (8), namely at least one color camera for recording image data, wherein the sensor (8) defines an optical axis (25) of the sensor (8) and a viewing direction of the sensor (8) along the optical axis (25), • the support (4, 4', 4") is implemented by means of a skeletal structure, • the support (4, 4', 4") comprises a cover carried by the skeletal structure and detachable therefrom as a shell element, • the flat sensor (8) is secured to the shell element and carried by the shell element, and • the control element (21) is arranged on the shell element.
  15. The laser scanner (1", 1‴) according to any one of the preceding claims, characterized in that the control element (21) is a single button or single switch.

Description

Die Erfindung bezieht sich auf Laserscanner zur optischen Vermessung und zur Darstellung einer Umgebung, insbesondere zur Erzeugung und Darstellung einer eingefärbten 3D-Punktwolke. Eine dreidimensionale Vermessung von Räumen und Umgebungen ist beispielsweise für Handwerker und Architekten von grossem Interesse, da auf diese Weise ein Ist-Zustand und/oder ein Baufortschritt von Räumen oder von einer Baustelle schnell erfasst und anstehende Arbeiten geplant werden können. Mittels einer Visualisierung in Form einer Punktwolke, beispielsweise in Kombination mit mehreren zeitlichen Ebenen mittels einer erweiterten Realität und/oder in Form einer virtuellen Realität, können anschliessend unterschiedliche Optionen für weitere Schritte oder Ausbaumöglichkeiten geprüft werden und gegebenenfalls einem Mitarbeiter oder Kunden auf einfache Weise präsentiert werden. Eine Umgebung kann mittels eines Laserscanners optisch abgetastet und vermessen werden. Ein gängiger Ansatz ist dabei eine Abtastung der Umgebung mittels gepulster elektromagnetischer Strahlung, wie z.B. Laserlicht, wobei ein Echo von einem rückstreuenden Oberflächenpunkt der Umgebung empfangen wird und beispielsweise anhand der Laufzeit, der Form, und/oder der Phase des Pulses eine Distanz zum Oberflächenpunkt abgeleitet wird und jeweils mit der räumlichen Position des Oberflächenpunktes verknüpft wird, beispielsweise mittels Winkelinformationen zum Zeitpunkt der Messung und mittels des bekannten Standorts des Laserscanners. Wesentliche Unterschiede in der Bauform eines Laserscanners ergeben sich insbesondere dadurch, ob der Laserscanner für eine optische Abtastung in Form einer Rasterabtastung oder in Form einer scannenden Abtastung vorgesehen ist, wobei sich die vorliegende Erfindung hauptsächlich auf scannende Laserscanner bezieht, im Speziellen auf Laserscanner mit einer mit grosser Geschwindigkeit rotierenden Strahlumlenkeinheit. Bei einer Rasterabtastung erfolgt die optische Abtastung beispielsweise mittels einer spezifischen Einzelabtastung mehrerer Oberflächenpunkte, z.B. anhand eines vorgegebenen Abtastrasters für die abzutastende Umgebung, also mittels spezifischen Anzielens einzelner vordefinierter Rasterpunkte. Bei einer scannenden Abtastung wird typischerweise mittels mindestens eines rotierenden Strahlumlenkelements zur Ausrichtungsvariation der Emissionsrichtung des Distanzmesstrahls, z.B. ein bezüglich einer Drehachse geneigter Planspiegel, eine Vielzahl von Messpunkten erfasst und räumlich vermessen, wobei beispielsweise eine gewünschte Punkt-Zu-Punkt-Auflösung mittels Einstellung der Pulsrate des Distanzmesstrahls und/oder mittels Anpassung der Rotationsgeschwindigkeit des Strahlumlenkelements erfolgt. Anschliessend kann die Umgebung basierend auf der Vielzahl von Messpunkten mittels gängiger Datenverarbeitungsschritten und/oder Darstellungsmöglichkeiten, insbesondere als 3D-Punktwolke, analysiert und/oder unterschiedlich dargestellt werden. Typischerweise weisen scannende Laserscanner eine oder zwei zueinander orthogonale Drehachsen auf, beispielsweise eine vertikale Drehachse für eine vergleichsweise langsame Rotation des gesamten Laserscanners, oft auch "Azimutachse" oder "langsame Achse" genannt, und eine dazu senkrecht stehende horizontale Drehachse für ein mit hoher Geschwindigkeit rotierendes Strahlumlenkelement. Aufgrund der oft verwendeten hohen Rotationsgeschwindigkeit des Strahlumlenkelements wird die zweite Achse auch als "die schnelle Achse" bezeichnet. Ein solcher Laserscanner wird beispielsweise in der DE 10 2013 102 554 A1 und DE 101 05 774 A1 beschrieben. US 2013/120738 A1 erwähnt eine Ein-Knopf-Bedienung, so dass der Bediener lediglich eine "Mess"-Taste drücken muss, woraufhin das System automatisch scannt und die Ergebnisse meldet. Für eine Abtastung von linearen oder linear befahrbaren Strukturen und Umgebungen, wie beispielsweise Gleisanlagen, Strassen, Tunnelsysteme oder Flugfelder, wird anstelle einer Rotation um die Azimutachse oft eine translatorische Bewegung des gesamten Laserscanners ausgenutzt, beispielsweise indem der Laserscanner auf einem Fahrzeug montiert wird. Solche, lediglich die schnelle Achse aufweisende, Laserscanner werden auch Profiler genannt. Derartige Laserscanner mit einer schnellen Achse, und gegebenenfalls mit einer Azimutachse oder in Kombination mit einer Translationsbewegung, befähigen einen Benutzer grosse Oberflächen und Objekte mit einem relativ geringen Zeitaufwand abzutasten. Für zusätzliche Informationen können die Informationen und Abtastdaten zum Beispiel mit Kameradaten kombiniert und verarbeitet werden, insbesondere RGB-Kameradaten oder Infrarotdaten. Gegebenenfalls weisen in Laserscannern zur räumlichen Vermessung verwendete Distanzmessmodule eine Intensitätsempfindlichkeit auf, jedoch keine Farbempfindlichkeit, weshalb die erzeugte 3D-Punktwolke ohne Zuhilfenahme von zusätzlichen Daten in Graustufen dargestellt werden. Mittels einer Referenzierung der "grauen" 3D-Punktwolke mit