Scanner system and method for registering surfaces

• US 8,379,191 B2
• Filed: 06/21/2005
• Issued: 02/19/2013
• Est. Priority Date: 06/23/2004
• Status: Active Grant

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Geosystems AG (Hexagon AB)
• Inventors: Braunecker, Bernhard, Stegmaier, Peter, Kipfer, Peter
• Primary Examiner(s): RATCLIFFE, LUKE D
• Application Number:
  US11/610,650
• Publication Number:
  US 20110032507A1
• Time in Patent Office: 2,800 Days
• Field of Search: 356/4.07, 356/5.01, 356/451, 356600-608
• US Class Current: 356/4.07
• CPC Class Codes: G01B 11/12 internal diameters
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence
• CPC Class Codes: G01N 21/3554 for determining moisture content
• CPC Class Codes: G01N 21/8422 Investigating thin films, e.g. matrix isolation method
• CPC Class Codes: G01N 21/8806 Specially adapted optical and illumination features
• CPC Class Codes: G01N 21/954 Inspecting the inner surface of hollow bodies, e.g. bores
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

The invention relates to a method for registering surfaces, using a scanner system comprising a radiation source for emitting electromagnetic radiation (ES), a scanning device for guiding the radiation over the surface in order to scan the latter and a receiver for receiving the radiation (RS) that is reflected by the surface. According to the invention, the radiation is spectrally separated to analyze the surface characteristics and a distance measuring unit is used to derive distance information in parallel from the received radiation.

Claims

1. A scanner system for registering and surveying surface topographies, comprising:

one radiation source for emitting electromagnetic radiation;

one scanning device for guiding the radiation over the surface in order to scan the surface; and

one receiver unit for receiving the radiation reflected by the surface, the receiver unit comprising a distance-measuring device that measures distance based on a pulse transit time or phase measurement method for deriving distance information from the radiation received, wherein the radiation source and the receiver unit are formed and tuned to one another in such a way that spectral separation of the radiation takes place, such that a composition or a state of the detected surface are determinable from spectral components of the radiation.

2. A scanner system as claimed in claim 1, wherein the electromagnetic radiation includes a laser light or white light.

3. The scanner system as claimed in claim 1, wherein the radiation source emits in at least two separate wavelength ranges.

4. The scanner system as claimed in claim 1, wherein the radiation source includes:

two laser emitters with a different wavelength;

or

one laser emitter and one terahertz emitter;

or

two spectrally broadband sources with a non-overlapping wavelength range;

or

one laser and one spectrally broadband source.

5. The scanner system as claimed in claim 1, wherein the radiation source includes a mode-coupled titanium sapphire laser with photoconductive dipole antenna.

6. A scanner system as claimed in claim 1, wherein the receiver unit has a spectrally separating sensor.

7. A scanner system as claimed in claim 6, wherein the spectrally separating sensor includes a spectrometer or a variable filter.

8. The scanner system as claimed in claim 6, wherein the receiver unit has a first beam splitter which splits the received radiation for use by the distance-measuring device and the sensor.

9. The scanner system as claimed in claim 6, wherein the spectrally separating sensor includes a prism spectrometer, a terahertz spectrometer, a grating spectrometer, or a Fourier spectrometer.

10. The scanner system as claimed in claim 9, wherein the spectrometer

includes the Fourier spectrometer, the Fourier spectrometer is of the Michelson type and is:

in the form of a scanning interferometer having a piezo actuator or an electrostatic comb as a drive;

or

in the form of a spatially modulating interferometer having a tilted minor or a rotatable Littrow grating.

11. The scanner system as claimed in claim 10, wherein the spatially modulating interferometer includes:

a linear or two-dimensional photodiode array;

a CCD camera;

or

a CMOS camera.

12. The scanner system as claimed in claim 9, wherein the Fourier spectrometer includes a liquid crystal for polarization-dependent generation of an optical path difference in transmission with upstream polarization separation, wherein the Forier spectrometer further includes a quarter-wave plate and polarizer.

13. The scanner system as claimed in claim 9, wherein the grating spectrometer is formed so as to scan as a function of time in reflection, wherein the spectrometer is formed so as to scan as a lamellar grating spectrometer or a grating on a curved and adjustable mirror.

14. The scanner system as claimed in claim 9, wherein the prism spectrometer is formed so as to scan as a function of time with a rotating prism or a rotating prism arrangement.

15. The scanner system as claimed in claim 1, further comprising a camera for image recording and/or image processing.

16. The scanner system as claimed in claim 15, further comprising a second beam splitter in the receiver unit, which guides a part of the radiation received onto the camera.

17. The scanner system as claimed in claim 1, further comprising suppression of scattered light.

18. A theodolite comprising a scanner system as claimed in claim 1.

19. A mobile scanning system for registering and/or monitoring constructions, the mobile scanning system comprising a scanner system as claimed in claim 1.

20. A method for registering surfaces by means of a scanner system, comprising the acts:

emitting electromagnetic radiation;

receiving radiation after reflection by the surface;

analyzing the radiation received;

repeating the emitting, receiving and analyzing acts several times during scanning of the surface; and

deriving distance information based on the analysis of the radiation, wherein the analysis of the radiation is effected with spectral separation of the radiation, such that a composition or a state of the detected surface are determinable from spectral components of the radiation.

21. The method as claimed in claim 20, wherein the radiation is spectrally resolved on reception and/or the radiation is selectively emitted spectrally on emission.

22. The method as claimed in claim 20, wherein the radiation is spectrally resolved by means of interferometry on reception.

23. The method as claimed in claim 20, further comprising drawing conclusions about a chemical composition or moisture content of the surface from the spectral separation.

24. A method for registering surfaces by means of a scanner system, comprising the acts:

emitting electromagnetic radiation;

receiving radiation after reflection by the surface;

analyzing the radiation received;

repeating the emitting, receiving and analyzing acts several times during scanning of the surface; and

deriving distance information based on the analysis of the radiation, wherein the analysis of the radiation is effected with spectral separation of the radiation; and

determining a composition of the detected surface from spectral components of the radiation.