Coordinate measuring device

Patent metadata

Field	Value
Publication number	US-9366531-B2
Application number	US-201414296293-A
Country	US
Kind code	B2
Filing date	Jun 4, 2014
Priority date	Jun 23, 2009
Publication date	Jun 14, 2016
Grant date	Jun 14, 2016

Abstract

A coordinate measuring device includes a carrier that automatically rotates about two axes and can be directed toward a measuring aid. The following are arranged on the carrier so as to be able to move together: a device for optically measuring the distance to the measuring aid; a first light source for emitting a target beam that is visible as a first target point when reflected on the measuring aid; a detection unit for determining a fine position of the first target point on a first position detection sensor; a second light source, the light of which is visible as a second target point when reflected on the measuring aid; a rough target detection unit for determining a rough position of the second target point on a second position detection sensor. A control device directs the carrier toward the measuring aid according to the fine and rough positions.

First claim

The invention claimed is:

1. A coordinate measurement apparatus, comprising:
a carrier which, with respect to a base, is rotatable about at least two axes, wherein the carrier by way of rotation about these at least two axes, by way of a closed-loop control device, is configured to be automatically aligned onto a measurement aid movable in space,
wherein:
at least in each case, one exit optical system and/or entry optical system of the following units are arranged on the carrier in a commonly movable manner:
at least one optical distance measurement device for measuring the distance to a measurement aid moved in space;
a first light source and optical elements for radiating a target beam, wherein the target beam, with a reflection on the measurement aid, is visible as a first target point;
a fine target detection unit for determining a fine position as the position of the image of the first target point on a first position detection sensor, wherein the fine target detection unit and the distance measurement device have common exit optical system;
a second light source which radiates light at least in the infrared region, wherein this light, with a reflection at the measurement aid, is visible as a second target point on a second position detection sensor of a coarse target detection unit; and
the coarse target detection unit for determining a coarse position as the position of the image of the second target point on the second position detection sensor, wherein the coarse target detection unit is only sensitive to light in the infrared region; and
the closed-loop control device is configured for aligning the carrier onto the measuring aid by way of rotation about the at least two axes of the carrier in accordance with the fine position and the coarse position, wherein the carrier is aligned onto the measurement aid on account of the coarse position until the fine target detection unit detects the target beam.

2. A coordinate measurement apparatus, comprising:
a carrier which, with respect to a base, is rotatable about at least two axes, wherein the carrier by way of rotation about these at least two axes, by way of a closed-loop control device, is configured to be automatically aligned onto a measurement aid movable in space,
wherein at least in each case, one exit optical system and/or entry optical system of the following units are arranged on the carrier in a commonly movable manner:
at least one optical distance measurement device for measuring the distance to a measurement aid moved in space;
a first light source and optical elements for radiating a target beam, wherein the target beam, with a reflection on the measurement aid, is visible as a first target point;
a fine target detection unit for determining a fine position as the position of the image of the first target point on a first position detection sensor, wherein the fine target detection unit and the distance measurement device have common exit optical system;
a second light source which radiates light at least in the infrared region, wherein this light, with a reflection at the measurement aid, is visible as a second target point on a second position detection sensor of a coarse target detection unit; and
the coarse target detection unit for determining a coarse position as the position of the image of the second target point on the second position detection sensor, wherein the coarse target detection unit is only sensitive to light in the infrared region;

wherein the closed-loop control device is configured for aligning the carrier onto the measuring aid by way of rotation about the at least two axes of the carrier in accordance with the fine position and the coarse position;
and wherein an overview camera is arranged on the carrier, the overview camera being sensitive at least in the visible range, such that pictures from the overview camera are displayable by a display device.

3. The coordinate measurement apparatus according to claim 1 or 2 , wherein:
the light radiated by the first light source, as the target beam, is coupled into the common beam path of the distance measurement device and of the fine target detection unit.

4. The coordinate measurement apparatus according to claim 3 , wherein:
an optical axis of the fine target detection unit runs outside the coordinate measurement apparatus coaxially to the optical axis of the distance measurement device on a common measurement axis.

5. The coordinate measurement apparatus according to claim 3 , wherein:
the optical axes of the fine target detection unit and of the coarse target detection unit do not run coaxially outside the carrier.

6. The coordinate measurement apparatus according to claim 1 or 2 , wherein:
the fine target detection unit has a viewing angle of less than 1° or less than 2° or less than 3°.

7. The coordinate measurement apparatus according to claim 1 or 2 , wherein:
the coarse target detection unit has a viewing angle of more than 3° or more than 10° or more than 15°.

8. A coordinate measurement apparatus according to claim 1 or 2 , wherein:
the fine target detection unit and the coarse target detection unit are sensitive in regions of the light spectrum which are different from one another, and the fine target detection unit is sensitive to light of the first light source and the coarse target detection unit to light of the second light source.

9. The coordinate measurement apparatus according to claim 8 , wherein:
the fine target detection unit comprises a first band-pass filter with a first transmission range, the coarse target detection unit a second band-pass filter with a second transmission range, and the two transmission ranges do not overlap, and the first band-pass filter filters out measurement light of the distance measurement device.

10. The coordinate measurement apparatus according to claim 1 or 2 , comprising:
a pointer light source for producing light in the visible region; and
an incoupling for coupling in said light as a beam into the common beam path of the distance measurement device and of the fine target detection unit.

11. The coordinate measurement apparatus according to claim 1 , comprising:
an overview camera sensitive at least in the visible range, for the coarse localisation of the measurement aid by way of light in the visible region.

12. The coordinate measurement apparatus according to claim 1 or 2 , wherein:
the first light source is an infrared light source for radiating an infrared target beam, the infrared target beam, with a reflection on the measurement aid, being visible as an infrared target point; and
the fine target detection unit is adapted for determining the fine position as the position of the image of the infrared target point on the first position detection sensor.

13. The coordinate measurement apparatus according to claim 1 or 2 , wherein:
the carrier is rotatable about a tilt axis running at least approximately horizontally in operation of the coordinate measurement apparatus, and about a pivot axis running at least approximately vertically; and
the measurement axis does not intersect the tilt axis and/or the measurement axis does not intersect the pivot axis.

14. The coordinate measurement apparatus according to claim 13 , wherein:
the measurement axis and the tilt axis are distanced to one another by a distance of at least one half or at least one millimeter.

15. The coordinate measurement apparatus according to claim 13 , wherein:
the light beam of the distance measurement device is coupled into the beam path of the fine target detection unit by way of a semit

Assignees

• Leica Geosystems Ag

Inventors

• Böckem Burkhard
• Fuchs Simon

Classifications

• G01S17/66

  Tracking systems using electromagnetic waves other than radio waves · CPC title

• G01S17/87

  Combinations of systems using electromagnetic waves other than radio waves · CPC title

• G01S17/86

  Combinations of lidar systems with systems other than lidar, radar or sonar, e.g. with direction finders · CPC title

• G01C15/002 Primary

  Active optical surveying means (optical plumbing G01C15/105) · CPC title

• G01C3/08 Primary

  Use of electric radiation detectors · CPC title