Laser tracker with a target sensing unit for target tracking and orientation detection

Patent metadata

Field	Value
Publication number	US-9322654-B2
Application number	US-201414274530-A
Country	US
Kind code	B2
Filing date	May 9, 2014
Priority date	May 10, 2013
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

Embodiments of the invention relates to a laser tracker for determining the position of an auxiliary measuring instrument that has a retroreflector and a multiplicity of target markings, and also for continuously tracking the auxiliary measuring instrument. The target markings may be arranged in a known fixed spatial distribution on the auxiliary measuring instrument and may be embodied to emit or reflect light beams. The laser tracker may have a first radiation source for producing measurement radiation, a distance measuring module, and a target sensing unit for determining an impingement point for radiation reflected by the retroreflector on a sensor of the target sensing unit and for producing an output signal in order to control a fine targeting functionality and a target tracking functionality.

First claim

The invention claimed is:

1. A laser tracker for determining the position of an auxiliary measuring instrument that has a retroreflector and a multiplicity of target markings, and also for continuously tracking the auxiliary measuring instrument, wherein the target markings are arranged in a known fixed spatial distribution on the auxiliary measuring instrument and are embodied to emit or reflect light beams, and wherein the laser tracker comprises:
a first radiation source for producing measurement radiation;
a distance measuring module having distance measuring functionality; and
a target sensing unit for determining an impingement point for radiation reflected by the retroreflector on a sensor of the target sensing unit and for producing an output signal in order to control a fine targeting functionality and a target tracking functionality, wherein the target sensing unit is configured to:
determine impingement points for light beams reflected or emitted by a multiplicity of target markings of the auxiliary measuring instrument on the sensor, and
ascertain the spatial orientation of the auxiliary measuring instrument on the basis of the distribution of the impingement points of the light beams,
the laser tracker further comprising means for wireless communication with the auxiliary measuring instrument, which means are used to embody the laser tracker to control an on state of the target markings of the auxiliary measuring instrument to switch the radiance of target markings on and off in sync.

2. The laser tracker according to claim 1 , further comprising:
a base that defines a vertical axis;
a support that defines a tilt axis that is essentially at right angles to the vertical axis, wherein the support can be pivoted about the vertical axis relative to the base in a motorized manner, and a horizontal pivot angle is defined by an orientation of the support relative to the base;
a beam deflection unit that can be pivoted about the tilt axis relative to the support in a motorized manner, wherein a vertical pivot angle is defined by an orientation of the beam deflection unit relative to the support, in order to emit and orient the measurement radiation along an emission axis and in order to receive at least one portion of the measurement radiation reflected at the retroreflector; and
angle measuring functionality for determining the horizontal pivot angle and the vertical pivot angle.

3. The laser tracker according to claim 1 , wherein the sensor of the target sensing unit comprises a two dimensional image sensor.

4. The laser tracker according to claim 1 , further comprising an optical system of the target sensing unit with unalterable focus and/or unalterable zoom.

5. The laser tracker according to claim 1 , further comprising a coarse targeting unit, having illumination means, for coarsely determining the position of the auxiliary measuring instrument and for producing an output signal in order to control a coarse targeting functionality.

6. The laser tracker according to claim 1 , further comprising:
an overview camera, having illumination means, for recording images of the measurement surroundings, and
a display unit for displaying images from the overview camera and/or information about performed measurements and the appliance state.

7. The laser tracker according to claim 1 , wherein the sensor of the target sensing unit is comprises a CMOS sensor or CCD sensor.

8. The laser tracker according to claim 1 , further comprising an optical system of the target sensing unit having a fixed focus lens.

9. A laser tracker for determining the position of an auxiliary measuring instrument that has a retroreflector and a multiplicity of target markings, and also for continuously tracking the auxiliary measuring instrument, wherein the target markings are arranged in a known fixed spatial distribution on the auxiliary measuring instrument and are embodied to emit or reflect light beams, and wherein the laser tracker comprises:
a first radiation source for producing measurement radiation;
a distance measuring module having distance measuring functionality; and
a target sensing unit for determining an impingement point for radiation reflected by the retroreflector on a sensor of the target sensing unit and for producing an output signal in order to control a fine targeting functionality and a target tracking functionality, wherein the target sensing unit is configured to:
determine impingement points for light beams reflected or emitted by a multiplicity of target markings of the auxiliary measuring instrument on the sensor, and ascertain the spatial orientation of the auxiliary measuring instrument on the basis of the distribution of the impingement points of the light beams,

laser tracker further comprising means for wireless communication with the auxiliary measuring instrument, which means are used to embody the laser tracker to control an on state of the target markings of the auxiliary measuring instrument to switch the radiance of target markings on and off in sync on the basis of a distance between the laser tracker and the auxiliary measuring instrument.

10. A laser tracker for determining the position of an auxiliary measuring instrument that has a retroreflector and a multiplicity of target markings, and also for continuously tracking the auxiliary measuring instrument, wherein the target markings are arranged in a known fixed spatial distribution on the auxiliary measuring instrument and are embodied to emit or reflect light beams, and wherein the laser tracker comprises:
a first radiation source for producing measurement radiation;
a distance measuring module having distance measuring functionality; and
a target sensing unit for determining an impingement point for radiation reflected by the retroreflector on a sensor of the target sensing unit and for producing an output signal in order to control a fine targeting functionality and a target tracking functionality, wherein the target sensing unit is configured to:
determine impingement points for light beams reflected or emitted by a multiplicity of target markings of the auxiliary measuring instrument on the sensor, and ascertain the spatial orientation of the auxiliary measuring instrument on the basis of the distribution of the impingement points of the light beams,

the laser tracker further comprising means for wireless communication with the auxiliary measuring instrument, which means are used to embody the laser tracker to control an on state of the target markings of the auxiliary measuring instrument to switch the radiance of target markings on and off in sync for the purpose of temporally successive target tracking and orientation determination by means of the target sensing unit.

11. A laser tracker for determining the position of an auxiliary measuring instrument that has a retroreflector and a multiplicity of target markings, and also for continuously tracking the auxiliary measuring instrument, wherein the target markings are arranged in a known fixed spatial distribution on the auxiliary measuring instrument and are embodied to emit or reflect light beams, and wherein the laser tracker comprises:
a first radiation source for producing measurement radiation;
a distance measuring module having distance measuring functionality; and
a target sensing unit for determining an impingement point for radiation reflected by the retroreflector on a sensor of the target sensing unit and for producing an output signal in order to control a fine targeting functionality and a target tracking functionality, wherein the target sensing unit is configured to:
determine impingement points for light beams reflected or emitted

Assignees

• Leica Geosystems Ag

Inventors

• Böckem Burkhard

Classifications

• G01C15/002 Primary

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

• G01S17/06

  Systems determining position data of a target · CPC title

• G01S17/66 Primary

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