Method for identifying measuring points in an optical measuring system

• US 7,184,151 B2
• Filed: 09/06/2001
• Issued: 02/27/2007
• Est. Priority Date: 09/11/2000
• Status: Expired due to Term

• Current Assignee: Leica Geosystems AG (Hexagon AB)
• Original Assignee: Leica Geosystems AG (Hexagon AB)
• Inventors: Clarke, Timothy Alan, Wang, Xinchi
• Primary Examiner(s): STAFIRA, MICHAEL PATRICK
• Application Number:
  US10/363,873
• Publication Number:
  US 20040027589A1
• Time in Patent Office: 2,000 Days
• Field of Search: 356/614, 356/616, 356/617, 356/620, 356/622, 356/373, 356/141, 382/170, 382/174, 250/231.13, 250/231.14, 250/231.17, 250/226.1, 250/206.2
• US Class Current: 356/620
• CPC Class Codes: G01B 11/00 Measuring arrangements characterised by the use of optical techniques
• CPC Class Codes: G01C 11/00 Photogrammetry or videogrammetry, e.g. stereogrammetry; Photographic surveying
• CPC Class Codes: G01C 15/02 Means for marking measuring points

Abstract

In an optical measuring system for determining spatial position and orientation of objects, a plurality of measuring points on the object is registered by cameras, laser measuring devices or a combination thereof. For identifying the measuring points, one target of a specific intensity and/or size or a predetermined pattern (3) of a plurality of targets (4) having specific differing intensities and/or sizes is associated with each measuring point. The intensities and/or sizes of the targets are detected in a pixel image of the target (4) by summing up intensities sensed by pixels included in the image of the target. The targets are light emitting devices consuming differing amounts of energy, reflecting, black or white spots of differing diameter or spots of differing shades of gray or other suitable color.

Claims

1. A method for identification of measuring points in an optical measuring system in which system an arrangement of a plurality of active targets is used for marking each one of the measuring points, each of said targets having a different intensity and wherein, for identification of the measuring points, the intensities of the active targets (4, 10) are registered.

2. The method according to claim 1, wherein the targets (4, 10) are imaged in pixel images (1) and wherein intensities and/or sizes of the pixel images (1) are determined by summing-up intensities (I_i) sensed by pixels (P_i) comprised in the image (1) of a target, by counting the pixels (P_i) comprised in the image (1) of a target or by determining a maximum intensity (I_M) sensed by one of the pixels (P_M) comprised in the image (1) of a target.

3. The method according to claim 1, wherein the targets (10) are light emitting means emitting differing amounts of light energy.

4. An optical measuring system comprising:

a set of arrangements of a plurality of active targets (4, 10) each arrangement serving for identifying one measuring point in an optical measuring system, wherein the targets (4, 10) of each arrangement are arranged in a same pattern (3) or in differing patterns and wherein the targets (4, 10) have differing intensities; and

sensor means being equipped for determining intensity of the targets in the target arrangements.

5. The optical measuring system according to claim 4, wherein the target pattern (3) is a circle.

6. The optical measuring system according to claim 4, wherein the targets (10) are light emitting means emitting differing amounts of light energy.

7. A method for identification of measuring points in an optical measuring system in which system an arrangement of a plurality of active targets is used for marking each one of the measuring points, wherein each arrangement is different from the other arrangements by different target intensities and wherein, for identification of the measuring points, the target intensities in each arrangement are registered.

8. The method according to claim 7, wherein the targets (4, 10) are imaged in pixel images (1) and wherein intensities and/or sizes of the pixel images (1) are determined by summing-up intensities (I_i) sensed by pixels (P_i) comprised in the image (1) of a target, by counting the pixels (P_i) comprised in the image (1) of a target or by determining a maximum intensity (I_M) sensed by one of the pixels (P_M) comprised in the image (1) of a target.

9. The method according to claim 7, wherein the targets (10) are light emitting means emitting differing amounts of light energy.

10. The method according to claim 7, wherein a plurality of targets (4, 10) are associated with each measuring point, the plurality of targets (4, 10) being arranged in a predetermined pattern (3) and the measuring point identity is encoded by specific intensities of the targets (4, 10) in the pattern (3).

11. The method according to claim 7, wherein, for computing a spatial position and/or orientation of a measuring point, a spatial position of the targets (4, 10) in the target pattern (3) associated with the measuring point are determined.