Spatial positioning system

• US 5,294,970 A
• Filed: 09/06/1991
• Issued: 03/15/1994
• Est. Priority Date: 12/31/1990
• Status: Expired due to Fees

• Current Assignee: Arc Second, Inc. (Nikon Corporation)
• Original Assignee: Spatial Positioning Systems, Inc.
• Inventors: Dornbusch, Andrew W., Pratt, Timothy, Lundberg, Eric J., Beliveau, Yvan J.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US07/755,780
• Time in Patent Office: 921 Days
• Field of Search: 356/1, 356/4, 356/141, 356/152, 172/4.5
• US Class Current: 356/141.1
• CPC Class Codes: G01C 15/002 Active optical surveying means optical plumbing G01C15/105
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G01S 7/4813 Housing arrangements

Abstract

A spatial positioning system includes fixed referent stations which emit rotating, divergent laser beams and a portable reflector. Each fixed station also includes a detector and a processor. The portable reflector may include retroreflectors or transponders. When the rotation of the laser beam is such that it is in line with a portable reflector, the transmitted laser beam is reflected off the portable reflector and received at the fixed receiver. For any point which is crossed by the fanned laser beams of a fixed station, a horizontal angle can be determined. Once these horizontal angles are known for three fixed stations, the point of intersection of three planes, and thus the three-dimensional position of the point, is determined.

Claims

1. A spatial positioning and measurement system for determining the instantaneous x-y-z position of an object in a three-dimensional Cartesian coordinate system, said system comprising:

a plurality of fixed referent stations located at known locations within a local coordinate system, each said referent station including emitter means for emitting at least two sweeping radiation beams which are divergent in a plane perpendicular to the plane in which they are swept;

a portable reflector means for reflecting said beams toward said fixed referent stations;

detecting means for detecting said beams, said detecting means generating a signal each time one of said beams is detected; and

determination means for determining the x-y-z position of said portable reflector means and each of said other fixed referent stations relative to each other within said local coordinate system based upon said signals generated by said detecting means.

2. A system as in claim 1, wherein said beams rotate.

3. A system as in claim 1, wherein said beams oscillate.

4. A system as in claim 1, wherein three of said fixed referent stations are used, each said fixed station producing two rotating laser beams.

5. A system as in claim 1, wherein three of said referent stations are used, each said fixed station producing a pair of counter-rotating laser beams.

6. A system as in claim 1, wherein said detecting means are disposed at each of said fixed referent stations.

7. A system as in claim 6, wherein said determination means includes a processor which time-labels each of said signals generated by said detecting means, and a central processing system which receives said time-labelled signals generated by said processor and calculates all angle and position information therefrom.

8. A system as in claim 7, wherein said reflecting means is a retroreflector.

9. A system as in claim 1, wherein said reflecting means is a retroreflector.

10. A system as in claim 1, wherein said reflecting means is a transponder, and said detecting means is a transponder receiver.

11. A system as in claim 10, wherein said determination means includes a processor which time-labels each of said signals generated by said detecting means, and a central processing system which receives said time-labelled signals generated by said processor and calculates all angle and position information therefrom.

12. A system as in claim 11, wherein said transponder receiver is disposed at said central processing system.

13. A system as in claim 1, wherein each of said fixed referent stations generates a pair of rotating laser beams and a third rotating laser beam.

14. A system as in claim 13, wherein the laser beams in said pair of laser beams rotate in opposite directions.

15. A system as in claim 13, wherein said laser beams pulse periodically.

16. A system as in claim 15, wherein a shutter is used to cause said laser beams to pulse periodically.