Optical coordinate measuring system for large objects
US5305091A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 7, 1992 |
| Grant date | Apr 19, 1994 |
| Priority date | — |
| Expiry date | Dec 7, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/497
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A coordinate measuring system consists of multiple optical transceivers (transmitter-receivers) mounted onto a stable reference frame such as the walls of a room. The object to be measured is touched with a hand-held measuring probe. To measure, the probe triggers the transceivers to read the distance to two retroreflectors mounted on the probe. The location of the probe tip relative to the reference frame is computed from at least six transceiver readings (three for each retroreflector). The accurate determination of the distance between the transceivers and retroreflectors is done by measuring the phase shift of a high frequency modulation superimposed on light beams. To avoid ambiguity two high frequencies are used, one for coarse and one for fine resolution. The initial location of the transceivers can be found out by measuring an accurately known object and computing the transceiver locations. The transceivers include a beam steering device to track the position of the probe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.