Robust index correction of an angular encoder in a three-dimensional coordinate measurement device
US9436003B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 29, 2015 |
| Grant date | Sep 6, 2016 |
| Priority date | — |
| Expiry date | Apr 29, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/66
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A 3D measurement device sends a beam of light to a point on an object, receives the reflected light, and determines a distance and two angles to the point, one of the angles measured by an angular encoder, which includes a disk having incremental marks and an index mark. Light from the 3D device is rotated to reflect light from a reference reflector to produce a first synchronization signal. A first difference angle is determined based on counts of the incremental marks and on the first synchronization signal. Light from the 3D device is rotated to reflect light from the reference reflector to produce a second synchronization signal. A second difference angle is determined based on counts of the incremental marks and on the second synchronization signal. The reference correction value of the index mark is determined based on the first and second difference angles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.