System and method for improving accuracy in a speckle-based image correlation displacement sensor
US7295324B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2004 |
| Grant date | Nov 13, 2007 |
| Priority date | — |
| Expiry date | Jan 28, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for improving the accuracy of a speckle-based image correlation displacement sensor provides ultra-high accuracy by ensuring that, in the absence of motion, the speckle image does not vary over time. In one embodiment, the speckle image is stabilized by reducing or compensating for laser diode wavelength changes. Various methods for stabilizing the wavelength include thermoelectric temperature control, measuring and correcting the wavelength by any suitable means, or providing a specific wavelength of light feedback from an external grating. Image stabilization may also be accomplished by monitoring the warm-up process of the system. Once the system is determined to have completed the warm-up process, an indicator is provided to the user to indicate that the system is ready for use. Sensor geometric configurations that reduce or eliminate wavelength-related errors are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.