Method for determining motion using a velocity predictor
US7298460B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 2006 |
| Grant date | Nov 20, 2007 |
| Priority date | — |
| Expiry date | Jan 3, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01P3/36
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is provided for determining motion of an optical sensor including a periodic photo-diode array relative to a surface. The method includes steps of (i) generating sets of quasi-sinusoidal signals responsive to motion along first and second directions; (ii) combining the sets of signals to generate a wrapped phase angle value for each direction at a first time; (iii) combining the sets of signals at a second time to generate a second wrapped phase angle value for each direction; (iv) computing wrapped phase angle changes for each direction between the first time and the second time; (v) computing velocity predictors for each direction using corrected average phase angle changes from a number of preceding successive frames; (vi) calculating the number of full 27π rotations needed to unwrap the phase angle changes for each direction using the velocity predictors; and (vii) computing the unwrapped or corrected phase angle changes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.