Encoder self-callibration apparatus and method
US6897435B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 2002 |
| Grant date | May 24, 2005 |
| Priority date | — |
| Expiry date | Sep 11, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/185
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The disclosed electronic processing apparatus calculates and applies calibrations to sensors that produce quasi-sinusoidal, quadrature signals. The apparatus includes either or both of fixed and programmable electronic circuits. The apparatus includes a circuit to calculate the phase and magnitude corresponding to the two input (quadrature) signals. The apparatus also includes a circuit for accumulating the number of cycles of the input signals. The apparatus also includes a circuit to generate Gain, Offset, and Phase calibration coefficients, wherein the circuit compares the phase space position of the measured phasor with the position of an idealized phasor, the locus of the idealized phasor in phase space being a circle of predetermined radius with no offset. The calculation of the coefficients occurs without user intervention, according to a pre-programmed rule or rules. The apparatus also includes a circuit to apply the Gain, Offset, and Phase calibration coefficients to the measured quadrature signals xi and yi according to the formulaeXi=(xi+Oxi+Pi×yi)×GxiYi=(yi+Oyi)×Gyiwhere Gxi and Gyi are the scaling coefficients, Oxi and Oyi are the offset coefficients and Pi is the phas…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.