Phase difference detection device for an inductive position detector
US5710509A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1995 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Oct 30, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/645
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(.omega.t .+-.d.+-..theta.), sin(.omega.t.+-.d-.theta.)) are electrically synthesized which have electric phase angles (.theta.) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. ".+-.d" here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (.+-.d) appear in the same direction, while the phase differences (.theta.) corresponding to the position are shifted in opposite, positive and negative, directions. Thus, by measuring the respective phase shift amounts (.+-.d.+-..theta., .+-.d-.theta.) and performing appropriate operation, it is allowed to cancel out or extract …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.