Apparatus for determining the position of an object
US5187475A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 10, 1991 |
| Grant date | Feb 16, 1993 |
| Priority date | — |
| Expiry date | Jun 10, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D2205/775
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A position sensor is provided which incorporates the first and second magnetic members which are attached to an object whose position is to be determined. First and second magnetic sensors are disposed at positions in association with the two magnetic members. As the object moves along a predetermined path, the first and second magnetic members dispose a predetermined amount of magnetic material in the zones of the two sensors. By measuring the changing impedance of the winding of one of the sensors and comparing that value to the impedance of the winding of the other sensor, corrections can be made to determine the position of the object notwithstanding the fact that external effects may have changed the conditions under which the measurements are being taken. For example, gaps between the magnetic members and the sensors can possibly change from one time to another or the ambient temperature surrounding the sensors and the magnetic members could have changed. By comparing the values of the two sensor readings, these variabilities can be factored out of the determination and the accurate position of the object can be measured.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.