System and method of magnetically sensing position of a moving component
US7259553B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2005 |
| Grant date | Aug 21, 2007 |
| Priority date | — |
| Expiry date | Sep 22, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/24476
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A position-sensing system magnetically senses the position of a piston rod moving with respect to a cylinder. A magnetically hard layer on the piston rod provides a recording medium. Information is magnetically recorded in regions of the magnetically hard layer. These regions provide a relative encoding scheme for determining the position of the piston rod. Magnetic-field sensors are positioned over redundant tracks of magnetically recorded regions. Each magnetic-field sensor positioned over a given track senses the same magnetized regions while the piston rod moves with respect to the cylinder. Other magnetic-field sensors can sense ambient fields for use in performing common-mode rejection. A write head can dynamically repair damaged or erased regions detected by the magnetic-field sensors. Energized by a battery-backup power source, the magnetic-field sensors and associated circuitry can continue to track movement of the piston rod when the machinery is off.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.