Passive position-sensing and communications for vehicles on a pathway
US6781524B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2000 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Mar 17, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08G1/017
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A pathway-based method, apparatus and system for tracking, sensing and communicating with an object, such as a carriage or vehicle moving on a pathway. The system includes a transmitter winding along the pathway that is energized by a transmitter and one or more sensing windings in which a signal is induced. The vehicle contains a transducer that creates a position-indicating coupling of the transmitted signal into the sensing windings. The transducer may be a passive ferromagnetic or conductive body that locally alters coupling between the windings, or a tuned coil carried on the vehicle that couples energy received from the transmitter into a sensing winding. Absolute position may be established at regular intervals using a discrete position sensor, such as a Hall Effect magnetic field sensor, and, the signal derived from the sensing windings can be monitored, by counting cycles or determining phase, to determine a precise vehicle position. With one sensing winding it is possible to determine distance to about ⅛ of a wavelength and by using two or more phased sensing windings a wayside controller determines the position within a wavelength to a smaller fraction of a wavele…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.