Method and system for locating subjects within a tracking environment
US6154139A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 21, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Apr 21, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B3/1083
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A method and system utilize both the radio frequency (RF) and infrared (IR) parts of the electromagnetic spectrum to locate subjects (i.e. objects and persons) within a tracking environment. The system includes a battery-operated, microprocessor-based badge for each subject to be located. Each badge automatically transmits digitized infrared light signals to provide a fine determination of its subject's location. Each badge transmits RF and IR signals upon actuation of a page request/alert push button switch on its badge. An RF signal is also generated at a timed interval as a "heartbeat" pulse. This pulse informs the host computer that the badge is both present and fully functional. The IR and RF signals are modulated or encoded with badge identification data, page request or alert notification data, and battery condition data. The system also includes ceiling or wall sensors in the form of IR and RF receivers. Each RF sensor converts the encoded RF signals into a first set of electrical signals. Each IR sensor converts encoded IR signals into a second set of electrical signals. In turn, the first and second sets of electrical signals are transmitted to a micro-processor-based col…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.