Location system adapted for use in multipath environments
US5119104A · kind A · utility
Inventor
Key dates
| Filing date | May 4, 1990 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | May 4, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K7/0008
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A radiolocation system for multipath environments, such as for tracking objects in a semiconductor fabrication facility (FIGS. 1a-1b), includes an array of receivers (20) distributed within the tracking area, coupled to a system processor (40) over a LAN. A TAG transmitter (30) located with each object transmits, at selected intervals, spread spectrum TAG transmissions including at least a unique TAG ID. In a high resolution embodiment, object location is accomplished by time-of-arrival (TOA) differentiation, with each receiver (FIG. 2b) including a TOA trigger circuit (64) for triggering on arrival of a TAG transmission, and a time base latching circuit (65) for latching the TOA count from an 800 MHz time base counter. In a low resolution embodiment, each receiver of the array is assigned a specific location-area, and receives TAG transmissions almost exclusively from TAGs located in that area, thereby eliminating the need for any time-of-arrival circuitry.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.