Automated highway tracking and communication system and method
US6219596A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 1997 |
| Grant date | Apr 17, 2001 |
| Priority date | — |
| Expiry date | Sep 18, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A vehicle borne transmitter transmits a spread spectrum transmit signal which is pseudo (PN) encoded. The transmitted signal is reflected off of a reflector on known position which may be a highway guardrail, tunnel wall, or the like. The reflected signal is detected by a receiver in the vehicle and a pseudo noise code (PN code) is synchronized to the reflected signal to accomplish maximum correlation. The phase delay between the transmitted PN code and received PN code is thereby utilized to determine the distance between the vehicle and reflector to maintain the vehicle in the center of a roadway lane. Roadway transponders may be periodically located adjacent the roadway and will be responsive to the vehicle borne interrogation signal. The periodically located transducers produce a reply signal including a PN code and imbedded data which data may represent transponder ID and position, roadway or map data, or other data which is desirable to transmit between the transducer and the vehicle travelling the highway.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.