Automatic determination of traffic signal preemption using differential GPS
US5926113A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 5, 1995 |
| Grant date | Jul 20, 1999 |
| Priority date | — |
| Expiry date | May 5, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S19/41
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A traffic signal preemption system, and a related method for its use, using differential global positioning system (GPS) measurements for accurate monitoring of the position, speed and direction of an emergency or service vehicle approaching a controlled intersection. The preemption system includes a reference GPS receiver, for computing GPS measurement corrections, and a GPS receiver in each vehicle, which transmits its GPS measurements by radio to a receiver located at the controlled intersection. A computer also located at the intersection uses corrected vehicle position, speed and direction measurements, in conjunction with previously recorded data defining approach routes to the intersection, to determine the optimum time to switch a traffic light controller to preemption mode to permit safe passage of the vehicle. GPS measurement corrections may be applied in a vehicle computer or in the computer located at the intersection. Other modes of operation of the system include a self-survey mode, whereby the reference GPS receiver determines its own true position by averaging position measurements over a period of a day or two, and a learn mode, whereby the intersection computer "l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.