Approaching vehicle informing system and method
US4747064A · kind A · utility
Inventor
Key dates
| Filing date | Oct 3, 1986 |
| Grant date | May 24, 1988 |
| Priority date | — |
| Expiry date | Oct 3, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B1/08
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An approaching vehicle informing system and method for informing the driver of a vehicle of the presence of a relatively approaching emergency vehicle and providing the driver with information regarding the amount of time until vehicles meet. Included are a transmitting station for simultaneously emitting periodic electromagnetic and sound pulses of preselected frequencies located on the emergency vehicle, and a receiving station located on the driver's vehicle. The receiving station includes circuitry to receive the electromagnetic and sound pulses and discriminate signals of the preselected frequencies. A microcomputer is programmed to measure the time interval between simultaneously emitted electromagnetic and sound pulses, determines the Doppler frequency shift of the received sound pulse, and calculates the time until vehicles meet, which is displayed in numerical form to the driver in the event the Doppler frequency of received sound pulses exceeds the frequency of emitted sound pulses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.