Vehicle RF device detection system and method
View Patent ↗A system and method are provided for detecting use of RF transmit devices (e.g., cellular phones) in a vehicle. The system includes a first RF antenna for detecting signal strength of an RF signals transmit device at a first location in a vehicle and a power first detector for generating a first output signal indicative thereof. The system also includes a second antenna for detecting signal strength of the RF signals at a second location in the vehicle and a second power detector for generating a second output signal indicative thereof. The system further includes a signal processor for processing the first and second output signals to determine the presence of an RF transmit device in use in the vehicle and to further determine the location of the RF transmit device to determine if a driver is using the device.
1. A system for detecting use and location of a RF transmit device in a vehicle, said system comprising:
a first RF signal receiver located in a vehicle for receiving RF signals at a first location generated by an RF transmit device;
a second RF signal receiver located in the vehicle for receiving RF signals at a second location generated by the RF transmit device;
one or more RF power detectors for detecting signal strength of each of the RF signals received at the first and second locations and generating first and second output signals indicative thereof; and
a signal processor for processing the first and second output signals to determine use of an RF transmit device in use in the vehicle and to further determine location of the RF transmit device in use, wherein the location of the RF transmit device in use is determined based on a comparison of the detected signal strength of the first and second output signals, wherein the vehicle comprises an automobile, and wherein the first location is located generally forward of a driver of the automobile and the second location is located generally rearward of the driver.
2. The system as defined in claim 1 , wherein the signal processor further determines if a driver of the vehicle is using the RF transmit device.
3. The system as defined in claim 2 , wherein the first location is nearer to the driver than the second location.
4. The system as defined in claim 1 , wherein the first RF signal receiver comprises a first receiving antenna covering the first location, and the second RF signal receiver comprises a second receiving antenna covering the second location.
5. The system as defined in claim 4 , wherein the first and second receiving antennas each comprises a patch antenna.
6. The system as defined in claim 4 , wherein the first antenna is located generally forward of the driver and the second antenna is located generally rearward of the driver.
7. The system as defined in claim 1 , wherein the signal processor further determines an intersection between energy patterns of the first and second output signals to determine the location of the RF transmit device in use.
8. The system as defined in claim 1 , wherein the signal processor comprises analog circuitry.
9. The system as defined in claim 1 , wherein the signal processor comprises a digital controller.
10. The system as defined in claim 1 further comprising a third RF signal receiver located in the vehicle for detecting signal strength of the RF signals at a third location and generating a third output signal indicative thereof, wherein the signal processor further processes the third output signal to determine the use and location of an RF transmit device in the vehicle.
11. The system as defined in claim 10 , wherein the RF transmit device comprises a cellular phone.
12. The system as defined in claim 1 , wherein the one or more RF power detectors comprises a first power detector for detecting signal strength of RF signals detected at the first location, and a second RF power detector for detecting signal strength of RF transmit signals at the second location.
13. A system for detecting use and location of an RF transmit device in a vehicle, said system comprising:
a first RF signal power detector located in a vehicle for detecting signal strength of RF transmit signals at a first location and generating a first output signal indicative thereof;
a second RF signal power detector located in the vehicle for detecting signal strength of RF transmit signals and at a second location and generating a second output signal indicative thereof; and
a signal processor for processing the first and second output signals to determine use of an RF transmit device in the vehicle and to further determine location of the RF transmit device in use, wherein the location of the RF transmit device in use is determined based on a comparison of the detected signal strength of the first and second output signals, wherein the vehicle comprises an automobile, and wherein the first location is located generally forward of a driver of the automobile and the second location is located generally rearward of the driver.
14. The system as defined in claim 13 , wherein the first RF signal power detector comprises a first receiving antenna covering the first location and signal strength detection circuitry, and wherein the second RF signal power detector comprises a second receiving antenna covering the second location and signal strength detection circuitry.
15. The system as defined in claim 14 , wherein the first and second receiving antennas each comprise a patch antenna.
16. The system as defined in claim 13 , wherein the signal processor further determines an intersection between energy patterns of the first and second output signals to determine the location of the RF transmit device in use.
17. The system as defined in claim 13 further comprising a third RF signal power detector located in the vehicle for detecting signal strength of the RF transmit signals at a third location and generating a third output signal indicative thereof, wherein the signal processor further processes the third output signal to determine the use and location of an RF transmit device in the vehicle.
18. The system as defined in claim 13 , wherein the RF transmit device comprises a cellular phone.