System and method for improving received signal strength for an in-vehicle wireless communication system

• US 20070052527A1
• Filed: 08/23/2005
• Published: 03/08/2007
• Est. Priority Date: 08/23/2005
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Hsu, Hui-Pin, Song, Hyok, Wiese, Richard
• Granted Patent: US 7,382,239 B2
• Time in Patent Office: Days
• US Class Current: 340/445
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/0444 Antenna structures, control or arrangements thereof, e.g. for directional antennas, diversity antenna, antenna multiplexing or antennas integrated in fenders
• CPC Class Codes: B60C 23/0483 Wireless routers between wheel mounted transmitters and chassis mounted receivers

Abstract

An onboard wireless communication system for a vehicle, such as a tire pressure monitoring system (“TPMS”) is disclosed. The TPMS includes wheel-mounted radio frequency (“RF“) sensor/transmitters that transmit RF signals conveying tire pressure information, at least one RF relay element, and an RF receiver coupled to a TPMS processor. The RF relay element(s) relay the RF signals from the sensor/transmitters to the RF receiver to reduce the negative effect of electromagnetic field scattering caused by conductive parts of the vehicle.

Claims

1. A radio frequency (“

RF”

) communication system for a vehicle, said system comprising;

an RF receiver configured to receive RF signals for processing by an onboard vehicle system;

an RF transmitter configured to transmit an RF signal intended for said RF receiver, said RF signal being susceptible to electromagnetic field scattering caused by the vehicle; and

an RF relay element located proximate to said RF transmitter, said RF relay element being configured to reduce signal strength loss of said RF signal, said signal strength loss resulting from electromagnetic field scattering caused by the vehicle.

2. A system according to claim 1, said RF receiver being an onboard RF receiver, said RF transmitter being an onboard RF transmitter, and said RF relay element being an onboard RF relay element.

3. A system according to claim 1, said RF relay element comprising an RF antenna tuned according to a frequency of said RF signal.

4. A system according to claim 1, said RF relay element comprising a resonant slot tuned according to a frequency of said RF signal.

5. A system according to claim 4, said resonant slot being formed in a conductive metal panel of the vehicle.

6. A system according to claim 1, said RF relay element comprising a passive component.

7. A system according to claim 1, said RF relay element being tuned according to RF characteristics of the vehicle.

8. A system according to claim 1, said RF transmitter comprising a wheel-mounted tire pressure sensor/transmitter, and said onboard vehicle system comprising a tire pressure monitoring system.

9. An onboard tire pressure monitoring system (“

TPMS”

) for a vehicle, said TPMS comprising;

a wheel-mounted tire pressure sensor/transmitter configured to transmit a radio frequency (“

RF”

) signal that conveys tire pressure information, said RF signal being susceptible to electromagnetic field scattering caused by the vehicle; and

an onboard RF relay element located proximate to said wheel-mounted tire pressure sensor/transmitter, said onboard RF relay element being configured to reduce signal strength loss of said RF signal, said signal strength loss resulting from electromagnetic field scattering caused by the vehicle.

10. A TPMS according to claim 9, further comprising:

an onboard RF receiver configured to receive said RF signal; and

an onboard TPMS processor coupled to said onboard RF receiver, said onboard TMPS processor being configured to process tire pressure information conveyed in said RF signal.

11. A TPMS according to claim 9, said onboard RF relay element comprising an RF antenna tuned according to a frequency of said RF signal.

12. A TPMS according to claim 9, said onboard RF relay element comprising a resonant slot tuned according to a frequency of said RF signal.

13. A TPMS according to claim 12, said resonant slot being formed in a conductive metal panel of the vehicle.

14. A TPMS according to claim 9, said onboard RF relay element comprising a passive component.

15. A TPMS according to claim 9, said onboard RF relay element being tuned according to RF characteristics of the vehicle.

16. A TPMS according to claim 9, wherein:

said wheel-mounted tire pressure sensor/transmitter is mounted on a first wheel of the vehicle;

said TPMS further comprises a second wheel-mounted tire pressure sensor/transmitter mounted on a second wheel of the vehicle, said second wheel-mounted tire pressure sensor/transmitter being configured to transmit a second RF signal that conveys tire pressure information, said second RF signal being susceptible to electromagnetic field scattering caused by the vehicle; and

said onboard RF relay element is configured to relay said RF signal transmitted by said wheel-mounted tire pressure sensor/transmitter, and to relay said second RF signal transmitted by said second wheel-mounted tire pressure sensor/transmitter.

17. A TPMS according to claim 9, wherein:

said wheel-mounted tire pressure sensor/transmitter is mounted on a first wheel of the vehicle;

said TPMS further comprises;

a second wheel-mounted tire pressure sensor/transmitter mounted on a second wheel of the vehicle, said second wheel-mounted tire pressure sensor/transmitter being configured to transmit a second RF signal that conveys tire pressure information, said second RF signal being susceptible to electromagnetic field scattering caused by the vehicle; and

a second onboard RF relay element located proximate to said second wheel-mounted tire pressure sensor/transmitter, said second onboard RF relay element being configured to reduce signal strength loss of said second RF signal;

said onboard RF relay element is configured to relay said RF signal transmitted by said wheel-mounted tire pressure sensor/transmitter; and

said second onboard RF relay element is configured to relay said second RF signal transmitted by said second wheel-mounted tire pressure sensor/transmitter.

18. An onboard wireless communication method for a vehicle, said method comprising:

transmitting a wireless signal that conveys information for processing by an onboard vehicle system, said wireless signal being susceptible to electromagnetic field scattering caused by the vehicle;

passively relaying said wireless signal to provide a relayed wireless signal in a manner that reduces signal strength loss of said relayed wireless signal, said signal strength loss resulting from said electromagnetic field scattering; and

receiving said relayed wireless signal.

19. A method according to claim 18, wherein:

said onboard vehicle system comprises a tire pressure monitoring system; and

said wireless signal conveys tire pressure information.

20. A method according to claim 19, wherein:

said transmitting step is performed for a plurality of wireless signals generated by a like plurality of wheel-mounted tire pressure sensor/transmitters; and

said passively relaying step is performed for said plurality of wireless signals.