Pneumatic tire monitor

• US 6,518,877 B1
• Filed: 05/31/2001
• Issued: 02/11/2003
• Est. Priority Date: 05/31/2001
• Status: Expired due to Term

• Current Assignee: Goodyear Tire & Rubber Company
• Original Assignee: Goodyear Tire & Rubber Company
• Inventors: Desimone, Joseph Paul II, Letkomiller, Joseph Michael, Yones, Dale Lee, Starkey, Gene Raymond
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/870,569
• Time in Patent Office: 621 Days
• Field of Search: 340/447, 340/445, 340/446, 340/442, 731/462, 731/468
• US Class Current: 340/447
• CPC Class Codes: B60C 23/004 the control being done on the wheel, e.g. using a wheel-mounted reservoir
• CPC Class Codes: B60C 23/0433 Radio signals
• CPC Class Codes: B60C 23/127 the pumps being mounted on the hubs
• CPC Class Codes: B60C 23/131 activated by force of gravity
• CPC Class Codes: H01Q 1/2241 used in or for vehicle tyres

Abstract

A pneumatic tire monitoring system for monitoring pneumatic tire conditions for one or more tire/wheel assemblies mounted on a vehicle, preferably in combination with a tire pressurizing and regulating apparatus, comprises a transponder with a transmitting antenna mounted on the wheel for transmitting a signal indicating tire condition, one or more receivers with receiving antennas fixedly mounted on the vehicle, and circuitry for processing the received signals; the system characterized in that: circuitry for each transponder is on a printed circuit board within a protective housing coaxial to the hub of the wheel or wheel carrier; and each transmitting antenna is selected from the group comprising a partial loop antenna, a helical antenna, a circular dipole antenna, and a small coupling coil adjacent to an endless hoop antenna. The partial loop antenna is mounted in each housing affixed around a portion of the circumference of the printed circuit board, having an angular arc length, and comprises a serpentine portion for increasing the effective length of the partial loop antenna without also extending the angular arc length. The angular arc length and the affixed placement are determined for avoiding RF signal interference due to interaction with signal-interfering objects in the housing. Additionally, the partial loop antenna has an end portion that can be trimmed for adjusting the effective length to enable tuning of the antenna for optimum transmission at different radio transmission frequencies.

Claims

1. A system for monitoring pneumatic tire conditions for one or more tire/wheel assemblies mounted on a vehicle;

each tire/wheel assembly comprising a tire mounted on a wheel or wheel carrier; and

the system comprising;

a transponder with a transmitting antenna mounted on the wheel or wheel carrier of the one or more tire/wheel assemblies for transmitting a signal indicating the condition of the tire of the one or more tire/wheel assemblies, one or more receivers each having one or more receiving antennas fixedly mounted on the vehicle, and circuitry for processing the signals received by the one or more receiving antennas to determine the condition of the tire of the one or more tire/wheel assemblies;

the system characterized in that;

circuitry for each transponder is disposed on a printed circuit board within a protective housing coaxial to the hub of the wheel or wheel carrier; and

each transmitting antenna is selected from the group consisting of a partial loop antenna, a helical antenna, a circular dipole antenna, and a small coupling coil adjacent to an endless hoop antenna.

2. A system, according to claim 1, characterized in that:

the transmitting antenna is a partial loop antenna;

the partial loop antenna is affixed on a surface of the printed circuit board around a portion of the circumference of the printed circuit board, and has an angular arc length; and

the partial loop antenna comprises a serpentine portion for increasing the effective length of the partial loop antenna without also extending the angular arc length.

3. A system, according to claim 2, characterized in that:

the transponder comprises one or more RF transmission-interfering objects; and

the angular arc length and the affixed placement of the partial loop antenna are determined for avoiding interference.

4. A system, according to claim 2, characterized in that:

the partial loop antenna comprises an end portion adjacent to a trimming scale imprinted on the printed circuit board, for indicating locations for trimming the end portion as a guide to proper antenna trimming.

5. A system, according to claim 2, characterized by:

means for trimming the partial loop antenna end portion to enable tuning of the antenna for optimum transmission at different radio transmission frequencies.

6. A system, according to claim 1, characterized in that:

the system comprises a pump system mounted on the wheel or wheel carrier of the one or more tire/wheel assemblies for tire pressure regulation; and

a tire pressure sensor connected to the wheel or wheel carrier transponder for measuring the tire pressure.

7. A system, according to claim 1, characterized in that:

the transmitted signal comprises a message packet short enough to transmit within less than one revolution period of the wheel or wheel carrier when the vehicle is moving at its fastest expected speed.

8. A system, according to claim 7, characterized in that:

the message packet begins with a 10 bit sync pattern which is not further encoded; and

the remainder of the message packet comprises data bits ending with an 8 bit CRC, wherein the remainder is encoded by a 4B/5B coding scheme using straight NRZI for bit determination.

9. A system for monitoring automatic tire pressure maintenance for one or more tires of a vehicle, wherein a pump system in a housing attached to each of one or more wheels or wheel carriers of the vehicle is utilized to automatically maintain a setpoint pressure in a pneumatic tire mounted on the wheel or wheel carrier, the system characterized by:

a transponder mounted in the housing with the pump system, wherein circuitry for the transponder is on a printed circuit board within the housing and coaxial to the hub of the wheel or wheel carrier;

a transmitting antenna associated with the transponder;

a receiver mounted on the vehicle;

a receiving antenna associated with the receiver;

a tire pressure sensor connected to the transponder; and

a control circuit associated with the transponder for measuring the tire pressure using the tire pressure sensor, for converting the tire pressure measurement to an RF signal, and for transmitting the RF signal to the receiving antenna and receiver using the transmitting antenna.

10. A system, according to claim 9, characterized in that:

the transmitting antenna is selected from the group consisting of a partial loop antenna, a helical antenna, a circular dipole antenna, and a small coupling coil adjacent to an endless hoop antenna.

11. A system, according to claim 10, characterized in that:

the transmitting antenna is a partial loop antenna;

the partial loop antenna is affixed on a surface of the printed circuit board around a portion of the circumference of the printed circuit board, and has an angular arc length; and

the partial loop antenna comprises a serpentine portion for increasing the effective length of the partial loop antenna without also extending the angular arc length.

12. A system, according to claim 11, characterized in that:

the system comprises one or more RF transmission-interfering objects contained in the housing; and

the angular arc length and the affixed placement of the partial loop antenna are determined for avoiding interference.

13. A system, according to claim 11, characterized in that:

the transmitted signal comprises a message packet short enough to transmit within less than one revolution period of the wheel or wheel carrier when the vehicle is moving at its fastest expected speed.

14. A system, according to claim 13, characterized in that:

the message packet begins with a 10 bit sync pattern which is not further encoded; and

the remainder of the message packet comprises data bits ending with an 8 bit CRC, wherein the remainder is encoded by a 4B/5B coding scheme using straight NRZI for bit determination.

15. A system, according to claim 9, characterized in that:

the pump system comprises a pendulum;

the transponder circuitry comprises one or more coils for interacting with the pendulum to determine a revolution angular position or a revolution count; and

the control circuit includes the revolution count in the transmitted RF signal.

16. A system, according to claim 9, characterized in that:

a temperature sensor is connected to the transponder for measuring temperature; and

the control circuit transmits an RF signal which includes the measured temperature.

17. A system, according to claim 9, characterized in that:

the receiver is a single unit; and

a display is associated with the receiver for informing a vehicle operator about tire pressure maintenance for each of the one or more tires.

18. A system, according to claim 17, characterized in that:

the receiving antenna is a single antenna; and

the control circuit associated with the transponder on each of the one or more wheels or wheel carriers of the vehicle includes a unique transponder identifying code in the transponder'"'"'s RF signal.

19. A pneumatic tire condition monitor in combination with a tire pressurizing and regulating apparatus for one or more tires of a vehicle, wherein the apparatus is in a housing attached to each of one or more wheels or wheel carriers of the vehicle, the monitor characterized by:

a partial loop antenna mounted in each housing with the apparatus, affixed on a printed circuit board which is coaxial to the hub of the wheel or wheel carrier;

the partial loop antenna is affixed around a portion of the circumference of the printed circuit board, having an angular arc length;

the partial loop antenna comprises a serpentine portion for increasing the effective length of the partial loop antenna without also extending the angular arc length; and

the angular arc length and the affixed placement of the partial loop antenna are determined for avoiding RF signal interference due to interaction with signal-interfering objects in the housing.

20. A pneumatic tire condition monitor according to claim 19, characterized in that:

the partial loop antenna has an end portion which is trimmed for adjusting the effective length to enable tuning of the antenna for optimum transmission at different radio transmission frequencies.