Apparatus for monitoring tire pressure

• US 20060276990A1
• Filed: 06/06/2005
• Published: 12/07/2006
• Est. Priority Date: 06/06/2005
• Status: Active Grant

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Inventors: Abramovitch, Daniel Yves
• Granted Patent: US 7,321,840 B2
• Time in Patent Office: Days
• US Class Current: 702/138
• CPC Class Codes: B60C 23/0408 transmitting the signals by non-mechanical means from the wheel or tyre to a vehicle body mounted receiver

Abstract

A tire monitor and a tire pressure gauge for reading the data from the tire monitor are disclosed. The tire monitor includes an in-tire controller that stores a target inflation pressure representing the pressure to which the tire should be inflated when the tire is at a standard temperature. The tire monitor transmits the target inflation pressure to the external processor when the external processor is connected to the in-tire monitor over a communication link. A sensor array in the tire monitor can provide pressure and temperature readings that are stored in the monitor and used to provide a temperature-compensated fill pressure for the tire. The tire pressure gauge provides the user with a fill pressure to be used in inflating the tire. The tire pressure gauge communicates with the tire monitor and obtains pressure and temperature readings stored in the tire monitor. These reading are used to provide the temperature-compensated fill pressure.

Claims

1. A tire monitor comprising

an in-tire controller that stores a target inflation pressure representing the pressure to which said tire should be inflated when said tire is at a standard temperature;

and

a communication link for coupling said in-tire controller to a processor external to said tire,

wherein said in-tire controller transmits said target inflation pressure to said external processor when said external processor is connected to said in-tire controller.

2. The tire monitor of claim 1 further comprising a temperature sensor that measures a temperature value for air within said tire, wherein said controller communicates said temperature reading to said external processor on said communication link

3. The tire monitor of claim 1 further comprising a sensor array comprising a pressure sensor and a temperature sensor mounted in said tire;

and

a memory that stores sensor readings including said pressure and temperature values generated by said pressure sensor and temperature sensor, respectively,

wherein said in-tire controller causes said temperature and pressure values to be stored in said memory and wherein said in-tire controller transmits said stored pressure and temperature readings to said external processor.

7. The tire monitor of claim 1 wherein said communication link comprises conductors in a valve stern assembly used for inflating said tire, said conductors making physical contact with corresponding conductors in said external processor.

8. The tire monitor of claim 1 wherein said communication link comprises a wireless communication link.

9. The tire monitor of claim 1 wherein said tire monitor has physical dimensions that allow said monitor to be inserted in said tire through a valve stern used for inflating said tire.

4. A tire monitor comprising

an in-tire controller that stores a target inflation pressure representing the pressure to which said tire should be inflated when said tire is at a standard temperature;

and

a communication link for coupling said in-tire controller to a processor external to said tire,

wherein said in-tire controller transmits said target inflation pressure to said external processor when said external processor is connected to said in-tire controller;

a sensor array comprising a pressure sensor and a temperature sensor mounted in said tire; and

a memory that stores sensor readings including said pressure and temperature values generated by said pressure sensor and temperature sensor, respectively,

wherein said in-tire controller causes said temperature and pressure values to be stored in said memory and wherein said in-tire controller transmits said stored pressure and temperature readings to said external processor; and

a motion sensor for generating a motion signal when said tire is moving.

5. The tire monitor of claim 4 wherein a motion value generated from said motion signal is stored in said memory when said temperature and pressure values are stored in said memory.

6. The tire monitor of claim 4 wherein said pressure and temperature values are not stored in said memory when said motion signal is present.

10. A tire pressure gauge comprising:

a communication link for communicating with an in-tire controller on a tire to be filled, said in-tire controller storing a target inflation pressure that is communicated to said tire pressure gauge on said communication link;

a gauge controller for causing said in-tire controller to communicate said target inflation pressure to said tire gauge; and

a display for displaying a fill pressure for said tire that depends on said target inflation pressure.

11. The tire pressure gauge of claim 10 wherein said in-tire controller communicates a temperature reading for said tire and wherein said fill pressure represents an estimate of the pressure needed in said tire such that said tire will be at said target inflation pressure when said tire is at a standard temperature.

12. The tire pressure gauge of claim 11 wherein said tire pressure gauge utilizes a calibration curve that assumes that said tire has a constant volume independent of temperature and pressure changes to arrive at said displayed fill pressure.

13. The tire pressure gauge of claim 11 wherein said in-tire controller provides a plurality of temperature and pressure values for said tire and wherein said tire pressure gauge utilizes said temperature and pressure values to arrive at said displayed fill pressure.

14. The tire pressure gauge of claim 13 wherein said tire pressure gauge generates a tire leak message on said display if said temperature and pressure values indicate that said tire has lost air at a rate greater than a threshold rate during a time period in which said temperature and pressure values were measured.

15. The tire pressure gauge of claim 10 wherein said communication link comprises conductors that connect to corresponding conductors that are part of a valve stem assembly used to inflate said tire.

16. The tire pressure gauge of claim 15 wherein information in said in-tire controller is communicated to said tire pressure gauge over said communication link when said tire pressure gauge is brought into contact with said valve stem assembly.

17. The tire pressure gauge of claim 10 further comprising an air hose connection for connecting said tire pressure gauge to an air hose;

a fill valve controlled by said gauge controller and connected to said air hose connection;

a tire connector connected to said fill valve for connecting said air hose to a valve stem assembly on said tire; and

a manually operated fill input that generates a signal indicating that said tire is to be inflated when actuated.

18. The tire pressure gauge of claim 17 wherein said tire pressure gauge controller causes said fill valve to operate to fill said tire to said fill pressure if said gauge controller detects an in-tire controller on said communication link and a fill signal is present.

19. The tire pressure gauge of claim 17 wherein said gauge controller connects said tire connector to said air hose as long as said fill input is present if said gauge controller does not detect an in-tire controller in said tire.

20. The tire pressure gauge of claim 17 wherein said display displays an air pressure reading for air in said tire connector.

21. A method for providing a fill pressure for a tire mounted on a vehicle, said method comprising:

providing a controller that stores a target inflation pressure representing the pressure to which said tire should be inflated when said tire is at a standard temperature;

reading said target inflation pressure with a tire pressure gauge that is exterior to said tire; and

inflating said tire to a fill pressure that depends on said target inflation pressure.

22. The method of claim 21 wherein said controller is located in said tire.

23. The method of claim 21 further comprising measuring a temperature value for air in said tire, wherein said fill pressure also depends on said temperature value.

24. The method of claim 21 further comprising

measuring a plurality of temperature and pressure readings for air in said tire during the operation of said vehicle;

storing said measured temperature and pressure readings; and

utilizing said stored temperature and pressure readings to provide a relationship between temperature and pressure for air in said tire,

wherein said fill pressure depends on said relationship.

25. The method of claim 24 wherein said measured temperature and pressure readings are stored in a device located in said tire.

26. The method of claim 24 wherein said vehicle comprises a data processing system and wherein said measured temperature and pressure readings are stored in said data processing system.

29. The method of claim 24 further comprising utilizing said stored temperature and pressure readings to detect a leak in said tire.

30. The method of claim 21 further comprising connecting said tire to an air delivery system that determines said fill pressure and automatically inflates said tire to said fill pressure.

27. A method for providing a fill pressure for a tire mounted on a vehicle, said method comprising:

providing a controller that stores a target inflation pressure representing the pressure to which said tire should be inflated when said tire is at a standard temperature;

reading said target inflation pressure with a tire pressure gauge that is exterior to said tire;

inflating said tire to a fill pressure that depends on said target inflation pressure;

measuring a plurality of temperature and pressure readings for air in said tire during the operation of said vehicle;

storing said measured temperature and pressure readings; and

utilizing said stored temperature and pressure readings to provide a relationship between temperature and pressure for air in said tire,

wherein said fill pressure depends on said relationship; and

determining if said vehicle is moving when each of said temperature and pressure readings is measured.

28. A method for providing a fill pressure for a tire mounted on a vehicle, said method comprising:

providing a controller that stores a target inflation pressure representing the pressure to which said tire should be inflated when said tire is at a standard temperature;

reading said target inflation pressure with a tire pressure gauge that is exterior to said tire;

inflating said tire to a fill pressure that depends on said target inflation pressure;

measuring a plurality of temperature and pressure readings for air in said tire during the operation of said vehicle;

storing said measured temperature and pressure readings; and

utilizing said stored temperature and pressure readings to provide a relationship between temperature and pressure for air in said tire

wherein said fill pressure depends on said relationship; and

wherein said relationship is determined only from those temperature and pressure readings that were measured when said vehicle was not moving.