Magnetic transmitter and receiver for a tire pressure monitoring system

• US 20070080794A1
• Filed: 09/28/2005
• Published: 04/12/2007
• Est. Priority Date: 09/28/2005
• Status: Active Grant

• Current Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Original Assignee: Honda Motor Co., Ltd. (Honda Motor Company)
• Inventors: Thiele, Steven
• Granted Patent: US 7,312,698 B2
• Time in Patent Office: Days
• US Class Current: 340/442
• 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 23/0425 Means comprising permanent magnets, e.g. Hall-effect or Reed-switches

Abstract

A vehicle tire pressure monitoring system and method is provided, the system including a tire pressure transducer affixed to either the tire or wheel of a vehicle. An electromagnet system is in electrical communication with the tire pressure transducer, the electromagnet system configured to generate pulses and transfer a single bit of data to a sensor system on the vehicle body upon each revolution of the tire or wheel. The sensor system in turn transfers the received bits to an electronic control unit wherein the code is converted into a read out for the vehicle operator. One or more bits within the code may be redundant checking bits or bits representing the status of the pressure transducer or electromagnet system.

Claims

1. A vehicle tire pressure monitoring system comprising:

a tire pressure transducer;

an electromagnet system supported on a vehicle wheel or tire in electrical communication with the tire pressure transducer, the electromagnet system configured to periodically send single bits of a code representing a tire pressure measured by the transducer;

a sensor system supported by the vehicle body configured to receive individually the single bits of the code periodically sent from the electromagnetic system; and

an electronic control unit that receives the code from the sensor system and converts the code into pressure information.

2. The vehicle tire pressure monitoring system of claim 1, wherein only one bit of the code representing the tire pressure measured by the transducer is received by the sensor system upon each revolution of the vehicle wheel or tire.

3. The vehicle tire pressure monitoring system of claim 1, further including a central processing unit that takes an electrical signal generated by the tire pressure transducer and converts the signal into at least a seven bit code.

4. The vehicle tire pressure monitoring system of claim 1, wherein the code is an eight bit code wherein one bit of the eight bit code indicates whether a measured tire pressure is represented by the other seven bits.

5. The vehicle tire pressure monitoring system of claim 1, wherein the electromagnet system comprises a magnet sensor, permanent magnet and electromagnet and the sensor system comprises a magnet sensor and permanent magnet and wherein:

the sensor system permanent magnet signals the electromagnet system magnet sensor to initiate the electromagnet system to send a pulse representing a single bit of code within a fixed a period of time;

the electromagnet system permanent magnet signals the sensor system magnet sensor to prepare to receive the pulse within the fixed period of time; and

the sensor system magnet sensor receives the pulse that is either a magnetic signal during the fixed period of time or a lack of a magnetic signal during the fixed period of time from the electromagnet within the electromagnet system.

6. The vehicle tire pressure monitoring system of claim 5, wherein only one bit of the code representing the tire pressure measured by the transducer is received by the sensor system upon each revolution of the vehicle wheel or tire.

7. The vehicle tire pressure monitoring system of claim 5, further including a central processing unit that takes an electrical signal generated by the tire pressure transducer and converts the signal into a seven bit code.

8. The vehicle tire pressure monitoring system of claim 5, wherein the electromagnet system further includes a second electromagnet and wherein the sensor system permanent magnet additionally signals the electromagnet system magnet sensor to initiate the second electromagnet to send a second pulse representing a single bit of code from the second electromagnet within a second fixed period of time.

9. The vehicle tire pressure monitoring system of claim 8, wherein both bits of the code representing the tire pressure measured by the transducer are received sequentially by the sensor system upon a single revolution of the vehicle wheel or tire.

10. The vehicle tire pressure monitoring system of claim 5, wherein the electromagnet system further includes a second magnet sensor, second permanent magnet and second electromagnet and wherein the sensor system permanent magnet additionally signals the electromagnet system second magnet sensor to initiate the second electromagnet to send a second pulse representing a single bit of code from the second electromagnet within a second fixed period of time and the electromagnet system second permanent magnet signals the sensor system magnet sensor to prepare to receive a second pulse within a second fixed period of time.

11. The vehicle tire pressure monitoring system of claim 10, wherein both bits of the code representing the tire pressure measured by the transducer are received by the sensor system upon a single revolution of the vehicle wheel or tire.

12. The vehicle tire pressure monitoring system of claim 1, further including a display upon which pressure information from the electronic control unit is shown to the vehicle operator.

13. A vehicle tire pressure monitoring system comprising:

a tire pressure transducer;

an electromagnet system supported on a vehicle wheel or tire in electrical communication with the tire pressure transducer, the electromagnet system configured to periodically send single bits of a code representing a tire pressure measured by the transducer or operational status of the monitoring system;

a sensor system supported by the vehicle body configured to receive individually the single bits of code periodically sent from the electromagnetic system; and

an electronic control unit that receives the code from the sensor system and converts the code into pressure information or status information.

14. The vehicle tire pressure monitoring system of claim 13, wherein the code is an eight bit code wherein one bit of the eight bit code indicates either a measured tire pressure is represented by the other seven bits or the operational status of the monitoring system is represented by the other seven bits.

15. The vehicle tire pressure monitoring system of claim 13, further including a central processing unit that produces a seven bit code representative of the operational status of the tire pressure monitoring system.

16. A method of monitoring vehicle tire pressure comprising the following steps:

(a) measuring tire pressure;

(b) transferring a single bit of data representing a portion of the measured tire pressure to a sensor system on a vehicle body from an electromagnet system on a wheel or tire;

(c) repeating steps (a) and (b) until a plurality of data bits, which is representative of the pressure within the vehicle tire, is received by the sensor system; and

(d) transferring the plurality of bits from the sensor system to a vehicle electronic control unit.

17. The method of monitoring vehicle tire pressure of claim 16, wherein step (b) occurs only once upon each revolution of the wheel or tire of the vehicle.

18. The method of monitoring vehicle tire pressure of claim 17, wherein steps (a) and (b) are repeated eight times before step (d) is executed.

19. The method of claim 16, including the steps of

(e) converting the bit code received from the pulse sensor into pressure information;

and repeating steps (a) through (d) at least ten times and generating an indication that a blow out or other catastrophic failure has occurred if the magnitude of the pressure information recorded drops more than fifty percent over a series of ten measurements.

20. The method of claim 19, further including the steps of checking the tire pressure information against reference pressure values representative of normally inflated tires and generating a warning signal if the measured values differ from the reference pressure values.