Tire pressure monitoring system transmission protocol

• US 20060238324A1
• Filed: 06/20/2006
• Published: 10/26/2006
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Seimens VDO Automotive Corporation
• Inventors: Kachouh, Patricia, Desai, Tejas B., VanDrus, Kurt
• Granted Patent: US 7,453,350 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 23/0462 Structure of transmission protocol
• CPC Class Codes: B60C 23/0464 to avoid signal interference

Abstract

A system for monitoring conditions within a tire includes a sensor assemblies (14). The sensor assemblies (14) emit a transmission (26) containing information indicative of conditions within a tire to a receiver (16). The transmission (26) from the sensor assemblies (14) includes an amplitude shift key wake up portion and various data packet portions. The data packet portions are separated by a variable interval to prevent collisions of transmissions at the receiver.

Claims

1. A system for monitoring conditions within a tire comprising;

a sensor disposed within a tire for sensing conditions within said tire;

a transmitter for transmitting a signal indicative of conditions within said tire; and

a receiver for receiving said signal, said signal indicative of conditions within a tire includes a first preamble portion and a plurality of data packets separated by a corresponding plurality of varying time intervals.

2. The system of claim 1, wherein said preamble portion includes an Amplitude Shift Keyed wake up signal.

3. The system of claim 1, wherein said plurality of data packets are transmitted in Frequency Shift Keyed format.

4. The system of claim 1, wherein each of said plurality of data packets includes a time interval value indicating when transmission of a subsequent one of said plurality of data packets will occur.

5. The system of claim 1, wherein said plurality of data packets include a data preamble including 15 data zero bits and one start bit having a data value of “

1”

.

6. The system of claim 1, wherein said signal indicative of tire conditions is initiated at predetermined intervals.

7. The system of claim 6, wherein said signal indicative of tire conditions is initiated at intervals shorter than said predetermined intervals in response to a desired rate of change of any conditions monitored within the tire.

8. The system of claim 1, wherein said time interval between said plurality of data packets is variable.

9. The system of claim 8, wherein said variable time interval varies between 100 milliseconds and 200 milliseconds.

10. The system of claim 1, including transmitting said signal at predetermined intervals in response to movement of the motor vehicle.

11. The system of claim 1, including increasing the duration between transmissions of signals in response to the motor vehicle decreasing in speed below a predetermined speed.

12. The system of claim 1, including a receiver for receiving ASK signals and FSK signals.

13. The system of claim 12, wherein said receiver defaults to receiving ASK signals.

14. The system of claim 13, wherein said receiver receives ASK signals from a remote keyless entry system.

15. A method of transmitting information indicative of conditions within a tire comprising the steps of:

a. transmitting a signal including an amplitude shift keyed transmission preamble to a receiver;

b. transmitting a frequency shift keyed (FSK) identification code;

c. transmitting a fsk signal indicative of pressure within the tire;

d. transmitting a fsk signal indicative of temperature within the tire, and

e. varying a time interval between portions of said identification code, said signal indicative of pressure within the tire, and said signal indicative of temperature within the tire.

16. The method of claim 15, wherein said step of varying said time interval includes transmitting a length of the interval to a receiver such that the receiver prepares to receive a next data packet at the communicated time interval.

17. The method of claim 16, wherein said time interval varies in response to vehicle operating parameters.

18. The method of claim 17, wherein said operating parameter includes vehicle speed, and a frequency of said transmissions are increased in response to an indication of pressure loss at a pre-selected rate.

19. The method of claim 18, wherein said frequency of said transmissions are decreased in response to a vehicle not moving for a set period.

20. The method of claim 19, wherein said frequency of said transmissions varies according to vehicle speed.