Tire pressure monitoring system transmission protocol

• US 20030122660A1
• Filed: 11/15/2002
• Published: 07/03/2003
• Est. Priority Date: 11/15/2001
• Status: Active Grant

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Siemens VDO Automotive Corporation (Siemens AG)
• Inventors: Kachouh, Patricia, Desai, Tejas B., VanDrus, Kurt
• Granted Patent: US 7,095,316 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

21. The system of claim 21, wherein said wake up status codes indicates a status of said sensor, said status includes learn, Normal, Over temp, Wake and LF.

24-1. The system of claim 24, wherein said receiver defaults to receiving ASK signals.

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

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

b. transmitting a frequency shift keyed identification code;

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

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

27. The method of claim 26, including a time interval between each of said data transmissions.

28. The method of claim 27, further including the step of varying said time interval to prevent repeated data collisions.

29. The method of claim 26, including the step of transmitting said transmission at a predetermined frequency.

30. The method of claim 29, wherein said predetermined frequency varies in response to vehicle operating parameters.

31. The method of claim 30, wherein said operating parameter includes vehicle speed, and said frequency of said transmissions are increased in response to an indication of pressure loss at a pre-selected rate.

32. The method of claim 30, wherein said frequency of said transmissions are decreased in response to a vehicle not moving for a set period.

33. The method of claim 30, wherein said frequency of said transmissions varies according to vehicle speed.