Tire pressure monitoring system transmission protocol

• US 7,453,350 B2
• Filed: 06/20/2006
• Issued: 11/18/2008
• Est. Priority Date: 11/15/2001
• Status: Expired due to Fees

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Continental Automotive Systems US Incorporated (Continental AG)
• Inventors: Desai, Tejas B., Kachouh, Patricia, VanDrus, Kurt
• Primary Examiner(s): GOINS, DAVETTA WOODS
• Application Number:
  US11/471,386
• Publication Number:
  US 20060238324A1
• Time in Patent Office: 882 Days
• Field of Search: 340/442, 340/447, 340/5.6, 340/5.61, 340/10.1, 340/10.2, 340/10.5, 340/5.64, 340/825.58, 340/825.69, 731/462
• 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 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 from a first transmitter;

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

d. transmitting a fsk signal indicative of temperature within the tire from the first transmitter,

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; and

f. receiving one of a frequency shift keyed (FSK) identification code, an FSK signal indicative of pressure within a tire, and an FSK signal indicative of a temperature within a tire from a second transmitter within the time interval between portions of any of the FSK signals from the first transmitter.

2. The method of claim 1, 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.

3. The method of claim 2, wherein said time interval varies in response to vehicle operating parameters.

4. The method of claim 3, 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.

5. The method of claim 4, wherein said frequency of said transmissions are decreased in response to a vehicle not moving for a set period.

6. The method of claim 5, wherein said frequency of said transmissions varies according to vehicle speed.