Tire sensor localization utilizing speed corrected frequency

• US 20040004556A1
• Filed: 05/08/2003
• Published: 01/08/2004
• Est. Priority Date: 07/03/2002
• Status: Active Grant

• Current Assignee: Siemens VDO Automotive Corporation (Siemens AG)
• Original Assignee: Siemens VDO Automotive Corporation (Siemens AG)
• Inventors: Desai, Tejas B.
• Granted Patent: US 6,972,672 B2
• Time in Patent Office: Days
• US Class Current: 340/870.07
• CPC Class Codes: B60C 23/0416 allocating a corresponding wheel position on vehicle, e.g. front/left or rear/right
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol

Abstract

A method of localizing the location of a received signal from a tire pressure sensor includes sending an AM identification signal. The AM signal is adjusted for speed such that the frequency of the signal equals a constant multiplied by the speed of the vehicle. Each of the tire locations on a vehicle have an expected sequence of black-out points in the signal received by a receiver at any point on the vehicle. That is, given a particular vehicle design, the AM signal described above would be received at a receiver with an expected sequence of received peaks and black-out points. Since the frequency of the signal is adjusted for speed, the received signal will accurately allow the location of black-out points to be utilized to identify the tire location for a particular signal.

Claims

1. A tire pressure monitoring system comprising:

a plurality of tire pressure sensor and transmitter;

a receiver and control for receiving signals transmitted by each of said tire pressure sensor/transmitters;

said tire pressure sensor/transmitters including the ability to send an identification signal; and

a control associate with said sensor/transmitters monitoring vehicle speed, and adjusting the frequency of transmission of said identification signal to be dependent upon said detected vehicle speed.

2. A system as set forth in claim 1, wherein said identification signal is an AM signal which has a frequency equal to some constant multiplied by said detected speed.

3. A system as set forth in claim 1, wherein said identification signal is only sent when the vehicle has been stopped for a predetermined period of time.

4. A system as set forth in claim 3, wherein said identification signal is only transmitted for a predetermined number of revolutions of the tire after beginning transmission.

5. A system as set forth in claim 1, wherein said identification signal includes an identifying code, and said tire pressure sensor/transmitters further periodically sending tire pressure signals also including said identifying code.

6. A method of localizing a received signal from a vehicle comprising the steps:

(1) identifying an expected sequence of black-outs in a received signal from each of four tire locations on a vehicle, and storing said expected sequence in a control;

(2) operating a vehicle and transmitting identification signals from each of said at least four tire locations on a vehicle, and receiving signals from each of said four tire locations, and identifying the sequence of black-outs in each of said four identified signals, said transmitting of said identification signal including the adjustment of the frequency of said transmission of said identification signal being based upon a detected vehicle speed; and

(3) comparing said sequence of black-out points in said received signals to said expected sequence of black-outs, and identifying a tire location for any of said sequence of said received signals which matches an expected sequence of said signals.

7. A method as set forth in claim 6, wherein said transmitted signals further include an identifier code, and said identifier code being stored in said control, said subsequent signals being identified for a particular tire location without any need for the comparison of Step (3).

8. A method as set forth in claim 6, wherein said adjustment of said frequency of transmission of said identification signal including making said frequency proportional to vehicle speed such that increasing vehicle speed results in increasing frequency of transmission of said identification signal.