Tire pressure monitoring apparatus and method

• US 20020190852A1
• Filed: 06/14/2001
• Published: 12/19/2002
• Est. Priority Date: 06/14/2001
• Status: Abandoned Application

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Lin, Xing Ping
• Application Number:
  US09/881,155
• Publication Number:
  US 20020190852A1
• Time in Patent Office: Days
• US Class Current: 340/445
• 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 23/0433 Radio signals
• CPC Class Codes: B60C 23/0462 Structure of transmission protocol

Abstract

An apparatus (24) and an associated method provide for monitoring of a condition of a tire (18) of a vehicle (12). A transmitter (34) is rotatable with the tire (18) and is operable to transmit a signal indicative of the tire condition. Amplitude variation is induced in the signal during rotation of the transmitter (34) with the tire (18). A receiver (28) is located at the vehicle (12) and is operable to receive the signal from the transmitter (34). The receiver (28) has circuitry (80) that compensates for the induced amplitude variation.

Claims

1. An apparatus for monitoring a condition of a tire of a vehicle, said apparatus including:

a transmitter rotatable with the tire and operable to transmit a signal indicative of the tire condition, amplitude variation being induced in the signal during rotation of said transmitter with the tire; and

a receiver located at the vehicle and operable to receive the signal from said transmitter, said receiver having circuitry that compensates for the induced amplitude variation.

2. An apparatus as set forth in claim 1 wherein said circuitry includes a limiter that reduces the maximum magnitude of the amplitude of the received signal.

3. An apparatus as set forth in claim 1 wherein said circuitry includes a portion effective to amplify a portion of the received signal having a maximum magnitude that is less than a predetermined magnitude and effective to compress a portion of the received signal having a maximum magnitude that is greater than a predetermined magnitude.

4. An apparatus as set forth in claim 1 wherein said circuitry includes a diode through that the received signal is conducted to limit the amplitude of the signal to a predetermined maximum amplitude that is less than the maximum amplitude of the received signal.

5. An apparatus as set forth in claim 1 wherein said circuitry includes a first circuit component through which a first portion of the received signal having a magnitude greater than a predetermined value is conducted to decrease the magnitude of the first portion and a second circuit component through which a second portion of the received signal having a magnitude less than a predetermined value is conducted to increase the magnitude of the second portion.

6. An apparatus as set forth in claim 1 wherein the received signal includes pulses, said receiver includes a portion that provides a reference signal that varies as a function of variation in amplitude in the received signal and that detects when portions of pulses in the received signal have a magnitude that is greater than the reference signal and a magnitude that is less than the reference signal, said circuitry that compensates for the induced amplitude variation being effective to reduce variation in the reference signal.

7. A method of monitoring a condition of a tire of a vehicle, said method including:

transmitting a signal indicative of the tire condition from a transmitter at the tire;

rotating the transmitter with the tire, amplitude variation being induced in the signal during rotation of the transmitter with the tire;

receiving the signal from the transmitter at a receiver located at the vehicle; and

compensating for the induced amplitude variation in the received signal.

8. A method as set forth in claim 7 wherein said step of compensating includes passing the received signal through a limiter arrangement that reduces the maximum magnitude of the amplitude of the received signal.

9. A method as set forth in claim 7 wherein said step of compensating includes amplifying a portion of the received signal having a maximum magnitude that is less than a predetermined magnitude and compressing a portion of the received signal having a maximum magnitude that is greater than a predetermined magnitude.

10. A method as set forth in claim 7 wherein said step of compensating includes passing the received signal through a diode to limit the amplitude of the signal to a predetermined maximum amplitude that is less than the maximum amplitude of the received signal.