WHEEL MONITORING SYSTEM

• US 20150377741A1
• Filed: 06/27/2014
• Published: 12/31/2015
• Est. Priority Date: 06/27/2014
• Status: Active Grant

• Current Assignee: Goodrich Corporation (Rtx Corporation)
• Original Assignee: Goodrich Corporation (Rtx Corporation)
• Inventors: Readio, Philip, Summers, Paul L., Stein, Eric
• Granted Patent: US 10,094,742 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60C 23/0413 Wireless charging of active radio frequency circuits
• CPC Class Codes: B60C 23/042 cooperating with wheel hub mounted speed sensors
• CPC Class Codes: B60C 23/043 using transformer type signal transducers, e.g. rotary transformers
• CPC Class Codes: G01M 17/02 Tyres
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer

Abstract

A control unit supplies power and data through a rotary transformer to a sensor assembly disposed on a wheel. The data sent by the control unit to the sensor assembly is produced by modulation of the power signal using frequency shift key or amplitude shift key modulation. The sensor assembly converts the received power signal that power to operate the circuitry and sensor assembly, converts the FSK or ASK data signal, and sends sensor data back to the control unit through the rotary transformer by load modulation. The control unit demodulates the load modulated sensor data.

Claims

1. A system comprising:

a control unit that produces a power signal at a carrier frequency and modulates the power signal to provide control unit data carried by the power signal;

a sensor assembly, powered by the power signal, that senses a parameter associated with a condition of a wheel, demodulates the power signal to derive the control unit data, and modulates the power signal to provide sensor data representative of the sensed parameter to the control unit; and

a rotary transformer connected to the control unit and to the sensor assembly for wirelessly transmitting the power signal and control unit data from the control unit to the sensor assembly and wirelessly transmitting the sensor data from the sensor assembly to the control unit.

2. The system of claim 1, wherein:

the rotary transformer includes a primary tank circuit and a secondary tank circuit;

the control unit includes;

a control digital processor;

a power wave generation circuit controlled by the control unit digital processor that produces the power signal and modulates the power signal based on the control unit data;

the sensor assembly includes;

a sensor for sensing the parameter;

a sensor assembly digital processor for producing sensor data representative of the parameter sensed by the sensor;

a power regulation circuit connected to the secondary tank circuit to provide electric power for the sensor assembly derived from the power signal;

a demodulation circuit electrically connected to the secondary tank circuit for demodulating the power signal to provide the control unit data to the sensor assembly digital processor; and

a load modulation circuit connected to the secondary tank circuit to produce a load modulation signal based on the sensor data.

3. The system of claim 2, wherein the power wave generation circuit modulates the power signal by frequency shift key (FSK) modulation, and the demodulation circuit is a FSK demodulation circuit.

4. The system of claim 3, wherein the power wave generation circuit is configured to modulate the power signal between at least two frequencies, wherein the two frequencies vary from the carrier frequency by an amount that is both greater than an amount necessary for the demodulation circuit to resolve the control unit data from the modulated power signal, and less than an amount needed to maintain a power transmission efficiency of the power signal through the rotary transformer to the power regulation circuit sufficient to provide the electric power required by the sensor assembly.

5. The system of claim 2, wherein the power wave generation circuit modulates the power signal by amplitude shift key (ASK) modulation, and the demodulation circuit is an ASK demodulation circuit.

6. The system of claim 5, wherein the power wave generation circuit is configured to modulate the power signal between at least two voltages, wherein the two voltages vary from each other by an amount that is greater than an amount necessary for the demodulation circuit to resolve the control unit data from the power signal, and the two voltages are greater than a minimum voltage required by the power regulation circuit to provide the electric power required by the sensor assembly.

7. The system of claim 2, wherein the control unit further includes a load demodulation circuit electrically connected to the primary tank circuit for demodulating the sensor data from the load modulation signal and providing the sensor data to the control unit digital processor.

8. The system of claim 2, wherein the sensor is a pressure sensor.

9. The system of claim 7, wherein the pressure sensor is an aircraft tire pressure sensor.

10. A method of simultaneously providing both power and control unit data from a control unit to a sensor assembly, the method comprising:

generating control unit data;

generating a power signal having a carrier frequency;

modulating the power signal according to the control unit data to encode the control unit data in the waveform;

transmitting the power signal across a rotary transformer;

receiving the power signal at the sensor assembly from the rotary transformer;

deriving electric power for the sensor assembly from the power signal; and

demodulating the power signal to derive the control unit data at the sensor assembly.

11. The method of claim 10, wherein modulating the power signal comprises frequency shift key (FSK) modulation, and demodulating the power signal comprises FSK demodulation.

12. The method of claim 10, wherein modulating the power signal comprises amplitude shift key (ASK) modulation and demodulation the power signal comprises ASK demodulation.

13. The method of claim 10 and further comprising:

sensing a parameter;

producing sensor data representative of the parameter sensed;

load modulating the power signal based on the sensor data at the sensor assembly; and

load demodulating the power signal at the control unit to derive the sensor data.