METHOD AND SYSTEM FOR WIRELESS COMMUNICATIONS IN A WAVEGUIDE ENVIRONMENT

• US 20120242454A1
• Filed: 03/21/2011
• Published: 09/27/2012
• Est. Priority Date: 03/21/2011
• Status: Active Grant

• Current Assignee: GE Aviation Systems LLC (GE Aerospace)
• Original Assignee: GE Aviation Systems LLC (GE Aerospace)
• Inventors: Wyler, John Stephen
• Granted Patent: US 8,816,822 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: H04B 17/0085 using test signal generators
• CPC Class Codes: H04B 17/102 Power radiated at antenna
• CPC Class Codes: H04B 17/14 of the whole transmission and reception path, e.g. self-test loop-back
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04Q 2209/886 using energy harvesting, e.g. solar, wind or mechanical
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A system and method of transmitting sensor signals in a waveguide environment are provided. A sensor assembly is configured to wirelessly receive a sensor interrogation signal, determine an input power level of the sensor interrogation signal, and transmit a message including the determined power level. The system also includes a sensor controller configured to transmit a sensor interrogation signal determine an output power of the transmitted sensor interrogation signal at a plurality of frequencies, receive an indication of the received input power level of the sensor interrogation signal from the sensor assembly at the plurality of frequencies, compare the transmitted output power of the sensor interrogation signal to the received power indication, and select a transmit frequency for transmitting messages between the senor assembly and the sensor controller based on the comparison.

Claims

1. A wireless sensor system comprising:

a sensor assembly comprising a radio frequency transceiver configured to wirelessly receive a sensor interrogation signal, said sensor assembly configured to determine an input power level of the sensor interrogation signal and transmit a message including the determined power level; and

a sensor controller comprising a radio frequency transceiver configured to transmit a sensor interrogation signal at a first frequency and at a second frequency, the second frequency different than the first frequency, said sensor controller comprising a processor and a memory programmed with instructions that cause the sensor controller to;

transmit a sensor interrogation signal into an aircraft fuselage at a frequency that varies over time;

determine an output power of the transmitted sensor interrogation signal at a plurality of frequencies;

receive an indication of the received input power level of the sensor interrogation signal from the sensor assembly at the plurality of frequencies;

compare the transmitted output power of the sensor interrogation signal to the received power indication; and

select a transmit frequency for transmitting messages between said senor assembly and said sensor controller based on the comparison.

2. A system in accordance with claim 1, wherein said wireless sensor system comprises a plurality of sensor assemblies located remotely from said sensor controller and each other, each of said plurality of sensor assemblies configured to transmit messages to said sensor controller on a frequency at which a power ratio of the input power level of the sensor interrogation signal measured by that sensor assembly and the transmitted output power is greater than the power ratio determined at the others of the plurality of frequencies.

3. A system in accordance with claim 2, wherein said plurality of sensor assemblies each determine their respective frequency of transmission independent of said sensor controller and each other, each of said plurality of sensor assemblies configured to transmit messages to said sensor controller on the determined frequency.

4. A system in accordance with claim 1, wherein said sensor controller periodically determines the transmit frequency.

5. A system in accordance with claim 1, wherein said sensor assembly determines a power ratio of the transmitted output power and the input power level received by said sensor assembly, an indication of the transmitted output power being received from said sensor controller in a message transmitted from said sensor controller.

6. A system in accordance with claim 1, wherein said sensor controller determines a power ratio of the transmitted output power and the input power level received by said sensor assembly, an indication of the input power level being received from said sensor assembly in a message transmitted from said sensor assembly.

7. A method of transmitting sensor signals comprising:

transmitting a sensor interrogation signal into an aircraft fuselage at a frequency that varies over time;

determining an output power of the transmitted sensor interrogation signal at a plurality of frequencies;

receiving an indication of a received power of the sensor interrogation signal from a wireless sensor at the plurality of frequencies;

comparing the transmitted output power of the sensor interrogation signal to the received power indication; and

selecting a transmit frequency based on the comparison.

8. A method in accordance with claim 7, wherein comparing the transmitted output power of the sensor interrogation signal to the received power indication comprises determining a power ratio of the received power indication and the transmitted output power.

9. A method in accordance with claim 7, further comprising transmitting information to the wireless sensor at the selected frequency.

10. A method in accordance with claim 7, further comprising receiving information from the wireless sensor at the selected frequency.

11. A method in accordance with claim 7, wherein receiving an indication of a received power of the sensor interrogation signal from a wireless sensor at the plurality of frequencies comprises receiving an indication of a received power of the sensor interrogation signal from a plurality of wireless sensors.

12. A method in accordance with claim 11, wherein selecting a transmit frequency based on the comparison comprises selecting a transmit frequency based on the comparison of the transmitted output power of the sensor interrogation signal to the received power indication for more than one of the plurality of wireless sensors.

13. A method in accordance with claim 11, wherein selecting a transmit frequency based on the comparison comprises selecting a transmit frequency that provides a maximum total ratio of the received power indication to the transmitted output power for the more than one of the plurality of wireless sensors.

14. A method in accordance with claim 11, wherein selecting a transmit frequency comprises selecting a single transmit frequency.

15. A method in accordance with claim 11, wherein selecting a transmit frequency comprises selecting a plurality of transmit frequencies, such that each of the plurality of transmit frequencies corresponds to one or more of the plurality of wireless sensors.

16. A method in accordance with claim 11, wherein selecting a transmit frequency comprises selecting a plurality of transmit frequencies, such that each of the selected transmit frequencies corresponds to a ratio of the received power indication to the transmitted output power for an associated sensor that is greater than or equal to a ratio of the received power indication to the transmitted output power for the associated sensor at each of the other frequencies.

17. A sensor controller system comprising:

a radio frequency transceiver configured to transmit data messages and to receive data messages at a plurality of predetermined frequencies; and

a processor comprising a memory and programmed to;

transmit a plurality of sensor interrogation signals into an aircraft fuselage, each of the plurality of sensor interrogation signals transmitted at a respective frequency different than others of respective frequencies;

determine an output power of each of the transmitted plurality of sensor interrogation signals at the respective frequency;

receive an indication of a received power of at least one of the plurality of sensor interrogation signals from a wireless sensor at the respective frequencies;

compare the transmitted output power of the sensor interrogation signal to the received power indication; and

select a transmit frequency based on the comparison.

18. A system in accordance with claim 17, wherein said processor is further programmed to select the transmit frequency having the largest ratio of the transmitted output power of the sensor interrogation signal to the received power indication.

19. A system in accordance with claim 17, wherein said processor is further programmed to periodically select a transmit frequency based on a comparison of a transmitted output power of a subsequent sensor interrogation signal to a received power indication of the subsequent sensor interrogation signal.

20. A system in accordance with claim 17, wherein said processor is further programmed to:

monitor responses from the wireless sensor;

transmit one or more sensor interrogation signals into the aircraft fuselage at the selected frequency for the non-responsive wireless sensor; and

vary the frequency of the one or more sensor interrogation signals in a predetermined frequency range about the selected frequency.