Sensor network using pulse width modulated signals

• US 9,582,452 B2
• Filed: 06/05/2013
• Issued: 02/28/2017
• Est. Priority Date: 06/05/2013
• Status: Active Grant

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Ray, Gary A., Petre, Peter
• Primary Examiner(s): Zaman, Faisal M
• Application Number:
  US13/910,851
• Publication Number:
  US 20140365702A1
• Time in Patent Office: 1,364 Days
• Field of Search: 710/305, 340/539.22, 370/336
• US Class Current: 1/1
• CPC Class Codes: G06F 13/4068 Electrical coupling
• CPC Class Codes: H04L 12/12 Arrangements for remote connection or disconnection of substations or of equipment thereof

Abstract

A device includes a bus interface to couple to a shared bus of a sensor network. The device also includes a sensor interface to couple to a sensor of the sensor network. The device further includes a gated pulse width modulation circuit coupled to the bus interface and to the sensor interface. The gated pulse width modulation circuit is configured to transmit, during a time slot determined based on a timing signal received via the shared bus, an analog pulse width modulated representation of a signal received from the sensor.

Claims

1. A device comprising:

a bus interface to couple to a shared bus of a sensor network;

a sensor interface to couple to a sensor of the sensor network;

a gated pulse width modulation circuit coupled to the bus interface and to the sensor interface, the gated pulse width modulation circuit configured to transmit, during a time slot, an analog pulse width modulated representation of a signal received from the sensor;

a second circuit coupled to the bus interface and to the sensor interface, the second circuit configured to receive a second signal via the shared bus and to provide a representation of the second signal to the sensor, wherein the representation of the second signal includes sensor data from a second sensor; and

a time slot assignment device coupled to the bus interface and configured to assign the time slot to the sensor in response to no transmission from another device being detected on the shared bus in the time slot during a monitoring time period, wherein the time slot assignment device identifies a first particular time slot to monitor based on a device identifier associated with the sensor.

2. The device of claim 1, wherein the time slot assignment device identifies a second particular time slot to monitor in response to a transmission from another device being detected on the shared bus in the first particular time slot, and wherein the second particular time slot is immediately subsequent to the first particular time slot.

3. The device of claim 1, wherein the time slot corresponds to a media access time during each frame of a plurality of frames that is allocated to the device for transmission on the shared bus, and wherein the monitoring time period includes the first particular time slot and a second particular time slot, wherein the first particular time slot corresponds to a first frame of the plurality of frames, and wherein the second particular time slot corresponds to a second frame of the plurality of frames.

4. The device of claim 3, wherein the gated pulse width modulation circuit is configured to transmit the analog pulse width modulated representation of the signal received from the sensor during the first frame of the plurality of frames and transmit at least a portion of a node identifier of the device during the second frame of the plurality of frames.

5. The device of claim 1, wherein the second circuit includes a low pass filter, wherein the low pass filter converts the second signal from an analog pulse width modulated format to the representation of the second signal, and wherein the representation of the second signal is an analog signal.

6. The device of claim 5, wherein the low pass filter includes an integrator, and wherein the low pass filter is configured to receive the second signal during a second time slot distinct from the time slot.

7. The device of claim 1, further comprising a receiver configured to:

receive analog pulse width modulation data via the shared bus during a second time slot;

convert the analog pulse width modulation data into a digital signal; and

provide a digital sensor record to a processor.

8. The device of claim 7, wherein the digital sensor record includes a value that corresponds to the digital signal, an identifier associated with a particular sensor the analog pulse width modulation data originated from, and a time stamp.

9. The device of claim 8, wherein the identifier corresponds to a particular digital signal converted from a particular analog signal received in a second particular time slot corresponding to the particular sensor.

17. The device of claim 1, wherein the time slot assignment device is further configured to receive a timing signal during a second time slot reserved for synchronization of a plurality of sensor interface devices.

18. The device of claim 1, wherein the second circuit includes a gated low pass filter configured to provide the representation of the second signal to the sensor during a second time slot.

10. A sensor network comprising:

multiple sensors;

a bus; and

multiple sensor interface devices, each sensor interface device of the multiple sensor interface devices coupling one or more sensors of the multiple sensors to the bus, wherein a first sensor interface device of the multiple sensor interface devices includes;

a bus interface coupled to the bus;

a sensor interface coupled to a first corresponding sensor of the multiple sensors;

a gated pulse width modulation circuit coupled to the bus interface and to the sensor interface, the gated pulse width modulation circuit configured to transmit, during a time slot, an analog pulse width modulated representation of a signal received from the first corresponding sensor;

a second circuit coupled to the bus interface and to the sensor interface, the second circuit configured to receive a second signal via the bus and to provide a representation of the second signal to the first corresponding sensor, wherein the representation of the second signal includes sensor data from a second sensor of the multiple sensors; and

a time slot assignment device coupled to the bus interface and configured to assign the time slot to the first corresponding sensor in response to no transmission from another device being detected on the bus in the time slot during a monitoring time period, wherein the time slot assignment device identifies a first particular time slot to monitor based on a device identifier associated with the sensor.

11. The sensor network of claim 10, integrated in a structure, wherein the structure includes an aircraft, a spacecraft, a land craft, a watercraft, a mobile platform, an infrastructure platform, or a building.

12. The sensor network of claim 10, further comprising a receiver coupled to the bus and configured to receive, during the time slot, the analog pulse width modulated representation, wherein the receiver is further configured to convert the analog pulse width modulated representation into a digital signal.

19. The sensor network of claim 10, wherein the second circuit comprises a selector configured to selectively provide the representation of the second signal to the second sensor during a second time slot assigned to the second sensor by the time slot assignment device.

13. A method comprising:

monitoring a bus during a monitoring time period;

identifying a first particular time slot to monitor based on a device identifier;

assigning a time slot to a sensor in response to no transmission from another device being detected on the bus in the time slot during the monitoring time period;

receiving a first signal including data from the sensor;

transmitting an analog pulse width modulated representation of the data via the bus during the time slot; and

providing, during a second time slot, a representation of a second signal to the sensor, the second signal received via the bus, wherein the representation of the second signal includes sensor data from a second sensor.

14. The method of claim 13, further comprising activating a switch based on identification of a beginning of a subsequent time slot corresponding to the time slot to enable a transmission of the analog pulse width modulated representation of the data.

15. The method of claim 13, further comprising generating the analog pulse width modulated representation of the data during the time slot.

16. The method of claim 13, further comprising combining a carrier signal with the analog pulse width modulated representation of the data prior to transmitting the analog pulse width modulated representation of the data via the bus.

20. The method of claim 13, wherein the data is generated based on the sensor data.