Method and apparatus for multiplexed time aligned analog input sampling

• US 9,231,719 B2
• Filed: 03/12/2013
• Issued: 01/05/2016
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Hamilton Sundstrand Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Hess, Gary L., Saloio, James
• Primary Examiner(s): Mattis, Jason
• Assistant Examiner(s): Duffy, James P
• Application Number:
  US13/795,815
• Publication Number:
  US 20140269775A1
• Time in Patent Office: 1,029 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G08C 15/00 Arrangements characterised by the use of multiplexing for the transmission of a plurality of signals over a common path
• CPC Class Codes: H04J 3/02 Details electronic switching or gating H03K17/00
• CPC Class Codes: H04Q 2209/845 where the measuring is synchronized between sensing devices
• 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 sensor system includes a first sensor and a second sensor and a multiplexor having at least two multiplexer inputs connected to the sensors. The output of the multiplexor is connected to a time correlation logic circuit via at least a signal conditioning and anti-aliasing filter, and the output of the time correlation logic is a time correlated sensor reading of the first and second sensor.

Claims

1. A sensor system comprising:

a first sensor and a second sensor;

a multiplexor having at least two multiplexer inputs, wherein a first multiplexer input is connected to an output of said first sensor and said second multiplexer input is connected to an output of said second sensor;

an output of said multiplexor is connected to a time correlation logic circuit via at least a signal conditioning and anti-aliasing filter, the time correlation logic circuit including logic circuitry operable to cause said time correlation logic circuit to perform the steps of determining a currently passed value of the multiplexed signal at time t, the currently passed value being an instantaneous value of one of the first sensor and the second sensor, determining an average value representative of a non-currently passed value of the multiplexed signal at time t, the average value of a non-currently passed value being an average output of the other of said first and second sensor, combining said currently passed value and said average value representative of said non-currently passed value at time t, thereby determining a time correlated sensor value at time t, and wherein the time correlated sensor value is an instantaneous value of one of the first sensor and the second sensor at time t and an average value of the other of the first sensor and the second sensor at time t;

wherein an output of said time correlation logic circuit is connected to an input of a signal processor; and

wherein said output of said time correlation logic is the time correlated sensor value.

2. The sensor system of claim 1, wherein said first sensor and said second sensor are analog sensors.

3. The sensor system of claim 2, wherein said output of said multiplexor is connected to said time correlation logic circuit via a signal conditioning and anti-aliasing filter in series with an analog to digital converter.

4. The sensor system of claim 1, wherein said time correlation logic circuit is hardware based.

5. The sensor system of claim 1, wherein said time correlation logic circuit includes an acceleration compensation logic circuit.

6. The sensor system of claim 1, wherein the currently passed value of the multiplexed signal is an instantaneous output of the first sensor, and the average value representative of a non-currently passed value is an average value of at least two outputs of the second sensor.

7. The sensor system of claim 6, wherein the at least two outputs of the second sensor include an instantaneous output of the second sensor in a previous time period and an instantaneous output of the second sensor in a future time period.

8. The sensor system of claim 7, wherein the at least two outputs of the second sensor include an instantaneous output of the second sensor in at least two previous time period and an instantaneous output of the second sensor in at least two future time periods.

9. A method for time correlating a multiplexed signal comprising the steps of:

receiving a multiplexed signal including at least a first sensor signal and a second sensor signal;

determining a value representative of a currently passed value of the multiplexed signal at time t, the currently passed value being an instantaneous value of one of the first sensor signal and the second sensor signal;

determining an average value representative of a non-currently passed value of the multiplexed signal at time t, the average value of a non-currently passed value being an average output of the other of said first sensor signal and second sensor signal;

combining said currently passed value and said average value representative of said non-currently passed value at time t, thereby determining a time correlated sensor value at time t; and

passing the time correlated sensor value to a signal processor configured to interpret the time correlated sensor value, thereby simultaneously passing a value representative of the first sensor signal at time t and a value representative of the second sensor signal at time t to said processor; and

generating control signals for an engine using said processor based at least in part on the simultaneously passed values.

10. The method of claim 9, wherein said step of determining an average value representative of a non-currently passed multiplexed signal at time t further comprises summing at least an immediately prior passed value of said non-currently passed multiplexed signal at time t−

1 and an immediately post passed value of said non-currently passed multiplexed signal at time t+1, thereby determining an intermediate sum value.

11. The method of claim 10, wherein said step of determining an average value representative of a non-currently passed multiplexed signal at time t further comprises dividing said intermediate sum value by the number of summed values, thereby determining the average value representative of said non-currently passed multiplexed signal for time t.

12. The method of claim 9, wherein said step of determining an average value representative of a non-currently passed multiplexed signal at time t further comprises summing at least a slope of an immediately prior passed value of said non-currently passed multiplexed signal at time t−

1 and a slope of an immediately post passed value of said non-currently passed multiplexed signal at time t+1, thereby determining an intermediate sum value.

13. The method of claim 12, wherein said step of determining an average value representative of a non-currently passed multiplexed signal at time t further comprises dividing said intermediate sum value by the number of summed values, thereby determining the average value representative of said non-currently passed multiplexed signal for time t.

14. The method of claim 12, wherein average value representative of a non-currently passed multiplexed signal at time t is a derivative with respect to time of the non-currently passed multiplexed signal.

15. The method of claim 14, wherein said value representative of a currently passed value of the multiplexed signal at time t is an instantaneous derivative of the currently passed value of the multiplexed signal.

16. A time correlated multiplexed sensor arrangement for an aircraft comprising:

at least a first sensor and a second sensor;

a multiplexor having at least two multiplexer inputs, wherein a first multiplexer input is connected to an output of said first sensor and said second multiplexer input is connected to an output of said second sensor;

an output of said multiplexor is connected to a time correlation logic circuit via at least a signal conditioning and anti-aliasing filter;

said time correlation logic circuit includes logic circuitry operable to cause said time correlation logic circuit to perform the steps of determining a currently passed value of the multiplexed signal at time t, the currently passed value being an instantaneous value of one of the first sensor and the second sensor, determining an average value representative of a non-currently passed value of the multiplexed signal at time t, the average value of a non-currently passed value is an average output of the other of said first and second sensor, combining said currently passed value and said average value representative of said non-currently passed value at time t, thereby determining a time correlated sensor value at time t, and the time correlated sensor value is an instantaneous value of one of the first sensor and the second sensor at time t and an average value of the other of the first sensor and the second sensor at time t;

wherein an output of said time correlation logic circuit is connected to an input of a signal processor; and

wherein said output of said time correlation logic is the time correlated sensor value.

17. The time correlated multiplexed sensor arrangement for an aircraft of claim 16, wherein said first sensor and said second sensor are analog sensors.

18. The time correlated multiplexed sensor arrangement for an aircraft of claim 17, wherein said output of said multiplexor is connected to said time correlation logic circuit via a signal conditioning and anti-aliasing filter in series with an analog to digital converter.

19. The time correlated multiplexed sensor arrangement for an aircraft of claim 16, wherein said time correlation logic circuit is hardware based.

20. The time correlated multiplexed sensor arrangement for an aircraft of claim 16, wherein said time correlation logic circuit includes an acceleration compensation logic circuit.