Multiplexed signal sampler and conditioner

• US 9,391,630 B2
• Filed: 06/13/2014
• Issued: 07/12/2016
• Est. Priority Date: 06/13/2014
• 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: Saloio, James, Reen, Kanwalpreet
• Primary Examiner(s): WILLIAMS, HOWARD L
• Application Number:
  US14/303,733
• Publication Number:
  US 20150365099A1
• Time in Patent Office: 760 Days
• Field of Search: 341111-117, 341/141
• US Class Current: 1/1
• CPC Class Codes: G01D 5/2291 Linear or rotary variable differential transformers (LVDTs/RVDTs) having a single primary coil and two secondary coils
• CPC Class Codes: H03M 1/122 Shared using a single converter or a part thereof for multiple channels, e.g. a residue amplifier for multiple stages

Abstract

A signal convertor includes a first sensor configured to generate a first signal and a second signal and first and second multiplexers configured receive the first and second signals, respectively, and generate samples. The signal convertor also includes an analog-to-digital (A/D) convertor configured to convert the samples and a processor configured to multiply the samples by a sine vector and by a cosine vector and determine a magnitude of the first and second signals based upon the product of the samples and the sine vector and the product of the samples and the cosine vector. A method for converting a signal is also disclosed.

Claims

1. A signal convertor, comprising:

a first sensor configured to generate a first signal and a second signal;

first and second multiplexers configured receive the first and second signals, respectively, and generate outputs;

an analog-to-digital (A/D) convertor configured to convert the outputs; and

a processor configured to multiply the outputs by a sine vector and by a cosine vector and determine a magnitude of the first and second signals based upon the product of the outputs and the sine vector and the product of the outputs and the cosine vector.

2. The signal convertor of claim 1, wherein the first and second multiplexers are first tier multiplexers, and further comprising a second tier multiplexer configured to receive outputs from the first-tier multiplexers and output outputs to the A/D convertor.

3. The signal convertor of claim 1, further comprising a second sensor configured to generate a third signal, and a third multiplexer configured to receive the third signal and generate outputs.

4. The signal convertor of claim 3, further comprising a third sensor configured to generate fourth and fifth signals, the fourth and fifth signals received by the first and second multiplexers, respectively.

5. The signal convertor of claim 1, further comprising an antialiasing filter configured to condition the outputs.

6. The signal convertor of claim 1, further comprising first and second equivalent alternating current (AC) gain signals received by the first and second multiplexers for compensating the first and second signals, respectively.

7. The signal convertor of claim 6, wherein the first and second AC gain signals are sampled on a different time frame than the first and second signals from the sensor.

8. The signal convertor of claim 7, wherein the time frame for sampling the first and second AC gain signals is dependent on a rate of change of a temperature of the signal convertor.

9. The signal convertor of claim 6, wherein the magnitude of the second signal is processed to compensate for a mismatch between signal conditioning paths of the first and second signals due to the first and second AC gain signals by multiplying by a ratio of a magnitude of the first AC gain signal to a magnitude of the second AC gain signal.

10. The signal convertor of claim 1, wherein the first sensor is a resolver, and an excitation of the resolver is synchronized with the A/D convertor.

16. The signal convertor of claim 1, wherein the first sensor is a five-wire LVDT.

17. The signal convertor of claim 1, wherein the first sensor is a resolver.

18. The signal convertor of claim 1, wherein the first and second signals are sampled almost simultaneously.

19. The signal convertor of claim 5, wherein the antialiasing filter is a first antialiasing filter that receives outputs from the first multiplexer.

20. The signal convertor of claim 1, further comprising a second antialiasing filter that receives outputs from the second multiplexer.

11. A method for converting a signal, comprising the steps of:

a) providing first and second signals from a sensor to first and second multiplexers, respectively;

b) multiplying outputs from the first and second multiplexers by a sine vector;

c) multiplying outputs from the first and second multiplexers by a cosine vector;

d) determining the magnitude of the first and second signals based upon steps b) and c); and

e) determining a mechanical angle of the first and second signals based upon step b).

12. The method of claim 11, wherein step d) further includes the steps of calculating a root mean square of an average of the products from said step b) and of an average of the products in step c).

13. The method of claim 11, further comprising the step of:

e) providing first and second equivalent alternating current (AC) gain compensation signals to the first and second multiplexers, respectively, for compensating the first and second signals.

14. The method of claim 13, further comprising the steps of:

f) multiplying outputs of the AC gain signals from the first and second multiplexers, respectively, by a sine wave and by a cosine wave;

g) determining a magnitude of the first and second AC gain signals based upon step f); and

h) compensating the magnitude of the second signal by multiplying by a ratio of the magnitude of the first AC gain signal to the magnitude of the second AC gain signal.

15. The method of claim 14, further comprising the step of:

i) determining a position of the sensor using the compensated magnitude of the second signal.