Sensors having signal redundancy
Methods and apparatus for combining redundant signals to generate outputs signals with enhanced accuracy and/or risk level. In embodiments, first signals are generated by a first transducer and second signals are generated by a second transducer. In other embodiments, first signals are generated by a first die and second signals are generated by a second die. An amount of overlap between error distributions of the first and second signals can be used to detect failure and/or indicate risk of failure.
1. A method, comprising:
receiving first signals from a first signal source;
receiving second signals from a second signal source, wherein the first and second signals are redundant; and
combining the first signals and the second signals to generate a first output signal from the first signals, a second output signal from the second signals, and a third output signal from the first signals and the second signals.
2. The method according to claim 1 , further including generating a fourth output signal from first and second signals providing uncertainty and/or risk information.
3. The method according to claim 1 , wherein the first signal source comprises a first transducer and the second signal source comprises a second transducer.
4. The method according to claim 3 , wherein the first and second transducers are substantially similar.
5. The method according to claim 3 , wherein the first and second transducers are substantially dissimilar or of different nature.
6. The method according to claim 1 , wherein the first signal source comprises a first die and the second signal source comprises a second die.
7. The method according to claim 1 , wherein the third output signal comprises a combination, such as average, of the first and second signals.
8. The method according to claim 7 , wherein the combination comprises an average.
9. The method according to claim 1 , wherein the third output signal is more accurate than the first or second output signals taken independently.
10. The method according to claim 1 , wherein the first and second signals each comprise sine and cosine values.
11. The method according to claim 10 , wherein the first, second, and third output signals each comprise processed signals from transducers.
12. The method according to claim 1 , further including generating a fourth output signal from first and second signals providing risk information based on a comparison of similarity of the first signals and the second signals.
13. The method according to claim 12 , wherein the comparison of similarity includes using a threshold based on degrees for angle signals generated from sine and cosine signals.
14. The method according to claim 1 , further including assigning a first error distribution to the first signals and a second error distribution to the second signals.
15. The method according to claim 14 , further including assigning rectangular functions to the first and second error distributions.
16. The method according to claim 15 , further including assigning a given number of standard deviations to defines the rectangular functions.
17. The method according to claim 14 , further including assigning Gaussian functions to the first and second error distributions.
18. The method according to claim 14 , further including determining an amount of overlap between the first and second error distributions.
19. The method according to claim 18 , further including determining a failure condition based on the amount of overlap.
20. The method according to claim 19 , further including determining a level of confidence in the first and/or second signals from the amount of overlap or intersection of distributions.
21. The method according to claim 18 , further including determining a best estimate for the first and/or second signals from the amount of overlap.
22. A system, comprising:
a first signal source configured to generate first signals;
a second signal source to generate second signals, wherein the first and second signals are redundant; and
a signal processing module configure to combine the first signals and the second signals to generate a first output signal from the first signals, a second output signal from the second signals, and a third output signal from the first signals and the second signals.
23. The system according to claim 22 , wherein the signal processing module is further configured to generate a fourth output signal from first and second signals providing risk information.
24. The system according to claim 22 , wherein the first signal source comprises a first transducer and the second signal source comprises a second transducer.
25. The system according to claim 24 , wherein the first and second transducers are substantially similar.
26. The system according to claim 22 , wherein the first signal source comprises a first die and the second signal source comprises a second die.
27. The system according to claim 22 , wherein the third output signal comprises a combination, of the first and second signals.
28. The system according to claim 22 , wherein the third output signal is more accurate than the first or second output signals.
29. The system according to claim 22 , wherein the first and second signals each comprise sine and cosine values.
30. The system according to claim 29 , wherein the first, second, and third output signals each comprise an angle output signal.
31. The system according to claim 22 , further including generating a fourth output signal from first and second signals providing risk information based on a comparison of similarity of the first signals and the second signals.
32. The system according to claim 31 , wherein the comparison of similarity includes using a threshold based on degrees for angle signals generated from sine and cosine signals.
33. The system according to claim 22 , further including assigning a first error distribution to the first signals and a second error distribution to the second signals.
34. The system according to claim 33 , further including assigning rectangular functions to the first and second error distributions.
35. The system according to claim 34 , further including assigning a given number of standard deviations to defines the rectangular functions.
36. The system according to claim 34 , further including determining an amount of overlap between the first and second error distributions.
37. The system according to claim 36 , further including determining a failure condition based on the amount of overlap.
38. The system according to claim 36 , further including determining a level of confidence in the first and/or second signals from the amount of overlap.
39. The system according to claim 36 , further including determining a best estimate for the first and/or second signals from the amount of overlap.
40. The system according to claim 33 , further including assigning Gaussian functions to the first and/or second error distributions.
41. A system, comprising:
a first signal source means for generating first signals;
a second signal source means for generating second signals, wherein the first and second signals are redundant; and
a signal processing means for combining the first signals and the second signals to generate a first output signal from the first signals, a second output signal from the second signals, and a third output signal from the first signals and the second signals.
42. The system according to claim 41 , wherein the signal processing means further generates a fourth output signal from first and second signals providing risk information.
43. The system according to claim 41 , wherein the first signal source means comprises a first transducer and the second signal source means comprises a second transducer.
44. The system according to claim 43 , wherein the first and second transducers are substantially similar.
45. The system according to claim 41 , wherein the first signal source means comprises a first die and the second signal source means comprises a second die.