Systems and methods for extracting system parameters from nonlinear periodic signals from sensors

• US 9,910,062 B2
• Filed: 06/26/2015
• Issued: 03/06/2018
• Est. Priority Date: 06/26/2014
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Lumedyne Technologies Incorporated (Alphabet Inc.)
• Inventors: Waters, Richard Lee, Jacobs, John David, Tally, IV, Charles Harold, Huang, Xiaojun, Zhang, Yanting, Fralick, Mark Steven
• Primary Examiner(s): Kwok, Helen
• Application Number:
  US14/751,536
• Publication Number:
  US 20150377918A1
• Time in Patent Office: 984 Days
• CPC Class Codes: G01C 19/5705 using masses driven in reciprocating rotary motion about an axis
• CPC Class Codes: G01C 19/5726 Signal processing
• CPC Class Codes: G01C 19/5747 each sensing mass being connected to a driving mass, e.g. driving frames
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/125 by capacitive pick-up

Abstract

Systems and methods are disclosed herein for extracting system parameters from nonlinear periodic signals from sensors. A sensor such as an inertial device includes a first structure and a second structure that is springedly coupled to the first structure. The sensor is configured to generate an output voltage based on a current between the first and second structures. Monotonic motion of the second structure relative to the first structure causes a reversal in direction of the current.

Claims

1. An inertial device, comprising:

a first structure including a first plurality of sub-structures arranged along a first axis;

a second structure including a second plurality of sub-structures arranged along the first axis, the second structure configured to;

move relative to the first structure and primarily along a second axis that is approximately perpendicular to the first axis and approximately perpendicular to a plane of the inertial device that is approximately parallel to a surface of a semiconductor wafer from which the inertial device is fabricated; and

enable monotonic motion of the second structure along the second axis to cause a reversal in a direction of a current between the first and second structures; and

a sensor configured to generate an output voltage based on the current.

2. The inertial device of claim 1, wherein the second structure is springedly coupled to the first structure.

3. The inertial device of claim 1, further comprising a drive unit configured to oscillate the second structure relative to the first structure and along the second axis.

4. The inertial device of claim 1, wherein:

the inertial device comprises an output unit configured to output, based on the output voltage, an output signal indicating an external perturbation acting on the inertial device.

5. The inertial device of claim 1, wherein:

each of the first plurality of sub-structures has a first height along the second axis; and

each of the second plurality of sub-structures has a second height along the second axis.

6. The inertial device of claim 5, wherein the second height is different from the first height.

7. The inertial device of claim 6, wherein motion of the first plurality of sub-structures past an aligned position with the second plurality of sub-structures causes the reversal in direction of the current.

8. The inertial device of claim 7, wherein the aligned position corresponds to a position in which a first midpoint of the first height is aligned with a second midpoint of the second height.

9. The inertial device of claim 4, wherein:

the output signal consists essentially of a first value and a second value; and

the output unit is configured to;

output the first value as the output signal,

receive, from the sensor, the output voltage,

compare a value of the output voltage to a threshold, and

output, based on the comparison, the second value as the output signal.

10. The inertial device of claim 9, wherein the output unit is further configured to:

compare the value of the output voltage to a plurality of thresholds;

determine, based on the comparison, that the output voltage crosses one of the plurality of thresholds; and

toggle, based on the determination, the output signal between the first value and the second value.

11. The inertial device of claim 10, wherein:

the output unit toggles the output signal in a toggling event; and

the inertial device further comprises a signal processing unit configured to;

receive the toggled output signal,

determine a time between the toggling event and a subsequent toggling event,

based on the determined time, determine an inertial parameter of the inertial device, and

based on the determined inertial parameter, output an inertial signal.

12. The inertial device of claim 4, further comprising:

a voltage source unit configured to apply a constant voltage to one of the first and second structures; and

a drive unit configured to drive the second structure in oscillatory motion relative to the first structure;

wherein the oscillatory motion of the second structure relative to the first structure results in oscillations in the current.

13. The inertial device of claim 12, wherein:

motion of the inertial device results in first modulation of the oscillations in the current; and

the first modulation of the oscillations in the current results in second modulation of the output signal.

14. The inertial device of claim 13, wherein the drive unit is further configured to:

receive the modulated output signal; and

based on the received modulated output signal, adjust the oscillatory motion of the second structure relative to the first structure.

15. The inertial device of claim 4, further comprising:

a voltage source unit configured to apply an oscillatory voltage to one of the first and second structures; and

wherein the oscillatory voltage results in oscillations in the current.

16. The inertial device of claim 15, wherein:

motion of the inertial device results in first modulation of the oscillations in the current; and

the first modulation of the oscillations in the current results in second modulation of the output signal.

17. A method of forming an inertial device from a semiconductor wafer, comprising:

forming a first structure including a first plurality of sub-structures arranged along a first axis;

forming a second structure including a second plurality of sub-structures arranged along the first axis, the second structure configured to;

move relative to the first structure and primarily along a second axis that is approximately perpendicular to the first axis and approximately perpendicular to a plane of the inertial device that is approximately parallel to a surface of a semiconductor wafer; and

enable monotonic motion of the second structure along the second axis to cause a reversal in a direction of a current between the first and second structures; and

forming electrical connections from the first and second structures to a sensor configured to generate an output voltage based on the current.

18. The method of claim 17, wherein the second structure is springedly coupled to the first structure.

19. The method of claim 17, further comprising forming a drive unit configured to oscillate the second structure relative to the first structure and along the second axis.

20. The method of claim 17, further comprising

forming an electrical connection from the sensor to an output unit configured to output, based on the output voltage, an output signal indicating an external perturbation acting on the inertial device.

21. The method of claim 17, further comprising:

forming each of the first plurality of sub-structures to have a first height along the second axis; and

forming each of the second plurality of sub-structures to have a second height along the second axis.

22. The method of claim 21, wherein the second height is different than the first height.

23. The method of claim 22, wherein:

motion of the first plurality of sub-structures past an aligned position with the second plurality of sub-structures causes the reversal in direction of the current.

24. The method of claim 23, wherein the aligned position corresponds to a position in which a first midpoint of the first height is aligned with a second midpoint of the second height.

25. The method of claim 20, wherein:

the output signal consists essentially of a first value and a second value; and

the output unit is configured to;

output the first value as the output signal,

receive, from the sensor, the output voltage,

compare a value of the output voltage to a threshold, and

output, based on the comparison, the second value as the output signal.

26. The method of claim 25, wherein the output unit is further configured to:

compare the value of the output voltage to a plurality of thresholds;

determine, based on the comparison, that the output voltage crosses one of the plurality of thresholds; and

toggle, based on the determination, the output signal between the first value and the second value.

27. The method of claim 26, wherein:

the output unit toggles the output signal in a toggling event; and

the method further comprises forming an electrical connection from the output unit to a signal processing unit configured to;

receive the toggled output signal,

determine a time between the toggling event and a subsequent toggling event,

based on the determined time, determine an inertial parameter of the inertial device, and

based on the determined inertial parameter, output an inertial signal.

28. The method of claim 20, further comprising:

forming respective electrical connections from the first and second structures to a voltage source unit configured to apply a constant voltage to one of the first and second structures; and

forming electrical connections to a drive unit configured to drive the second structure in oscillatory motion relative to the first structure;

wherein the oscillatory motion of the second structure relative to the first structure results in oscillations in the current.

29. The method of claim 28, wherein:

motion of the inertial device results in first modulation of the oscillations in the current;

the first modulation of the oscillations in the current results in second modulation of the output signal.

30. The method of claim 29, wherein the drive unit is further configured to:

receive the modulated output signal; and

based on the received modulated output signal, adjust the oscillatory motion of the second structure relative to the first structure.

31. The method of claim 20, further comprising:

forming connections from one of the first and second structures to a voltage source unit configured to apply an oscillatory voltage to the one of the first and second structures; and

wherein the oscillatory voltage results in oscillations in the current.

32. The method of claim 31, wherein:

motion of the inertial device results in first modulation of the oscillations in the current; and

the first modulation of the oscillations in the current results in second modulation of the output signal.