Angular rate sensor with temperature compensation and vibration compensation

• US 20060101909A1
• Filed: 10/19/2005
• Published: 05/18/2006
• Est. Priority Date: 11/12/2004
• Status: Abandoned Application

• Current Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China)
• Inventors: Lo, Yuan, Tseng, Chih-Wei, Lin, Lung-Yung, Hsu, Chaug-Liang
• Application Number:
  US11/252,571
• Publication Number:
  US 20060101909A1
• Time in Patent Office: Days
• US Class Current: 73/497
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure

Abstract

An angular rate sensing device with temperature compensation and vibration compensation is provided. The device includes a base; a vibrator having multiple proof masses, arranged in the base; a plurality of flexible supporting members connected to the vibrator and supporting the vibrator to be suspended in the base; and a plurality of planar electrodes arranged relative to the proof masses, wherein each of the planar electrodes is connected to two signal lines with phase difference of 180 degree. The vibration error is compensated by way of connecting the signal lines, whose phase difference is of 0 degree, of the planar electrodes, whose position difference is of 180 degree; wherein the thermal expansion error is compensated by way of connecting the signal lines, whose phase difference is of 180 degree, of the planar electrodes, whose position difference is of 90 degree.

Claims

1. An angular rate sensing device with temperature compensation and vibration compensation comprising:

a base;

a vibrator having multiple proof masses, arranged in the base;

a plurality of flexible supporting members connected to the vibrator and supporting the vibrator to be suspended in the base; and

a plurality of planar electrodes arranged relative to the proof masses, wherein each of the planar electrodes is connected to two signal lines with phase difference of 180 degree, for sensing motion of the proof masses relative to the planar electrodes through the capacitance variation between the planar electrodes and the proof masses;

wherein the vibration error is compensated by way of connecting the signal lines, whose phase difference is of 0 degree, of the planar electrodes, whose position difference is of 180 degree;

wherein the thermal expansion error is compensated by way of connecting the signal lines, whose phase difference is of 180 degree, of the planar electrodes, whose position difference is of 90 degree.

2. The device of claim 1, wherein each of the planar electrodes comprises a first comb electrode and a second comb electrode.

3. The device of claim 2, wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 0 degree, the first comb electrode arranged at 180 degree, the second comb electrode arranged at 90 degree, and the second comb electrode arranged at 270 degree;

wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 90 degree, the first comb electrode arranged at 270 degree, the second comb electrode arranged at 0 degree, and the second comb electrode arranged at 180 degree.

4. The device of claim 2, wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 45 degree, the first comb electrode arranged at 225 degree, the second comb electrode arranged at 135 degree, and the second comb electrode arranged at 315 degree;

wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 135 degree, the first comb electrode arranged at 315 degree, the second comb electrode arranged at 45 degree, and the second comb electrode arranged at 225 degree.

5. The device of claim 1 further comprises a sensing circuit connected to the signals of the planar electrodes, for receiving the sensing signals of the planar electrodes, and summing and differentially amplifying all the sensing signals of the planar electrodes.

6. The device of claim 1, wherein the vibrator comprises a ring and a plurality of proof masses.

7. The device of claim 6 further comprises a first connecting member connects each of the proof masses to the ring.

8. The device of claim 6, wherein the proof masses are floating parallel electrodes.

9. The device of claim 8, wherein the electrodes are slot type floating parallel electrodes, which are configured in differential circuits.

10. The device of claim 1, wherein the plurality of flexible supporting members comprises elements symmetrical to the driving axis or sensing axis of the vibrator, and are equally arranged at the periphery of the vibrator.

11. The device of claim 10, wherein the flexible supporting member comprises a flexible supporter set comprising:

a pair of first supporters; and

a second supporter connected to the pair of the first supporters.

12. The device of claim 11, wherein each of the pair of the first supporters further comprises a bending portion connecting the pair of the first supporters and the second supporter.

13. The device of claim 11, wherein the flexible supporting member further comprises a second connecting member connecting the second supporter and the vibrator to keep a predetermined distance between the second supporter and the vibrator.

14. The device of claim 1, wherein the flexible supporting members are arranged at the interior periphery of the vibrator, and the proof mass is arranged at the exterior periphery of the vibrator.

15. The device of claim 1, wherein the flexible supporting members are arranged at the exterior periphery of the vibrator, and the proof mass is arranged at the interior periphery of the vibrator.

16. The device of claim 15 further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

17. The device of claim 1, wherein the material of the base is silicon-based material or glass, and that of the vibrator is silicon-based material or metal.

18. An angular rate sensing device with temperature compensation and vibration compensation comprising:

a first base and a second base;

a vibrator having multiple proof masses, arranged in the first base, wherein the proof masses are connected to the vibrator;

a plurality of flexible supporting members connected to the vibrator and supporting the vibrator to be suspended in the first base;

a plurality of electrodes for driving and controlling the flexible supporting members to oscillate such that the oscillation mode of the vibrator in driving mode may be controlled; and

a plurality of planar electrodes arranged relative to the proof masses, wherein each of the planar electrodes is connected to two signal lines with phase difference of 180 degree, for sensing motion of the proof masses relative to the planar electrodes through the capacitance variation between the planar electrodes and the proof masses;

wherein the vibration error is compensated by way of connecting the signal lines, whose phase difference is of 0 degree, of the planar electrodes, whose position difference is of 180 degree;

wherein the thermal expansion error is compensated by way of connecting the signal lines, whose phase difference is of 180 degree, of the planar electrodes, whose position difference is of 90 degree.

19. The device of claim 18, wherein each of the planar electrodes comprises a first comb electrode and a second comb electrode.

20. The device of claim 19, wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 0 degree, the first comb electrode arranged at 180 degree, the second comb electrode arranged at 90 degree, and the second comb electrode arranged at 270 degree;

wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 90 degree, the first comb electrode arranged at 270 degree, the second comb electrode arranged at 0 degree, and the second comb electrode arranged at 180 degree.

21. The device of claim 19, wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 45 degree, the first comb electrode arranged at 225 degree, the second comb electrode arranged at 135 degree, and the second comb electrode arranged at 315 degree;

wherein the error caused by vibration and temperature variation is compensated by way of summing the signals of the first comb electrode arranged at 135 degree, the first comb electrode arranged at 315 degree, the second comb electrode arranged at 45 degree, and the second comb electrode arranged at 225 degree.

22. The device of claim 18 further comprises a sensing circuit connected to the signals of the planar electrodes, for receiving the sensing signals of the planar electrodes, and summing and differentially amplifying all the sensing signals of the planar electrodes.

23. The device of claim 18, wherein the vibrator comprises a ring and a plurality of proof masses.

24. The device of claim 23 further comprises a first connecting member connects each of the proof masses to the ring.

25. The device of claim 23, wherein the proof masses are floating parallel electrodes.

26. The device of claim 25, wherein the electrodes are slot type floating parallel electrodes, which are configured in differential circuits.

27. The device of claim 18, wherein the plurality of flexible supporting members comprises elements symmetrical to the driving axis or sensing axis of the vibrator, and are equally arranged at the periphery of the vibrator.

28. The device of claim 27, wherein the flexible supporting member comprises a flexible supporter set comprising:

a pair of first supporters; and

a second supporter connected to the pair of the first supporters.

29. The device of claim 28, wherein each of the pair of the first supporters further comprises a bending portion connecting the pair of the first supporters and the second supporter.

30. The device of claim 18, wherein the flexible supporting member further comprises a second connecting member connecting the second supporter and the vibrator to keep a predetermined distance between the second supporter and the vibrator.

31. The device of claim 18, wherein the flexible supporting members are arranged at the interior periphery of the vibrator, and the proof mass is arranged at the exterior periphery of the vibrator.

32. The device of claim 18, wherein the flexible supporting members are arranged at the exterior periphery of the vibrator, and the proof mass is arranged at the interior periphery of the vibrator.

33. The device of claim 32 further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

34. The device of claim 18, wherein each of the electrodes is arranged on a third base, each is in each of the flexible supporting member, wherein the first base and the third base are boned together such that the vibrator suspense in the first base and the third base.

35. The device of claim 18, wherein the second base is provided with the planar electrodes corresponding to the proof masses of the floating parallel electrodes and the control circuits, wherein the first base, the second base and the third base are boned together, and the material of the third base is silicon-based material or glass.

36. The device of claim 18 further comprises a third base provided with control circuits for the driving electrodes and the sensing electrodes, wherein the first base, the second base and the third base are boned together, and the material of the third base is silicon-based material or glass.

37. The device of claim 18, wherein the material of the base is silicon-based material or glass, and that of the vibrator is silicon-based material or metal.