Micro angular rate sensor

• US 7,155,978 B2
• Filed: 10/28/2004
• Issued: 01/02/2007
• Est. Priority Date: 05/14/2004
• Status: Expired due to Fees

• Current Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China), Neostones Microfabrication Corporation
• Original Assignee: Chung-Shan Institute of Science & Technology Armaments Bureau MND (Government of The Republic of China), Neostones Microfabrication Corporation
• Inventors: Ho, Kye-Chyn, Lo, Yuan, Tseng, Chih-Wei, Lin, Lung-Yung, Sche, Schiu
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US10/974,760
• Publication Number:
  US 20050252292A1
• Time in Patent Office: 796 Days
• Field of Search: 735/041.3, 735/141.2, 735/041.4, 735/041.6
• US Class Current: 73/504.13
• CPC Class Codes: G01C 19/5712 the devices involving a micromechanical structure

Abstract

A micro angular rate-sensing device is provided. A vibrator, having a plurality of proof masses connected to a ring, is arranged in a first base. Flexible supporting members connect to the vibrator to suspend the vibrator in the first base. Electrodes drive the vibrator to oscillate and control the oscillation mode of the vibrator in driving mode. Planar electrodes are arranged relative to the proof masses on a second base. The motion of the proof masses relative to the planar electrodes is sensed through the capacitance between the proof masses and the planar electrodes. The resonant structure with greater mass of the device generates greater Coriolis force and increases the sensing area. Thus, the intensity of sensed signals and noise-signal ratio are greatly increased. Furthermore, the device does not rely much on high aspect ratio manufacturing technology. Thus the manufacturing cost is reduced and the yield rate is increased.

Claims

1. An angular rate sensing device comprising:

a base;

a vibrator having a ring and a plurality of proof masses, arranged in the base, wherein the plurality of proof masses are parallel electrodes; and

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

2. The angular rate sensing device of claim 1, further comprises a first connecting member that connects each of the proof masses to the ring.

3. The angular rate sensing device of claim 1, wherein the electrodes are slot type parallel electrodes, which are configured in differential circuits.

4. The angular rate sensing 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.

5. The angular rate sensing device of claim 4, 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.

6. The angular rate sensing device of claim 5, 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.

7. The angular rate sensing device of claim 5, 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.

8. The angular rate sensing 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.

9. The angular rate sensing 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.

10. The angular rate sensing device of claim 8, further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

11. The angular rate sensing 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.

12. An angular rate sensing device comprising:

a base;

a vibrator having a ring and a plurality of proof masses, arranged in the base, wherein the plurality of proof masses are parallel electrodes; and

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

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

13. The angular rate sensing device of claim 12, further comprises a first connecting member that connects each of the proof masses to the ring.

14. The angular rate sensing device of claim 12, wherein the electrodes are slot type parallel electrodes, which are configured in differential circuits.

15. The angular rate sensing device of claim 12, 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.

16. The angular rate sensing device of claim 15, 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.

17. The angular rate sensing device of claim 16, 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.

18. The angular rate sensing device of claim 16, 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.

19. The angular rate sensing device of claim 12, 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.

20. The angular rate sensing device of claim 12, 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.

21. The angular rate sensing device of claim 19, further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

22. The angular rate sensing device of claim 12, wherein the electrodes comprise:

a plurality of driving electrodes arranged at the positions of 0° and

180°

of the vibrator;

a plurality of close loop control electrodes arranged at the positions of 45° and

225°

of the vibrator; and

a plurality of compensating and control electrodes at the positions of 90°

, 135°

, 270° and

315°

of the vibrator.

23. An angular rate sensing device comprising:

a base;

a vibrator having a ring and a plurality of proof masses, arranged in the base, wherein the plurality of proof masses are parallel electrodes;

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, for sensing motion of the proof masses relative to the planar electrodes through the capacitance variation between the planar electrodes and the proof masses.

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

25. The angular rate sensing device of claim 23, wherein the electrodes are slot type parallel electrodes, which are configured in differential circuits.

26. The angular rate sensing device of claim 23, 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.

27. The angular rate sensing device of claim 26, 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.

28. The angular rate sensing device of claim 27, 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.

29. The angular rate sensing device of claim 27, 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.

30. The angular rate sensing device of claim 27, 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.

31. The angular rate sensing device of claim 23, 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.

32. The angular rate sensing device of claim 30, further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

33. The angular rate sensing device of claim 23, wherein the proof masses are employed as sensing electrodes, comprising:

a plurality of first sensing electrodes arranged at the positions of 0°

, 90°

, 180° and

270°

of the vibrator; and

a plurality of second sensing electrodes arranged at the positions of 45°

, 135°

, 225° and

315°

of the vibrator.

34. The angular rate sensing device of claim 23, wherein the material of the base is silicon-based material or glass, and that of the vibrator is silicon-based material or metal.

35. An angular rate sensing device comprising:

a first base and a second base;

a vibrator having a ring and a plurality of proof masses, arranged in the first base, wherein the plurality of proof masses are parallel electrodes and 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 controlling and driving the vibrator to oscillate such that the oscillation mode of the vibrator in driving mode may be controlled; and

a plurality of planar electrodes on the second base and arranged relative to the proof masses for sensing motion of the proof masses relative to the planar electrodes through the capacitance variation between the planar electrodes and the proof masses.

36. The angular rate sensing device of claim 35, further comprises a first connecting member that connects each of the proof masses to the ring.

37. The angular rate sensing device of claim 35, wherein the electrodes are slot type parallel electrodes, which are configured in differential circuits.

38. The angular rate sensing device of claim 35, 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.

39. The angular rate sensing device of claim 38, 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.

40. The angular rate sensing device of claim 39, 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.

41. The angular rate sensing device of claim 39, 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.

42. The angular rate sensing device of claim 35, 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.

43. The angular rate sensing device of claim 35, 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.

44. The angular rate sensing device of claim 42, further comprises an anchor or a concentric ring base arranged in the central portion of the vibrator to connect the flexible supporting members.

45. The angular rate sensing device of claim 41, wherein the electrodes comprise:

a plurality of driving electrodes arranged at the positions of 0° and

180°

of the vibrator;

a plurality of close loop control electrodes arranged at the positions of 45° and

225°

of the vibrator; and

a plurality of compensating and control electrodes at the positions of 90°

, 135°

, 270° and

315°

of the vibrator.

46. The angular rate sensing device of claim 45, wherein each of the electrodes for controlling and driving the vibrator is arranged on a third base and in the flexible supporting members;

the first base and the third base are bonded together such that the vibrator suspends in the bases.

47. The angular rate sensing device of claim 35, wherein the proof masses are employed as sensing electrodes, comprising:

a plurality of first sensing electrodes arranged at the positions of 0°

, 90°

, 180° and

270°

of the vibrator; and

a plurality of second sensing electrodes arranged at the positions of 45°

, 135°

, 225° and

315°

of the vibrator.

48. The angular rate sensing device of claim 35, further comprises control circuits for the planar electrodes arranged on the second base.

49. The angular rate sensing device of claim 35 further comprises a third base, and control circuits for the driving electrodes and the sensing electrodes arranged on the third base, wherein the first base, the second base and the third base are bonded together, and the material of the third base is silicon-based material or glass.

50. The angular rate sensing device of claim 35, wherein the material of the base is silicon-based material or glass, and that of the vibrator is silicon-based material or metal.