Pendulous oscillating gyroscopic and accelerometer multisensor and amplitude oscillating gyroscope

• US 5,712,426 A
• Filed: 10/16/1995
• Issued: 01/27/1998
• Est. Priority Date: 08/03/1993
• Status: Expired due to Term

• Current Assignee: Milli Sensor Systems & Actuators, Inc.
• Original Assignee: Milli Sensor Systems & Actuators, Inc.
• Inventors: Sapuppo, Michele S., Reed, Thomas E., Cardarelli, Donato
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Kwok, Helen C.
• Application Number:
  US08/551,878
• Time in Patent Office: 834 Days
• Field of Search: 73/504.3, 73/504.2, 73/504.09, 73/504.12, 73/504.18, 73/510, 73/511, 73/514.01, 73/514.02, 74/5 R, 74/5.34
• US Class Current: 73/504.03
• CPC Class Codes: G01C 19/42 for indicating rate of turn; for integrating rate of turn
• CPC Class Codes: G01P 15/13 by measuring the force required to restore a proofmass subjected to inertial forces to a null position
• CPC Class Codes: G01P 15/14 by making use of gyroscopes gyroscopes per se G01C19/00

Abstract

A pendulous oscillating gyroscope and accelerometer multisensor having an accelerometer input axis and a gyroscopic input axis, comprising: a fixed case; a servo driven member mounted to the case for sinusoidal oscillation about an accelerometer servo axis which is the same as the gyroscopic input axis; a torque summing member mounted to the servo driven member to allow rotational motion about an output axis transverse to the servo axis; a rotor driven member mounted to the torque summing member for sinusoidal oscillation about a reference axis transverse to both the output axis and the servo axis; and a pendulosity carried by at least one of the torque summing member and the rotor driven member to create a mass imbalance about an output axis, in which pendulosity torque due to acceleration along the accelerometer input axis causes a DC rotation of the torque summing member about the output axis. The rotor driven member is sinusoidally oscillated about the reference axis, and the servo driven member is sinusoidally oscillated about the servo axis. The two sinusoidal oscillations create a first gyroscopic torque, which causes DC rotation of the torque summing member about the output axis, and in which DC rotation of the fixed case about the gyroscopic input axis creates a second gyroscopic torque, which causes an AC oscillation of the torque summing member about the output axis. A measurement device determines the rotational motion of the torque summing member about the output axis. A controller responsive to the measurement device alters the oscillation of at least one of the oscillating members to create change in the first gyroscopic torque to counterbalance pendulosity torque. Acceleration along the input axis, and rotation about the servo axis, are both determined.

Claims

1. A pendulous oscillating gyroscope and accelerometer multisensor having an accelerometer input axis and a gyroscopic input axis, comprising:

a fixed case;

a servo driven member mounted to said case for sinusoidal oscillation about an accelerometer servo axis which is the same as the gyroscopic input axis;

a torque summing member mounted to said servo driven member to allow rotational motion about an output axis transverse to said servo axis;

a rotor driven member mounted to said torque summing member for sinusoidal oscillation about a reference axis transverse to both said output axis and said servo axis;

a pendulosity carried by at least one of said torque summing member and said rotor driven member to create a mass imbalance about the output axis, in which pendulosity torque due to acceleration along the accelerometer input axis causes a DC rotation of said torque summing member about said output axis;

first oscillation means for sinusoidally oscillating said rotor driven member about said reference axis, the oscillation having a first amplitude, a first frequency and a first phase;

second oscillation means for sinusoidally oscillating said servo driven member about said servo axis, the oscillation having a second amplitude, a second frequency and a second phase;

wherein the oscillations of said rotor driven member and of said servo driven member create a first gyroscopic torque, which causes DC rotation of said torque summing member about said output axis, and wherein DC rotation of said fixed case about said gyroscopic input axis creates a second gyroscopic torque, which causes an AC oscillation of said torque summing member about said output axis;

measurement means for determining the rotational motion of said torque summing member about said output axis;

control means, responsive to said measurement means, for altering the oscillation of at least one of said first and second oscillation means to create a change in said first gyroscopic torque to counterbalance pendulosity torque;

means, responsive to said control means, for determining acceleration of said multisensor along said accelerometer input axis; and

means, responsive to said measurement means, for determining the rotational rate of said multisensor about said gyroscopic input axis.

2. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first frequency and said second frequency are the same.

3. The pendulous oscillating gyroscope and accelerometer multisensor of claim 2 in which the phase difference of the oscillations of said rotor driven member and of said servo driven member is constant.

4. The pendulous oscillating gyroscope and accelerometer multisensor of claim 3 in which said control means alters at least one of said first and second amplitudes.

5. The pendulous oscillating gyroscope and accelerometer multisensor of claim 2 in which said control means alters the phase difference between the first phase and the second phase.

6. The pendulous oscillating gyroscope and accelerometer multisensor of claim 2 in which said control means alters both said first and second frequencies together.

7. The pendulous oscillating gyroscope and accelerometer multisensor of claim 6 in which said control means maintains said first and sensor amplitudes constant.

8. The pendulous oscillating gyroscope and accelerometer multisensor of claim 6 in which said control means maintains the phase difference between the first phase and the second phase constant.

9. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first oscillation means oscillates said rotor driven member at resonance.

10. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said second oscillation means oscillates said servo driven member at resonance.

11. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first oscillation means oscillates said rotor driven member at resonance, and said second oscillation means oscillates said servo driven member at resonance.

12. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first and said second oscillation means are both electromagnetic drives.

13. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first oscillation means is an electromagnetic drive and said second oscillation means is an electrostatic drive.

14. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 further including means for determining the oscillation of said rotor driven member about said reference axis.

15. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first oscillation means is an electrostatic drive and said second oscillation means is an electromagnetic drive.

16. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said first and said second oscillation means are both electrostatic drives.

17. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said measurement means includes a non-contact measurement device.

18. The pendulous oscillating gyroscope and accelerometer multisensor of claim 17 in which said measurement device is capacitive.

19. The pendulous oscillating gyroscope and accelerometer multisensor of claim 17 in which said measurement device is electromagnetic.

20. The pendulous oscillating gyroscope and accelerometer multisensor of claim 17 in which said measurement device is optical.

21. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 further including means for determining the oscillation of said servo driven member about said servo axis.

22. The pendulous oscillating gyroscope and accelerometer multisensor of claim 1 in which said means for determining rotation includes a phase sensitive demodulator for producing a signal related to the angular rate of rotation of said pendulous oscillating gyroscope and accelerometer about said servo axis.

23. The pendulous oscillating gyroscope and accelerometer multisensor of claim 22 in which said phase sensitive demodulator has two inputs, one from said measurement means, and one from at least one of said first and second oscillation means.

24. A pendulous oscillating gyroscope, comprising:

a fixed case;

a torque summing member mounted to said case for rotation about an output axis;

a rotor driven member mounted to said torque summing member for sinuodial oscillation about a reference axis transverse to said output axis;

oscillation means for oscillating said rotor driven member about said reference axis, the oscillation having an amplitude and a frequency;

measurement means for determining the rotational motion of said torque summing member about said output axis caused by rotation of said gyroscope about an input axis transverse to both said output axis and said reference axis; and

means, responsive to said measurement means, for determining rotation of said gyroscope about said input axis.

25. The pendulous oscillating gyroscope of claim 24 in which said means for determining rotation is further responsive to said oscillation means.

26. The pendulous oscillating gyroscope of claim 25 in which said means for determining rotation includes a phase sensitive demodulator for producing a signal related to the angular rate of rotation of said gyroscope about said input axis.

27. The pendulous oscillating gyroscope of claim 24 further including control means for altering said oscillation means to maintain the rotor driven member oscillation amplitude constant.

28. The pendulous oscillating gyroscope of claim 24 in which said rotor driven member is a generally planar member mounted by a plurality of spaced flexures to said torque summing member, and said torque summing member is generally planar, and the reference axis is normal to the rotor driven member, whereby the oscillation of said rotor driven member is within the plane of said rotor driven member.

29. The pendulous oscillating gyroscope of claim 28 in which said torque summing member is a generally planar member surrounding said rotor driven member, and is pivotably mounted to said fixed case to pivot about the output axis.

30. The pendulous oscillating gyroscope of claim 24 in which said rotor driven member is generally planar and is pivotably mounted within said torque summing member, to pivot about the reference axis.

31. The pendulous oscillating gyroscope of claim 30 in which said torque summing member is a generally planar member and is mounted by a plurality of spaced flexures to said fixed case, and the output axis is normal to the torque summing member, whereby the torque summing member pivots within its plane about the output axis.

32. The pendulous oscillating gyroscope of claim 24 in which said rotor driven member is pivotably mounted within said torque summing member, to pivot about the reference axis, and said rotor driven member and said torque summing member are each generally planar.

33. The pendulous oscillating gyroscope of claim 32 in which said torque summing member is pivotably mounted to said fixed case, to pivot about the output axis.

34. A pendulous oscillating gyroscope and accelerometer multisensor having an accelerometer input axis and a gyroscopic input axis, comprising:

a fixed case;

a generally planar servo driven member mounted to said case for sinusoidal oscillation within the plane of said servo driven member and about an accelerometer servo axis which is the same as the gyroscopic input axis;

a generally planar torque summing member mounted to said servo driven member to allow rotational motion about an output axis transverse to said servo axis;

a generally planar rotor driven member mounted to said torque summing member for sinusoidal oscillation about a reference axis transverse to both said output axis and said servo axis;

a pendulosity carried by at least one of said torque summing member and said rotor driven member to create a mass imbalance about the output axis, in which pendulosity torque due to acceleration along the accelerometer input axis causes a DC rotation of said torque summing member about said output axis;

first oscillation means for sinusoidally oscillating said rotor driven member about said reference axis, the oscillation having a first amplitude, a first frequency and a first phase;

second oscillation means for sinusoidally oscillating said servo driven member about said servo axis, the oscillation having a second amplitude, a second frequency and a second phase;

wherein the oscillations of said rotor driven member and of said servo driven member create a first gyroscopic torque, which causes DC rotation of said torque summing member about said output axis, and wherein DC rotation of said fixed case about said gyroscopic input axis creates a second gyroscopic torque, which causes an AC oscillation of said torque summing member about said output axis;

measurement means for determining the rotational motion of said torque summing member about said output axis;

control means, responsive to said measurement means, for altering the oscillation of at least one of said first and second oscillation means to create a change in said first gyroscopic torque to counterbalance pendulosity torque;

means, responsive to said control means, for determining acceleration of said multisensor along said accelerometer input axis; and

means, responsive to said measurement means, for determining the rotational rate of said multisensor about said gyroscopic input axis.

35. A pendulous oscillating gyroscope and accelerometer multisensor having an accelerometer input axis and a gyroscopic input axis, comprising:

a fixed case;

a generally planar servo driven member mounted to said case for sinusoidal oscillation about an accelerometer servo axis which is the same as the gyroscopic input axis;

a generally planar torque summing member mounted to said servo driven member to allow rotational motion within the plane of said torque summing member and about an output axis transverse to said servo axis;

a generally planar rotor driven member mounted to said torque summing member for sinusoidal oscillation about a reference axis transverse to both said output axis and said servo axis;

a pendulosity carried by at least one of said torque summing member and said rotor driven member to create a mass imbalance about the output axis, in which pendulosity torque due to acceleration along the accelerometer input axis causes a DC rotation of said torque summing member about said output axis;

first oscillation means for sinusoidally oscillating said rotor driven member about said reference axis, the oscillation having a first amplitude, a first frequency and a first phase;

second oscillation means for sinusoidally oscillating said servo driven member about said servo axis, the oscillation having a second amplitude, a second frequency and a second phase;

wherein the oscillations of said rotor driven member and of said servo driven member create a first gyroscopic torque, which causes DC rotation of said torque summing member about said output axis, and wherein DC rotation of said fixed case about said gyroscopic input axis creates a second gyroscopic torque, which causes an AC oscillation of said torque summing member about said output axis;

measurement means for determining the rotational motion of said torque summing member about said output axis;

control means, responsive to said measurement means, for altering the oscillation of at least one of said first and second oscillation means to create a change in said first gyroscopic torque to counterbalance pendulosity torque;

means, responsive to said control means, for determining acceleration of said multisensor along said accelerometer input axis; and

means, responsive to said measurement means, for determining the rotational rate of said multisensor about said gyroscopic input axis.

36. A pendulous oscillating gyroscope and accelerometer multisensor having an accelerometer input axis and a gyroscopic input axis, comprising:

a fixed case;

a generally planar servo driven member mounted to said case for sinusoidal oscillation about an accelerometer servo axis which is the same as the gyroscopic input axis;

a generally planar torque summing member mounted to said servo driven member to allow rotational motion about an output axis transverse to said servo axis;

a generally planar rotor driven member mounted to said torque summing member for sinusoidal oscillation within the plane of said rotor driven member and about a reference axis transverse to both said output axis and said servo axis;

a pendulosity carried by at least one of said torque summing member and said rotor driven member to create a mass imbalance about the output axis, in which pendulosity torque due to acceleration along the accelerometer input axis causes a DC rotation of said torque summing member about said output axis;

first oscillation means for sinusoidally oscillating said rotor driven member about said reference axis, the oscillation having a first amplitude, a first frequency and a first phase;

second oscillation means for sinusoidally oscillating said servo driven member about said servo axis, the oscillation having a second amplitude, a second frequency and a second phase;

wherein the oscillations of said rotor driven member and of said servo driven member create a first gyroscopic torque, which causes DC rotation of said torque summing member about said output axis, and wherein DC rotation of said fixed case about said gyroscopic input axis creates a second gyroscopic torque, which causes an AC oscillation of said torque summing member about said output axis;

measurement means for determining the rotational motion of said torque summing member about said output axis;

control means, responsive to said measurement means, for altering the oscillation of at least one of said first and second oscillation means to create a change in said first gyroscopic torque to counterbalance pendulosity torque;

means, responsive to said control means, for determining acceleration of said multisensor along said accelerometer input axis; and

means, responsive to said measurement means, for determining the rotational rate of said multisensor about said gyroscopic input axis.