FULLY BALANCED MICRO-MACHINED INERTIAL SENSOR

• US 20160084654A1
• Filed: 09/23/2015
• Published: 03/24/2016
• Est. Priority Date: 09/24/2014
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Senkal, Doruk, Zotov, Sergei A., Shkel, Andrei M.
• Granted Patent: US 10,247,554 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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

Abstract

The improvement includes an outer proof mass having a corresponding center of mass; and an inner proof mass having a corresponding center of mass, where the corresponding centers of mass of the outer proof mass and the inner proof mass are approximately co-located. Thus, a double Foucault pendulum is essentially provided in a micromachined gyroscope.

Claims

1. An improvement in a vibratory structure gyroscope comprising:

an outer proof mass having a corresponding center of mass; and

an inner proof mass having a corresponding center of mass, where the corresponding centers of mass of the outer proof mass and the inner proof mass are approximately co-located.

2. The improvement of claim 1, where the inner proof mass is nested within the outer proof mass.

3. The improvement of claim 1,

where the inner proof mass is in the shape of a rectangular prism and the outer proof mass is in the shape of a frame;

where the inner proof mass is in the shape of a disk and outer mask is in the shape of a ring;

where both the inner proof mass and outer proof mass are in the shape of a frame;

where both the inner and outer proof masses are in the shape of rings;

or

where the inner and outer proof masses are in the shape of multiple concentric rings coupled to each other through spokes.

4. The improvement of claim 1, further comprising:

actuators which vibrate the inner and outer proof masses in anti-phase translational motion;

or

actuators which vibrate the inner and outer proof masses in a higher order Wineglass or Lame mode.

5. The improvement of claim 1, further comprising actuators which vibrate the two proof masses in synchronicity.

6. The improvement of claim 5, further comprising a flexural connection between inner and outer proof masses and where the synchronization of the vibratory motion is accomplished by the flexural connection between inner and outer proof masses.

7. The improvement of claim 6, further comprising means for utilizing a closed loop algorithm acting on the inner and outer proof masses to synchronize the vibratory motion.

8. The improvement of claim 1, further comprising:

means for vibrating the inner and outer proof masses in an anti-phase linear vibratory motion with approximately equal inertial forces, such that the net force generated due to vibratory motion is approximately zero;

means for vibrating the inner and outer proof masses in an in-phase linear vibratory motion such that the net force generated due to vibratory motion is non-zero;

means for vibrating the inner and outer proof masses in an anti-phase torsional vibratory motion with approximately equal rotational inertia, such that the net torque generated due to vibratory motion is approximately zero;

means for vibrating the inner and outer proof masses in an in-phase torsional vibratory motion such that the net torque generated due to vibratory motion is non-zero;

means for sensing linear motion of the inner and outer proof masses along x, y or z axis to measure angular velocity of the gyroscope along x, y or z axis;

means for sensing linear motion along x, y or z axis to measure linear acceleration of the gyroscope along x, y or z axis;

means for sensing torsional motion along x, y or z axis of the inner and outer proof masses to measure angular velocity of the gyroscope along x, y or z axis;

or

means for sensing torsional motion along x, y, z axis to generate a timing reference signal.

9. The improvement of claim 1,

where the gyroscope is anchored to the inner proof mass;

where the gyroscope is anchored to the outer proof mass;

or

where the gyroscope is anchored to both the inner and outer proof masses.

10. The improvement of claim 1, further comprising:

parallel plate electrodes located on the inner and outer proof masses, which parallel plate electrodes are used to drive and sense the vibratory motion of the inner and outer proof masses through electrostatic transduction;

comb finger electrodes located on the inner and outer proof masses, which comb finger electrodes are used to drive and sense the vibratory motion through electrostatic transduction;

or

electrodes coupled to the inner and outer proof masses and a plurality of shuttles coupled to the inner and outer proof masses for the purpose of decoupling vibratory motion from the electrodes.

11. The improvement of claim 1, further comprising a pressure membrane and a mechanical element coupled to the pressure membrane to measure pressure in addition to inertial forces.

12. The improvement of claim 1, further comprising a source of current coupled to the mechanical element making the mechanical element sensitive to magnetic fields, changing vibration amplitude, phase or frequency of the inner and outer proof masses in the presence of magnetic fields.

13. An electronic device for measuring inertial force comprising:

a processor configured to calculate inertial measurements;

a memory coupled to the processor; and

a gyroscopic mechanical element comprised of two vibratory parts having a common center of mass and generating inertial information communicated to the processor, and where the center of mass of the two vibratory parts are approximately co-located.

14. The electronic device of claim 13, further comprising a pressure membrane, where the gyroscopic mechanical element is attached to the pressure membrane, generates pressure information communicated to the processor, and where the processor is configured to calculate absolute or gage pressure in addition to inertial measurements.

15. The electronic device of claim 13, further comprising a source of current coupled through the gyroscopic mechanical element, which current makes the gyroscopic mechanical element sensitive to magnetic fields and where the processor is configured to calculate magnetic fields in addition to inertial measurements.

16. The electronic device of claim 13, further comprising an absorption/desorption element coupled to the gyroscopic mechanical element, which absorption/desorption element changes the total mass or stiffness of the gyroscopic mechanical element in the presence of a specific chemical/biological substance to measure concentration of a specific chemical/biological substance in the environment.

17. An electronic device for measuring pressure comprising:

a processor configured to calculate pressure forces;

a memory coupled to the processor;

a gyroscopic sensor having two vibrator parts and providing amplitude, phase or frequency information communicated to the processor, where the two vibratory parts have an approximately matched common center of mass; and

a pressure membrane coupled to the gyroscopic sensor that changes the vibration amplitude, phase or frequency of the gyroscopic sensor proportionally to the pressure change.

18. An electronic device for measuring magnetic fields comprising:

a processor configured to calculate magnetic fields;

a memory coupled to the processor;

a gyroscopic sensor having two vibrator parts and providing amplitude, phase or frequency information communicated to the processor, where the two vibratory parts have an approximately matched common center of mass; and

a source of current coupled to the gyroscopic sensor making it sensitive to magnetic fields (Lorentz Force Magnetometer).

19. An electronic device for measuring concentration of chemical or biological substances comprising:

a processor configured to calculate an amount of chemical or biological substance in an environment;

a memory coupled to the processor;

a gyroscopic sensor having two vibrator parts and providing amplitude, phase or frequency information communicated to the processor, where the two vibratory parts have an approximately matched common center of mass; and

an absorption/desorption element coupled to the gyroscopic sensor which changes the total mass or stiffness of the gyroscopic sensor when a specific chemical/biological substance is present on or in the absorption/desorption element.