Gyroscopes and compensation

• US 6,079,272 A
• Filed: 08/07/1998
• Issued: 06/27/2000
• Est. Priority Date: 08/13/1997
• Status: Expired due to Term

• Current Assignee: California Institute of Technology
• Original Assignee: California Institute of Technology
• Inventors: Gutierrez, Roman C., Vorperian, Vatche, Stell, Christopher B., Tang, Tony K.
• Primary Examiner(s): CHAPMAN JR, JOHN E
• Application Number:
  US09/130,696
• Time in Patent Office: 690 Days
• Field of Search: 73/504.12, 73/504.14, 73/504.15, 73/504.16, 73/504.04
• US Class Current: 73/504.12
• CPC Class Codes: G01C 19/5649 Signal processing
• CPC Class Codes: G01C 19/5719 using planar vibrating masses driven in a translation vibration along an axis
• CPC Class Codes: G01P 2015/084 the mass being suspended at more than one of its sides, e.g. membrane-type suspension, so as to permit multi-axis movement of the mass
• CPC Class Codes: G01P 2015/0842 the mass being of clover leaf shape

Abstract

A gyroscope system can detect the amount of movement of the system. The gyroscope system includes a circuit that has a number of different features and detects movement independent of any circuit parameters. The first feature uses a feedback loop to compensate for difference in Q factors between the circuits. Another feature regulates the amplitude of the resonator. Yet another feature extracts the rotation rate signals from the gyroscope in a new way.

Claims

1. A gyroscope circuit, comprising:

a resonator having a variable capacitor;

an outputting element configured to drive said resonator;

a receiving element configured to receive a signal from the resonator indicative of a movement to be detected;

a reference; and

a feedback loop that establishes an amount of drive to the resonator based on the signal from the resonator and said reference, said feedback loop including an element operating to hold a voltage on the capacitor constant, such that a charge on the capacitor varies when its capacitance is varied.

2. A circuit as in claim 1, wherein said feedback loop comprises a first circuit that establishes a peak output indicative of a peak received value on said input, a first amplifier, and a second amplifier, said first amplifier producing a control signal used to control the gain of said second amplifier, such that said second amplifier produces a driving output indicative of a difference between said peak output and said reference, said driving output used for driving said resonator, to thereby produce a larger output from said resonator to thereby increase said input and hence said peak received value and thereby reduce said difference.

3. A circuit as in claim 1, wherein said element in said feedback loop causes a charge on said variable capacitor to vary based on said movement to be detected.

4. A circuit as in claim 2, further comprising a element for providing an output signal indicative of rotation rate and which is based on both amplitude and phase of a signal from said resonator.

5. A gyroscope circuit, which operates based on an output from a gyroscope element, comprising:

a gyroscope element, including a variable capacitor, which produces an output indicative of movement to be measured; and

a sensing circuit that produces an output indicative of the movement based on both amplitude and phase detected from the gyroscope element, said sensing circuit configured to hold a voltage on the capacitor constant, such that a charge on the capacitor varies based on movement of the variable capacitor.

6. A gyroscope circuit, which operates based on an output from a gyroscope element, comprising:

a gyroscope element that produces an output indicative of movement to be measured;

at least one amplifier, including transconductance amplifiers, which operates to produce signals indicative of first and second parts of movement from said gyroscope element;

a summing circuit, summing said first and second parts;

a differencing circuit, differencing said first and second parts; and

a detection circuit, producing a movement indicative output based on outputs of both said summing circuit and said differencing circuit.

7. A method of detecting movement, comprising:

obtaining an output signal from a gyroscope element indicative of movement to be measured said obtaining including using a variable capacitor associated with said gyroscope, such that a voltage on the capacitor is held constant to vary a charge on the capacitor; and

using both an amplitude and a phase of the output signal to detect the movement.