Determining and compensating for modulator dynamics in interferometric fiber-optic gyroscopes

• US 8,102,536 B2
• Filed: 12/09/2010
• Issued: 01/24/2012
• Est. Priority Date: 01/22/2007
• Status: Active Grant

• Current Assignee: Charles Stark Draper Laboratory Incorporated
• Original Assignee: Charles Stark Draper Laboratory Incorporated
• Inventors: Ward, Paul A., Kishinevsky, Michael, Soucy, Matthew, Smith, Stephen P., Zarinetchi, Farhad
• Primary Examiner(s): Lee, Hwa
• Application Number:
  US12/963,977
• Publication Number:
  US 20110102801A1
• Time in Patent Office: 411 Days
• Field of Search: 356459-476
• US Class Current: 356/460
• CPC Class Codes: G01C 19/726 Phase nulling gyrometers, i.e. compensating the Sagnac phase shift in a closed loop system

Abstract

Determining linear modulator dynamics in an interferometric fiber-optic gyroscope may be accomplished by applying a stimulus at a point within the gyroscope, observing a response in an output of the gyroscope, and determining, from the observed response, the linear modulator dynamics.

Claims

1. An interferometric fiber-optic gyroscope, comprising:

a phase modulator; and

a digital pre-emphasis filter for pre-filtering a drive signal before it drives the phase modulator, thereby compensating for linear modulator dynamics present in the interferometric fiber-optic gyroscope.

2. The interferometric fiber-optic gyroscope of claim 1 further comprising a means for determining a transfer function of the phase modulator.

3. The interferometric fiber-optic gyroscope of claim 2, wherein the digital pre-emphasis filter multiplies the drive signal by an inverse of the transfer function.

4. A method for compensating a frequency-dependent complex gain of a phase modulator, comprising:

applying a first signal to a phase modulator located within an interferometric fiber-optic gyroscope;

determining a transfer function of the phase modulator based, at least in part, on a response in an output of the interferometric fiber-optic gyroscope to the first signal; and

multiplying a drive signal of the phase modulator with an inverse of the transfer function.

5. An interferometric fiber-optic gyroscope, comprising:

a phase modulator; and

a means for multiplying a drive signal for the phase modulator with an inverse of a transfer function of the phase modulator before the drive signal drives the phase modulator, thereby compensating for linear modulator dynamics present in the interferometric fiber-optic gyroscope.

6. The interferometric fiber-optic gyroscope of claim 5 further comprising a means for determining the transfer function of the phase modulator.