SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  AF071-216 (AirForce)
Title:  Precision Navigation Grade Fiber-Optic Gyroscope (FOG)
Research & Technical Areas:  Sensors, Electronics

  STATEMENT OF INTENT: Improve Fiber-optic gyroscopes
  Objective:  Develop a FOG which significantly reduces error sources such as noise and phase bias drift commonly found in today’s FOGs.
  Description:  Gyroscopes and accelerometers are the critical components in an inertial measurement unit (IMU). A promising approach to precision gyroscopes that has not met expectations is the Sagnac interferometric fiber-optic gyroscope (FOG). A FOG is typically made with an optical fiber which guides light around a loop forming the interferometer. The basic concept splits light into two waves which pass around a fiber coil in opposite directions. When light returns to a coupler, the waves are split and sent to a detector. The intensity of the light at the detector is a direct measure of the interference between the two counterrotating beams and, thus, an indication of the rotation rate of the FOG. FOGs are more reliable and less costly inertial sensors than mechanical gyroscopes and ring laser gyroscopes (RLGs). However, current manufacturing techniques require skilled manual labor which negatively impacts the low cost potential of these devices. In addition, error sources due to the fiber, the light source, and the architecture of the gyro have prevented FOGs from achieving the navigation-grade performance originally sought. A new, novel approach to the FOG fiber, and/or light source, and/or architecture is desired to develop and produce a high performance navigation grade FOG. In general, the goal of the program is to significantly improve the error performance (for example, gyro bias < 0.001 °/h) over production FOGs currently available today, while maintaining current size, weight, and power requirements.

  PHASE I: Identify the critical technology challenges, synthesize advanced architectures, perform concept feasibility analysis and define the Phase II approach.
  
  PHASE II: The Phase II effort will produce and demonstrate the precision navigation-grade FOG.

  DUAL USE COMMERCIALIZATION: Military application: A navigational-grade FOG has the potential to positively impact military and civilian inertial navigation units. Commercial application: These high-precision FOGs would provide a highly reliable, small size, low power, and low cost solution to current navigational requirements.

  References:  1. E.J. Post, Rev. Modern Physics, volume 39, page 475 (1967) 2. H. J. Arditty and H. C. Lefevre, Optics Letters, volume 6, page 401, (1981) 3. S. Ezekiel and S.R. Balsamo, Applied Physics Letter, volume 30, page 478, (1977)

Keywords:  guidance, navigation, control sensors, electronics

Questions and Answers:
Q: 1. Can you give us some ranges for "current size, weight, and power requirements"?

2. Can you be more specific as to desired error performance, ie, random walk coefficient, time period for maintaining quoted bias stability, temperature range, etc.?
A: 1. There is no range for size, weight, and power at this point but smaller, lighter, and less power are more anticipated.

2. The goal of this program is; Bias Drift stability is less then 0.001 deg/hr, G-sensitive bias drift is less then 0.005 deg/hr/g, Angular Cross-axis sensitivity is less than 0.1 %, Operating Temperature range is -54 to 85 deg C.
Q: 1. Can you give us some ranges for "current size, weight, and power requirements"?

2. Can you be more specific as to desired error performance, ie, random walk coefficient, time period for maintaining quoted bias stability, temperature range, etc.?
A: 1. There is no range for size, weight, and power at this point but smaller, lighter, and less power are more anticipated.

2. The goal of this program is; Bias Drift stability is less then 0.001 deg/hr, G-sensitive bias drift is less then 0.005 deg/hr/g, Angular Cross-axis sensitivity is less than 0.1 %, Operating Temperature range is -54 to 85 deg C.

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