Low Cost Inertial Rate Sensors with Long Term Stability

The Air Force is seeking rate sensors that can provide long term stability for augmenting antenna pedestal gyro units and replacing overly expensive devices used to overcome attitude limitations in existing inertial navigators. IFOS proposes to develop an innovative fiber-optic gyro (FOG) with excellent long-term stability features from a light-weight, compact and low-cost device. The proposed device will be designed to also counteract vibration environments typically encountered in inertial navigation platforms, which could have frequency contents as high as 1 kilohertz. Phase I proposes to demonstrate a proof-of-concept two-axis open -loop FOG prototype comprising a polarization maintaining coiled fiber, a specially designed phase modulator an ultra-efficient optical source, and packaging designed to minimize size and weight. Preliminary experiments will be undertaken to establish feasibility of achieving the requisite stability and attitude accuracy over a period of several hours. IFOS has also initiated a collaborative effort with a prime contractor to incorporate the proposed FOG into a demonstration IMUs that can provide high-resolution Line-of-Sight (LOS) stabilization, with better than 1-deg attitude accuracy over the requisite temperature range. This effort is expected to culminate in Phase II designs and test protocols for a FOG-based IMU functioning as a complete navigation grade unit. BENEFIT: proposed IFOS FOGs for IMUs will have significantly enhanced stability, lighter weight and ruggedized components designed to meet specifications for inertial navigation systems. Such high performance, robust and cost-effective gyroscopes will also have significant impact on LOS stabilization systems for radiometry, isolated space platforms and many other DOD applications including for MDA’s ballistic missile defense systems. Non-DoD applications include active suspension systems, large 6-degrees-of-freeedom (DOF) vibration test systems, manufacturing robotic control sensors, stabilization for apertures or antennas used for pointing, tracking, surveillance and communications as well as commercial aircraft inertial navigation systems (INS).