Tamim F. El-Wailly

Test results of Honeywell's first-generation high-performance interferometric fiber optic gyroscope

Honeywells first-generation, high-performance interferometric fiber-optic gyroscope (IFOG) was tested along with sensor electronics over a limited static and dynamic temperature environment. This serrodyne closed-loop IFOG consisting of polarization-maintaining fiber components and a LiNbO3 phase modulator has simultaneously achieved inertial-grade requirements for bias stability, bias repeatability, bias temperature sensitivity, bias temperature-rate sensitivity, random noise, and scale-factor error over the tested temperature range.

Miniaturized, low-cost IFOG IMU for tactical weapon applications

Honeywell, under contract to the US Air Force, has developed a 25 cubic-inch IFOG IMU brassboard which demonstrated performance of < deg/hr bias stability, < 0.05 deg/(root) hr random noise and < 250 ppm scale factor accuracy over the full military temperature range. To overcome the size constraint of 25 cubic-inch, the three-axis IFOG optical cluster was configured with the minimum IMU configuration having only eight optical components. Special loop-closure signal processing was developed to accommodate all three- axis sensor electronics within a single 3.4-inch electronic board. To achieve the IMU cost target of < 6000 dollars, the design utilizes a very lowest cost optical components such as an 830nm light source along with a 1300 nm single- mode fiber sensing coil. Further cost reduction was realized through the robust design which provides very relaxed gyro assembly tolerances. The 25 cubic-inch IFOG IMU will have sufficient performance, small size, ruggedness for high-g launch, and low unit production cost to be suitable for use in a wide variety of tactical weapon systems.

Test Results Of A Prototype Serrodyne Closed-Loop Interferometric Fiber Optic Gyroscope

The test results of a prototype serrodyne closed-loop interferometric fiber optic gyroscope are reported. The rotation sensor used a low-coherence superradiant diode at 0.85 microns wavelength with a polarization-maintaining sensing coil, polarizer and loop coupler. A wide bandwidth Ti:LiNb03 phase modulator was used to provide bias modulation and serrodyne frequency shifting. Performance of the sensor before and after loop closure is discussed. No degradation of the random walk or bias stability was noted with loop closure. The scale factor and dynamic range were improved. Various contributors to scale factor error are discussed.