Localized thermal tuning in fused silica inductive vibrating ring gyroscopes

Area of Science:

• Mechanical Engineering
• Materials Science
• Physics

Background:

• Inductive vibrating ring gyroscopes (IVRGs) offer superior shock tolerance over capacitive types, ideal for harsh environments.
• High-precision IVRG operation requires minimizing frequency split between degenerate modes to prevent errors.
• Conventional electrostatic tuning is incompatible with electromagnetic IVRG configurations.

Purpose of the Study:

• To propose and validate a localized thermal tuning technique for real-time frequency adjustment in IVRGs.
• To address the limitations of traditional tuning methods in electromagnetic gyroscope designs.
• To enhance the precision and reliability of IVRGs for demanding applications.

Main Methods:

• Developed a localized thermal tuning technique using patterned electrodes for controlled Joule heating.
• Utilized the temperature-dependent Young's modulus of fused silica for frequency adjustment.
• Employed finite element simulations to optimize electrode design and minimize thermal coupling.
• Fabricated and characterized prototype IVRGs with localized thermal electrodes.

Main Results:

• Achieved efficient frequency split suppression, reducing the split to 14 mHz.
• Significantly reduced angle-dependent bias from 0.928°/s to 0.146°/s.
• Improved scale factor nonlinearity from 4321 ppm to 61.3 ppm and bias instability from 4.8°/h to 0.67°/h.
• Demonstrated robust performance across -40°C to 60°C with negligible impact on quality factor.

Conclusions:

• Localized thermal tuning is a viable and effective strategy for inductive vibrating ring gyroscopes.
• This technique enables real-time frequency adjustment, crucial for high-precision whole-angle mode operation.
• The method enhances IVRG performance, paving the way for improved inertial measurements in harsh environments.