Decreasing Frequency Splits of Hemispherical Resonators by Chemical Etching

Area of Science:

• Inertial navigation systems
• Precision measurement devices
• Mechanical engineering

Background:

• Hemispherical resonator gyroscopes (HRGs) are valued for high performance, reliability, and miniaturization potential.
• Optimal HRG performance requires minimizing frequency differences between degenerate working modes.
• Existing tuning methods (mechanical, laser, ion-beam) are often costly or degrade resonator quality factors.

Purpose of the Study:

• To experimentally investigate chemical etching as a novel method for tuning HRG frequency splits.
• To provide theoretical analysis of chemical etching's effect on frequency splits and mass errors.
• To demonstrate the efficacy and practicality of chemical etching for HRG frequency tuning.

Main Methods:

• Experimental application of a chemical etching procedure to hemispherical resonators.
• Theoretical analysis correlating frequency splits with mass errors.
• Measurement of frequency splits and quality factors before and after etching.

Main Results:

• Successfully decreased frequency splits in hemispherical resonators to below 0.05 Hz.
• Demonstrated that chemical etching does not negatively impact resonator quality factors.
• Established a theoretical link between frequency splits and mass errors for chemical etching.

Conclusions:

• Chemical etching is a viable, convenient, and cost-effective method for tuning HRGs.
• This technique is suitable for producing medium-accuracy hemispherical resonator gyroscopes.
• The method requires less time and labor compared to traditional tuning approaches.