Analysis and Improvement of Frequency Stabilization Characteristics of a Total Reflection Prism Laser Gyro

To rectify the low accuracy of frequency stabilization for a total reflection prism laser gyro (TRPLG), a mathematical model for TRPLG frequency stabilization was established. Wavelet filtering was introduced into the phase-sensitive demodulation process, with a 6-scale decomposition for the alternating current (AC) signal of light intensity used with the db4 wavelet. Combined with soft threshold and forced denoising, the signal-to-noise ratio (SNR) of the phase-sensitive signal was improved by 23.3%, with the accuracy of the frequency stabilization improved by 0.5 orders of magnitude. Increasing the variable gain in the forward channel stabilized the dynamic performance of the frequency stabilization control system. A temperature-compensated feed-forward control system was used to achieve full compensation for the temperature-induced frequency stabilization error, which also improved the accuracy of the frequency stabilization by 1 order of magnitude. Combined with wavelet filtering and feed-forward compensation, the optimized frequency stabilization control system improved the accuracy of frequency stabilization by 1.5 orders of magnitude compared with the original frequency stabilization control system in the full temperature range, and it improved the gyro’s accuracy by more than 40%.