Narrow Grooves Make Tuning Fork Gyroscope Easier to Achieve Tactical-Grade

This article proposes a novel piezoelectric detection method based on flexible hinges with narrow grooves, which significantly enhance the sensitivity and resolution of tuning fork gyroscope (TFG) and make it reach tactical-grade specifications. Aimed to elevate the performance of the classic TFG (C-TFG) to tactical-grade, we introduced narrow grooves to the vibration arms in sensing direction to amplify stress concentration effects under Coriolis force, thereby improving the charge-output efficiency on sensing PZT pieces and achieving a high signal-to-noise ratio (SNR). Through simulation, we optimized the parameters of the narrow grooves (1 mm width and 1.7 mm depth finally), and the experiment shows that a 690% improvement in sensing coefficient has been achieved. It also demonstrates that major breakthroughs have been staged in the modified TFG (M-TFG) compared to the C-TFG: sensitivity is increased by 520% and reached to 92.2 mV/(°/s), angular random walk (ARW) is optimized to 0.03°/ $\surd $ h, bias drift is reduced to 5.43°/h, and resolution is improved by nearly an order (about 0.0048°/s/ $\surd $ Hz to 0.00048°/s/ $\surd $ Hz). Notably, the modified gyroscope (M-TFG) exhibits excellent long-term stability while meeting tactical-grade specifications with a practical bandwidth of 100 Hz. This research provides an innovative solution for low-cost and high-performance TFGs, with close-loop excitation and open-loop detection. At the same time, we also verified the structural optimization’s efficacy in sensitivity increase, resolution improvement.