半球谐振子超精密修调方法研究

目的 研究因谐振子质量缺陷而引起的频率裂解机制，进而对刚性轴位置进行质量高分辨率可控去除，提高陀螺精度。方法 首先基于多区域配合划分法建立半球谐振子高精度有限元仿真模型，分析质量大小与位置对谐振子频差的影响规律。其次搭建谐振子振动特性检测平台，利用拍频法实现其频差值和刚性轴位置的精确辨识。最后结合仿真与辨识结果以及离子束加工方法确定谐振子超精密修调方案。结果 优化网格划分方法后，谐振子有限元模型频差值小于0.000 1 Hz，当修调定位误差相同时，在一个范围内的质量去除比单点质量去除的修调效率更高；谐振子质量缺陷四次谐波刚性轴位置辨识精度可达0.1°，与常见的幅值法相比，其精度提高了一个数量级；通过三次点线结合方式进行质量修调后，谐振子频差值小于0.001 Hz，修调效率与精度得到了提升。结论 提出的谐振子仿真模型、振动特性测试方法以及离子束修调工艺精度较高且可行性较强，对实现半球谐振子性能高精度检测以及高质量加工具有重要意义。

Method of Ultra-precision Modification and Levelling of Hemispherical Harmonic Resonators

The work aims to study the frequency splitting mechanism caused by quality defects of the resonator and conduct high-resolution controllable quality removal on rigid axis position to improve the accuracy of hemispherical resonant gyroscope (HRG). Firstly, a high-precision finite element simulation model of a hemispherical harmonic resonator was established based on the method of multi region coordination division, and the effect of mass size and position on the frequency difference of the harmonic resonator was analyzed. Secondly, a platform for measuring the vibration characteristics of the harmonic resonator was establish, and the frequency difference value and the position of rigid axis were accurately identified based on the beat frequency method. Finally, the ultra-precision modification and levelling scheme of the harmonic resonator was determined by combining simulation and identification results with ion beam processing methods. After optimizing the grid division method, the frequency difference value of the finite element model of the harmonic resonator was less than 0.000 1 Hz. Compared with single point removal, when the positioning error was the same, the modification efficiency of quality removal within a range was higher than that of single point quality removal. The identification accuracy of the fourth harmonic rigid axis position of the quality defect of the harmonic resonator was able to reach 0.1°, which was an order of magnitude higher than the common amplitude method. The frequency difference value of the harmonic resonator after three rounds of modification and levelling through the combination of dots and lines was less than 0.001 Hz, which improved the efficiency and accuracy of modification and levelling. The proposed harmonic resonator simulation model, vibration characteristic testing method, and ion beam tuning process have high accuracy and strong feasibility, which is of great significance for achieving high-precision detection and high-performance processing of hemispherical harmonic resonator.