Zhai Dede, Guo Jingyang, Chen Shanyong, Lu Wenwen
Appl Opt. 2022 Oct 1;61(28):8435-8445. doi: 10.1364/AO.467742.
Hemispherical resonant gyroscopes (HRGs) are solid-state vibration gyroscopes with the highest precision and are widely used in the aerospace field. The core part of the gyroscope is the resonator, which is a thin-walled hemispherical shell. Surface error and thickness variation of a hemispherical shell causes frequency splitting, which degrades the performance of the HRG. In order to guide the mass leveling of hemispherical resonator, this paper presents a new method for scanning measurement of the surface error and thickness variation of hemispherical resonators. First, a multi-axis platform is designed for noncontact sensor scanning measurements along the meridian and latitudinal lines of the hemispherical resonator. Second, the error model of the measurement system is established. The surface error of the standard sphere is measured to calibrate and compensate for the assembly errors of the measuring device. In addition, the identification accuracy of assembly errors and the influence of assembly errors on thickness measurement are simulated by a computer. Finally, the surface error and thickness variation of the hemispherical resonators are measured. The method is experimentally demonstrated and validated with a wavefront interferometry test. The results show that the method can achieve high precision and high repeatability, which is instructive for assessment of the machining error and further evaluation of the hemispherical resonator.
半球谐振陀螺仪（HRG）是精度最高的固态振动陀螺仪，广泛应用于航空航天领域。陀螺仪的核心部件是谐振器，它是一个薄壁半球形壳体。半球形壳体的表面误差和厚度变化会导致频率分裂，从而降低HRG的性能。为了指导半球谐振器的质量调平，本文提出了一种扫描测量半球谐振器表面误差和厚度变化的新方法。首先，设计了一个多轴平台，用于沿半球谐振器的子午线和纬线进行非接触式传感器扫描测量。其次，建立了测量系统的误差模型。测量标准球体的表面误差，以校准和补偿测量装置的装配误差。此外，通过计算机模拟了装配误差的识别精度以及装配误差对厚度测量的影响。最后，测量了半球谐振器的表面误差和厚度变化。该方法通过波前干涉测试进行了实验验证。结果表明，该方法能够实现高精度和高重复性，对评估加工误差和进一步评估半球谐振器具有指导意义。
