振动式微机械陀螺动态特性光学测试

Optical Testing of Dynamic Characteristics of a Micro-Machined Vibratory Gyroscope

针对振动式微机械陀螺的设计过程中对微振子动态特性的精确评价问题,提出一种测量微振子动态特性的光学方法。该方法利用高速摄像机获取陀螺微振子在振动时的时间序列图像,然后采用数字图像相关技术对序列图像进行相关计算,以获得微振子在大气中振动的位移、速度和加速度曲线,并由此计算微振子的固有频率和品质因数。该方法对位移的分辨力在亚微米量级,具有较高的测量精度。对文中被测陀螺驱动模态的固有频率测量结果为2061.67 Hz,大气压下的品质因数测量结果为66.67。提出的方法可为微陀螺动态特性的测量提供一种精确、有效的途径。

To evaluate precisely the dynamic characteristics of the resonator of a micro-machined vibratory gyroscope during its design process, an optical method for measuring the dynamic characteristics of a micro-resonator is proposed. In the proposed method, a digital image correlation technique is used to calculate the correlation coefficients among the temporal series images of the micro-resonator captured using a high-speed video camera in order to acquire the displacement, velocity and accelerator curves of the micro-resonator in the atmosphere, and then the natural frequency and the quality factor of the micro-resonator is obtained accordingly. The proposed approach has a high precision since the vibrating displacement is measured at submicrometer resolution. The natural frequency and the quality factor in atmosphere for the driving mode of the tested gyroscope are measured as 2061.67 Hz and 66.67 respectively. The present method may provide an accurate and effective measurement tool for the evaluation of the dynamic characteristics of a micro-machined vibratory gyroscope.