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航天器在轨运行过程中,由于内部存在多种活动部件,会使结构体产生微小角振动,微小角振动呈现振幅较小、频率较高的特点,微小角振动会造成光学载荷成像质量的下降。光纤陀螺从组成原理上具有宽频带和高灵敏度的特点,能够输出采样周期内的角度增量,可以作为微小角振动测量部件。但是,基于航天器整体时序的综合考虑,无法对光纤陀螺进行均匀采样,提出了非均匀采样条件下的频谱分析方法,将经过非均匀采样得到的整周期时间序列进行傅里叶变换,得到原始信号的幅值和频率,进而实现微小角振动的高精度检测。通过数字仿真和六自由度微振动台试验验证了上述方法的可行性,检测精度优于0.04″。
During the orbit of spacecraft, due to the existence of a variety of moving parts, the structure will produce tiny angular vibration, the tiny angular vibration presents the characteristics of small amplitude and high frequency. The vibration of the small angle will cause the degradation of the quality of optical load imaging . FOG from the composition of the principle of broadband and high sensitivity characteristics, can output the angle of the sampling period incremental, can be used as a small angular vibration measurement unit. However, considering the overall timing of the spacecraft, it is impossible to uniformly sample the optical fiber gyroscope. A spectrum analysis method under non-uniform sampling conditions is proposed. The entire periodic time series obtained through non-uniform sampling is subjected to Fourier transform to obtain the original Signal amplitude and frequency, and then to achieve high-precision detection of small angular vibration. The feasibility of the above method is verified by digital simulation and six degrees of freedom micro-shaking table test, the detection accuracy is better than 0.04 ".