数字闭环光纤陀螺输出滤波器设计

Design of output filter of digital closed-loop fiber optic gyroscopes

在数字闭环光纤陀螺中,数字输出信号由高抽样率的反馈信号抽取得到,为避免抽取过程中发生频域混迭,应加入输出滤波器对信号进行低通滤波。根据多抽样率数字信号理论,采用多级抽取滤波器的设计方法,为陀螺设计输出滤波器。和一级低通滤波器比较说明,所设计的三级抽取滤波器,运算量小、滤波效果好。测试结果表明,加入输出滤波器不改变陀螺静态特性,抑制了振动时引起的高频误差,提高了陀螺精度。

The output of digital closed-loop fiber optic gyroscope （FOG） was decimated from a high sample rate feedback signal. To avoid alias in frequency domain during decimation process, a low-pass filter was needed. A multi-stage decimation filter was designed on the theory of multi-rate digital signal processing. Compared with the one stage low-pass filter, the designed three stage decimation filter has much less computation and better filter character. The testing results show that the designed decimation filter did not change the static performance of the fiber optic gyroscope, but it suppressed the high frequency error caused by vibration, and improved the precision of the fiber optic gyroscope.