数字闭环光纤陀螺死区机理研究与抑制

在数字闭环光纤陀螺中,死区产生及其附近噪声特性恶化的主要因素可以归结于施加在相位调制器上信号的串扰。根据死区产生机理的不同,提出了偏置相位调制和阶梯波反馈调制两种死区串扰误差因素的观点。通过对这两种死区误差机理的分析和比较,提出了采用模拟相加反馈方案可以避免偏置相位调制死区误差的观点。采用速率转台法测试了光纤陀螺的死区特性,验证了理论仿真和计算的正确性。最后,通过采用三角波相位抖动抑制死区误差技术,将一种高精度光纤陀螺0.08(°)/h的死区误差抑制到0.001(°)/h以下。

Analysis and Suppression of Dead Band in Digital Closed-loop Fiber Optic Gyro

In the digital closed-loop interferometric fiber optic gyro, the dead band and the increased noise result from the signal crosstalk which is applied to the phase modulator. According to the different causes, a point of view is proposed that there are two different sources causing the dead band, which are the bias modulation phase error and the step wave modulation phase error. Through the analysis and comparison of these two sources, it is proposed that there is no bias modulation phase error when using analog adding feedback method. The dead band of a fiber optic gyro is tested using the rate table, which validated the correctness of the simulation and the computation. At last a dead band of 0.08(°)/h for a high precision fiber optic gyro is suppressed under 0.001(°)/h using triangle phase jitter technique