机抖激光陀螺的伪圆锥运动研究

Pseudo coning motion for dithered ring laser gyro

对于机抖激光陀螺捷联惯导系统,激光陀螺的机械抖动偏频引入伪圆锥运动。本文推导了伪圆锥运动情况下等效旋转矢量的误差表达式。分析了伪圆锥误差的起因、影响因素。研究了圆锥补偿算法在伪圆锥运动中的适用性。从最小化姿态计算误差的角度,提出了机械抖动频率的设计准则,并设计数字滤波器去除抖动信号噪声。分析结果表明:合理设置抖动频率,再结合数字滤波器可以有效提高的姿态计算精度。

The mechanical dithering of ring laser gyro （RLG） brings pseudo coning motion for strapdown inertial navigation system （SINS） with dithered RLG. This paper deduces the error expressions of the rotating vector under the pseudo coning motion and analyses the origin and infection factor of pseudo coning error. The applicability of coning compensation algorithm is studied too. The design rules for dithered frequency are presented in order to minimize the attitude errors. Digital filter is designed to wipe off noise signal. The results show reasonable dithered frequency and filter design can improve attitude accuracy.