基于空间三轴激光陀螺的恒速偏频寻北技术

Constant-Rate Biased North Finding Technique Based on Monolithic Triaxial Ring Laser Gyro

激光陀螺特有的闭锁效应使得其在应用中必须采取偏频去锁的方法,速率偏频技术可以有效降低激光陀螺随机游走误差,提高测量精度。基于空间三轴激光陀螺自身特有的三轴正交斜置特性,采用恒速偏频方法,通过建立新的系统误差方程,引入刻度系数误差状态量,采用卡尔曼滤波方法实现了系统的高精度寻北。这种初始对准方法对准速度快,对准精度也有较大提高,5min寻北精度能达到90″(3σ)。

To reduce or eliminate the lock-in effect of Laser Gyro, biasing is commonly used in engineering applications. With rate-bias technique, all the random walk errors can be virtually decreased and the measuring accuracy can be improved. Based on the orthogonal-diagonal lattice of the monolithic triaxial ring laser gyro, with constant-rate biased technique, new equations for Strapdown Inertial Navigation Sys- tem are built and scale factor error is imported as the state variable, and finally high precision north find- ing is realized by using Kalman filter method. Experiment result shows that this initial alignment method can not only speed up convergence, but also improve estimation accuracy. And the north finding precision can achieve 90 seconds of arc（3a） in five minutes.