To satisfy the engineering requirement of high precision north-finding, the north-finder based on a Rate Biased Ring Laser Gyroscope (RBRLG) and its measurement error come from the scale factor of RBRLG were studied to solve the problem on the scale factor slow change resulted from the inner temperature change and the instability of lock-in region of the RBRLG. Firstly, the change rule of scale factor was researched by a scale factor test. Then, the influence of the scale factor change on the north-finding precision was analyzed by a simulation. Finally, an online first order recursive algorithm was established to estimate the scale factor change according to the periodicity of RBRLG measurement. By introducing the platform angle measurement, the scale factor changes could be obtained. Simulated results indicate that the estimation error for the scale factor of RBRLG is less than 1 × 10-6 by the proposed algorithm, and the standard deviations of north-finding results caused by the scale factor change decrease to about 2". The experiment on the north-finder results shows that this algorithm can effectively restrain the north-finding error caused by scale factor change,and the standard deviation is about 24" for 5 min, which can basically satisfy the requirement of high precision northfinding.%为满足高精度寻北的工程需求,针对激光陀螺内部腔体温度变化和锁区不稳定性等因素会使速率偏频激光陀螺标度因数发生缓慢变化的问题,提出了在线估计标定因数的方法,并研究了速率偏频激光陀螺寻北仪及其标度因数测量误差.首先,通过标度因数实验研究其变化规律;然后,仿真分析了激光陀螺标度因数测量误差对寻北精度的影响;最后,根据陀螺测量值周期重复变化规律,提出了一种在线一阶递推估计标度因数变化的算法,通过引入单轴转台的角度测量值,得到了标度因数的变化参数.仿真分析表明,该算法对速率偏频激光陀螺标度因数变化的估计误差优于1×10-6,由标度因数变化引起的寻北标准差减小至2″左右.寻北实验结果表明,该算法能够有效抑制标度因数变化引起的寻北误差,5 min寻北标准差达到24″,基本满足高精度寻北的需求.
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