总方差方法在光纤陀螺随机误差分析中的应用

Applications of Total Variance Method in Random Error Analysis of the Fiber Optic Gyro Signal

总方差方法被引入到光纤陀螺随机误差特性分析当中,有效克服了传统Allan方差法在长相关时间上计算易出现"崩溃"的问题。但用它直接分析光纤陀螺随机噪声存在算法偏差,不能真实反映角度随机游走噪声、量化噪声和指数相关噪声方差值,因此在算法上对总方差提出改进,使其适用于光纤陀螺噪声分析。对模拟的各项随机噪声进行仿真计算,验证改进后总方差方法可有效辨识噪声类型和水平。对光纤陀螺实测数据方差分析表明改进的总方差方法在平均因子较大的情况下可提高估计置信度,方差值稳定性好,比Allan方差法能更精确地分析出噪声项系数。

Total variance is used to analyze the random noise of Fiber Optic Gyroscope（FOG）,which efficiently solves the problem that the Allan variance calculation is easy to be unstable at long-term τ values.But there is algorithm error with total variance when analyzing the random noise of FOG directly,which cannot really reflect the variances of rate random walk noise,quantization noise and exponentially correlated noise.So an improved method based on total variance is presented to suit random noise analysis of FOG.The estimation performance with the simulated random noise shows that the improved total variance can efficiently identify the noise types and levels.According to the analysis of measured FOG signal,it can improve the confidence in the case of great mean index,the values of variance have a good stability,and it is better and more exact than Allan Variance in identifying noise coefficient.