FOG信号的变步长符号LMS自适应消噪方法

Variable Step-size Sign LMS Self-adaptive Filtering Method for Fiber Optic Gyro

针对光纤陀螺输出信号的随机漂移,本文提出了变步长符号LMS自适应消噪方法。结合工程实际需要,该方法在常规最小均方算法(LMS)的基础上进行了两方面改进:一方面,从提高滤波精度和稳定性角度引入输入信号的归一化功率;另一方面,从减少计算复杂性、提高算法实时性角度引入误差符号函数;并通过收敛性分析确定了变步长符号LMS算法的步长参数。某型光纤陀螺的静态实验和转动实验结果表明变步长符号LMS算法不仅可以提前确定步长参数,且在滤波稳定性、滤波精度和实时性等综合性能方面具有优越性,适合工程应用。

To reduce the random drift in Fiber Optic Gyro （FOG）, a self-adaptive filtering method called variable step-size sign Least Mean Square （LMS） algorithm was presented. Considering the practical engineering requirement, some positive work was carried on based on the traditional LMS algorithm. On one hand, normalized power value of input signal was introduced to improve filtering accuracy and stability; on the other hand, sign function of error was used as well in order to decrease calculation burden and increase real-time performance. Besides, the step-size parameter was determined by convergence analysis. The actual static and rotation experiment results indicate that the new algorithm is able to select the step-size parameter in advance and with more favorable filtering stability, accuracy and real-time performance. The variable step-size sign LMS filtering method is suitable for engineering application.