Abstract—

Ring Laser Gyroscopes (RLGs) are widely used in many airborne and navigation systems for accurate measurement of the true rotation of the body movement. But the RLG’s suffer a serious problem at low frequencies known as Lock–in frequency. To avoid lock-in problem, the RLG is vibrated mechanically to a high frequency which is known as Dithering. In order to get the true rotation of the body the dither signal has to be removed. Single stage, multistage and multirate filters are suggested to remove the dither signal. These filters have the disadvantage that either the FIR filter length is too large or the phase characteristics are nonlinear. In this work, multiresolution Wavelet Transform (WT) techniques are used to remove the dither signal. Five level multiresolution analysis is carried out with various types of wavelets like Discrete Meyer and Daubechies 45 (db45) etc. With none of the standard wavelets, the original and reconstructed signals are matched. A new wavelet is designed to remove the dither signal. The required signal can be reconstructed back using the approximation coefficients at level 5. The dither signal is attenuated by 107.0 dB, and the phase characteristics are found to be linear in the pass band. The computational complexity is also less compared to the three stage combined filter reported earlier.

中文翻译：

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使用小波变换对真实RLG信号进行抖动滤波

摘要—

环形激光陀螺仪（RLG）广泛用于许多机载和导航系统中，可精确测量人体运动的真实旋转。但是RLG在称为锁定频率的低频下遭受了严重的困扰。为了避免锁定问题，RLG会机械振动至高频，这称为抖动。为了使身体真正旋转，必须去除抖动信号。建议使用单级，多级和多速率滤波器来消除抖动信号。这些滤波器的缺点是FIR滤波器的长度太大或相位特性是非线性的。在这项工作中，多分辨率小波变换（WT）技术用于去除抖动信号。使用各种类型的小波（如离散Meyer和Daubechies 45（db45）等）进行五级多分辨率分析。在没有标准小波的情况下，原始信号和重构信号都将匹配。设计了一个新的小波以消除抖动信号。可以使用5级近似系数来重新构造所需的信号。抖动信号衰减了107.0 dB，并且发现相位特性在通带中呈线性。与之前报道的三级组合滤波器相比，计算复杂度也更低。抖动信号衰减了107.0 dB，并且在通带中发现相位特性呈线性。与之前报道的三级组合滤波器相比，计算复杂度也更低。抖动信号衰减了107.0 dB，并且在通带中发现相位特性呈线性。与之前报道的三级组合滤波器相比，计算复杂度也更低。