光纤陀螺信号小波滤波技术

发布时间：2018-02-03 02:35

本文关键词： 光纤陀螺提升小波谐波小波滤波技术　出处：《中国科学院大学(中国科学院光电技术研究所)》2017年硕士论文　论文类型：学位论文

【摘要】：在船载光电跟踪系统中,要保证对运动目标的跟踪精度,首先要保证系统中视轴的稳定精度。系统通常采用惯性稳定平台来隔离载体对跟踪系统的干扰,实现系统视轴的稳定。惯性稳定平台中光纤陀螺敏感运动目标以及载体相对于惯性空间的实时扰动量(角度、角速度等)。在船载视轴稳定控制中,经常采用前馈加反馈的复合控制设计,将光纤陀螺输出信号作为反馈控制信号传递给系统,将辨识出来的扰动信息作为前馈控制信号,传递给系统进行前馈控制。由于扰动信号的低频段与运动目标信号相重合,难以分离,且稳定平台对低频的扰动抑制能力较好,因此考虑将光纤陀螺输出信号进行滤波得到中高频信号作为前馈控制信号。在此背景下,对光纤陀螺输出信号进行滤波,在幅值和相位失真都较小的情况下辨识中高频信号作为稳定平台的前馈控制信号,对提高视轴稳定精度具有重要意义。本文首先对光纤陀螺输出信号进行频谱分析,为后续研究提供依据,重点分析几种常用的光纤陀螺信号处理方法,从中选IIR滤波、提升小波滤波以及谐波小波滤波三种方法对光纤陀螺输出信号进行滤波处理,并进行滤波效果比较。采用基于提升小波阈值滤波法对信号进行滤波处理,通过选择合适的小波基,分解尺度以及阈值,对光纤陀螺输出信号滤波输出中高频信号;采用基于谐波小波滤波方法对光纤陀螺输出信号进行滤波处理,通过设置合适的谐波小波上下限频率值提取目标信号。分析及实验结果表明谐波小波滤波的效果比提升小波滤波和IIR滤波效果好,提升小波滤波效果比IIR滤波效果好。本文在以上研究基础上选择谐波小波滤波方案为光纤陀螺输出信号滤波。最后,本文提出一种对光纤陀螺输出信号进行实时滤波、分离提取中高频信号的算法:首先对信号进行数据窗截取,对称延拓处理,然后采用谐波小波滤波得到中高频段信号的算法;并用实际数据处理给出了实验结果。本文将提出的信号处理方法在实验平台上进行实验验证,结果表明此方法能够有效的对光纤陀螺的中高频信号进行分离,且分离度高、存在的幅值和相位失真小,能够有效提高数据处理精度,进而提高视轴稳定精度。
[Abstract]:In the shipborne photoelectric tracking system, in order to ensure the tracking accuracy of moving targets, the first step is to ensure the stability of the visual axis in the system. The inertial stabilization platform is usually used to isolate the interference of the carrier to the tracking system. In the inertial stability platform, the sensitive moving target of fiber optic gyroscope and the real-time disturbance (angle, angular velocity, etc.) of the carrier relative to the inertial space are realized. The compound control design of feedforward and feedback is often used, the output signal of fog is transmitted to the system as feedback control signal, and the disturbance information is recognized as feedforward control signal. Because the low frequency band of the disturbance signal coincides with the moving target signal, it is difficult to separate, and the stable platform has good disturbance suppression ability to the low frequency. Therefore, the output signal of fiber optic gyroscope is filtered to get the middle and high frequency signal as feedforward control signal. Under this background, the output signal of fiber optic gyro is filtered. In the case of small amplitude and phase distortion, the high frequency signal is identified as the feedforward control signal of the stable platform. In this paper, the output signal of fiber optic gyroscope (fog) is analyzed by frequency spectrum analysis, which provides the basis for further research, focusing on the analysis of several commonly used signal processing methods of fiber optic gyroscope (fog). IIR filter, lifting wavelet filter and harmonic wavelet filter are selected to filter the output signal of fog. The filtering effect is compared. The signal is filtered based on lifting wavelet threshold filtering method. By selecting the appropriate wavelet basis, decomposing the scale and threshold. The output signal of fiber optic gyroscope is filtered out and the middle and high frequency signal is output. The output signal of fiber optic gyroscope is filtered based on harmonic wavelet filter. The analysis and experimental results show that the effect of harmonic wavelet filter is better than that of lifting wavelet filter and IIR filter. The effect of lifting wavelet filter is better than that of IIR filter. On the basis of the above research, the harmonic wavelet filtering scheme is selected as fiber optic gyroscope output signal filtering. Finally. In this paper, a real-time filtering algorithm for the output signal of fiber optic gyroscope (fog) is proposed to separate and extract the middle and high frequency signals. Firstly, the data window is used to intercept the signal and the symmetrical continuation is processed. Then the algorithm of obtaining the medium and high frequency band signal by harmonic wavelet filter is presented. The experimental results are given with actual data processing. The proposed signal processing method is verified on the experimental platform. The results show that this method can effectively separate the middle and high frequency signals of fiber optic gyroscope. The separation degree is high and the distortion of amplitude and phase is small, which can effectively improve the accuracy of data processing and thus improve the stability accuracy of the axis of view.
【学位授予单位】：中国科学院大学(中国科学院光电技术研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212;U665

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