自混合干涉测速技术研究

【作者】 刘盛刚；

【导师】 李泽仁；

【作者基本信息】 中国工程物理研究院 ， 光学， 2009， 硕士

【摘要】 本文阐述了激光自混合干涉测速技术的研究背景和意义,综述了国内外自混合干涉测速技术的研究现状,以建立完善的自混合干涉测速系统为目的,进行了深入、广泛的理论研究和实验研究。在理论上,运用Doppler效应,复合腔理论,建立了自混合干涉的数学模型,研究了自混合干涉测速的基本原理,对自混合干涉测速上限问题进行了详实的讨论,对信号调制深度进行了分析,数值模拟研究了光纤耦合系统各个参数对自混合信号波形的影响。设计了自由空间自混合干涉和全光纤自混合散斑干涉两套实验系统。重点研究了光纤传光、自聚焦透镜收集反馈光的全光纤自混合散斑干涉系统的可行性,建立了自聚焦透镜收集效率的模型,并进行了收集效率的实验研究,从理论上证明了全光纤自混合散斑干涉的可行性。开展了信号处理研究。研究了信号的消噪与归一化处理;通过分析自混合干涉信号的特征,提出采用时频分析技术处理自混合干涉信号,进行了相应的数值模拟研究;理论上得到了位移信息重构的解析解,提出了积分速度曲线获得位移的数值方法。对比研究了自混合散斑干涉信号处理的计数法和自相关法,最后采用简单的计数法来处理自混合散斑信号。搭建了自由空间自混合干涉和全光纤自混合散斑干涉两套实验系统,进行了实验研究,获得了较好的实验信号,最后给出了实验结果。更多还原

【Abstract】 In this dissertation, the background and the significance of self-mixing interference velocity measurement technique are introduced. The state of the self-mixing interference velocity measurement is reviewed. In order to construct the perfect technique for this measurement, the theoretical analysis and the experimental research are extensively and deeply studied.In theory, the model of self-mixing interference has been build based on the Doppler effects and the compound cavity theory. The principle of self-mixing velocity measurement bas been studied, the problem of upper limit has been discussed carefully, the depth of modulation has been analyzed. At last, the parameters of the fiber-coupled self-mixing interference system how to influence the waveform of self-mixing interference signal have been simulated.The systems of free-space self-mixing interference and all-fiber speckle self-mixing interference have been designed. We put stress on the study of the feasibility using fiber to transmit light and using self-focus lens to collect feedback light. Firstly, we build the model of self-focus lens, and then, we study the collection efficiency of the self-focus lens how to change with radius and working distance, at last, the experiments of collection efficiency have been done. The feasibility of using fiber to transmit light and using self-focus lens to collect feedback light is theoretically proved.The signal processing has been studied. These researches include how to normalize the self-mixing interference signal, how to acquire the velocity from the self-mixing interference signal, and how to acquire the displacement. At last, we compare threshold method and auto-correlation method which are used to process the self-mixing speckle interference signal. At last, we adopt the threshold method to process the self-mixing speckle interference signal.The systems of free-space self-mixing interference and all-fiber speckle self-mixing interference have been constructed, the experiments have been carried through, the ideal signals have been acquired, and at last, the experimental results are given.更多还原