烟尘环境下激光传输回波分析与抗干扰研究

发布时间：2018-03-20 06:15

本文选题：烟尘回波特性　切入点：抗干扰分析　出处：《西安工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：脉冲式激光探测系统在很多领域都有着非常广泛的应用,然而在一些特定环境下,空气中漂浮的烟尘粒子和激光光束之间产生的互相影响,特别是烟尘粒子会对激光光束发生吸收和散射,导致激光收发系统性能的下降甚至失效,从而造成严重的误判。本文针对这种情况,首先对激光在烟尘中的回波特性进行了深入探讨和研究,其次通过对其结果的分析,针对性的提出了激光抗烟尘干扰电路的设计。首先,文章对光的散射理论做了深入的探讨,着重研究瑞利和米氏散射理论,分析了不同烟尘粒径下激光的散射机理,并采用Monte Carlo方法,对单次和多次散射理论进行了公式推导。其次,设计了激光近距探测的收发系统,对其各模块的参数和指标进行了分析和计算,并搭建了定量烟尘颗粒分析试验箱,并对烟尘干扰形成波形特征进行深入研究,建立了激光在烟尘环境下的传输模型。同时,建立物体目标模型,通过Matlab软件对其回波进行模拟仿真,通过两者比较,得出抗烟尘干扰的理论依据。在信号处理模块,从激光抗干扰的角度出发,针对前面归纳的特征,分别提出了脉宽测量和时间门选通复合识别技术、阈值电压自适应技术、时间中心捕获法,并借助于ISE对信号处理各功能模块进行编程设计。通过ISM,编写激励文件,对其进行测试,使其各模块功能的可行性都得到了很好的验证。在信号确认模块,因为伪随机序列优异的抗干扰性能,通过采用延时相关的方法,对其进行峰值检测,达到了课题预期的效果。
[Abstract]:Pulse laser detection systems are widely used in many fields, but in certain environments, the interaction between aerosol particles floating in the air and laser beams, In particular, the soot particles will absorb and scatter the laser beam, which will lead to the degradation or even failure of the laser transceiver system, thus causing serious misjudgment. First of all, the characteristics of laser echo in smoke dust are deeply discussed and studied. Secondly, through the analysis of the results, the design of laser anti-soot interference circuit is put forward. Firstly, the scattering theory of light is deeply discussed in this paper. The Rayleigh and Michelson scattering theories are studied emphatically, the scattering mechanism of laser under different particle size of smoke is analyzed, and the single and multiple scattering theories are deduced by Monte Carlo method. Secondly, the receiving and sending system of laser short range detection is designed. The parameters and indexes of each module are analyzed and calculated, and the quantitative smoke particle analysis test box is built, and the waveform characteristics of smoke interference are deeply studied, and the laser transmission model in smoke environment is established. The object target model is established, and its echo is simulated by Matlab software. Through the comparison of the two, the theoretical basis of anti-soot interference is obtained. In the signal processing module, from the point of view of laser anti-jamming, aiming at the characteristics summarized above, The techniques of pulse width measurement and time gate gating combined identification, threshold voltage adaptive technology, time center acquisition method are put forward, and the signal processing function modules are programmed by ISE. In the signal confirmation module, because of the excellent anti-interference performance of pseudorandom sequence, the peak value detection is carried out by using the method of time-delay correlation. The expected effect of the project is achieved.
【学位授予单位】：西安工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN24

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