基于FPGA的激光自混合干涉信号高速数据处理系统设计

发布时间：2018-02-04 19:09

  本文关键词： 激光自混合干涉 光学测量 氦氖激光器 FPGA 数据处理　出处：《南京信息工程大学》2016年硕士论文　论文类型：学位论文

【摘要】：激光自混合干涉是指激光器中的激光发射到外界物体上,被外界物体反射或折射以后,有一部分激光反馈到激光器中,与腔内激光产生混合,导致激光器输出功率、频率发生改变,所以称为自混合干涉。作为一门新兴的光信号测量技术,具有非接触性、高准确性、高精密度等特点,已经越来越普遍的应用于外部物体机械量、几何量及激光器参数等的测量。其中对于外部物体位移的测量和相位的提取是两个主要的应用。外部物体位移的传统测量方法通常是先将实验数据采集并保存下来,再通过MatLab等数学软件结合算法进行处理最后得到物体的位移量和方向。这种方法的优点是算法灵活、处理精度高；缺点是不能对干涉信号进行高速实时处理与显示。外部物体相位提取的传统方法通常是利用MatLab等数学软件结合算法进行线下处理,没有达到高速实时提取相位信息的目的。FPGA,即现场可编程门阵列,芯片具有开发周期短、工作频率高、内部程序并行运行等特点,是一种可集成如数据采集、处理和传输等功能的一种芯片。目前FPGA芯片在高速数据采集、高性能数字信号处理等领域应用比较广泛,因此可以采用FPGA设计一种高速有效的数据处理系统。本文以激光自混合干涉信号为研究对象,利用FPGA高速采集处理数字信号等优势,设计了基于FPGA的激光自混合数据处理系统,本文主要完成的工作如下：1、提出了计算自混合干涉信号微位移的归置比较法。完成了对振动条纹整数个数、小数值及方向的判断,进而求出微位移。将该算法结合QuartusⅡ进行Verilog HDL实现。设计了基于FPGA的自混合干涉信号微位移测量系统,进行实验验证及分析,实验结果表明,该微位移测量系统具有高速实时性,数据反馈时间为0.5s,位移测量结果相对误差较低,分别率可达兄／20,该微位移测量系统满足对激光自混合干涉信号高速准确的测量要求。2、分析了FFT相位提取理论并进行了MatLab仿真分析。结合QuartusⅡ进行FFT的Verilog HDL实现。设计了基于FPGA的干涉信号相位提取系统,并通过实验验证。实验结果表明,该相位提取系统具有高速实时性,数据反馈时间为0.5s,基于FFT得到的相位值相对于实际相位值相对误差较低,该相位提取系统满足对干涉信号高速准确的测量要求。
[Abstract]:Laser self-mixing interference refers to the laser in the laser emitted on the external object, reflected or refracted by the external object, a part of the laser feedback to the laser, and the intracavity laser mixing. As a new optical signal measurement technology, it has the characteristics of non-contact, high accuracy, high precision and so on. It has been more and more widely used in the mechanical volume of external objects. The measurement of geometric parameters and laser parameters. The measurement of displacement of external objects and the extraction of phase are two main applications. The traditional method of measuring displacement of external objects is usually to collect and save the experimental data first. Come on. Finally, the displacement and direction of the object are obtained by using MatLab and other mathematical software. The advantage of this method is that the algorithm is flexible and the processing accuracy is high. The disadvantage is that the interference signal can not be processed and displayed in high speed and real-time. The traditional method of phase extraction of external object is usually using MatLab and other mathematical software combined with algorithm for offline processing. The purpose of extracting phase information at high speed and real time. FPGA-Field Programmable Gate Array (FPGA). The chip has the characteristics of short development period, high working frequency, and internal program running in parallel. FPGA chips are widely used in high speed data acquisition, high performance digital signal processing and other fields. Therefore, FPGA can be used to design a high-speed and effective data processing system. In this paper, the laser self-mixing interference signal is taken as the research object, and the advantages of FPGA high-speed acquisition and processing of digital signal are used. A laser self-mixing data processing system based on FPGA is designed. The main work of this paper is as follows: 1. The homing comparison method for calculating the micro-displacement of self-mixing interference signal is proposed. The integer number, small value and direction of vibration fringes are judged. Then the micro-displacement is obtained. The algorithm is implemented with Verilog HDL combined with Quartus 鈪，

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