HgCdTe红外探测器的微弱信号检测系统设计

发布时间：2018-05-07 05:20

本文选题：热扩散率 + 红外探测　；参考：《哈尔滨理工大学》2015年硕士论文

【摘要】：热扩散率是表征材料热物理性能的重要参数之一，对航天航空飞行器和武装设备的关键部件设计具有重要意义。红外探测技术也越来越多的应用在航天材料热扩散率测量装置中，其中红外信号的检测是热扩散率测量装置的重要组成部分，红外信号检测系统指标参数的好坏也直接影响到热扩散率测量的精确性。本文以航天材料热扩散率测量技术为研究背景，设计了HgCdTe红外探测器的微弱信号检测采集系统。由于红外探测器输出的信号极其微弱，很容易淹没在噪声中，因此在整个系统的设计上都突出了微弱信号检测技术，抑制噪声，提高整个系统的信噪比的特点。硬件部分设计了信号调理电路，将信道板输出的信号通过数字采集卡DaqBook200中的A/D转换引入PC机。软件部分使用VC++语言编写，并采用软件滤波的方法对微弱信号进行滤波，实现信号的实时检测、采集和显示，为热扩散率测量的下一步进行提供了支持。本文重点研究了航天材料热扩散率测量技术中的HgCdTe红外探测器的微弱信号检测采集系统的设计及分析，具体内容主要包括： 1．通过相关资料的分析研究，综述了课题背景及实际意义，，并重点研究了激光脉冲法测量热扩散率的原理； 2．设计了微弱信号检测系统的整体方案，针对红外探测器的能量转换以及HgCdTe红外探测器的选择等问题，并以高共模抑制比，高信噪比，高灵敏度和强抗干扰能力为设计原则，对HgCdTe红外探测器的具体检测电路进行了总体的设计，包括电源模块的滤波处理，高精度高速低噪声仪表放大器的选用，差分输入信号的引入以及整体电路的匹配设计。软件部分采用多线程编程模式，完成了信号采集显示的界面设计，将数字采集卡DaqBook200采集的信号在PC机上显示出来。 3．调试及校准实验设备，多次测量调整试验参数获得实验数据，通过实验结果分析了影响系统的误差来源，对整个系统的准确性、可靠性做出评估。
[Abstract]:Thermal diffusivity is one of the important parameters to characterize the thermal physical properties of materials. It is of great significance for the design of key components of aerospace vehicles and armed equipment. Infrared detection technology is also more and more used in aerospace materials thermal diffusivity measurement device, in which infrared signal detection is an important part of thermal diffusivity measurement device. The accuracy of thermal diffusivity measurement is also directly affected by the index parameters of infrared signal detection system. Based on the thermal diffusivity measurement technology of aerospace materials, a weak signal detection and acquisition system for HgCdTe infrared detector is designed in this paper. Because the signal output of the infrared detector is very weak, it is easy to be submerged in the noise, so the weak signal detection technology is highlighted in the design of the whole system, which can suppress the noise and improve the signal-to-noise ratio of the whole system. In the hardware part, the signal conditioning circuit is designed, and the signal output from the channel board is introduced into the PC through the A / D conversion in the digital acquisition card DaqBook200. The software part is written in VC language, and the weak signal is filtered by software filtering method, which realizes the real-time detection, collection and display of the signal, which provides the support for the next step in the measurement of thermal diffusivity. This paper focuses on the design and analysis of the weak signal acquisition system of HgCdTe infrared detector in the thermal diffusivity measurement technology of aerospace materials. The main contents are as follows: 1. Through the analysis and research of related data, the background and practical significance of the subject are summarized, and the principle of measuring thermal diffusivity by laser pulse method is emphatically studied. 2. The whole scheme of weak signal detection system is designed. Aiming at the problems of energy conversion of infrared detector and selection of HgCdTe infrared detector, the design principle is high common-mode rejection ratio, high signal-to-noise ratio, high sensitivity and strong anti-jamming ability. The detection circuit of HgCdTe infrared detector is designed as a whole, including the filter processing of power supply module, the selection of high precision, high speed and low noise instrument amplifier, the introduction of differential input signal and the matching design of the whole circuit. In the software part, the multi-thread programming mode is used to complete the interface design of signal acquisition and display, and the signal collected by DaqBook200 is displayed on PC. 3. The experimental data are obtained by debugging and calibrating the experimental equipment. The error sources affecting the system are analyzed through the experimental results, and the accuracy and reliability of the whole system are evaluated.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN215;TP274

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