在基于TDLAS 的汽車尾氣測(cè)量系統(tǒng)中，由于待測(cè)量激光信號(hào)的強(qiáng)度變化非常微弱且處于很強(qiáng)的噪聲背景中，因此必須采用微弱信號(hào)檢測(cè)中常用的鎖定放大器來(lái)檢測(cè)激光的微弱變化。本文對(duì)鎖定放大器對(duì)微弱信號(hào)的測(cè)量原理、數(shù)字鎖放在尾氣測(cè)量系統(tǒng)中的系統(tǒng)框架設(shè)計(jì)以及用DSP 芯片TMS320F2812 軟件設(shè)計(jì)數(shù)字鎖定放大器作了詳細(xì)的分析和介紹。
關(guān)鍵詞：數(shù)字鎖定放大器微弱信號(hào) 數(shù)字信號(hào)處理器
Abstract: In the measurement system of vehicle’s dynamic concentrations based on TDLAS, the variation of laser light intensity is very weak and in a very strong background noise, thus it needs to use the Lock-in amplifier to detect the weak signal. This paper introduce a method about the measuring principle of Lock-in amplifier, the system diagram design of digital Lock-in amplifier for detecting weak signal, and the design of the software with the help of DSP chip TMS320F2812.
Keywords: Digital Lock-in Amplifier weak signal DSP