本文選題：量子級聯(lián)激光器　切入點：鎖相放大器　出處：《吉林大學》2017年碩士論文　論文類型：學位論文

【摘要】：在開采難度大的地區(qū)進行礦井開采作業(yè)極易造成煤氣層泄漏和煤塵自燃等重大安全事故。因此研制出可實時監(jiān)控礦井下CO氣體濃度的傳感器具有重大的安全意義。目前礦用氣體檢測儀主要的研究發(fā)展方向是應用紅外光譜吸收技術對有毒氣體進行識別與濃度測量。其中選用單色性好、準直度的量子級聯(lián)激光器(QCL)作為紅外檢測系統(tǒng)的光源與其他紅外光譜吸收技術相比,具有更強的分子鑒別力和更高的檢測精度。因此本課題具有十分重要的研究意義�；诿}沖式中紅外QCL的氣體檢測系統(tǒng)中主要存在兩大關鍵問題:一、應用脈沖鎖相放大技術精準提取窄脈沖傳感信號;二、有效調控氣體吸收池溫度、壓強等參數(shù),實現(xiàn)最佳檢測過程。本論文研究基于以上關鍵問題展開。首先設計并實現(xiàn)一種窄脈沖鎖相放大器,主要由窄帶濾波電路、乘法器電路、低通濾波電路等構成。并對其開展了詳細的功能驗證實驗,實驗結果表明該窄脈沖鎖相放大器具有良好的頻率響應(中心頻率5k Hz)、較低的通頻帶寬度(帶寬80Hz)、較高的線性度(擬合優(yōu)度98.043%)。其次對紅外吸收池的多種參數(shù)進行控制,包括溫度控制單元和流量控制單元兩部分。利用Fuzzy-PID復合控制理論對不銹鋼密閉腔體開展溫度控制實驗,實驗曲線表明該溫控系統(tǒng)具有較快的響應速度(響應時間7mins)及較低的穩(wěn)態(tài)誤差(控制精度±0.2℃)。并利用質量流量計對模擬氣室的流量進行調控,多次控制結果證明,該流量控制單元可實現(xiàn)誤差在滿程的5%左右的控制功能,且具有良好的重復性。最后通過實驗室完整的CO檢測平臺進行了CO氣體標定實驗,測試結果證實了在紅外吸收池溫度、流量等參數(shù)選定時,所研制的鎖相放大器可以有效地檢測出紅外吸收池通入的CO氣體濃度,且系統(tǒng)檢測精度較高、穩(wěn)定性較好。
[Abstract]:It is easy to cause gas leakage and coal dust spontaneous combustion and other major safety accidents in mining operation in areas where mining is difficult. Therefore, it is of great safety significance to develop a sensor that can monitor CO concentration under mine in real time. At present, the main research direction of mine gas detector is to use infrared spectrum absorption technology to identify and measure the concentration of toxic gas. As the light source of infrared detection system, the collimated quantum cascade laser (QCL) is compared with other infrared absorption techniques. Therefore, this subject has very important research significance. There are two key problems in the gas detection system based on pulse mid-infrared QCL: first, The pulse phase-locked amplification technique is used to accurately extract the narrow pulse sensing signal. Second, the parameters such as temperature and pressure of the gas absorption cell are effectively controlled. This thesis is based on the above key problems. Firstly, a narrow pulse phase-locked amplifier is designed and implemented, which consists of narrow band filter circuit and multiplier circuit. The low pass filter circuit and so on, and carried out the detailed function verification experiment to it, The experimental results show that the narrow-pulse phase-locked amplifier has a good frequency response (center frequency 5k Hz), low bandwidth (bandwidth 80 Hz), high linearity (good fit degree 98.043). Secondly, various parameters of infrared absorption cell are controlled. It includes two parts: temperature control unit and flow control unit. Using Fuzzy-PID compound control theory, the temperature control experiment of stainless steel airtight chamber is carried out. The experimental results show that the temperature control system has fast response speed (response time 7 mins) and low steady-state error (control accuracy 鹵0.2 鈩，

本文編號：1629098