TDLAS气体检测系统中浓度反演算法的实现

摘要

基于可调谐半导体激光吸收光谱(TDLAS)技术的气体检测系统,因气体吸收产生的二次谐波信号携带浓度信息,通过浓度反演可实现浓度信息的提取.本文简要介绍了TDLAS气体检测系统,对Matlab下完成的曲线拟合和反演算法仿真以及FPGA内部设计实现的反演算法进行了详细描述,并在一氧化碳检测系统下利用多组待测浓度完成了反演算法的验证.验证结果表明:浓度反演吻合度超过99.9％,反演算法正确,能够完全满足系统设计要求,做到浓度信息的精确提取.基于Matlab的前期数据分析和误差控制设计方法可应用于多领域的产品研制和系统综合测试中.%In the gas detection systembased on Tunable Diode Laser Absorption Spectroscopy(TDLAS) technology,for gas absorbing,concentration information carried by the second harmonic signal can be extracted throughthe way of concentration inversion.In this paper,the TDLAS gas detection systemis briefly introduced,the curve fitting and inversion algorithm simulation completed in Matlab and the inversion algorithm designed in FPGA internal are described in detail,and the inversion algorithm validation is accomplished in carbon monoxide detection system with multiple sets of measured concentration.The validation results show that the coincidence degree of concentration inversion is more than 99.9％,and the inversion algorithm is correct,which can fully meet the system design requirement and accurately extract the concentration information.The design methodsof pre-data analysis and error control based onMatlabcan be applied to multi-field product development and system integration tests.