基于MATLAB洛伦兹线型非线性拟合算法实现

Algorithm Implementation of Lorentz Linetype Nonlinear Fitting Based on MATLAB

可调谐半导体吸收光谱(TDLAS)技术具有高选择性、高分辨率和速度快等优点,已经在环境检测、工业过程检测等方面得到广泛应用。主要分析洛伦兹线型拟合,研究Levenberg-Marquardt算法的原理及实现步骤,基于Levenberg-Marquardt算法实现吸收谱线的洛伦兹线型拟合。对六组不同浓度的CO_2标准气体进行浓度反演,反演浓度与实际浓度的相关系数达0.9928,表明洛伦兹线型拟合可以准确反演出气体的浓度,对TDLAS技术中浓度的反演具有实际的指导意义。

Because of the advantages of high selectivity~ high resolution and fast speed, the tunable diode laser absorption spectroscopy（TDLAS） technology is widely used in such aspects as environmental testing and industrial process testing. The Lorentz linetype fitting, the principle and implementation steps of Levenberg- Marquardt algorithm, and the realization researches of Lorentz linetype fitting of absorption lines based on Levenberg-Marquardt algorithm are investigated. After concentration inversion of six group different con- centrations of CO2 standard gas, the correlation coefficient between inversion concentration and the actual concentration is 0.9928. The result shows that Lorentz linetype fitting can invert gas concentration accurately, which has practical guiding significance for concentration inversion in the TDLAS technology.