【目的】激光诱导击穿光谱(LIBS)技术由于具有无需复杂样品预处理、多指标同步检测、快速分析等优点,在煤质快速分析领域极具应用潜力。然而,由于不同仪器对光谱信号响应差异,基于主仪器光谱数据训练的定量分析模型应用于其他从仪器时精确度严重下降。因此,本研究基于TrAdaBoost迁移学习,结合不同机器学习算法构建跨仪器LIBS的煤质定量分析模型。【方法】将2台LIBS煤质快速检测仪分别视为主仪器和从仪器,在主从仪器上采集不同数量煤样的LIBS光谱。分别利用随机森林(RF)、支持向量机(SVR)以及Tr Ada Boost结合RF(Tr A-RF)和Tr Ada Boost结合SVR(Tr A-SVR)构建煤质定量分析模型,并在从仪器上分析未知煤样煤质对比模型性能。【结果】结果表明,与RF和SVR模型相比,Tr A-RF和Tr A-SVR模型预测煤质准确性均显著提高。其中,Tr A-RF模型预测准确性最好,与RF模型对比,发热量、灰分和含碳量预测平均绝对误差由1.390 MJ/kg、4.774%和3.826%减小到0.654 MJ/kg、2.338%和1.927%;Tr A-SVR模型预测挥发分的准确性最高,与SVR模型对比,预测平均绝对误差由2.722%减小到了2.524%。【结论】研究结果表明,迁移学习结合合适的基础学习器能够提高煤质定量分析模型对不同仪器的适应性。
Abstract
[Objective] Laser-induced breakdown spectroscopy(LIBS) holds significant potential for application in the field of coal property analysis
due to its advantages of eliminating complex sample pretreatment
enabling multi-parameter synchronous detection
and offering rapid analysis. However
discrepancies in spectral responses exist among different instruments. These discrepancies cause severe accuracy degradation when a quantitative model trained on spectra acquired by a master instrument is applied to slave instruments. Therefore
this study constructed cross-instrument LIBS quantitative analysis models of coal property by integrating TrAdaBoost transfer learning with various machine-learning algorithms. [Methods] Two LIBS-based coal analyzers were designated as the master and slave instruments respectively
and LIBS spectra were collected from different numbers of coal samples on both devices. Random forest(RF)
support-vector regression(SVR)
and their TrAdaBoost-enhanced counterparts(TrA-RF and TrA-SVR) were employed to build quantitative analysis models. Model performance was evaluated by predicting the coal properties of unknown coal samples on the slave instrument. [Results] The results indicated that both TrA-RF and TrA-SVR models significantly outperformed their non-transfer counterparts. The Tr A-RF model achieved the highest accuracy for calorific value
ash content
and carbon content. Compared with RF model
the mean absolute errors decreased from 1.390 MJ/kg
4.774 %
and 3.826 % to 0.654 MJ/kg
2.338%
and 1.927%
respectively. TrA-SVR model yielded the highest accuracy for volatile matter prediction. Compared with the SVR model
the mean absolute error decreased from 2.722%(SVR) to 2.524%. [Conclusion] These findings demonstrate that coupling transfer learning with an appropriate base learner markedly enhances the adaptability of LIBS-based coal property models across different instruments.