Short-Time Fourier Transform and Decision Tree-Based Pattern Recognition for Gas Identification Using Temperature Modulated Microhotplate Gas Sensors
Short-Time Fourier Transform and Decision Tree-Based Pattern Recognition for Gas Identification Using Temperature Modulated Microhotplate Gas Sensors
复制标题
使用温度调制微热板气体传感器进行气体识别的短时傅立叶变换和基于决策树的模式识别
DOI：
10.1155/2016/7603931
复制
发表时间：
2016-01-01
影响因子：
1.9
通讯作者：
Tang, Zhenan
中科院分区：
文献类型：
--
作者：
He, Aixiang;Yu, Jun;Tang, Zhenan
由于传感器的响应依赖于其工作温度，因此通常在气体传感器中采用调温操作来识别不同的气体。本文结合短时傅里叶变换（STFT）的特征提取方法，介绍了微热板气体传感器工作温度的调制方法。由于环境空气中气体浓度通常具有较大的波动，采用STFT提取时频域瞬态特征，并进一步探讨了STFT频谱与传感器响应之间的关系。由于热时间常数较低，在响应曲线的包络线中充分保留了不同气体的区别信息。特征信息往往包含在较低的频率中，而不包含在较高的频率中。因此，从0 Hz到基频范围内的STFT幅值中提取特征来完成识别任务。这些低频特征被提取出来并通过基于决策树的模式识别进行进一步处理。通过对不同浓度的一氧化碳、甲烷和乙醇的分析，表明该方法具有较高的分类能力。
Because the sensor response is dependent on its operating temperature, modulated temperature operation is usually applied in gas sensors for the identification of different gases. In this paper, the modulated operating temperature of microhotplate gas sensors combined with a feature extraction method based on Short-Time Fourier Transform (STFT) is introduced. Because the gas concentration in the ambient air usually has high fluctuation, STFT is applied to extract transient features from time-frequency domain, and the relationship between the STFT spectrum and sensor response is further explored. Because of the low thermal time constant, the sufficient discriminatory information of different gases is preserved in the envelope of the response curve. Feature information tends to be contained in the lower frequencies, but not at higher frequencies. Therefore, features are extracted from the STFT amplitude values at the frequencies ranging from 0 Hz to the fundamental frequency to accomplish the identification task. These lower frequency features are extracted and further processed by decision tree-based pattern recognition. The proposed method shows high classification capability by the analysis of different concentration of carbon monoxide, methane, and ethanol.