基于自编码器和PCA的滚筒烘丝机多块过程监测方法

Multi block process monitoring method of drum dryer based on autoencoder and PCA

鉴于滚筒烘丝干燥过程的多变量、强耦合、非线性的复杂特征,而传统主成分分析(PCA)过程监测方法不具有非线性表达能力及全局建模无法精确检测故障的问题,提出自动编码器特征提取和多块主成分分析联合驱动的多块建模方法。首先,依据叶丝干燥工作原理对变量进行分块,以突出过程局部特征;其次,使用自编码器提取每个子块的非线性特征;再次,分别建立相应的PCA监测模型;最后,通过贝叶斯推理对多个子空间的监测结果进行融合决策。以两个实际叶丝干燥案例进行验证,结果表明:该方法的报警率分别高达91.67%和98.21%,相比传统PCA和AE-PCA检测方法,该方法能准确揭示并表征干燥过程的整体运行状态及局部特征信息,提高对滚筒叶丝干燥生产过程的异常检测精度,实现对质量异常情况的准确报警,有利于保证滚筒叶丝干燥过程的稳定生产。

The process of drum drying silk has complex characteristics of multivariability,strong coupling,and nonlinearity.Traditional Principal Component Analysis(PCA)method lacks strong nonlinear ability,and global modeling method is difficult to achieve accurate fault detection of the process.Therefore,this paper proposed a novel multi-block approach by integrating Autoencoder(AE)for feature extraction and PCA model.Initially,in order to capture local features,the process variables were divided into blocks according to the drying process principle of tobacco leaf.Secondly,autoencoder was used to extract the nonlinear features of each sub-block.Then,the corresponding PCA models are established for each sub-block,respectively.Lastly,the monitoring results of multiple subspaces were fused for decision-making by Bayesian inference.Two actual leaf silk drying cases were used for verification,and the results showed that the alarm rates of this method were as high as 91.67% and 98.21%.Com-pared to traditional PCA and AE-PCA detection methods,this algorithm could accurately reveal and characterize the overall operating status and local feature information of the drying process,improve the accuracy of anomaly detection in the drum leaf silk drying production process and achieve accurate alarm for quality anomalies,to ensure stable production of the drum leaf silk drying process.