基于WPRKPCA的非线性化工过程微小故障检测

传统核主元分析法（KPCA）是一种广泛应用的非线性化工过程故障检测方法，但是其未充分利用过程数据的概率分布信息，往往难以有效检测过程中的微小故障。针对传统KPCA方法的局限性，本文提出了一种基于加权概率相关核主元分析（WPRKPCA）的非线性化工过程微小故障检测方法。与传统KPCA方法监控核成分的变化不同，该方法利用Kullback Leibler散度（KLD）度量核成分的概率分布变化，进而建立基于KLD成分的统计监控模型，以充分挖掘过程数据所包含的概率信息。进一步考虑到不同KLD成分承载故障信息的差异性，该方法设计了一种基于核密度估计的指数加权策略，根据KLD成分描述故障信息程度的差异分配相应的权值，以加强监控模型对微小故障检测的灵敏性。在一个数值例子和连续搅拌反应器（CSTR）系统上的仿真结果表明，本文所提方法具有比传统KPCA方法更好的微小故障检测性能。

Incipient fault detection of nonlinear chemical processes based on weighted probability related KPCA

The traditional kernel principal component analysis (KPCA) is a widely used nonlinear chemical process fault detection method, but it is often difficult to detect the incipient fault in the process effectively because it does not make full use of the probability distribution information of process data. Aiming at the limitations of the traditional KPCA method, a new incipient fault detection method of nonlinear chemical process based on weighted probability related KPCA (WPRKPCA) was proposed. Different from the traditional KPCA method monitoring the change of kernel components, the WPRKPCA uses Kullback Leibler divergence (KLD) to measure the variations of the probability distribution of the kernel components, and then establishes a statistical monitoring model based on KLD components to fully exploit the probability information contained in the process data. Taking into account the difference of fault information carried by different KLD components, the WPRKPCA designs an exponential weighting strategy based on kernel density estimation (KDE). The different weights are assigned to enhance the incipient fault detection sensitivity of the monitoring model according to the difference of fault information described by the KLD component. The simulation results on a numerical example and the continuous stirred reactor (CSTR) system showed that the WPRKPCA has better performance than the traditional KPCA for the detection of incipient faults.