非局部约束下的局部稀疏保持投影及其在故障检测中的应用

Nonlocality-constrained Locality Sparse Preserving Projections and Its Application to Fault Detection

  • 摘要: 局部保持投影,保持数据的邻域关系,已成功应用于过程监测.然而,局部保持投影忽略了非局部结构信息,不能保证远距离样本之间的关系.最近提出的局部保持稀疏模型,利用稀疏编码获得一组超完备基,较好地表征原始数据的内在结构特征.鉴于稀疏编码能够较好地实现过程数据的局部稀疏表示,提出了非局部约束下的局部稀疏保持投影方法.首先,利用稀疏编码获取表征全局结构信息的稀疏码;其次,在非局部关系约束下保持局部结构特征,估计出不同稀疏码的概率密度,赋以相应权重,以便突出其对故障的贡献度;然后,融合过程状态信息构建合成统计量指标实施故障检测;最后,将提出的方法用于数值系统和TE化工过程仿真验证,并与现有的几种模型进行对比,结果表明了该方法的优越性.

     

    Abstract: Locality preserving projections, which preserve the neighborhood relationship of data, has been successfully applied in process monitoring. However, these methods neglect non-locality structure information and cannot guarantee the relationship of samples faraway. Locality preserving sparse modeling proposed recently use sparse coding to get a set of overcomplete basis, and well-represented inherent structural features from the raw data. Owing to sparse coding for learning local sparse structure features and representing raw data appropriately, we propose non-locality-constrained locality sparse preserving projections. First, we extract the sparse code and represent the global structure information by using sparse coding; second, we preserve the locality structure characteristics with non-locality relationship constraint, and estimate the probability densities of different sparse codes, which are set up with different weighting values to evaluate their contribution to faults; then, we build a combined statistical index for fault detection based on process status; Finally, we validate the proposed method using a numerical study and the Tennessee Eastman benchmark process, and compare it with several models. The monitoring results indicate its superior performance.

     

/

返回文章
返回