Data-driven soft sensors are extensively used in industrial and chemical processes to predict hard-to-measure process variables whose real value is difficult to track during routine operations. The regression models used by these sensors often require a large number of labeled examples, yet obtaining the label information can be very expensive given the high time and cost required by quality inspections. In this context, active learning methods can be highly beneficial as they can suggest the most informative labels to query. However, most of the active learning strategies proposed for regression focus on the offline setting. In this work, we adapt some of these approaches to the stream-based scenario and show how they can be used to select the most informative data points. We also demonstrate how to use a semi-supervised architecture based on orthogonal autoencoders to learn salient features in a lower dimensional space. The Tennessee Eastman Process is used to compare the predictive performance of the proposed approaches.

本文提出了一种将主动学习方法和半监督学习结合的数据驱动软测量方法，通过正交自编码器学习低维特征，以预测化工过程中难以测量的过程变量，实验证明，在流式数据下，该方法可以选择最具信息量的数据点，与传统离线环境相比获得更好的预测表现。

基于半监督自编码器的软测量在线主动学习方法