Implementation of an Ontology-based Data Access Application for Cross-domain Access of Energy Efficiency KPIs in Smart Factories

摘要

A smart factory is defined as a factory, which is composed of automated energy consumer machines and facilities that are integrated with IT technologies. Factories are considered as one of the highest energy consumers in 21st century. Increasing energy prices due to the limited nature of fossil energy sources and environmental legislation stresses on the importance of energy efficiency performance of smart factories. Many Manufacturers by taking the advantage of energy management systems are trying to improve energy efficiency of the factories. There are many factories which are applying different tools aiming to compute energy efficiency Key Performance Indicators (KPIs). In order to have an energy efficient factory and subsequently stronger energy management, these KPIs are needed to be usable, operational and easily accessible by the factory’s experts. Data relevant to the Energy efficiency KPIs are usually stored in Relational Databases (RDB). RDBs are working under Relational Database Management Systems (RDBMS). However, RDBMS has a rigid data structure and basically are built biased to serve the implementations and component installation strategies of the manufacturing process. Therefore, RDBs cannot meet the requirements to have a conceptual data model. Use of a proper ontology as a semantic model of the manufacturing domain, on top of RDBs seems to be a promising solution to overcome this problem. Ontologies are considered as a reliable tool for providing a shared conceptualization of the domain of interest. This facilitates the cross-domain access of KPIs in the factory. Retrieving data from RDBs through on ontology model is called Ontology-Based Data Access (OBDA). OBDA is based on correspondences between the relational database and ontology model.This research work results in development of OBDA application for energy efficiency KPIs. The designed OBDA for KPIs is applicable within a service-oriented manufacturing enterprise. The developed OBDA application was implemented in premises of Tampere University of Technology. The results of this implementation demonstrate ease of cross-domain access to energy efficiency KPIs. The research leading to these results was partially funded by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 600058.