Conflict Detection Scheme Based on Formal Rule Model for Smart Building Systems

Abstract—Smart building systems can provide flexible and con-figurational sensing and controlling operations according to users’ requirements. As the number and the complexity of service rules customized by users have significantly increased, there is an in-creasing danger of conflict during the interaction process between users and the system. To address this issue, we propose a new rule conflict detection scheme tailored for the smart building system. First, we present a formal rule model UTEA based on User, Trig-gers, Environment entities, and Actuators. This model can handle not only controlled devices with discrete status but also real-valued environmental data such as temperature and humidity. In addi-tion, this model takes multiple users with different authorities into account. Second, we define 11 rule relations and further classify conflicts into five categories. Third, we implement a rule storage system for detecting conflicts and design a conflict detection al-gorithm, which can detect the conflict between two rules as well as cycle conflict/multicross contradiction among multiple rules. We evaluated our scheme in a real smart building system with more than 30 000 service rules. The experiment results show that our scheme improves the performance in terms of error/missed-detection rates and running time. Index Terms—Conflict detection, rule model, service, smart building system. I