An Application Conflict Detection and Resolution System for Smart Homes

One of the applications of Cyber-Physical Systems (CPSs) is the Smart Homes. In Smart Homes, multiple apps operate the sensors and actuators to provide rich user experience in a living environment. Because actuators are entities that affect the surrounding environment, conflicts may occur if two or more apps are running simultaneously, especially when they try to use a single actuator or when they use different actuators causing different effects. There have been attempts to resolve these conflicts at app installation time. However the state-of-the-art solutions can detect conflicts only if the apps actuate on devices with conditions based on time, and resolute conflicts by creating a total order between all apps, regardless of the situations of the conflicts. In this paper, we create a Kripke structure to detect conflicts by model-checking the assertion "no two apps use actuators to create different effects at the same location". Our proposed system, which provides install-time conflict detection, enables detection of application conflicts triggered by conditions based on events. In addition, it supports users in prioritising apps by reducing the number of conflicts by dividing them into groups of the same situation which are meaningful to the users. By prioritising apps for each situation, rather than creating a total order, our system allows the apps to run in a more flexible way.