Sensor Data Simulation for Anomaly Detection of the Elderly Living Alone

With the increase of the number of elderly people living alone around the world, there is a growing demand for sensor-based detection of anomalous behaviors. Although smart homes with ambient sensors could be useful for detecting such anomalies, there is a problem of lack of sufficient real data for developing detection algorithms. For coping with this problem, several sensor data simulators have been proposed, but they have not been able to model appropriately the long-term transitions and correlations between anomalies that exist in reality. In this article, therefore, we propose a novel sensor data simulator that can model these factors in generation of sensor data. Anomalies considered in this study were classified into three types of state anomalies, activity anomalies, and moving anomalies. The simulator produces ten years data in 100 min, including six anomalies, two for each type. Numerical evaluations based on edit distance between activity series show that this simulator is superior to the past simulators in the sense that it simulates well day-to-day variations of real data.