Author(s)

Hiroyuki Matsubara

Department of Information and Systems Engineering, Fukuoka Institute of Technology, Fukuoka, Japan.

Activity recognition of indoor occupants using indirect sensing with less privacy violation is one of the hot research topics. This paper proposes a CO₂ sensor-based indoor occupant activity monitoring system. Using the IoT sensor node that contains CO₂ sensors, the measured CO₂ concentrations in three locations (laboratory, office, and bedroom) were stored in a cloud server for up to 35 days starting July 1, 2023. The CO₂ measurements stored at 30-second intervals were statistically processed to produce a heat-mapped display of the hourly average or maximum CO₂ concentration. From the heatmap visualizations of CO₂ concentration, the proposed system estimated meeting, heating water using a portable stove, and sleep for the occupants’ activity recognition.

Activity Recognition, CO₂ Sensor, Internet of Things (IoT), Low Privacy-Intrusion, Heat Map

Matsubara, H. (2023) An Activity Recognition System at Home Based on CO₂ Sensors. Journal of Computer and Communications, 11, 64-77. doi: 10.4236/jcc.2023.1111004.