A dynamic CO₂ mapping system with real-time location system for smart factory

The coronavirus outbreak has heightened concerns about indoor air quality, yet CO2 concentration in densely populated factories remains insufficiently monitored. Effective CO₂ monitoring supports workplace safety and improves HVAC efficiency for better air quality and energy savings. However, traditional indoor CO₂ monitoring for spatiotemporal data relies on fixed sensor arrays, which complicate installation and maintenance. Thus this paper proposes a real-time dynamic CO₂ mapping system (DCMS) to continuously monitor CO₂ levels in factories by integrating CO₂ sensing, real-time location systems (RTLS), and spatial mapping technology. The prototype was developed and validated in a pilot factory. It consists of a wireless CO₂ sensor node, data server, and dynamic mapping application to collect and visualize real-time spatiotemporal CO₂ data. The results show that the dynamic map effectively captures CO2 distribution and aids decision-making. The optimal interpolation method for CO2 mapping was identified as inverse distance weighting with a power parameter of 4, yielding a relative error of 0.5%. These findings support the potential of this method for continuous CO2 monitoring in factory settings, contributing to occupational health and safety in smart factories.