WIRELESS MEASUREMENT AND CONTROL SYSTEM OF CARBON DIOXIDE USING INFRARED SENSOR IN GREENHOUSE ENVIRONMENT

A carbon dioxide detecting and controlling system has been experimentally established in a greenhouse located in northern China. The developed system consists of several major parts including wireless infrared gas sensor node, wireless receiver and CO2 concentration controller with pure CO2 cylinder. The wireless infrared gas sensor was developed for real time detection of CO2 which is essential for plant photosynthesis. Digitalized data of concentration can be received by the wireless receiver which connects to a laptop installed developed LabVIEW program. Ambient CO2 concentration can be controlled automatically by the concentration controller based on fuzzy PID algorithm. Experiments demonstrate that the stability fluctuation of detection results is less than 2.2%. The fluctuation of ambient CO2 concentration under automatic control is less than 60 ppm which proves good efficiency of the system. The proposed CO2 detecting and controlling system is suitable for precision management of key factors along with temperature, humidity and luminance in greenhouse for optimal production.