基于无线传感网的设施环境二氧化碳精准调控系统

设计了一套基于无线传感网的设施环境二氧化碳精准调控系统,包括主控节点、监测节点及补施节点,通过Zig Bee协议实现节点间信息交互。监测节点实时获取设施内多点二氧化碳浓度、温度、光照数据;主控节点根据作物各阶段最适生长环境,结合温度与光照阈值,动态计算二氧化碳浓度目标值与实时值之间的差值作为调控参数,采用反馈控制实现二氧化碳动态调控;为改善以往设施二氧化碳补施不均的普遍现象,设施中气体扩散管道采取双M型布置方式,设计开孔大小不同的二氧化碳扩散孔,由补施节点配合对流装置控制各小区域的二氧化碳排放量,达到均匀和定量补施的目的。实地布置和试验表明基于无线传感网的设施环境二氧化碳调控系统可实现稳定可靠运行,以设施番茄为研究对象,在面积36.66 m~2日光温室内补施目标值与实时值的相对误差小于3.5%,在面积27.74 m~2玻璃温室内验证监测节点间二氧化碳浓度变异系数小于2.93%,证明本系统可实现二氧化碳精准及均匀补充。

Regulation System of CO2 in Facilities Based on Wireless Sensor Network

Carbon dioxide is the necessary material for plant photosynthesis, and building favorable carbon dioxide environment in facilities is essential for crop growth. The design of an environment carbon dioxide precision control system based on wireless sensor network (WSN) was introduced, which was composed of master node, monitoring node and fertilizing node. Information interaction among nodes were achieved with ZigBee protocol, which was a general protocol for wireless sensor network. Monitoring node was used to monitor real-time carbon dioxide concentration, temperature and light intensity in facilities environment. With a feedback control, master nodes achieved dynamic adjustment of carbon dioxide based on different growing seasons for various plants in facilities and combining optimum thresholds of temperature and lights. To improve the disadvantage of uneven carbon dioxide implementation, double M type conductive pipe was deployed in facilities. Meanwhile, different hole sizes on the pipe were designed for acquiring the same instantaneous flow. In collaboration with convection device, fertilizing node controlled the carbon dioxide emissions through gas tank passing and breaking, and guaranteed the uniformity of carbon dioxide implementation. The results show that the relative error between the target and the real-time value is less than 3.5% in solar greenhouse with area of 36.66m2. The designed experiment result shows that the variation coefficient of carbon dioxide concentration among monitoring nodes is less than 2.93% in glasshouse with area of 27.74m2, which proves that the system can realize precise and uniform fertilizing of carbon dioxide.