一种可靠低功耗的温室无线监控系统

Reliable Wireless Monitoring System with Low-Power Consumption for Greenhouse

目的由于无线通信质量和能耗是制约无线传感器网络在温室监控领域广泛应用的关键因素,因此在温室无线监控系统中必须确保设备控制命令和设备状态信息能够可靠地传输,同时降低节点运行功耗以延长其工作寿命。方法提出基于接收确认机制和数据发送标志检测相结合的数据传输方式。设计一套温室无线监测系统。在节点软件设计中采用了低功耗侦听技术。分别在采取接收确认机制、接收确认机制和数据发送标志检测相结合以及不采取任何措施3种情况下,测试了设备控制命令和设备状态信息传输的无线通信质量。环境数据的无线传输仅采用了接收确认机制。测量了节点在发射、接收、空闲和低功耗侦听4种工作状态下的功耗。结果试验结果表明,在设备控制命令和设备状态信息的无线传输中,仅采用接收确认机制时,数据仍有小量丢失。当采用接收确认机制与数据发送标志检测相结合的方法时无任何数据丢失。环境数据传输在4h中仅丢失过1次数据。节点在发射、接收和空闲3种工作状态下的工作电流均在30mA左右,而在低功耗侦听状态下的电流仅为3mA。结论采用接收确认机制和数据发送标志检测相结合的方法能够确保设备控制命令和设备状态信息的可靠无线传输。温室环境数据的传输仅采用接收确认机制即可满足要求。低功耗侦听技术能够显著降低节点功耗,这对于电池供电的无线节点来说非常重要。

Objective The wireless communication quality and the energy consumption of sensor nodes are the key factors that restrict the widespread application of wireless sensor networks in the field of greenhouse monitoring,so it is necessary to ensure that the device control commands and device status information are transmitted reliably and that the power consumption of nodes is simultaneously reduced to extend their operating life.Methods A data transmission mode based on the combination of acknowledgement mechanism and data sending flag detection was proposed.A greenhouse wireless monitoring system was constructed.The low-power consumption monitoring technology was adopted in the design of node software.The wireless communication quality for transmitting the device control commands and device status information was tested in three cases:1)wireless communication only with the acknowledgement mechanism;2)with the combination of acknowledgement mechanism and data sending flag detection;3)without neither of them.The environmental data were transmitted wirelessly with only the acknowledgement mechanism.The power consumption of nodes under four working conditions(transmit,receive,idle and low power listening),was measured.Results The experimental results showed that a small amount of data was lost when only the acknowledgement mechanism was adopted in the wireless transmission of device control commands and device status information;while there was no data loss when the acknowledgement mechanism was combined with data sending flag detection method.There was only one data loss of environmental data in four hours.The working currents of node were about 30 mA in the three working states,i.e.,transmit,receive,idle state,while the current in the low power listening state is only 3 mA.Conclusion The combination of acknowledgement mechanism and data sending flag detection can ensure the reliable wireless transmission for device control commands and device status information.The acknowledgement mechanism can ensure good wireless transmission for greenhouse environment data.The low-power listening technology can significantly reduce the power consumption of nodes,which is very important for wireless nodes powered by battery.