摘要
针对农田环境信息监测存在能量有限、节点通信距离各异等特点,设计了一种基于接收信号强度和丢包率的发射功率自适应水稻田监测系统,并搭建了一个长期、稳定且可靠的低功耗无线传感网络。硬件方面,为扩大网络的覆盖范围和提高系统的稳定性,采用频率异构的方式对节点分簇,为不同类型的节点配置不同类型的天线。软件方面,为提高CPU利用率,各类节点程序设计采用基于小型嵌入式实时操作系统FreeRTOS;为降低功耗,采取定时休眠唤醒、传感器掉电控制的工作模式和基于感知数据差的低功耗自适应机制。试验结果表明,在150 m通信距离内,系统可以根据当前的通信质量,将节点的发射功率自适应地调整到实现当前通信可靠性所要求(丢包率小于1.3%)的最小发射功率上;对比10 d Bm固定发射功率,当发射功率自适应算法调整为8、6、3 d Bm时,节点续航能力分别提升了11.9%、21.4%和33.3%。通讯性能对比表明,本设计节点的通讯性能明显优于其他3种基于不同发射功率自适应算法的节点,从而验证了本系统的可靠性与实用性。
To solve the problems occurring in surveying the farmland environment such as limited energy and different distances of communication among the nodes,a monitoring system with adaptive transmitting power for rice fields based on received signal strength indication（ RSSI） and packet loss rate（ PLR） was designed and a long-time,stable and highly reliable wireless sensor network（ WSN） running this algorithm with low power consumption was established. In the aspect of hardware,to extend the network coverage and improve the stability of the system,the method of frequency heterogeneity was adopted to cluster the nodes and configure different antennas for different nodes. In the aspect of software,the mini embedded free real-time operating system（ FreeRTOS） was selected to improve the utilization of CPU and prolong the working life of the clusters. Additionally,to reduce the power consumption,the mode of timed sleeping and waking as well as the power-down control of sensor were selected as the working pattern and the adaptive low-power-consumption mechanism were used on the basis of data deviation perception. The result of tests showed that the system can adaptively adjust the transmitting power to the minimum value which can meet the demand of the stability of communication（ PLR was less than 1. 3%）within the communication distance of 150 m according to the quality of current communication. In this situation,when the algorithms of adaptive transmitting power was adjusted to 8 d Bm,6 d Bm and 3 d Bm,respectively,from 10 d Bm,the battery duration of nodes was increased by 11. 9%,21. 4% and 33. 3%.As the result revealed,the communication performance of the nodes was significantly better than those of three other nodes with different adaptive transmission power algorithms. Thus it can be seen that thesystem was highly stable and practical in the application of WSN for the monitoring of farmland environment.
作者
王卫星
陈华强
姜晟
铁风莲
孙宝霞
余杰平
WANG Weixing1,2 CHEN Huaqiang1 JIANG Sheng1,3 TIE Fenglian1 SUN Baoxia1 YU Jieping1(1. College of Electronic Engineering, South China Agricultural University, Guangzhou 510642, China 2. Guangdong Engineering Research Center Jbr Monitoring Agricultural Information, Guangzhou 510642, China Guangdong Modern Agricultural Science and Technology Innovation Center for Intelligent Orchard, Guangzhou 510642, Chin)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2018年第3期150-157,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
广东省自然科学基金项目(2014A030313451)
广州市科技计划项目(201605030013)
关键词
水稻田
监测系统
无线传感网络
发射功率自适应
低功耗
rice field
monitoring system
wireless sensor network
adaptive transmitting power
lowpower consumption
