温室无线传感器网络节点发射功率自适应控制算法  

Adaptive control algorithms of transmitting power for greenhouse WSN nodes

作　　者：徐立鸿[1] 早明华 蔚瑞华[1] 林维威 

机构地区：[1]同济大学电子与信息工程学院,上海201804

出　　处：《农业工程学报》2014年第8期142-148,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家863高技术重大课题(2012AA10A507);国家自然科学基金项目(61174090);中央高校基本科研业务费专项资金(2870-219-013)

摘　　要：为了提高无线数据传输的可靠性，基于无线传感器网络（wireless sensor network，WSN）的温室环境数据采集系统，采用试验的方法研究温室中不同环境下WSN节点之间通信的可靠性。在通信距离为5～40 m，存在作物、温室设施等遮挡影响，相对湿度为35%～80%的情况下，对丢包率和接收信号强度指示（received signal strength indication，RSSI）的关系进行研究，通过RSSI对节点间通信可靠性进行评价。在此基础上，提出WSN节点发射功率自适应控制算法。该算法以 RSSI 作为通信质量的评价因子，通过增大节点的发射功率来提高通信可靠性。测试结果表明，该算法能够根据当前通信状况，自适应地设置节点的发射功率，以尽可能小的发射功率将丢包率维持在1%左右。该算法对WSN在温室中的应用具有实用价值。In order to improve the reliability of wireless data transmission of a greenhouse environment data acquisition system, this paper studied the reliability between WSN nodes in several cases in a greenhouse based on an experimental method. When the communication quality was affected by distance, obstacles, and high humidity, the relationship between packet loss rate and RSSI （Received Signal Strength Indication） was analyzed, and then RSSI was used to evaluate the reliability of communication. In the experiment, the distance between nodes had been set from 5 m to 40 m at intervals of 5 m, and the humidity varied from 35%RH to 80%RH at intervals of 15% RH. The obstacles included tomato plants, hanging strawberry, greenhouse facilities such as shade net, heat insulation nets, and exhaust fans. The experiment results showed that the packet loss rate increased when the distance between nodes extended or the obstacles existed while it was not affected by the humidity in the greenhouse. In these circumstances, when the transmitting power of the node had been set as 0, 4, 8, 12, or 19 dBm, both the RSSI and packet loss rate changed so that the relationship between the RSSI and packet loss rate could be studied in coordinates. The results included two situations. The first was when there was no obstacle. In those cases, we found that：1） with the increase of the RSSI of the receiving node, the packet loss rate changed with a certain trend to decrease; 2） when the RSSI value was greater than -58 dBm, the packet loss rate was almost zero. The second was when there were different kinds of obstacles. In those cases, we found that：1） packet loss rate decreased when the RSSI got smaller. 2） when packet loss rate was about 1%, for different obstacles, the RSSI values varied from -58 dBm to -50 dBm. 3） for the same RSSI, it was the smallest when there was no obstacle. Based on this study, an adaptive transmitting power control algorithm for WSN nodes was proposed in which RSSI was used to evaluate communication qu

关 键 词：温室 无线传感器网络 数据采集 可靠性 发射功率 

分 类 号：S126[农业科学—农业基础科学] S625.51