小麦不同生育期的无线传感器网络透地通信特性研究

Research on the Communication Characteristics of Wireless Sensor Network in Wheat Different Breeding Stages

为了在小麦大田中合理布置无线地下传感器网络节点,研究了433 MHz无线地下传感器网络在小麦四个主要生育期的传输特性,通过MATLAB建立小麦4个生育期中RSSI变化的三维曲面模型,得出RSSI拟合模型和拟合优度,并采用SPASS对模型进行了验证。分蘖期试验中,拟合优度R^2最小为0.714,最大为0.927,RMSE在1.518~3.372 dBm之间。拔节期试验中,拟合优度R^2最小为0.664,最大为0.986,RMSE在0.571~3.491 dBm之间。抽穗期试验中,拟合优度R^2最小为0.673,最大为0.888,RMSE在1.569~4.372 dBm之间。灌浆期试验中,拟合优度R^2最小为0.665,最大为0.784,RMSE在4.062~4.842 dBm之间。该模型可以较好地预测不同条件下透地通信中的RSSI,为土壤信息采集中传感器网络的节点部署和系统的建立提供了技术支持。

In order to rationally arrange wireless underground sensor networks(WUSN)nodes in wheat field, this paper studies the transmission characteristics of 433 MHz wireless underground sensor network during the four main growth periods of wheat. Besides, three-dimensional surface of RSSI is built in four wheat growing periods through Matlab, whose fitting model and goodness of fit of RSSI are obtained, and the model verification is conducted through SPASS software. In the tillering stage experiment, the minimum of goodness of fit R^2 is 0.741, the maximum is 0.927. Root mean square error is in the range of 1.518~3.372 dBm. In the jointing stage experiment, the minimum of goodness of fit R^2 is 0.664, the maximum is 0.986. Root mean square error is in the range of 0.571~3.491 dBm. In the heading stage experiment, the minimum of goodness of fit R^2 is 0.673, the maximum is 0.888, Root mean square error is in the range of 1.569~4.372 dBm. In the watery stage experiment, the minimum of goodness of fit R^2 is 0.665, the maximum is 0.784. Root mean square error is in the range of 4.062~4.842 dBm. The model can better predict the received signal strength under different conditions through-the-earth communication and provide the technical support for sensor network node deployment and the establishment of the system in soil information acquisition.