A Monitoring System Based On Wireless Sensor Network With Mobile Node

China owns vast farmland,but the croplands are relatively dispersed,and many of them are hilly mountainous areas.In this kind of areas,agricultural information acquisition is very hard.Traditional static wireless sensor network(WSN)nodes are very difficult to set up.Coverage distance between each node is very long.Energy of each node on the ground is difficult to top up,the invalid node after exhaustion of the energy would divide the wireless sensor network into several sub-networks which would lead to network failure,data loss and the other problems.At the same time,communication quality would declined because of the terrain blocking.It makes the collection of information to be very inconvenient.To solve the shortcomings of the traditional static wireless sensor network,this study proposes to bring a mobile nodes into the traditional static wireless sensor network and install the mobile node on the aircraft,set up the ground space communication model.Then we apply the Wireless Sensor Network based on Unmanned Aerial Vehicle(UAV-WSN)to the acquisition of the ground node data.Thus we establish the Agricultural Monitoring System Based on Wireless Sensor Network with Mobile Node.In this system,we install a mobile sensor which is installed on the unmanned aerial vehicle in the wireless sensor network.The UAV airborne node could communicate with the ground sensor node.The experiments proves that the communication quality is obviously improved compared with the traditional static wireless sensor network.As the UAV can access the more distant locations in the shorter time,it is possible to obtain the information of the terrestrial sensor nodes and improve the efficiency of data collection much more easily.At the same time,this paper improves the data storage mode of the nodes,uses the distributed data storage,stores the data collected by the sensors in the data buffer area of each sub-node,effectively prevents the loss of sampling data,reduces the energy consumption of the sub-node and extend the network's survival time.The farmland monitoring system of UAV-WSN could be implemented as follow: chosing several natural and environmental factors which influence the cultivated land characterization indicators,acquitting these factors through WSN,then the UAV with mobile node would fly to these fields to collects information stored in the ground sensor network acquirers,and the mobile node retransmit the collected information through ZigBee wireless terminal transceiver coordinator,while the terminal transceiver coordinator sending information to the data center to let people analyse and process data.We also customized the host computer monitoring system,displays the data information in the monitoring system and completes the necessary data analysis.After realizing the hardware design of this proposed system,a serial of test have been carried out as follow: ground acquisition node funct ion test,wireless communication quality test between WSN and mobile node on UAV and joint debugging of whole system.After the tests,It is proved that the system based on UAV-WSN can be applied in the farmland information monitoring and improve the communication quality.From the final result,we can see that the system could run very well,and it is easy to be used.It can provide decision support for scientific management of cultivated land.