农业复杂环境下无线传感器网络构建若干问题的研究

发布时间：2018-10-15 09:00

【摘要】：随着传感器技术、无线通信技术、移动嵌入式技术等的发展,同时由于人们对智能农业、精准农业的急切需求,使得无线传感器网络广泛的应用于现代农业中。通过在农业环境中采用无线传感网络,不仅可以降低人力消耗,还可以远程准确的获取农业环境信息和农作物信息。从而实现科学种植、科学管理。但是由于农业环境的复杂性,使得无线传感网络在农业应用中的性能不及在工业中的稳定、健壮。本论文围绕农业环境的复杂性,以Zigbee无线网络作为研究对象,从信号强度、节点电量以及远程诊断三个方面进行研究,具体研究内容如下:农业环境分为设施农业和大田农业,设施农业需要考虑农业大棚墙壁的厚度、材质对节点之间信息传输的影响;农作物的高度、田间地貌、田间遮挡物都需要作为考虑影响大田农业物联网的因素,因为他们都能在一定程度上对节点通信产生干扰。无线传感网络中的无线传输信号在不同农业环境下、不同障碍物、不同高度的情况下传播特性、信号递减方式也不同。因此,针对这两种农业生长环境,本文分别从不同的农业环境进行了信号强度测试,研究了不同农业种植环境条件下,Zigbee无线传感网络信号强度衰减变化情况。本文采用电量监测技术,实时监测电源参数,这种供电方式在太阳辐射充足的情况下能够有效的为系统正常供电,但当Zigbee节点遇到连续阴雨天且无其他电源供电时,如果不及时补充电能且以高频方式进行数据收发将导致设备无法正常工作。基于此种关系,为保证节点在农田中无太阳能补充条件下持续性高效率正常工作,本文提出了一种基于太阳能蓄电池的采集频率调控策略。由于在农业监测环境中,无线网络节点设备通常分布在野外,与环境的监测者距离相对较远,使得设备的维护相对较为困难。针对这一问题,本文提出了基于硬件诊断的远程诊断系统。在基于信号强度监测技术和电量监测技术基础之上,通过通信系统将硬件设备的状态信息发送给用户,使得用户了解设备的运行状态,如果设备出现故障,用户可以在第一时间内了解故障原因,随之做出相应的解决措施。为了降低农业环境中无线传感网络成本,本文设计了适合农业环境的Zigbee/GPRS网关。Zigbee/GPRS网关采用Zigbee无线通信技术、GPRS技术、RS232通信技术,实现节点数据转发、Zigbee协议与Internet协议转换。
[Abstract]:With the development of sensor technology, wireless communication technology, mobile embedded technology and so on, wireless sensor network (WSN) is widely used in modern agriculture because of the urgent need of intelligent agriculture and precision agriculture. Through the use of wireless sensor network in the agricultural environment, not only can the human consumption be reduced, but also the agricultural environment information and crop information can be obtained remotely and accurately. In order to achieve scientific planting, scientific management. However, due to the complexity of agricultural environment, the performance of wireless sensor networks in agricultural applications is not as stable and robust as in industry. This paper focuses on the complexity of the agricultural environment, taking Zigbee wireless network as the research object, from three aspects of signal intensity, node electricity and remote diagnosis, the specific research contents are as follows: the agricultural environment is divided into facility agriculture and field agriculture. Facility agriculture needs to consider the thickness of the walls of the agricultural greenhouse and the effect of the material on the information transmission between the nodes; the height of the crops, the field landforms, and the field obstructions are all the factors that need to be considered to affect the agricultural Internet of things in the field. Because they can interfere with node communication to a certain extent. Wireless transmission signals in wireless sensor networks in different agricultural environment, different obstacles, different height of the transmission characteristics of the signal in different ways. Therefore, in view of these two kinds of agricultural growth environment, the signal intensity of Zigbee wireless sensor network was tested from different agricultural environment, and the change of signal intensity attenuation of Zigbee wireless sensor network was studied under different agricultural planting environment. In this paper, the electric quantity monitoring technology is used to monitor the power supply parameters in real time. This power supply method can effectively supply the system with sufficient solar radiation, but when the Zigbee node encounters continuous rainy weather and no other power supply, If the power is not replenished in time and the data is sent and received in high frequency mode, the equipment will not work properly. Based on this relationship, in order to ensure that the node can work effectively and efficiently in farmland without solar energy supplement, a frequency control strategy based on solar battery is proposed in this paper. In the agricultural monitoring environment, the wireless network node equipment is usually distributed in the field, which is relatively far away from the monitor of the environment, which makes the maintenance of the equipment relatively difficult. To solve this problem, a remote diagnosis system based on hardware diagnosis is proposed in this paper. Based on the signal strength monitoring technology and the electric quantity monitoring technology, the state information of the hardware equipment is sent to the user through the communication system, so that the user can know the running state of the device, and if the equipment fails, Users can understand the cause of the failure in the first time, and then make corresponding solutions. In order to reduce the cost of wireless sensor network in agricultural environment, this paper designs a Zigbee/GPRS gateway suitable for agricultural environment. Zigbee wireless communication technology, GPRS technology and RS232 communication technology are used in Zigbee/GPRS gateway to realize node data forwarding, Zigbee protocol and Internet protocol conversion.
【学位授予单位】：吉林农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.9;TN92

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