【作者】 苏令永；

【导师】 张瑞华；

【作者基本信息】 山东大学 ， 计算机系统结构， 2008， 硕士

【摘要】 无线传感器网络融合了传感器技术、通信技术和数据处理技术;无线传感器网络因其巨大的应用前景而受到学术界和工业界越来越广泛的重视。本文首先对无线传感器网络进行了概述,介绍了国内外无线传感器网络的研究现状、无线传感器网络体系结构和特点等;无线传感器网络的技术标准IEEE802.15.4把低能量消耗、低速率传输、低成本作为重点,为LR-WPAN(low-ratewireless personal area network)网络制定了物理层和MAC子层协议;ZigBee技术建立在IEEE802.15.4标准之上,ZigBee联盟对网络层协议和API进行了标准化;在此基础上我们设计了基于CC2420射频芯片与ATmegal28单片机的无线传感器网络的硬件平台。在节点的硬件设计上重点阐述:ATmegal28L主要特点,管脚资源的使用,CC2420特性,工作模式,CC2420内部寄存器的构成,CC2420与处理器的接口,温度传感器DS1822和振动传感器ADXL202的特点和操作,节点的软件协议栈,Coordinator、RFD节点的软件协议栈的程序流程,以及软件协议栈中数据帧的结构的定义以及配置。利用设计讨论的硬件节点,基于ZigBee规范组建了线性多跳网络,深入讨论了在网络的运行过程中Coordinator、Router、End Device节点之间以及各个节点的应用层、网络层、媒体接入控制层之间消息的传送,对各种节点的主要程序进行了描述,针对网络的运行过程进行了讨论:节点短地址的分配、路由表及路由过程,最后截取了网络运行的结果进行分析。针对无线传感器网络后台管理:探讨了后台管理软件应提供的基本功能,重点论述了管理软件的模块化结构、串口通信过程中串口数据的处理、串口的初始化操作;就节点原始数据包数据进行可视化实现过程进行简要的概述,依据无线网络能量消耗模型和CC2420性能指标获取了网络运行过程中的能量消耗,在管理软件实现的可视化窗口的状态栏添加了显示网络能耗窗口,以此来实时获取网络运行中的能耗情况。以无线传感器网络单跳状态下的能量消耗模型为基础,进行分析推导得出等间距线性网络最优单跳距离与源节点和汇聚节点的距离无关,仅仅依赖于传输数据包的电路特性以及信道损耗;优化间距线性网络的优化间距,以此间距配置节点,网络运行过程中系统的能耗最低,并且能够均衡各个节点的能耗,从而避免了因某些节点能量消耗过多而过早死亡,从整体上延长了网络能耗。基于组建的线性多跳网络结合后台管理软件通过实验验证了上述结论的正确性。进而提出了一种低能耗的无线传感器网络节点的配置方案。更多还原

【Abstract】 Wireless Sensor Network(WSN)combined sensor technology,communication technology and computer technology together.More and more researchers and industries were engaged in developing wireless sensor networks due to its great promise of various applications。At first,this paper introduced domestic and international research condition,studies making progress,system structure and characteristics of the wireless sensor network. Low-rate wireless personal area network established standard—IEEE802.15.4,which drew up Physical layer and Medium access control layer protocol for the LR-WPAN.It was important for IEEE802.15.4 to reduce energy consumption,make the low rate delivery and low cost.ZigBee Specification based on IEEE802.15.4and ZigBee Alliance carried on standard to Network layer and Application Layer(APL).We selected the transceiver CC2420 and MCU Atmega128 as key chip set and designed the hardware platform which adapt to IEEE802.15.4 and ZigBee Specification.We discussed the main characteristics of MCU,the usage of pin resources,the CC2420 characteristics,work mode,the composing of the inner register and the characteristics and operation of the temperature sensor DS1822 and the vibration sensor ADXL202 in detail.We analyzed the protocol stack of WSN which included program design of Coordinator and RFD,definition of the data frame and data process etc.Making use of the hardware node we designed set up a more hops linear network according to the ZigBee Specification.We discussed thoroughly the transmission of the messages among the APL,MAC,PHY of each node when the network worked,studied the running condition of the network which Coordinator built a new network and allocated short address to each node and intercepted a picture of the network running in order to analyze it.We discussed the management platform which could show directly the result of the network.At first we introduced management platform should provide the basic function, then the point of modular assembly design about platform.This modular structure was benefit for the second time development.We added a view to show original data from every node,and intercepted a picture of the network running in order to show the original data.According to the one-hop energy consumption model and the CC2420 function index sign we could obtain easily network’s energy consumption,so we added a window to show the energy consumption at the management platform’s appearance column. When it was running we could obtain the network’s energy consumption at any time.With the one-hop energy consumption model of WSN we analyzed and made a conclusion which the superior one-hop distance of Equal Distance Linear Network was apart from the communication distance between the source node and sink,only depended on electric circuit in delivering data packages and lost of the channel.At the same time we obtained the optimize distance of the Linear Network.Configed the node according to optimize distance not only the network would consume lowest energy but also every node would consume the same energy approximately.Thus avoided some nodes to die early because of energy consumption exclusively and promoted the network’s life entirely.Using the line more hops network we designed and management platform we could test conclusions easily.Finally we put forward a configuration of WSN.更多还原