In order to realize the effective communication among nodes and between nodes in wireless sensor networks,according to the application requirements of the location network and the use of data commands,the node message format,message type and message con-tent are developed,the specific direction of the message is clarified and the application layer framework of nodes is determined. The Sink node is responsible for monitoring the network establishment,analysis and operation of upper commands,data collection and other tasks, which is the center of data storing and processing in whole network,as the bridge between the upper computer and the monitoring net-works. Each node is composed of wireless data transmission module and DSP control module. The two modules of the same node are in the communication through the UART bus,and the nodes by wireless RF radio frequency. The Sink node communicates with the upper computer by UART bus. The location and ranging performance of network nodes is analyzed by means of ultrasonic correlation location ranging in the experiment which shows that the maximum distance measured by the node of the constructed system is 19 m,the average positioning error is 3. 6 cm,the maximum positioning error is 17. 2 cm,and the range of relative positioning range is 0% ~0. 91%.%为了实现无线传感器网络节点内部、节点与节点之间有效的通信,根据定位网络的应用需求以及数据命令的用途,制定了节点消息格式、消息类型和消息内容,明确了消息的具体走向,确定了节点的应用层框架结构.其中,Sink节点主要负责监控网络的建立、上位机命令的分析处理和操作、数据的收集等任务,是整个网络的数据存储和处理中心,在上位机和监控网络之间起到桥梁的作用;每个节点由无线数据传输模块和主控DSP模块组成,同一节点的两个模块之间通过UART总线进行通信,节点之间通过无线RF射频方式进行通信;Sink节点与上位机使用UART总线进行通信,通过超声波相关定位测距的算法来对网络节点的定位测距性能进行实验分析.定位测距实验结果表明,构建系统的节点可测得最远距离为19 m,平均定位测距误差为3.6 cm,最大定位测距误差为17.2 cm,相对定位测距误差范围为0%~0.91%.
展开▼
