对于定位一般的理解就是确定位置。
在无线传感网中,定位是指网络通过特定的方法确定节点的位置信息。
其可分为节点的自身定位和目标定位。
节点自身定位是确定网络中节点位置坐标的过程,它是网络自身属性的确定过程,是网络的支撑,可以通过人工配置或各种节点自定位算法完成; 目标定位是指在网络覆盖范围内确定一个事件或一个目标的位置坐标,这可以通过把位置已知的网络节点作为参考节点来确定事件或目标在网络中所处的位置。
无线传感网定位问题就是寻求利用少量的锚节点来确定网络中未知节点的位置坐标的方法。
无线传感网中,传感器节点的可靠性差、能量有限、节点数量庞大且节点部署具有不确定性等,这些限制因素对定位技术提出了更高的要求。
通常无线传感网定位技术具备以下特点:①自组织性通常无线传感网中的节点是随机布设的,不能依靠全局的基础设施的协助确定每个节点的位置所在。
因此,自组织性就显得格外重要。
②容错性传感器节点的硬件配置低、处理能力弱、可靠性差、能量少以及测距时会产生误差等因素决定了传感器节点本身的脆弱性,因此定位算法必须具有良好的容错性。
③能量高效性为了尽量延长网络的生存周期,要尽可能的减少节点间的通信开销,减少算法中计算的复杂度,用尽量少的能量完成尽可能多的工作。
④分布式计算每个节点自己对自身的位置进行估算,不需要将所有信息传送到某个特定的节点进行集中计算。
For a general understanding of the positioning is to determine the location. In wireless sensor networks, localization refers to the network to determine the node location information by a specific method. It can be divided into self-positioning and targeting nodes. Node positioning itself to determine the location coordinates of nodes in the network process, which is the process of determining the properties of the network itself, is to support the network, you can manually configure various nodes or self-localization algorithm is complete; the goal is to determine the location within the network coverage an event or position coordinate of an object, which can be known by the location of the network node as a reference node to determine the event or target location in the network. Wireless sensor network localization problem is to seek the use of a small amount of anchor nodes in the network to determine the location coordinates of the unknown node approach.Wireless sensor networks, sensor nodes poor reliability, energy is limited, a large number of nodes and node deployment uncertainties and other factors which limit the positioning technology has put forward higher requirements. Wireless sensor network positioning technology usually have the following characteristics:① self-organizationTypically Wireless Sensor Network nodes are randomly laid, can not rely on a global infrastructure assistance to determine the location where each node. Thus, self-organization is particularly important.② fault toleranceHardware configuration of the sensor nodes is low, the processing capacity is weak, poor reliability, less energy and will produce an error and other factors that determine the vulnerability of the sensor node itself when ranging, so the localization algorithm must have good fault tolerance.③ energy efficiencyIn order to try to extend the lifetime of the network, to minimize the communication overhead between nodes, reducing the complexity of the algorithm calculated as few as much energy to complete the work.④ Distributed ComputingEach node's own estimate of its own position, without the transfer of all information to a particular node centralized computing.无线智能传感网主要由终端节点、协调器和上位机组成，其中终端节点和协调器需要进行硬件设计，上位机选用一台个人电脑。
终端节点是网络的最底层，其负责感知信号并与协调器通信，对应于IEEE1451 标准中定义的智能变送器模块。
协调器是网络中协调终端节点和上位机的中间层，既要与终端节点通信，又要支持TCP/IP 协议接入局域网允许上位机与其通信，还要具有本地数据存储等能力，其对应于IEEE 1451 标准中定义的网络适配器模块。
无线智能变送器对应的网络中的终端节点，其主要作用包括数据的采集和传输。
数据的采集需要通过传感器感知，随着科技的发展，对于传感器的设计已日渐丰富和成熟，而且本文主要针对对象是无线智能传感网的设计，所以对传感器的设计不做介绍，硬件单元的重点放在了数据的传输部分，但对传感器单元留有数字通信接口，支持不同传感器的接入。
一个微处理器的最小系统设计的例子。
STM32F103 系列微处理器采用ARM 的Cortex-M3 内核，它是ARM 系列新一代的低功耗嵌入式ARM 处理器，它为替代单片机的需要提供低成本的应用平台。
相比其他系列ARM 处理器，Cortex-M3 内核系列提供了更优越的计算性能和更先进的中断响应系统，并且在低功耗属性上表现的更加优越。
STM32F103 系列采用Cortex-M3 内核，它是32 位的RISC 结构，兼容所有的ARM 工具及软件。
Wireless intelligent sensor network consists of terminal nodes, the coordinator and the host computer, of which the terminal node and coordinator needed hardware design, the choice of a PC personal computer. Terminal node is the lowest level of the network, which is responsible for sensing signals and communicate with the coordinator, corresponding to the IEEE1451 standard defined smart transmitter module. The coordinator is the middle layer of the network coordination and PC terminal nodes, both to communicate with the terminal node, but also supports TCP / IP protocol to allow access to the LAN to communicate with the host computer, but also with local data storage capacity, which corresponds to IEEE 1451 network adapter module defined in the standard.Wireless Intelligent Transmitter corresponding terminal nodes in the network, and its main role, including the collection and transmission of data. Data collection requiredby the sensor perception, along with the development of technology for the design of the sensor has been increasingly rich and mature, and this paper is focused on the object of wireless smart sensor network design, so the sensor does not describe the design of the hardware unit focused on the portion of the data transmission, but leave the sensor unit the digital communication interface to support access different sensors. Minimum system a microprocessor design examples. STM32F103 series microprocessor with ARM's Cortex-M3 core, it is a new generation of low-power ARM family of embedded ARM processor, which provides low-cost alternative application platform for microcontroller needs. Compared to other series of ARM processors, Cortex-M3 core family provides superior computing performance and more advanced interrupt response systems, and in the low-power performance is more superior properties. STM32F103 series with Cortex-M3 core, it is a 32-bit RISC architecture, compatible with all ARM tools and software.。