无线传感网定位

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-organization

Typically 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 tolerance

Hardware 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 efficiency

In 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.