改进的DV-HOP无线传感器网络定位算法

为了提高无需测距的距离矢量（DV-Hop）定位算法对随机分布网络节点的定位精度。在分析了DV-Hop算法实现思想的基础上,提出了一种锚节点整体均匀分布优化方案,对该算法节点跳数进行优化。另一方面,在双通信半径算法基础上提出了一种三通信半径改进方法,使得两节点之间的跳数与距离的关系更接近线性规律,最后结合两种改进方法,进行整体仿真。仿真结果表明,锚节点均匀分布的三通信半径DV-Hop算法比双通信半径DV-Hop算法提高定位精度约为7%~8%。     

WSN中基于最佳指数的加权DV-Hop算法

DV-Hop算法是一种低成本、低定位精度的无需测距定位算法,在粗精度定位中应用广泛。为提高DV-Hop算法定位精度,从减小锚节点的平均每一跳距离误差和减小未知节点平均每一跳校正值误差两方面考虑。首先,用最佳指数值下的公式计算锚节点平均每一跳距离。然后,将未知节点的校正值加权处理,使所有的锚节点根据与未知节点距离的远近影响校正值的大小。MATLAB实验证明,改进的基于最佳指数值下的加权DV-Hop算法比DV-Hop算法、加权DV-Hop、最佳指数值下DV-Hop算法定位精度分别提高2%左右、1.65%左右、1.15%左右,同时不会增加网络硬件成本。     

基于跳距修正粒子群优化的WSN定位算法

针对DV-Hop算法在节点随机分布的网络拓扑环境中存在较大误差的问题,提出了一种基于跳距修正粒子群优化的定位算法WPDV-Hop(weight PSO DV-Hop)。本算法通过对锚节点广播的数据分组结构进行了改进,对参考锚节点的平均每跳距离的误差进行加权处理以及用改进的粒子群(PSO)算法对定位中的迭代过程进行优化,实现WPDV-Hop定位算法的全面改进,以提高定位精度。仿真结果表明,改进的算法与原始算法相比,定位精度和算法的稳定性有明显提高。     

改进的DV-Hop无线传感网络节点定位算法

针对传感器部署密度大、分布不均匀,DV-Hop定位算法误差大等问题,提出了一种改进DV-Hop的无线传感器节点定位算法.首先采用DV-Hop算法对未知传感器节点位置进行计算,然后在采用遗传算法对DV-Hop定位的误差进行修正.仿真结果表明,改进DV-Hop算法提高了节点的定位精度,降低定位的误差,更能真实地反映传感器网络节点的实际分布情况.     

无线传感器网络中分阶段的无需测距定位算法

为了提高无线传感器网络中基于无需测距算法定位精度,改进质心算法和DV-Hop算法,定位过程分为两个阶段:第一阶段在最佳通信半径与最佳阈值下,用基于阈值的优先质心算法定位部分节点;第二阶段在最佳通信半径与最佳指数值下用DV-Hop算法定位剩余节点。将算法应用在一种锚节点人工部署环境下,并与其他算法对比。MTLAB仿真结果表明,改进的算法在不增加泛洪次数、计算量和网络硬件成本下能提高定位精度,同时实现100%定位。     

无线传感器网络中DV-Hop定位算法的改进

无线传感器网络中基于无需测距的节点定位算法定位精度不高,一般应用在粗精度定位中。为了提高基于无需测距的DV-Hop算法定位精度,利用最小均方差准则改进算法,通过修改指数值精化平均每一跳距离,提出不同通信半径、不同锚节点覆盖率下的最佳指数值概念,并应用在一种锚节点均匀分布环境中,进一步提高定位精度。MTLAB仿真结果表明,在最佳指数值下,改进的算法在不同锚节点覆盖率、不同通信半径下能提高定位精度,同时不会增加节点能量消耗与硬件成本。     

DV-Hop定位算法在随机传感器网络中的应用研究

DV-Hop节点定位算法是一种重要的与距离无关的定位算法。在各向同性的密集网络中,DV-Hop可以得到比较合理的定位精度,然而在随机分布的网络中,节点定位误差较大。该文根据DV-Hop算法定位过程,在平均每跳距离估计、未知节点到各参考节点之间距离的计算和节点位置估计方法等3个方面进行了改进,分析和仿真了不同改进措施和综合改进的定位性能。结果表明,与有关方法相比,该文提出的改进措施可极大地提高节点定位精度。此外,该文改进措施不改变DV-Hop算法的定位过程,因此不需要增加网络通信量和额外硬件支持,是理想的与距离无关算法。     

一种改进的无线传感器网络节点定位算法

DV-Hop定位算法,其根据距离矢量路由得到的平均每跳距离和跳数来计算未知节点到锚节点的距离存在比较大的误差。针对此问题,提出一种改进算法。首先,使用整个网络中计算出的所有锚节点的平均每跳距离的无偏估计值的平均值来取代最相邻锚节点计算出的平均每跳距离;然后,通过选取符合条件的锚节点来参与未知节点的定位计算。仿真结果表明,该算法与传统的DV-Hop定位算法相比定位精度有较好的改善,具有一定的可用性.     

无线传感器网络中一种改进的DV-Hop定位算法研究

节点定位算法是无线传感器网络中的关键技术。针对DV-Hop定位算法定位精度不高的问题,提出一种改进的DV-Hop定位算法,通过减小全网平均跳距与真实的平均跳距的差距,重新修订不在网络区域的未知节点的坐标,提高平均跳距取值的准确性。仿真结果表明,在同等网络环境下,改进的DV-Hop定位算法的定位误差减小,能有效提高节点的定位精度。     

基于混合人工蜂群策略的改进DV-Hop定位算法

为了减小DV-Hop算法在无线传感器网络节点定位中的误差,提出了一种基于混合人工蜂群算法的改进算法。该算法结合了粒子群算法收敛速度快和蜂群算法搜索能力强的特性,首先通过DV-Hop算法估计锚节点与未知节点之间的距离,然后采用粒子群算法计算未知节点的初始位置,最后利用蜂群算法进行迭代求精,从而实现基于不同距离测量方法的总体优化。仿真结果表明,改进算法的定位精度较DV-Hop算法和基于粒子群的定位算法有明显改善。     

Power efficient range-free localization algorithm for wireless sensor networks

Considering energy consumption, hardware requirements, and the need of high localization accuracy, we proposed a power efficient range-free localization algorithm for wireless sensor networks. In the proposed algorithm, anchor node communicates to unknown nodes only one time by which anchor nodes inform about their coordinates to unknown nodes. By calculating hop-size of anchor nodes at unknown nodes one complete communication between anchor node and unknown node is eliminated which drastically reduce the energy consumption of nodes. Further, unknown node refines estimated hop-size for better estimation of distance from the anchor nodes. Moreover, using average hop-size of anchor nodes, unknown node calculates distance from all anchor nodes. To reduce error propagation, involved in solving for location of unknown node, a new procedure is adopted. Further, unknown node upgrades its location by exploiting the obtained information in solving the system of equations. In mathematical analysis we prove that proposed algorithm has lesser propagation error than distance vector-hop (DV-Hop) and other considered improved DV-Hop algorithms. Simulation experiments show that our proposed algorithm has better localization performance, and is more computationally efficient than DV-Hop and other compared improved DV-Hop algorithms.     

一种基于误差距离加权与跳段算法选择的遗传优化DV-Hop定位算法

针对Distance Vector-Hop (DV-Hop) 定位算法存在较大定位误差的问题,该文提出了一种基于误差距离加权与跳段算法选择的遗传优化DV-Hop定位算法,即WSGDV-Hop定位算法。改进算法用基于误差与距离的权值处理锚节点的平均每跳距离;根据判断的位置关系选择适合的跳段距离计算方法;用改进的遗传算法优化未知节点坐标。仿真结果表明,WSGDV-Hop定位算法的性能明显优于Distance Vector-Hop (DV-Hop) 定位算法,减小了节点定位误差、提高了算法定位精度。     

An Advanced DV-Hop Localization Algorithm for Wireless Sensor Networks

In emerging sensor network applications, localization in wireless sensor network is a recent area of research. Requirement of its applications and availability of resources need feasible localization algorithm with lower cost and higher accuracy. In this paper, we propose an Advanced DV-Hop localization algorithm that reduces the localization error without requiring additional hardware and computational costs. The proposed algorithm uses the hop-size of the anchor (which knows its location) node, from which unknown node measures the distance. In the third step of Advanced DV-Hop algorithm, inherent error in the estimated distance between anchor and unknown node is reduced. To improve the localization accuracy, we use weighted least square algorithm. Furthermore, location of unknown nodes is refined by using extraneous information obtained by solving the equations. By mathematical analysis, we prove that Advanced DV-Hop algorithm has lesser correction factor in the distance between anchor and the unknown node compared with DV-Hop algorithm, improved DV-Hop algorithm (Chen et al. 2008) and improved DV-Hop algorithm (Chen et al. in IEICE Trans Fundam E91-A(8), 2008), which is cause of better location accuracy. Simulation results show that the performance of our proposed algorithm is superior to DV-Hop algorithm and improved DV-Hop algorithms in all considered scenarios.     

Weighted Hyperbolic DV-Hop Positioning Node Localization Algorithm in WSNs

The localization of nodes plays a fundamental role in Wireless Sensor and Actors Networks (WSAN) identifying geographically where an event occurred, which facilitates timely response to this action. This article presents a performance evaluation of multi-hop localization range-free algorithms used in WSAN, such as Distance Vector Hop (DV-Hop), Improved DV-Hop (IDV-Hop), and the Weighted DV-Hop (WDV-Hop). In addition, we propose a new localization algorithm, merging WDV-Hop, with the weighted hyperbolic localization algorithm (WH), which includes weights to the correlation matrix of the estimated distances between the node of interest (NOI) and the reference nodes (RN) in order to improve accuracy and precision. As performance metrics, the accuracy, precision, and computational complexity are evaluated. The algorithms are evaluated in three scenarios where all nodes are randomly distributed in a given area, varying the number of RNs, the density of nodes in the network, and radio coverage of the nodes. The results show that in networks with 100 nodes, WDV-Hop outperforms the DV-Hop and IDV-Hop even if the number of RNs is reduced to 10. Moreover, our proposal shows an improvement in terms of accuracy and precision at the cost of increased computational complexity, specifically in the algorithm execution time, but without affecting the hardware cost or power consumption.     

Research on mobile strategy of anchor node based on weighted virtual force model

The existing mobility strategy of the anchor node in wireless sensor network (WSN) has the shortcomings of too long moving path and low positioning accuracy when the anchor node traverses the network voids area.A new mobility strategy of WSN anchor node was proposed based on an improved virtual forces model.The number of neighbor nodes and the distance between the neighbor nodes to the anchor nodes were introduced as their own dense weight attributes.The unknown nodes intensity was used as weights to improve the traditional virtual force model.Meantime the distance-measuring error ε was taken into account.The optimal distribution,direction selection,shift step length and fallback strategy of anchor node could be analyzed by the trilateration.Using the number of virtual beacon received by the unknown node and the distance between the unknown node to the anchor node calculate the virtual force.Then according to the virtual force,the direction was chosen and the anchor nodes were moved.Simulation experiments show that the strategy can make the anchor nodes move according to the specific circumstances of unknown node distribution.It has a high positioning accuracy and strong adaptability.It can successfully shorten the path of the anchor node movement and reduce the number of virtual beacon.Moreover it can effectively avoid the anchor node to enter the network voids area and reduce the number of collinear virtual anchor nodes.     

Novel DV-Hop localization algorithm for wireless sensor networks

Many improved DV-Hop localization algorithm have been proposed to enhance the localization accuracy of DV-Hop algorithm for wireless sensor networks. These proposed improvements of DV-Hop also have some drawbacks in terms of time and energy consumption. In this paper, we propose Novel DV-Hop localization algorithm that provides efficient localization with lesser communication cost without requiring additional hardware. The proposed algorithm completely eliminates communication from one of the steps by calculating hop-size at unknown nodes. It significantly reduces time and energy consumption, which is an important improvement over DV-Hop—based algorithms. The algorithm also uses improvement term to refine the hop-size of anchor nodes. Furthermore, unconstrained optimization is used to achieve better localization accuracy by minimizing the error terms (ranging error) in the estimated distance between anchor node and unknown node. Log-normal shadowing path loss model is used to simulate the algorithms in a more realistic environment. Simulation results show that the performance of our proposed algorithm is better when compared with DV-Hop algorithm and improved DV-Hop—based algorithms in all considered scenarios.     

WSN节点定位算法改进研究

在无线传感网络(WSN)中,节点的定位是一个非常之关键的问题,而DV-Hop算法是节点定位诸多算法中最主要的一个算法,但它计算未知节点到锚节点的距离时存在些许问题,所以提出了一个新的计算节点间距离的方法,考虑到在未知节点到锚节点路径上三个连续的节点所形成的角度的影响,使得距离的计算更精确.通过仿真可以得知这个改进算法能有效地提高未知节点定位的覆盖率和精度.