共查询到19条相似文献,搜索用时 281 毫秒
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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。 相似文献
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针对现有组合加权算法对定位区域边缘的目标定位时精度较低的问题,在现有组合加权算法的基础上提出了一种改进算法。首先,将基站分组,以到达时差算法得到目标位置的多个估计结果;其次,计算各估计结果之间距离值并排序,以滑动窗口法判断是否存在基站组出现异常定位估计;最后,当任意基站组的定位结果发生异常时,使用目标位置估计结果及其估计克拉美罗下界值设计两个加权步骤的权值,通过二步组合加权算法得到最终定位结果。仿真结果表明,所提算法有效减少了原组合加权算法对定位区域边缘的目标定位时的误差,当测量噪声标准差为0.8 m时,所提算法相较于原算法在正方形边缘区域定位均方根误差减小了0.35 m;在定位狭窄矩形区域时,所提算法平均定位均方根误差减小了0.11 m。 相似文献
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针对基于RSSI测距的定位算法定位误差较大的问题,通过加入多组已知节点之间的距离和接收功率作为参考,提出了一种改进的RSSI测距算法,并将改进的RSSI测距作为最小二乘支持向量回归机LSSVR的输入向量,获得基于改进RSSI测距的LSSVR三维定位算法模型。MATLAB仿真结果表明,在节点随机分布的三维环境中,基于改进RSSI测距的LSSVR定位算法的定位误差比传统LSSVR定位算法减小了13.6%~21.2%,另外,可以通过增加已知节点数量等方法,进一步提高目标定位的准确性。 相似文献
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针对DV-Hop距算法定位误差大的难题,提出一种改进离估计误差,并利用DV-Hop的传感器节点定位算法。首先修正知节点与信标节DV-Hop算法对节点进行定位;然后对进V-Hop算法定位误差行校正,最后在Matlab 2012平台上对算法性能进行仿真分析。仿真结果表明,本文算法可以较好地克服DV-Hop算法存在的不足,提高了传感器节点的定位精度。 相似文献
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在无线传感器网络中传统的序列定位算法将空间划分为点、边和面等不同的区域,但以面重心为未知点定位时误差较大. 针对此节点自定位算法的误差问题,提出了一种序列定位与三点垂心法相结合的节点定位改进算法,给出了该算法的基本原理与实现方法. 通过进一步判断排列顺序相关系数的三个最大值,求出离未知节点“最近”的三个区域的重心构成的三角形的垂心,进一步滤掉节点不可能存在的区域,减少定位误差. 该算法增加了计算未知节点精确位置的计算量,但不需要增加节点的硬件条件和计算复杂度. 仿真结果表明,与传统序列定位算法和三点垂心法相比,新算法可以明显的提高定位精度,随着锚节点数的增多,定位误差呈大幅度的减少. 相似文献
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Guangjie Han Deokjai Choi Wontaek Lim 《Wireless Communications and Mobile Computing》2009,9(8):1017-1027
The key problem of location service in indoor sensor networks is to quickly and precisely acquire the position information of mobile nodes. Due to resource limitation of the sensor nodes, some of the traditional positioning algorithms, such as two‐phase positioning (TPP) algorithm, are too complicated to be implemented and they cannot provide the real‐time localization of the mobile node. We analyze the localization error, which is produced when one tries to estimate the mobile node using trilateration method in the localization process. We draw the conclusion that the localization error is the least when three reference nodes form an equilateral triangle. Therefore, we improve the TPP algorithm and propose reference node selection algorithm based on trilateration (RNST), which can provide real‐time localization service for the mobile nodes. Our proposed algorithm is verified by the simulation experiment. Based on the analysis of the acquired data and comparison with that of the TPP algorithm, we conclude that our algorithm can meet real‐time localization requirement of the mobile nodes in an indoor environment, and make the localization error less than that of the traditional algorithm; therefore our proposed algorithm can effectively solve the real‐time localization problem of the mobile nodes in indoor sensor networks. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Guangjie Han Huihui Xu Jinfang Jiang Lei Shu Takahiro Hara Shojiro Nishio 《Wireless Communications and Mobile Computing》2013,13(14):1324-1336
In wireless sensor networks (WSNs), many applications require sensor nodes to obtain their locations. Now, the main idea in most existing localization algorithms has been that a mobile anchor node (e.g., global positioning system‐equipped nodes) broadcasts its coordinates to help other unknown nodes to localize themselves while moving according to a specified trajectory. This method not only reduces the cost of WSNs but also gets high localization accuracy. In this case, a basic problem is that the path planning of the mobile anchor node should move along the trajectory to minimize the localization error and to localize the unknown nodes. In this paper, we propose a Localization algorithm with a Mobile Anchor node based on Trilateration (LMAT) in WSNs. LMAT algorithm uses a mobile anchor node to move according to trilateration trajectory in deployment area and broadcasts its current position periodically. Simulation results show that the performance of our LMAT algorithm is better than that of other similar algorithms. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Achieving Max–Min lifetime and fairness with rate allocation for data aggregation in sensor networks
We consider the rate allocation problem for data aggregation in wireless sensor networks with two objectives: (1) maximizing the minimum (Max–Min) lifetime of an aggregation cluster and (2) achieving fairness among all data sources. The two objectives are generally correlated with each other and usually, they cannot be maximized simultaneously. We adopt a lexicographic method to solve this multi-objective programming problem. First, we recursively induce the Max–Min lifetime for the aggregation cluster. Under the given Max–Min lifetime, we then formulate the problem of maximizing fairness as a convex optimization problem, and derive the optimal rate allocation strategy by iterations. We also present low-complexity algorithms that an aggregation cluster can use to determine the Max–Min network lifetime and the fair rate allocation. Our simulation results validate our analytical results and illustrate the effectiveness of the approach. 相似文献
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在无线传感器网络中,监测到时间之后关心的一个重要问题就是该事件发生的位置。传感器节点能量有限、可靠性差、节点规模大且随机布放、无线模块通信距离有限,对定位算法和定位技术提出了很高的要求。针对随机布放、节点配置低的无线传感器网络,提出一种新的RSSI-Hop定位方法,该方法可以在不增加硬件开销的基础上,有效降低节点能量消耗,较准确地估算未知节点到参考节点之间的距离,减少累积误差,提高定位的准确性。其主要思想是,节点信息根据RSSI强弱,估算各节点到信标节点之间的距离。实验表明,新算法比以前的算法定位更准确。 相似文献
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Position centric approaches, such as Cartesian routing, geographic routing, and the recently proposed trajectory based forwarding, address scalability issues in large ad hoc networks by using Euclidean space as a complementary name space. These approaches require that nodes know their position in a common coordinate system. While a GPS receiver in each node would be ideal, in many cases an approximation algorithm is necessary for networks with only a few GPS enabled nodes. These algorithms however require collaboration of large portions of the network, thus imposing an overhead for nodes which do not need positioning, or are mobile. We propose local positioning system, a method that makes use of local node capabilities––angle of arrival, range estimations, compasses and accelerometers, in order to internally position only the groups of nodes involved in particular conversations. Localized positioning enables position centric uses, like discovery, flooding and routing in networks where global positioning is not available. 相似文献