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1.
有向传感器网络最大覆盖调度算法   总被引:7,自引:1,他引:6       下载免费PDF全文
与传统的全向传感器不同,有向传感器可以切换到不同的方向,并且每个方向覆盖有限角度的感应范围.针对有向传感器网络的区域覆盖问题,研究了“最大有向区域覆盖”MDAC(maximum directional area coverage)问题,期望通过调度传感器的工作方向,最大化覆盖区域面积.首先给出了MDAC 的问题定义,使用整数线性规划描述MDAC 问题,并且证明其是NP 完全的.然后提出一种分布式贪心算法DGreedy(distributed greedy algorithm)解决MDAC 问题.在此基础上,通过计算可能的覆盖贡献比例来反映网络拓扑信息.还提出了一种增强的算法PGreedy(distributed probability-enhanced greedy algorithm)使覆盖区域更大.证明了所提算法的收敛性,并通过详细的模拟实验验证了其有效性.  相似文献
2.
Coverage and connectivity issues in wireless sensor networks: A survey   总被引:5,自引:0,他引:5  
Sensing coverage and network connectivity are two of the most fundamental problems in wireless sensor networks. Finding an optimal node deployment strategy that would minimize cost, reduce computation and communication overhead, be resilient to node failures, and provide a high degree of coverage with network connectivity is extremely challenging. Coverage and connectivity together can be treated as a measure of quality of service in a sensor network; it tells us how well each point in the region is covered and how accurate is the information gathered by the nodes. Therefore, maximizing coverage as well as maintaining network connectivity using the resource constrained nodes is a non-trivial problem. In this survey article, we present and compare several state-of-the-art algorithms and techniques that aim to address this coverage–connectivity issue.  相似文献
3.
WSN关键区域覆盖启发式优化算法   总被引:4,自引:0,他引:4       下载免费PDF全文
针对无线传感器网络关键区域覆盖NP完全问题,提出一种关键区域覆盖启发式优化(CACHO)算法。该算法基于单位圆通信模型对关键区域覆盖问题进行描述,为关键区域格点与一般区域格点分配不同权值,以创建感知区域图和终端集合,形成具有最少数量的关键区域覆盖格点集合。与现有覆盖算法NPCC的比较结果表明,CACHO算法放置的传感器数量较少,能完全覆盖关键区域。  相似文献
4.
有向传感器网络覆盖增强研究   总被引:2,自引:1,他引:1       下载免费PDF全文
为提高视频传感器网络的感知覆盖率,基于有向传感器感知模型,提出一种利用Voronoi图的视频传感器网络覆盖增强算法。该算法采用质心替代节点扇形感知区域并构造Voronoi图,通过调整节点感知方向对代替扇形感知区域的质心进行均匀分布,以消除网络中感知重叠区和盲区,提高整个有向传感器网络覆盖率。仿真结果表明,该算法能够有效提高网络覆盖率并能快速收敛。  相似文献
5.
WSN中基于能量的分布式覆盖控制算法   总被引:1,自引:1,他引:0       下载免费PDF全文
陈白  杜硕  刘彬  郝晓辰 《计算机工程》2010,36(14):102-104
针对无线传感器网络中节点密度过大、节点剩余能量不均等问题,设计一种基于节点剩余能量的分布式覆盖控制算法,基于概率覆盖模型,按目标区域内节点剩余能量从小到大的顺序,依次通过计算各个节点的区域覆盖概率判定其冗余性,并使冗余节点转入休眠状态。仿真结果表明,该算法能有效降低网络中节点冗余度,延长网络生存时间。  相似文献
6.
Ben-Jye  Jia-Bin   《Computer Communications》2007,30(18):3892-3903
Wireless sensor networks have recently become new techniques and popular research issues. A wireless sensor network consists of a large number of sensor nodes that have the capabilities of sensing, computing and wireless transmission. Wireless sensor networks (namely WSNs) assist people in working under dangerous environments, provide long-term target observations and track on moving objects. Consequently, WSNs decrease risk and increase efficiency. Although WSNs have been studied extensively, several problems should be addressed, such as sensor-deployment policy, data aggregation/fusion issue, and data transmission issue. An efficient sensor-deployment approach could decrease cost, minimize transmission delay and reduce time complexity. Most studies have proposed the probability-based sensor-deployment policies to monitor an overall area. However, not the entire network is interested to be sensed/monitored. Monitoring of an entire area brings several disadvantages: (1) high cost of placing large number of sensors, (2) long delay of data transmission, (3) slow response and (4) unnecessary data aggregation. Furthermore, previous works were lack of considering the difference between the sensing and the transmission radii, and then yield inaccurate analysis. This work thus proposes an efficient sensor placement approach (namely ESP) for a sparse interested area with considering of obstructers that block the data transmission and sensing signal. Additionally, the issue of different radii of sensing and transmission is analyzed in detail. Numerical results demonstrate that the proposed ESP approach requires the least number of sensor nodes under various network sizes and different number of obstacles. Simulation results indicate that the number of sensor nodes decreases when the sensing or transmission radius increases. The running time of ESP, O(K2), is also analyzed, which is better than that of the probability-based approaches, O(N2), where K is the number of interested grids and N is the number of grids.  相似文献
7.
庞思红  李维  李春书  富大伟  许波 《微计算机信息》2007,23(35):250-251,304
本文对全区域覆盖的局部路径规划,采用了一种模糊控制算法,利用模糊控制算法自身所具有的鲁棒性和基于生物学上的感知一动作的行为相结合。对于移动机器人的避障系统提出了充分接近障碍的避障策略,并对相关理论和实现方法作了深入的研究。  相似文献
8.
We developed a new 6-year daily, daytime and nighttime, NOAA-14 AVHRR based land surface temperature (LST) dataset over continental Africa for the period 1995 through 2000. The processing chain was developed within the Global Inventory Modeling and Mapping System (GIMMS) at NASA's Goddard Space Flight Center. This paper describes the processing methodology used to convert the Global Area Coverage Level-1b data into LST and collateral data layers, such as sun and view geometries, cloud mask, local time of observation, and latitude and longitude. We used the Ulivieri et al. [Ulivieri, C., M.M. Castronuovo, R. Francioni, and A. Cardillo (1994), A split window algorithm for estimating land surface temperature from satellites, Adv. Space Research, 14(3):59-65.] split window algorithm to determine LST values. This algorithm requires as input values of surface emissivity in AVHRR channels 4 and 5. Thus, we developed continental maps of emissivity using an ensemble approach that combines laboratory emissivity spectra, MODIS-derived maps of herbaceous and woody fractional cover, and the UNESCO FAO soil map. A preliminary evaluation of the resulting LST product over a savanna woodland in South Africa showed a bias of < 0.3 K and an uncertainty of < 1.3 K for daytime retrievals (< 2.5 K for night). More extensive validation is required before statistically significant uncertainties can be determined. The LST production chain described here could be adapted for any wide field of view sensor (e.g., MODIS, VIIRS), and the LST product may be suitable for monitoring spatial and temporal temperature trends, or as input to many process models (e.g., hydrological, ecosystem).  相似文献
9.
How can a mobile robot measure the area of a closed region that is beyond its immediate sensing range? This problem, which we name as blind area measurement, is inspired from scout worker ants who assess potential nest cavities. We first review the insect studies that have shown that these scouts, who work in dark, seem to assess arbitrary closed spaces and reliably reject nest sites that are small for the colony. We briefly describe the hypothesis that these scouts use “Buffon’s needle method” to measure the area of the nest. Then we evaluate and analyze this method for mobile robots to measure large closed regions. We use a simulated mobile robot system to evaluate the performance of the method through systematic experiments. The results showed that the method can reliably measure the area of large and rather open, closed regions regardless of their shape and compactness. Moreover, the method’s performance seems to be undisturbed by the existence of objects and by partial barriers placed inside these regions. Finally, at a smaller scale, we partially verified some of these results on a real mobile robot platform.  相似文献
10.
肖潇  方勇纯  贺锋  马博军 《机器人》2007,29(3):224-229
将全区域搜索技术与基于动态模板匹配的目标识别方法相结合,提出了一种适用于未知环境的目标物体自主搜索方法,实现了移动机器人在陌生环境下的目标搜索任务.具体而言,移动机器人利用声纳和全景摄像头作为传感器来感知周围环境,并利用模糊逻辑方法来进行局部路径规划,在此基础上通过全区域搜索技术实现对空间的遍历,并采用动态模板匹配方法来实现目标物体的识别及其方位的确定.本文所提出的目标物体自主搜索方法可以从任意位置开始进行,算法对于陌生环境具有良好的适应性.论文最后通过实验结果证实了算法的良好性能.  相似文献
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