【摘要】：隨著無線傳感器網(wǎng)絡(luò)的廣泛應(yīng)用,針對其研究也越來越多,一個熱點問題是能源供應(yīng)。眾所周知,工業(yè)電池仍是各種移動設(shè)備的瓶頸,頻繁更換電池消耗大量人力、物力和財力。在這種情況下,無線可充電傳感器網(wǎng)絡(luò)應(yīng)運而生。在無線可充電傳感器網(wǎng)絡(luò)中,充電器節(jié)點通過無線充電技術(shù)為傳感器節(jié)點提供能量。這種能量供應(yīng)模式大大增加了網(wǎng)絡(luò)的可靠性、靈活性及可擴(kuò)展性。本文研究無線可充電傳感器網(wǎng)絡(luò)中的全向充電問題。全向充電是我們首次提出的概念,指目標(biāo)區(qū)域內(nèi)任意點上的傳感器不管其接收天線朝哪個方向都能被一個或多個定向充電器充電而且充電功率不小于某個給定閾值。我們主要解決兩個問題:一、在充電器位置確定情況下,檢測目標(biāo)區(qū)域是否能夠?qū)崿F(xiàn)全向充電;二、在充電器位置隨機(jī)情況下,確定目標(biāo)區(qū)域?qū)崿F(xiàn)全向充電的上限概率。我們的主要貢獻(xiàn)有如下四點:1.我們第一個提出并研究全向充電問題,建立了充電器和充電設(shè)備之間的定向充電模型。全向充電模型廣泛適應(yīng)于無線可充電傳感器網(wǎng)絡(luò)及毫米波蜂窩網(wǎng)等領(lǐng)域中。2.我們提出一個行之有效的方法來檢測充電器位置確定時目標(biāo)區(qū)域是否實現(xiàn)全向充電。首先,我們設(shè)計分段常量近似方法把非線性的充電模型離散化,根據(jù)充電器充電范圍的相互疊加將目標(biāo)區(qū)域劃分為多個子區(qū)域,進(jìn)而轉(zhuǎn)化為研究所有子區(qū)域上的全向充電問題。接著,我們提出了區(qū)域最小覆蓋集提取算法,此算法將子區(qū)域上的全向充電問題轉(zhuǎn)化為其邊界上若干點的全向充電問題,大大降低了計算復(fù)雜度。最后,如果所有子區(qū)域都實現(xiàn)全向充電,則目標(biāo)區(qū)域?qū)崿F(xiàn)全向充電,否則目標(biāo)區(qū)域未實現(xiàn)全向充電。3.我們推導(dǎo)出充電器位置隨機(jī)分布情況下目標(biāo)區(qū)域?qū)崿F(xiàn)全向充電的上限概率。首先,我們將目標(biāo)區(qū)域劃分為多個等邊三角形。我們證明了如果某種弱化配置的充電器網(wǎng)絡(luò)可實現(xiàn)所有三角形頂點的全向充電,那么在正常配置下目標(biāo)區(qū)域即可實現(xiàn)全向充電。隨后,我們計算目標(biāo)區(qū)域內(nèi)一個隨機(jī)點被全向充電的概率,進(jìn)而得出所有三角形頂點實現(xiàn)全向充電的概率。最終,我們得到目標(biāo)區(qū)域?qū)崿F(xiàn)全向充電的上限概率。4.我們做了仿真實驗和現(xiàn)場實驗來驗證我們算法的準(zhǔn)確性和高效性。實驗結(jié)果表明,我們的算法比在無線傳感器網(wǎng)絡(luò)中廣泛應(yīng)用的基于自適應(yīng)算法的全向覆蓋檢測算法性能提高至少20%;我們的理論結(jié)果與現(xiàn)場實驗的一致性高達(dá)93.6%。
[Abstract]:With the wide application of wireless sensor networks (WSNs), there are more and more researches on WSNs, one of the hot issues is energy supply. As we all know, industrial batteries are still the bottleneck of various mobile devices, the frequent replacement of batteries consumes a lot of manpower, material and financial resources. In this case, wireless rechargeable sensor networks emerge as the times require. In wireless rechargeable sensor networks, charger nodes provide energy for sensor nodes through wireless charging technology. This energy supply mode greatly increases the reliability, flexibility and scalability of the network. In this paper, the omni-directional charging problem in wireless rechargeable sensor networks is studied. Omni-directional charging is the first concept that the sensor at any point in the target region can be charged by one or more directional chargers regardless of the direction of the receiving antenna and the charging power is no less than a given threshold. We mainly solve two problems: one is to detect whether the target region can achieve omnidirectional charging when the charger position is determined and the other is to determine the upper limit probability of the target region to realize omnidirectional charging under the random charger position. Our main contributions are as follows: 1. We first proposed and studied the omni-directional charging problem and established a directional charging model between the charger and the charging device. The omni-directional charging model is widely used in wireless rechargeable sensor networks and millimeter wave cellular networks. We propose an effective method to detect whether the target area can achieve omni-directional charging when the charger position is determined. Firstly, we design a piecewise constant approximation method to discretize the nonlinear charging model. According to the superposition of charging range of charger, the target region is divided into several sub-regions, and then the problem of omni-directional charging on the sub-region is studied. Then, we propose a region minimum covering set extraction algorithm, which transforms the omni-directional charging problem on the sub-region into the omni-directional charging problem at several points on the boundary of the sub-region, which greatly reduces the computational complexity. Finally, if all sub-areas are charged omni-directional, the target area will be charged omni-directional, otherwise the target area will not be charged omni-directional. We derive the upper bound probability of the target region to realize omni-directional charging under the random distribution of the charger position. First, we divide the target region into multiple equilateral triangles. We have proved that if a certain weakly configured charger network can achieve omni-directional charging of all triangle vertices, then the target area can be charged omni-directionally under normal configuration. Then, we calculate the probability that a random point in the target region is charged omni-directionally, and then get the probability that all triangle vertices can realize omni-directional charging. Finally, we get the upper bound probability of achieving omni-directional charging in the target region. 4. We have done simulation and field experiments to verify the accuracy and efficiency of our algorithm. The experimental results show that the performance of our algorithm is at least 20% higher than that of the algorithm based on adaptive algorithm which is widely used in wireless sensor networks, and the agreement of our theoretical results with the field experiments is as high as 93.6%.
【學(xué)位授予單位】：南京大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TP212.9;TN929.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 戴海鵬;陳貴海;徐力杰;劉云淮;吳小兵;何田;;一種高效有向無線充電器的布置算法[J];軟件學(xué)報;2015年07期

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本文編號：2444580