【作者】 孙顺远；

【导师】 徐保国；

【作者基本信息】 江南大学 ， 控制理论与控制工程， 2014， 博士

【摘要】 无线传感器网络是随着无线通信、嵌入式技术、传感器技术、微机电技术及分布式信息处理技术的进步而发展起来的一门新兴的信息获取技术。其在军事和民用方面均有着非常广阔的市场，在具体应用中，定位信息十分重要，所涉及到的数据只有包含对应的定位信息，才是有效的；实现整个WSNs中节点的定位，能够有效提高整个WSNs路由效率，并且为整个网络的系统管理、均衡负载、拓扑控制的自动实现提供有效的技术保证。设计出精度高、计算复杂度低的WSNs节点定位算法，一直是无线研究领域一个亟待解决的技术热点问题。本论文结合当前WSNs节点主流定位算法，采用无线通信原理与数学模型相结合的技术研究手段，从低运算量（低功耗）、实际产品可行性高的科研本质要求出发，以设计出使用少量锚无线参考节点、取得较好定位性能、满足多种场景需求的定位算法为最终研究目标，针对目前主流信号到达时间（TOA）及接受信号强度（RSSI）测距技术，提出三种新型无线传感器节点定位算法。在此理论研究基础下，本论文中将部分定位技术应用于实际无线测温系统中，取得一些有意义的成果，其主要研究内容如下：1.对目前WSNs节点定位算法进行了全面的综述。针对无线定位算法中定位精度的评估方法，推导在WSNs视距条件下的克拉美罗下界(CRLB)在定位算法评估定位精度方法中使用过程，得出了距离效应、到达角误差及锚节点位置误差是如何影响CRLB的具体结论。2.针对TOA源定位相应观察方程中存在测量值和未知参量的非线性关系，无法逼近CRLB有效无偏估计值，提出利用坐标系平移的线性化方法即通过相应的公式变换来剔除观察方程的非线性变量的新方法，并提出基于TOA的源节点定位算法。从时间测量误差、计算复杂度、定位误差、CRLB来评价该算法性能，仿真表明，当独立零均值高斯测量误差足够小时，该算法逼近CRLB，其适用TOA测量模型的WSNs节点定位。3.针对节点发射功率和路径损耗系数未知这一情况，提出基于RSS测量值的未知功率及路径损耗系数的各项同向衰减源定位算法。其中，未知源节点位置和另两个未知参数(衰减源发射功率和路径损耗系数)可通过彼此的交替方式进行估算，此方法需结合本节提出的RSS测量值最佳初始源位置判断方法。通过锚节点数目、迭代次数、定位误差及CRLB来评价该算法性能，假设RSS测量误差属于独立零均值高斯测量误差，仿真表明所提出的定位迭代算法趋于最小二乘算法(LS)的解，其逼近CRLB的下界值。4.针对目前主流分布式协作定位方法如连续多点定位、基于可信度传播模型定位及基于目标函数凸域松弛度定位算法相应局限性，提出采用持续距离评估的无线连通传感器源自定位算法。其利用邻节点协作技术，即利用节点与锚节点之间距离的连续性估计，进行网络节点整体定位。通过通信距离、节点间距离测量误差、均方定位误差及CRLB来评价该算法性能，仿真表明，假设独立、零均值高斯测量误差的情况下，该方案达到最佳的定位性能，其适用于大范围无线节点定位系统。5.结合实际酒厂窖池测温需要及无线传感器网络在环境信息监测方面的优势，本文中设计并实现具有节点自定位功能的窖池无线测温系统。其中考虑感温子节点数目众多，采用通过节点定位功能取其相应位置信息将网络内感温子节点分组分频段通信的方案，有效的将低功耗工业监测系统与传感网节点定位技术结合起来，实现了对酒厂1200多口窖池温度的实时监测功能。为了保证系统运行长期稳定性，设计了针对无线系统整体技术性能指标的测试实验，并进行相应的现场测试工作，对相应结果进行分析研究。更多还原

【Abstract】 With the progress of wireless communication, embedded technology, sensor technology,micro-electromechanical technology and distributed information processing technology,wireless sensor networks (WSNs) developed a new access to information technology. In bothmilitary and civilian aspects which has a broad application prospect and in the specificapplication, location information is very important, only obtained location information, thedata which involved is valid. In addition, localization of all nodes of the wireless sensornetworks can effectively improve the efficiency of the whole wireless sensor networks rootingand provide the network’s automatic implementation of system management, the balancedload and topology control with effective technology guarantee. So we can see that to design ahigh precision, low complexity of the wireless sensor node localization algorithm has alwaysbeen a technical hot topic to be resolved.In this paper, based on the specific performance of current mainstream WSNs nodelocalization algorithm, we adopt the technical research by means with the combination of theprinciple of wireless communication and mathematical model, starting from the essentialrequirement of scientific research with the low computational cost (low-power) and the actualproduct feasibility of high demand, to design a localization algorithm which uses a smallamount of anchor with wireless reference nodes, obtains better location performance andmeets the demand of a variety of scenarios for the final research goal, based on the currentmainstream signal arrival time TOA and received signal strength RSSI ranging technology,we put forward three new kinds of wireless sensor node localization algorithm. Under thebasis of the theory research, this paper will apply partly location technology to the actualwireless temperature measuring system, some meaningful results are obtained, and the mainresearch contents are as follow:1. For the current wireless sensor networks node localization algorithm has carried onthe comprehensive review. In the evaluation method of wireless location algorithmpositioning accuracy, the theoretical analysis was deduced the Cramer-rao lower bound(CRLB) under the condition of WSNs, and in the process of the positioning accuracylocalization algorithm assessment methods, we conclude that the distance effect, the angle ofarrival error, the error of anchor position are how to influence the CRLB.2. In general, the nonlinear relationship exist between the TOA measurements and theunknown parameter value in the observation equation corresponding to TOA-based sourcelocation, it normally results in the nonexistence of any efficient unbiased estimator that attainsthe (CRLB). This paper proposes a new method of translating a linear method i.e. by using thecoordinate system transformation corresponding to the formula Nonlinear Equations removedobserved variables. Then it proposes an appropriate method based on the use of lineartranslational coordinates of the source node TOA localization algorithm. From themeasurement error of time, computational complexity, the mean square error and CRLB fouraspects to evaluate the algorithm performance, the performance analysis and simulation study conducted show that our proposed algorithm can achieve CRLB when the zero-meanGaussian and independent measurement errors are sufficiently small.3. In general wireless sensor nodes transmit power source and the path loss coefficientsare unknown, we addresses the localization of an isotropically decaying source based on thereceived signal strength (RSS) measurements that are collected from nearby active sensorsthat are position-known and wirelessly connected. For such a source localization problem, wepropose an iterative algorithm, in which the unknown source position and two other unknownparameters (i.e. the source power and pathloss factor) are estimated in an alternating waybased on each other, with our proposed sub-optimum initial estimate on source positionobtained based on the RSS measurements. Analysis and simulation study show that ourproposed iterative algorithm guarantees globally convergence to the least-squares (LS)solution, where for our suitably assumed independent and identically distributed (i.i.d.)zero-mean Gaussian RSS measurement errors the converged localization performanceachieves the optimum that corresponds to CRLB.4. This paper deals with self-localization of wirelessly connected sensors, based onpartially available pairwise distance measurements among these randomly deployed sensorsand a few ad hoc deployed position-known anchors. We propose a distributed cooperativescheme that can be implemented at all individual sensors in such networks to self-identify andself-localize a dominant class of localizable sensors. The new scheme exploits successivesensor anchor distance estimations (i.e. prospective sensors successively, starting from theones neighboring to anchors, obtain their distances to these closest anchors). Analysis andsimulation study show that our proposed scheme can be used to identify the consideredlocalizable sensors, and also can perform accurate localization on these localizable sensors inthe absence of any measurement error or achieve optimum localization performance in thepresence of our suitably assumed independent zero-mean Gaussian measurement errors.5. Considering actual winery cellar pool temperature measurement needs and theadvantages of WSNs that in terms of environmental information monitoring, a low-powerindustrial monitoring system with location information is designed and implemented in thisarticle. Efficient low-power industrial monitoring systems and sensor network nodepositioning technology combined up and realized in the winery over1200ports pits real-timetemperature monitoring function, which has great practical value. In order to ensure thelong-term stability of system operation, designing a test experiment for the overall technologyperformance of wireless system and proceeding field test work accordingly. Then we analyzethe corresponding results of research work. The low-power monitoring system has more than1200industrial temperature sensing end nodes, and it has run stably more than two years at awinery, which is enough to prove the feasibility and rationality of the overall system solution.更多还原