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1.
    
This article is concerned with state estimation and data fusion of a linear dynamic system observed by multirate sensors in the environment of wireless sensor networks. The sampling, estimation, and transmission rates in the wireless sensor networks are different. We derive the optimal linear estimation in the centralized, sequential, and distributed forms. A numerical example is given to show the feasibility and effectiveness of the proposed algorithms. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

2.
无线传感器网络已广泛应用在智能电网的建设中。针对传感器节点随机唤醒机制的缺点,提出了节点轮流工作机制。该机制有两个优点:一是在满足所有被监测目标获得监测的条件下,使所有节点能耗达到平衡;二是去除了冗余活动节点,并对节点工作顺序进行了调整,以减少节点在睡眠模式与唤醒模式之间进行转换时的能量消耗。仿真结果表明,与随机唤醒机制相比,该机制提高了网络中所有节点能耗均衡性,降低了节点能耗和节点的模式转换次数。  相似文献   

3.
    
This paper describes circuit design considerations for realization of low power dissipation successive approximation register (SAR) analog‐to‐digital converter (ADC) with a time‐mode comparator. A number of design issues related to time‐mode SAR ADC are discussed. Also, noise and offset models describing the impact of the noise and offset on the timing error of time‐domain comparator are presented. The results are verified by comparison to simulations. The design considerations mentioned in this paper are useful for the initial design and the improvements of time‐mode SAR ADC. Then, a number of practical design aspects are illustrated with discussion of an experimental 12‐bit SAR ADC that incorporates a highly dynamic voltage‐to‐time converter and a symmetrical input time‐to‐digital converter. Prototyped in a 0.18‐µm six‐metal one‐polysilicon Complementary Metal‐Oxide‐Semiconductor (CMOS) process, the ADC, at 12 bit, 500 kS/s, achieves a Nyquist signal‐to‐noise‐and‐distortion ratio of 53.24 dB (8.55 effective number of bits) and a spurious‐free dynamic range of 70.73 dB, while dissipating 27.17 μW from a 1.3‐V supply, giving a figure of merit of 145 fJ/conversion‐step. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

4.
特高压输电塔形成的强电磁场干扰及所处的野外恶劣自然环境严重影响无线传感器网络的数据传输质量,造成了无线传感网络通信数据溢出、误码率增加等问题,文章以基于无线传感器网络构建的特高压输电塔实时监测系统为基础,对无线传感器网络在强电磁环境下的通信特性进行了研究,提出了一种基于压缩感知理论的低信噪比信道编码传输方法( LSCC ),该方法对测量矩阵进行了改进,并在信道删除概率的基础上自适应调整信息发送的比特量,减少重构所需测量值个数。实验验证表明,低信噪比信道编码传输方法降低了特高压输电塔强电磁场引起的信道干扰带来的数据溢出率11.29%,有效地增强了输电塔监测系统的实际应用性能。  相似文献   

5.
    
In the consensus‐based state estimation, multiple neighboring nodes iteratively exchange their local information with each other and the goal is to get more accurate and more convergent state estimation on each node. In order to improve network scalability and fault tolerance, the distributed sensor networks are desirable because the requirements of the fusion node are eliminated. However, the state estimation becomes challenging in the case of limited sensing regions and/or distinct measurement‐noise covariances. A novel distributed average information‐weighted consensus filter (AICF) is proposed, which does not require the knowledge of the total number of sensor nodes. Based on the weighted average consensus, AICF effectively addresses the naivety issues caused by unequal measurement‐noise covariances. Theoretical analysis and experimental verification show that AICF can approach the optimal centralized state estimation.  相似文献   

6.
高级量测体系(AMI)是智能电网的关键组成部分,无线传感器网络(WSNs)在AMI中正发挥着越来越重要的作用。网络安全是保证AMI可靠运行的前提,因此为了保证AMI中WSNs的网络安全,文中提出了一种基于椭圆曲线密码(ECC)的密钥管理方案。该方案根据AMI中信息传输方式的不同分为单播通信密钥管理机制和多播通信密钥管理机制两部分。详细阐述了椭圆曲线的选取、传感器节点中ECC公钥和私钥的求取、单播通信链路密钥和多播通信网络密钥的建立、分发及更新过程。研究结果表明,提出的密钥管理方案具有较好的安全性、较少的存储开销和能耗,能够满足AMI的通信安全需求。  相似文献   

7.
    
This paper presents a novel distributed media access control (MAC) address assignment algorithm, namely virtual grid spatial reusing (VGSR), for wireless sensor networks, which reduces the size of the MAC address efficiently on the basis of both the spatial reuse of MAC address and the mapping of geographical position. By adjusting the communication range of sensor nodes, VGSR algorithm can minimize the size of MAC address and meanwhile guarantee the connectivity of the sensor network. Theoretical analysis and experimental results show that VGSR algorithm is not only of low energy cost, but also scales well with the network size, with its performance superior to that of other existing algorithms. __________ Translated from Journal of Xidian University, 2006, 33(5): 716–720 [译自: 西安电子科技大学学报 (自然科学版)]  相似文献   

8.
    
In this paper, the problem of state estimation in an asynchronous distributed multi‐sensor estimation (ADE) system is considered. In such an ADE system, the state of a plant of interest is estimated by a group of local estimators. Each local estimator based, for example, on a Kalman filter, performs fusion of data from its local sensor and other (remote) processors to compute possibly best state estimates. In performing data fusion, however, two important issues need to be addressed, namely, the problem of asynchronism of local processors and the one of unknown correlation between asynchronous data in local processors. Consequently, there are two main contributions proposed in this paper. The first is a method to deal with asynchronous discrete‐time data based on a continuous‐time stochastic plant model. The second contribution is an asynchronous distributed data‐fusion algorithm. Simulated experiments illustrate the effectiveness of the proposed ADE approach. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

9.
随着无线传感器网络技术应用于海洋监测,节点的部署及网络的性能必然受到海面环境的影响。文中引入并改进了在海洋搜救中常用的Leeway漂流模型,对随机部署在海洋表面的传感器节点运动状态进行建模。仿真分析了在不同海况下,传感器网络区域覆盖率及网络连通性受其运动状态的影响。最后,从工程应用的角度提出对于特定区域的持续监测时间这一概念,来衡量运动的传感器网络对于特定海域的监测能力,仿真并验证给出了满足该指标所要部署节点的具体数目。  相似文献   

10.
研究了基于GIS的无线传感网架构方法,建立了适用于大规模广域无线传感网的软件体系,开发了GIS服务、数据库服务、可视化与分析服务,形成了数据采集、汇聚、存储、与地理数据的融合、展示的完整流程,实现了无线采集的海量数据与GIS平台的动态融合,用户可以通过计算机、安卓智能手机等各种网络化终端设备由Internet访问传感系统,获取实时采集数据。最后对基于GIS的无线传感网系统进行了性能综合测试,结果表明系统能满足铁路轨道广域快速监测等重大工程需求。  相似文献   

11.
无人巴士在定位循迹过程中,采样信号受噪声方差、带宽和采样率的影响,易出现信号缺失或间断现象,加之相关滤波算法缺乏异步采样和平滑能力,导致定位失败。为了提高定位精度并补充缺失数据,本文基于异步扩展卡尔曼滤波和非因果滤波平滑,提出一种改进的传感器异步采样融合平滑算法。首先利用异步扩展卡尔曼滤波对连续时间随机微分方程进行指数离散化,以处理任意时刻的测量值,预测更新下一时刻状态值之后,引入非因果滤波平滑给定可用的初始方差信息,使噪声方差影响更小,估计性能更好。将本算法在无人巴士上进行物理实验验证,结果表明这种多传感器异步融合平滑算法在车辆行驶中效果良好,与异步卡尔曼滤波算法结果相比,可以达到优于05 m的定位精度,数据预测误差均有明显降低,提高了定位精度和补充缺失数据。  相似文献   

12.
节点定位是无线传感器网络的一项关键技术,为了提高精确度和避免使用对参数要求苛刻的传统算法,提出了一种新思路:基于ROAN(Ratio of Arrival Numbers,信号到达个数比)法。该法将原本需测节点间实际距离的难题,通过统计信号到达的数目,转化为计算距离比的模型,进而采用迭代法求解出位置信息。经过数学建模分...  相似文献   

13.
    
This paper addresses a novel prescribed performance synchronization of complex dynamical networks by means of event‐triggered communication protocols. With the designed controller and proposed even‐triggered communication strategy, this paper have advantages of guaranteeing the transient and steady‐state performance of complex dynamic networks and avoiding the continuous communication of networks for reducing the number of communications and saving the network resources. In addition, the Zeno behavior is avoided in the networks. At last, the effectiveness of the theoretic results obtained is verified via the application in the complex dynamical network with Chua's circuit.  相似文献   

14.
针对传统多跳路由协议的“热区”问题,提出一种面向用电信息采集的WSN非均匀分簇多跳路由算法。算法将网络分为虚拟块,并在簇头路由时考虑节点位置和剩余能量的影响,利用三角模融合算子对基于节点位置的隶属度函数和剩余能量隶属度函数进行融合判决,并根据最大隶属度原则选择父节点,优化路由选择。实验结果表明,改进后的算法显著延长了网络生存时间,同时具有更好的负载平衡程度。将该路由算法应用于用电信息采集系统中,能达到较好的性能。  相似文献   

15.
为了实现现代公交系统的智能化管理,设计了一种利用TI公司CC2530芯片的基于ZigBee技术的智能公交系统。提出了基于接收信号强度值(RSSI)的定位技术和3种定位改进算法。分析了系统的工作原理、硬件组成、软件工作流程。实验结果表明该系统能够实现公交系统的定位、自动报站、特定位置安全提醒等功能,实现了公交系统的智能化管理。  相似文献   

16.
    
For the multi‐sensor multi‐channel autoregressive (AR) moving average signals with white measurement noises and an AR‐colored measurement noise, a multi‐stage information fusion identification method is presented when model parameters and noise variances are partially unknown. The local estimators of model parameters and noise variances are obtained by the multidimensional recursive instrumental variable algorithm and correlation method, and the fused estimators are obtained by taking the average of the local estimators. They have the strong consistency. Substituting them into the optimal information fusion Kalman filter weighted by scalars, a self‐tuning fusion Kalman filter for multi‐channel AR moving average signals is presented. Applying the dynamic error system analysis method, it is proved that the proposed self‐tuning fusion Kalman filter converges to the optimal fusion Kalman filter in a realization, so that it has asymptotic optimality. A simulation example for a target tracking system with three sensors shows its effectiveness. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

17.
针对电容法测量河流含沙量过程中易受环境因素影响而导致测量结果不准确的问题,提出基于卡尔曼滤波和长短期记忆神经网络(Kalman-LSTM)的融合模型。先采用卡尔曼滤波器进行滤波处理,减小传感器测量的随机误差;再通过LSTM神经网络模型对含沙量信息和环境量信息进行多传感器数据融合,减小环境因素对电容法测量含沙量的影响;最后建立了电容法测量含沙量的Kalman-LSTM融合模型。为了验证Kalman-LSTM融合模型的融合效果,与BP模型、RBF模型和LSTM模型对比,比较各模型的均方根误差、最大绝对误差、平均绝对误差和平均相对误差。实验结果表明,Kalman-LSTM融合模型的平均相对误差为2.54%,均方根误差为2.47 kg/m3,该融合模型能有效降低环境因素对含沙量测量的影响,提高电容法测量含沙量的准确性。  相似文献   

18.
针对无线传感器网络(WSNs)节点定位问题,提出一种移动机器人辅助作用下,融入高斯混合容积卡尔曼滤波(GM-CKF)优化的节点定位方法。将移动机器人与WSNs结合,发挥两者的特点和优势,充分利用机器人的机动性及无线传感器节点的可计算性,设计并仿真了一种机器人-节点、节点-节点协作的节点定位方式,并利用带有门限判别和选择性高斯分割的GM-CKF算法,对目标节点的预估位置实施预测修正。仿真结果表明,所提出的移动机器人与WSNs协作定位方法实现了对节点的定位估计,GM-CKF算法的融合有效提高了定位的精度和稳定性。  相似文献   

19.
根据电力系统和无线传感器网络本身的特点,简单分析了无线传感器网络在电力系统中应用需解决的关键技术,并总结了一些解决方案,以加快无线传感器网络在电力系统中的应用步伐.  相似文献   

20.
在使用多个无线传感器对目标语音信号进行检测的语音增强系统中,由于网络环境带来的信息丢失,会对其滤波稳定性造成影响.以卡尔曼滤波为背景,探讨三传感器语音增强系统中量测缺失对卡尔曼滤波稳定性带来的影响.得出一些重要结论.在期望有界准则下,每个通道的量测成功传递概率存在一个关键值,该关键值的变化范围存在上界和下界.当量测成功...  相似文献   

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