遗传算法的DV-Hop算法改进

DV-Hop算法中,平均每跳距离是影响定位精度的因素之一。针对平均每跳距离带来的定位误差,对锚节点和未知节点的平均每跳距离进行了改进和优化。首先引入遗传算法计算锚节点的平均每跳距离;然后利用跳数小于等于3的锚节点的平均每跳距离加权处理未知节点的平均每跳距离,减少平均每跳距离带来的误差。仿真结果表明,在不增加硬件开销的基础上,改进算法能够有效提高算法的定位精度,并且具有较好的稳定性。     

Optimal sensor deployment scheme for heterogeneous wireless sensor networks

For the high density of distributed heterogeneity nodes in wireless sensor networks (WSNs), the optimal sensor deployment is studied. A cost optimal heterogeneous sensor deployment scheme based on genetic algorithm is proposed. The cost of sensor node deployment is used as objective function for optimization computation subjected to network coverage and fault tolerance to obtain the suitable types and positions of the sensors. The algorithm can be used for boolean sensing model as well as probabilistic sensing model. The simulation results demonstrate that the proposed algorithm converges fast toward the optimal solutions and reduces the cost of sensor deployment, which is feasible for heterogenous nodes deployment in WSNs.     

Worst and Best Coverage Based on Probability Model of Wireless Sensor Network

The worst and best-case coverage algorithm is presented based on probability mode of wireless sensor network. The main idea is that choose these lattice points possibly with lowest detection probability by nodes to form the most breach path and choose those lattice points possibly with maximal detection probability by nodes to form the most support path. Simulation experiment validates the algorithm.     

一种基于距离和角度的无线传感器网络GPSR协议

传感器节点能量是影响无线传感器网络的生存周期的关键因素,基本的GPSR协议所使用的贪婪算法忽略了角度因素对下一跳选择的影响,在转发失败遇到空洞问题时只能进行周边边界转发算法,以损耗节点能量为代价。为了节约节点能量,延长网络生存周期,从改进GPSR协议出发,综合考虑距离和角度这两个因素解决路由过程中的空洞问题。仿真实验表明,改进后的协议是网络节点消耗大大减少,网络生存时间为300 s,长于基本GPSR协议下的200 s。该协议缩短了路径长度,节约节点能量,减少能量的消耗,延长了网络生存时间。     

A cooperative localization algorithm for wireless sensor networks

Aiming at the shortcomings of the existing RSS(received signal strength) based localization algorithm for wireless sensor networks (WSN), a cooperative localization algorithm (CLA) is proposed. A reference anchor node is introduced to tolerant some minor error including the node position error. Dixon detection method is applied to remove abnormal RSS values, while the standard deviation threshold of RSS and learning model are introduced to reduce the RSS ranging error and effectively improve the precision. Simulation experiments are performed to evaluate the performance of the proposed algorithm. The results demonstrate that the localization accuracy is improved effectively, while the stability and robustness are better.     

The optimal energy efficiency of wireless networks nodes based on solar cells

To improve the energy efficiency of solar cells in wireless sensor networks nodes, the energy relationship between solar cells and the wireless sensor networks nodes is studied. An adaptive algorithm is adopted to ensure the wireless sensor networks work normally at different sunlight intensities. An energy model is designed that reveals the energy relationship between the output power of the solar cells and the power of nodes working normally at a standard sunlight intensity. The experimental results show that the model represents the adaptive energy relationship between the solar cells and the nodes, ensures that the nodes work stably in a long term, and extends the life cycle of the sensor networks as long as possible. The model has important guiding significance for wireless sensor networks designation.     

An improved HEED clustering algorithm for Wireless Sensor Network

In wireless sensor network, routing protocols which based on clustering have the advantages of energy consumption, topology management and data fusion. The HEED protocol, which generates cluster heads based on distributed algorithm, drives up the rate of clustering and creates well distributed cluster heads. However, it does not consider the mobility of nodes in the network. When the distance between neighbor nodes has changed, the AMRP method which decides the node belongs to different cluster heads would cause problems such as high energy consumption, short lifetime of network and so on. Responding to these problems, the paper proposes the S HEED, a clustering algorithm based on stability, which chooses the stability as a parameter of nodes when choosing a cluster head. With S HEED algorithm, the high energy consumption problem among cluster nodes and cluster heads caused by the mobility is tackled. The simulation experiment demonstrates that the S HEED algorithm lower the energy consumption of cluster heads and prolongs the network lifetime.     

Construction and Application of GPS Location-based Services System Based on JAVA

A method of constructing GPS-based positioning services system by means of JAVA technology is introduced in this paper. The position data, which are sent from GPS satellites, are received by GPS receiving terminal and are analyzed by mobile computing client developed on J2ME in accordance with the differential GPS algorithm. The client submits special position querying information to position server in way of wireless GPRS network. After computing and data querying, the server developed by J2EE returns results to the mobile device. Then, the mobile computing client displays the position map or carries out further processing. All of these form a highly precise location-based services system.     

Fatigue monitoring of metallic structures by wireless smart sensor networks

Recent advanced sensor technology has enabled wireless smart sensor network (WSSN) for structural health monitoring (SHM). Because of many attractive features such as wireless communication, battery powered, on board computation, and low cost, the WSSN makes the dense array of sensors feasible for engineering practice.In this study, a method for fatigue life monitoring using wireless smart sensor networks is explored by implementing Rainflow cycle counting algorithm in the sensor network, which extracts the loading features including the number of each load cycles, amplitude and mean of strain.Instead of sending back raw strain data to basestation, only the onboard processed histogram of the strain data is transmitted, which tremendously reduces the amount of data and the associated energy consumption in the wireless smart sensor networks.In addition, the feasibility of the method is experimentally verified through lab-scale tests.     

Analysis on the optimum dynamic quality of wireless mesh network

In order to procure the optimum quality of control for full-controlled wireless mesh network, the primary influencing factor network time delay is analyzed. In order to get the optimum quality of control,the minimum network time delay should be acquired,and the algorithm of branch and bound is given to solve this problem. According to the numerical simulation, the quality of control for the whole network system with decreasing the delay time can be optimized by adjusting the number of nodes, the average transmission hop counts, and the probability of successful channel access and transmission for random nodes.     

基于无线传感器网络的精准农业研究进展

无线传感器网络是集传感器、微处理器和无线通信等技术为一体的多学科的综合性技术,是当今信息领域中的一个研究热点。通过简述无线传感器网络的国内外研究现状,概括其特点与结构体系,重点分析了其在精准农业中的应用,并展望了其发展趋势。认为以无线传感器网络技术为基础的农业物联网是精准农业的发展方向。     

Algorithm Discussion of High Precision for Wireless User Location

In recent years , because of increasing mobile users ,the wireless location and business is the most attractive business in the world , accurate location information to users has become one of criterion business for mobile communication ,so a discussed deeply wireless location technology is very value. This paper discusses it from high accuracy algorithm for wireless location on the network , by the emulation and comparison, it has shown that there are different algorithms in different surroundings for arriving at satisfied precision     

基于物联网的农田环境监测无线传感器网络的管理

针对农田环境监测无线传感器网络中网络节点电量和处理能力有限等特点,分别从网络拓扑管理、位置管理、能量管理和故障管理等4个方面提出了一套完整的网络管理方案,以对网络运行状况进行监测和管理。为了用户能够远程监控和管理无线传感器监测网络,开发了远程监控管理平台,该平台由后台数据库和前端监测管理软件组成。试验结果表明,所提出的网络管理方案,能够实时监测网络的运行情况,及时诊断网络中的异常,保障了网络正常运行、数据实时传输;所开发的远程监控管理平台人机交互界面良好、功能完善、运行稳定,实现了用户对无线传感器监测网络的远程管理和对农田环境的有效监测。     

Improvement and performances of DV hop localization algorithm in wireless sensor networks

In order to improve the node localization precision of Range Free based DV Hop localization algorithm in wireless sensor networks (WSNs) with randomly distributed nodes and dynamic topology, the improved algorithm is proposed. After analyzing the DV Hop algorithm, considering the obvious errors of the estimated node coordinates calculated by Polygon based method in traditional DV Hop algorithm, the numerical iterative algorithm is constructed by employing Taylor series expansion, and simulation studies for the improved DV Hop algorithm are conducted. The selection criteria for the convergent threshold of iterative step is determined, the localization performance of the improved localization algorithm is analyzed by comparing with the traditional DV Hop algorithm under the same condition of selected convergent threshold and simulation parameters, while the calculation amount and convergence rate of the improved algorithm are also measured by the statistic iterations. The simulation results show that by selecting reasonable iterative threshold values and appropriately increasing calculation amount for node localization, the improved DV Hop localization algorithm greatly improves the localization precision and the error stability, which is feasible for node localization in WSNs with both randomly distributed nodes and dynamic topology.     

A new pattern recognition method of gas sensor array detection

BP neural network based gas sensor array detection pattern recognition has some disadvantages, such as slow convergence and local minimum problem. A modified immune neural network model which combines BP algorithm and immune algorithm is proposed to enhance global search capability and improve the performance of the neural network model. Orthogonal test is adopted to design the study samples of neural network. This ensures the accuracy of neural network while reducing the number of samples. The simulation results show that the proposed pattern recognition method solves the cross sensitivity of gas sensor effectively, overcomes the disadvantages of traditional BP neural network and improves the learning speed and detection accuracy.     

基于无线传感器网络的鱼塘监控系统

本文设计了基于无线传感器网络的鱼塘实时在线智能监控系统,有效解决了传统的鱼塘观测手段存在的问题,例如：费时费力、步骤复杂、成本高等。该系统在鱼塘的监测区域中利用无线传感器节点,测得该区域中的温度和溶氧量,并通过Zigbee网络将数据传输到终端控制系统,控制系统作出判断并发出报警信号和控制增氧机的状态。系统中以MSP430和XBEE模块为核心芯片,能够实时在线监测鱼塘中的一些参数,例如温度、溶氧量等。同时该系统还可以进一步扩展使用GPRS或3G网络实现远程监控。     

基于ZigBee技术的物流仓库温湿度监控系统设计

针对电商快速发展导致物流交易量增加,从而给仓库存储带来较高成本的问题,提出了一种基于ZigBee技术的物流仓库温湿度监控系统设计。本文结合快速发展的无线传感器网络技术,对物流仓库的温度和湿度状态进行监测,并通过ZigBee技术将传感器数据传输至汇聚节点和嵌入式网关设备,并由嵌入式网关设备将数据转发至监控中心,同时监控中心可以根据仓库状态自动开启相关控温和控湿设备。经实际运行验证,本系统可以实现数据自动化采集、传输和显示温湿度,所设计的系统可以有效提升物流企业的仓库状态监控效率,达到智能化管理要求。     

基于Zigbee无线冷藏车厢信息采集节点设计

摘 要：针对食品冷链全过程中运输环节实时监测的需要,利用无线传感器网络布线容易、成本低、低功耗等特点设计出能有效的实现物流配送中环境信息的在线采集与实时监测的Zigbee无线冷藏车厢信息采集节点。该节点使用以Jennic公司生产的Zigbee无线微型控制器JN5139-Z01-M02R1模块为核心,英国SENSIRION公司的SHT75为传感器,在实际应用中测试,证明该系统可行,可靠。     

An improved localization algorithm based on RSSI for landslide monitoring

In order to overcome the existing problems of low automation, high cost and difficult to implement in the area of landslide monitoring, this paper presents a new method of RSSI (Received Signal Strength Indicator)based positioning technology without any one-off instruments to monitor landslide surface displacement. By adding weighted factors, the improved positioning algorithm can estimate the parameters of the path loss model dynamically and calculates the communication distance of network nodes in real-time, which can improve positioning precision and reduce the impact of environmental changes on it. The MATLAB experiments show that, compared with the traditional RSSI based localization algorithm using fixed pass loss model, the improved algorithm could significantly reduce the average error.