煤矿井下应急无线通信系统设计研究

针对煤矿井下巷道通信特点及井下应急通信对通信质量的需求,结合无线Mesh网络技术特点,设计了一种基于无线Mesh网络的井下应急通信系统,并且给出了其硬件设计与实现方案。本系统可以在煤矿事故发生时有效支持井下救援工作的通信需求,对降低煤矿灾害损失具有较强的实践意义。     

基于Mesh网络的煤矿救灾通讯技术

提出了一种基于无线Mesh网络技术的煤矿救援通讯指挥技术,介绍了煤矿救灾无线通讯系统总体设计,深入研究了煤矿井下无线Mesh网络通讯技术,设计了煤矿应急救援通讯无线传输节点,并对新型救灾通信技术进行了现场应用方案设计。     

无线Mesh网络在综采面机电设备远程监控的研究

为了实现煤矿综采工作面机电装备的远程监控,分析了有线工业以太网、传统无线通信方式及新型技术Z igbee等在煤矿井下应用的优缺点;提出基于无线Mesh技术研发本安型无线网络系统;构建了煤矿综采工作面机电设备的无线Mesh网络;阐述了其总体架构、节点的设计原则及其工作原理。在平煤股份二矿进行的工业性试验结果表明:根据工作面的长度和坡度,选择一定数量的无线Mesh交换机,以接收信号强度-85 dBm为临界点,调整Mesh交换机之间的距离,一般以任意2个Mesh交换机间的距离不超过66 m为宜,且交换机的天线要水平或向上安装,可使该无线Mesh网络在煤矿综采工作面具有良好的通信效果,能够满足机电装备工况数据和视频传输的需求。     

混合结构矿井应急救援无线Mesh网络及其路由算法

为提高井下应急救援无线Mesh网络的鲁棒性,提出了基于混合网状网结构的组网模式。在该模式下,无线终端参与无线Mesh网络组网,能够在骨干传输网络出现问题时对数据进行路由转发,从而消除了传统基础设施结构应急救援无线Mesh网络中终端通信对骨干传输网络的绝对依赖。此外,针对该模式下Mesh终端能耗较高的问题,进一步提出了一种改进AODV路由策略。该策略在AODV路由协议的基础上增加了节点类型信息与通信状态信息,根据节点类型与通信状态决定路由选择方式,实现了路由选择过程对Mesh终端的识别与避免,从而节约了无线Mesh终端能量。针对该策略的路由性能的仿真结果表明,该策略相比AODV提高了矿井应急救援无线Mesh网络的吞吐性能、传输稳定性与实时性;当骨干路由节点发生故障时,该策略能够快速重建路由,具有较强的路由恢复能力。     

矿山无线救援通信技术研究

提出矿山无线救援通信环境特殊(有限空间,线状场景,短距离通信),对设备要求高(便携式,本质安全,动态拓扑,宽带自组网络,即铺即用等).分析并比较了小灵通、无线局域网、蓝牙、ZigBee、超宽带、Ad Hoe网络、无线Mesh网络等短距离无线通信技术,指出无线Mesh网络技术具有速率高、传输距离远、移动性强、自组织、自愈合等特点,目前更适合于井下无线救援通信.基于三核(DSP ARM MCU)技术实现的Mesh矿井无线救援终端由多媒体采集平台和无线Mesh网卡组成,将无线客户端与无线路由器连接到一起,能实时采集、传输井下现场的视频、音频、环境参数(氧气、一氧化碳、瓦斯浓度和环境温度)等信息,并具有存储、显示、报警等功能,实现了"即铺即用"的矿山救援应急通信服务.     

无线Mesh网络在井下应急通信系统中的应用

针对煤矿应急通信系统的特点以及现存的问题展开分析和讨论,基于无线Mesh网络技术的基本原理及结构,构建了井下应急救援无线通信系统,从系统的组网方式以及整体结构方面进行分析和论证,为新的井下应急通信系统的设计提供技术支持。     

基于无线Mesh网络的煤矿救援通讯指挥系统

针对目前煤矿灾后救援通讯系统存在的不足,本文提出了一种基于无线Mesh网络技术的煤矿救援通讯指挥系统,介绍了煤矿应急救援通讯系统网络结构,深入研究了煤矿井下无线Mesh网络通讯技术,设计了煤矿应急救援通讯系统节点硬件。研究结果将为矿井灾变条件下,极大提高救灾的安全性、可靠性奠定技术基础。     

无线Mesh技术在煤矿井下应急通信系统中的应用

本文针对煤矿复杂、危险的生产环境及井下应急通信的需求,探讨了井下应急通信技术的选择,介绍了基于无线以太网(WLAN)的Mesh技术与VoIP技术在煤矿应急通信系统中的应用。     

长距离WMSN的矿井多媒体救灾通信系统关键技术的展望

煤矿灾难严重威胁人的生命,并且给煤矿带来毁灭性的破坏,发生灾难的煤矿井下电力及通信系统部分受损或完全瘫痪,文章提出了使用多媒体无线传感器网络(WMSN)建立有效的矿井多媒体救灾通信系统,阐述了矿井应用中WMSN的关键技术,对多媒体无线传感器网络在矿井应用过程中的技术问题做了简要介绍,指出了WMSN在煤矿中应用的发展方向。     

基于PT2262的矿用无线遥控信号发送器的设计及应用

主要介绍了一种煤矿井下无线遥控高频信号发送器的设计及应用,该遥控信号发送器是基于PT2262的编码电路,具有高频传输,低功耗,低价位,发送准确,抗干扰能力强等特点,十分适合煤矿井下恶劣的通信条件,适用于控制要求精准度高的煤矿井下机电设备。     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

2014 second batch of rare earth quota released

正~~     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.