李健 外文翻译

淮 阴 工 学 院毕业设计(论文)外文资料翻译学 院：电子与电气工程学院专 业：自动化姓 名： 李健学 号：1081205614外文出处：The realization of wireless sensor (用外文写)networks and applications in agriculture附 件：1.外文资料翻译译文；2.外文原文。指导教师评语： 年月日签名： 注：请将该封面与附件装订成册。附件1：外文资料翻译译文无线传感器网络的实现及在农业上的应用1引言无线传感器网络（Wireless Sensor Network ,WSN）就是由部署在监测区域内大量的廉价微型传感器节点组成，通过无线通信方式形成的一个多跳的自组织的网络系统。其目的是协作地感知、采集和处理网络覆盖区域中感知对象的信息，并发送给观察者。“传感器、感知对象和观察者”构成了网络的三个要素。这里说的传感器，并不是传统意义上的单纯的对物理信号进行感知并转化为数字信号的传感器，它是将传感器模块、数据处理模块和无线通信模块集成在一块很小的物理单元，即传感器节点上，功能比传统的传感器增强了许多，不仅能够对环境信息进行感知，而且具有数据处理及无线通信的功能。借助传感器节点中内置的形式多样的传感器件，可以测量所在环境中的热、红外、声纳、雷达和地震波信号等信号，从而探测包括温度、湿度、噪声、光强度、压力、土壤成分、移动物体的大小、速度和方向等等众多我们感兴趣的物质现象。无线传感器网络是一种全新的信息获取和信息处理模式。由于我国水资源已处于相当紧缺的程度,加上全国90%的废、污水未经处理或处理未达标就直接排放的水污染,11%的河流水质低于农田供水标准。水是农业的命脉,是生态环境的控制性要素,同时又是战略性的经济资源,因此采用水泵抽取地下水灌溉农田,实现水资源合理利用,发展节水供水,改善生态环境,是我国目前精确农业的关键，因此采用节水和节能的灌水方法是当今世界供水技术发展的总趋势。2无线传感器网络概述2.1无线传感器网络的系统架构无线传感器网络的系统架构如图1所示，通常包括传感器节点、汇聚节点和管理节点。传感器节点密布于观测区域，以自组织的方式构成网络。传感器节点对所采集信息进行处理后，以多跳中继方式将信息传输到汇聚节点。然后经由互联网或移动通信网络等途径到达管理节点。终端用户可以通过管理节点对无线传感器网络进行管理和配置、发布监测任务或收集回传数据。 图1无线传感器网络的系统架构2.2无线传感器网络的特点（1）自组织。由于网络所处物理环境及网络本身的不可预测因素，如：不能预先精确设定节点的位置，也不能预先知道节点之间的相邻关系，部分节点由于能量耗尽或其他原因而死亡，新的节点的加入等，使得网络的布设和展开能够无需依赖于任何预设的网络设施，节点之间通过分层协议和分布式算法协调各自的行为，节点开机后就可以快速自动地组成一个独立的网络多跳路由。（2）多跳路由。网络中节点通信距离有限,节点只能与它的邻居直接通信，如果与其射频覆盖范围之外的节点进行通信，则需要通过中间节点进行路由。（3）大面积的空间分布，节点密集，数量巨大。（4）以数据为中心。在无线传感器网络中，人们通常只关心某个区域内某个观测指标的数值，而不会去具体关心单个节点的观测数据。（5）节点能力受限。传感器节点的能量、处理能力、存储能力和通信能力等都十分有限。电源能量受限。由于传感器节点的微型化，节点的电池能量有限，而且由于物理限制难以给节点更换电池，所以传感器节点的电池能量限制是整个无线传感器网络设计最关键的约束之一，它直接决定了网络的工作寿命。计算和存储能力有限。廉价微型的传感器节点带来了处理器能力弱、存储器容量小的特点，使得其不能进行复杂的计算，而传统Internet网络上成熟的协议和算法相对无线传感器网络而言开销太大，难以使用，因此必须使用简单、有效的协议及算法，如ZigBee协议。通信能力有限。通常，无线通信的能耗E与通信距离d的关系为：E=kdn。其中2n4。通常取n为3。2.3无线传感器网络存在的不足（1）能量受限。传感器节点通常由普通电池或锂电池供电，能量有限。在无人值守的环境中，也是无线传感器网络应用的瓶颈之一。（2）节点成本较高。目前市面上销售的传感器节点价格在千元以上，而无线传感器网络所需要的节点众多，因此限制了无线传感器网络的推广使用。（3）安全性差。由于采用了无线信道、分布式控制等技术，网络更容易受到被动窃听、主动入侵等攻击。（4）协作能力。单个的传感器节点往往不能完成对目标的测量、跟踪和识别，而需要多个传感器节点通过算法交换信息，对所获得的数据进行加工、汇总和过滤，得到最终结果。3 无线传感器网络当前在农业中的应用 针对我国水资源紧缺以及农田节水灌溉的需求,根据现有的农田灌溉装备条件,应用领域作物、土壤、水源布点等情况,分析了目前实现精确农业亟待解决的关键技术问题,提出一套采用无线传感器网络技术、适合大面积农田智能灌溉控制方法。3.1系统工作原理研究单片机系统通过多个传感器对湿度、温度、降雨量、酸碱度、水分蒸发量(风速)和空气温度等多种信息的采集来实现对农田的精确自动灌溉控制,输出的信号信息通过无线全双工数传收发模块传送给控制中心(嵌入式系统)来确定是否启动水泵为农田供水,同时将此供水与否信息由GPRS通信通过Internet传送到远方控制中心实现远程监控,并通过计算机中的一些模型来处理信息,做出供水计划。3.2无线传感器网络硬件设计无线传感器网络模型是不同于传统无线网络的基础设施网,通过在监测区域内随意布撒大量传感器节点(简称节点),由各节点自行协调并迅速组建通信网络,在能量利用率优先考虑原则下进行工作任务划分以获取监视区域信息。网络的自组织特性体现在当节点失效或新节点加入时网络能够自适应重新组建,以调整全局的探测精度,充分发挥资源优势,即网络中的各节点除具备数据采集功能外兼有数据转发实现多跳的路由功能。无线传感器网络每类节点的组成一般都由数据采集、数据处理、数据传输和电源这四部分组成。其中每一个单片机系统的硬件设计和软件设计都是一样。本设计的研究设计方案是只针对一个单片机系统的。被监测物理信号的形式决定了传感器的类型。处理器通常选用嵌入式CPU,如MOTOROLA公司的68HC16、C51系列单片机等。数据传输单元可以选择由低功耗、短距离的无线通信模块组成,但考虑防盗与自然损坏,本系统选择功耗较大、传输距离较远的SA68D21DL,农民可以在办公室或家中安放主控制器。图2描述了节点的组成,其中,箭头的方向表示数据在节点中的流动方向。图2传感器网络框图3.3主控系统在该系统中,控制主机作为连接Internet网和无线传感器网络之间的协议转换网关。其硬件采用致远电子公司MiniARM嵌入式工控模块。MiniISA系列采集板卡采用智能型板卡结构,即在板卡上内置MCU。板载MCU对板卡上I/O端口进行控制,实现I/O数据的缓存,从而降低板卡对于MiniISA接口主机的依赖,节省主机处理数据的时间,保证MiniISA系统更加高效的运行。此外板载MCU可以对采集的数据或者输出数据进行进一步的处理。系统电路图如图3所示。 图3主控系统结构图3.4远程控制系统主要设计GPRS通信系统、GPRS与Internet网络接入系统、监控中心主机友好界面显示控制系统。这一部分硬件部分可以应用现有的移动公司与电信等互联网资源,软件考虑成本和专业功能可以自主开发,建议应用现有远程软件,如波尔远程控制软件、湖南省远程监控设备有限公司的RC-2000可视化远程控制软件系统。结语本文综述了无线传感器网络的节点构成、特点，以及当前在农业领域的应用,研究了基于嵌入式系统而设计出来的智能广域农田供水系统,当检测到农田缺水信息时能够通过自动控制继电器来启动供水水泵,而且实现了远程GPRS通信,可以通过PC机来了解系统的运行状况并可对其控制,能够自动采集土壤信息来自行确定是否启动水泵为农田供水,这正符合我国农村的基本国情。本系统操作简单,对系统改造一下,可以设计成庭院自动供水系统、温室自动供水系统和花园自动供水系统等,故本系统的可扩展性比较好,前景比较广阔。无线传感器网络作为当今信息领域新的研究热点，涉及多学科交叉。随着传感器成本的降低以及相关问题解决方案的不断优化，如能耗更加小和数据融合算法、节点定位算法的不断完善，以及更加优秀的无线射频模块，无线传感器网络将会在农业领域有更广泛的应用。附件2：外文原文The realization of wireless sensor networks and applications in agriculture1 IntroductionWireless sensor networks (Wireless Sensor Network, WSN) are deployed in the monitoring area by the large number of low-cost micro sensor nodes, wireless communication through the formation of a multi-hop network self-organization. The aim is to perceive collaboration, collection and processing of network coverage in the perception of objects, and send observers. Sensors, sensing object and the observer, constitute the three elements of the network. Here that the sensor is not in the traditional sense of the simple perception of physical signals and the sensor into a digital signal, which is the sensor module, data processing module and wireless communication module integrated in a small physical unit, that is , enhanced features than many traditional sensors can not only be aware of environmental information, but also data processing and wireless communication capabilities. With the built-in sensor nodes in a variety of sensors, where the environment can measure heat, infrared, sonar, radar and seismic signals and other signals to detect temperature, humidity, noise, light intensity, pressure, soil composition, moving object the size, speed and direction, and so many physical phenomena of interest to us. Wireless sensor network is a new mode of information acquisition and information processing. Because of the shortage of water resources are at a considerable degree, plus 90% of the waste, untreated sewage or handling standards for direct discharge of water pollution, water quality is lower than 11% of agricultural water supply standards. Water is the lifeblood of agriculture, is the controlling element of the ecological environment, but it is also strategic economic resources, extraction of groundwater by pump irrigation of farmland, rational use of water resources, development of water supply, improve the ecological environment in China is currently accurate Agriculture key, so use of irrigation water and energy supply in todays world is the general trend of technological development.2 Overview of wireless sensor networks2.1 The system architecture of wireless sensor networksWireless sensor network system architecture shown in Figure 1, typically include sensor nodes, aggregation nodes and management nodes. Clouds in the observation area sensor nodes in order to constitute a network of self-organized manner. Sensor node processing the collected information, the way to multi-hop relay the information transmitted to the sink node. Then through the Internet or mobile communication network and other channels to reach management node. End-users through the management of wireless sensor network node management and configuration, release monitoring tasks or collect return data.2.2 The characteristics of wireless sensor networks(1) self-organization. As the network and the network itself, the physical environment in which the unpredictability of factors, such as: can not pre-set exact location of the node can not know in advance the relationship between the nodes adjacent to some nodes because of energy depletion or other causes of death, newnodes join and so on, make the network deployment and expansion without the need to rely on any of the default network infrastructure, layered protocol between nodes and distributed algorithms by coordinating their behavior, a node can quickly start automatically after the formation of a separatemulti-hop routing network.(2) multi-hop routing.Limited communication distance of nodes in the network, the node can only communicate directly with its neighbors, if beyond the range of its RF communication nodes, you need to be routed through intermediate nodes.(3) the spatial distribution of a large area, node density, the number is huge.(4) data-center.In wireless sensor networks, people usually only care about a region within a certain numerical observations, and not to the specific observations concerned a single node.(5) node capacity constraints.The energy of sensor nodes, processing power, storage capacity and communication ability and so is very limited. power energy restricted.As the miniaturization of sensor nodes, node battery power is limited, and because physical constraints make it difficult for nodes to replace the battery, so battery power limitations of sensor nodes is the wireless sensor network design one of the most critical constraints, which directly determines the networks worklife. computing and storage capacity is limited.Bring low-cost micro sensor nodes weak processor, memory capacity of small features, so it can not perform complex calculations, and the traditional Internet network protocols and algorithms on the relative maturity of wireless sensor networks, too costly, difficult to use,must therefore be simple, effective protocols and algorithms, such as the ZigBee protocol. communication is limited.Typically, the energy consumption of wireless communication and communication distance d E the relation: E = kdn.Where 2 n 4.N is usually taken as 3.2.3 The shortcomings of wireless sensor networks(1) energy is limited. Sensor nodes are usually powered by ordinary batteries or lithium batteries, the energy limited.In unattended environments, wireless sensor network applications is one of the bottlenecks.(2) node cost is higher. Currently on the market price in thousands of sensor nodes over the wireless sensor network nodes need many, limiting promote the use of wireless sensor networks.(3) The poor security. As a result of wireless channel, distributed control technology, the network more vulnerable to passive eavesdropping, active intrusion and other attacks.(4) collaboration. Individual sensor nodes are often unable to complete the target of measurement, tracking and recognition, while the number of sensor nodes need to exchange information through the algorithm on data obtained for processing, aggregation and filtering, the final result.3 the current wireless sensor network applications in agricultureView of the water shortage and the demand for farmland irrigation, irrigation equipment under the existing conditions of application fields of crops, soil, water distribution, etc., for precise analysis of the current agricultural solved key technical problems, we propose a use ofwireless sensor network technology, suitable for large areas of agricultural land Intelligent Irrigation Control.3.1 The system worksOf SCM system with multiple sensors on the humidity, temperature, rainfall, pH, water evaporation (wind speed) and air temperature, and other information collection to achieve the precise automatic irrigation control field, the output of the signal information through a wireless full-dup lex Public data transmission sent to the control center transceiver module (embedded systems) to determine whether to activate the pump for the farm water supply, water supply or not, this same information sent by the GPRS communication through the Internet to remote control centers, remote monitoring, and some models by computer to process information, make a water supply plan.3.2 Hardware Design of Wireless Sensor NetworksWireless sensor network model is different from the traditional wireless network infrastructure, network, monitoring the region by a large number of sensor nodes randomly dispenser (the node), coordinated by the node and quickly set up their own communications network, under the principle of priority for energy efficiency division of work tasks for monitoring regional information .Self-organizing properties of the network when the node failure is reflected in the new node is added or when the network is capable of adaptive re-established to adjust the overall detection accuracy, give full play to its advantages in resources, that is, each node in the network with data collected in addition both data forwarding function smulti-hop routing. Wireless sensor networks composed of nodes in each category by the general data acquisition, data processing, data transmission and power the four parts. Each of microcontroller hardware and software design are the same. The design of the study design was only for a single chip system. Be monitored in the form of physical signals determines the type of sensor .Embedded processors are often used CPU, such as the MOTOROLA companys 68HC16, C51 MCU and so on. Data transmission unit can be selected from low-power, short-range wireless communication modules, but considering the anti-theft and natural damage, the system chooses the larger power, transmission distance of SA68D21DL, farmers can be placed in the office or home, the main controller. Figure 2 depicts the composition of the node, in which the direction of the arrow indicates that the data flow direction in the node.3.3 The main control systemIn this system, the control network and Internet hosts as the connection between the wireless sensor network protocol conversion gateway. The hardware used Zhiyuan Electronics Mini ARM embedded computer modules. MiniISA series acquisition board structure using smart card, that card on the built-in MCU.MCU on the board on-board I / O ports control, to achieve I / O data buffer, thereby reducing the interface to the host board for Mini ISA dependence, saving the host data processing time, to ensure MiniISA system more efficient operation. MCU board can also collect data or output data for further processing. System schematic shown in Figure 3.3.4 Design of the remote control system is mainlyGPRS communication system, GPRS and Internet network access system, the monitoring center console-friendly interface display control system. This part of the hardware can be applied to existing mobile telecommunications companies and Internet resources, software and professional capabilities to consider the cost of independent development, the proposed application of the existing remote software, such as Ball Remote Control software, remote monitoring equipment Co., Ltd. in Hunan Province The RC-2000 remote control software visualization system.Concluding RemarksThis paper reviews the nodes of wireless sensor networks, characteristics, and current applications in agriculture, research-based embedded systems, intelligent wide are a of farmland out of the water supply system, water is detected field information to continue through the automatic control Electric water pump to start, and realized the remote GPRS communications, PC, to learn through the health system and over which it controlled, automatic acquisition of soil information to determine whether to activate the pump from the line for the farm water supply, which is in line with Chinas rural areasbasic national conditions. The system is simple, click on the system transformation, can be designed courtyard automatic water supply systems, automatic water supply system and a garden greenhouse automatic water supply system, so the scalability of the system is better, relatively broad prospects.Todays wireless sensor network as a new hotspot in the field of information, involving interdisciplinary. With the reduced cost sensors and related solutions to continuous optimization problems, such as power consumption and data fusion algorithm is more small, node localization algorithm in continuous improvement, and more advanced wireless RF module, wireless sensor networks will be more in agriculture wide range of applications.