移动目标点数与红外传感器网络 毕业论文外文翻译.docx

外文资料翻译moving object counting with an infrared sensor network by ki, chi keung abstract wireless sensor network (wsn) has become a hot research topic recently. great benefit can be gained through the deployment of the wsn over a wide range of applications, covering the domains of commercial, military as well as residential. in this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. such a system can be deployed in traffic control, resource management, and human flow control. our design is based on our self-made cost-effective infrared sensing module board which co-operates with a wsn. the design of our system includes infrared sensing module design, sensor clustering, node communication, system architecture and deployment. we conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our moving object counting system. keywords: infrared radiation，wireless sensor node1.1 introduction to infrared infrared radiation is a part of the electromagnetic radiation with a wavelength lying between visible light and radio waves. infrared have be widely used nowadays including data communications, night vision, object tracking and so on. people commonly use infrared in data communication, since it is easily generated and only suffers little from electromagnetic interference. take the tv remote control as an example, which can be found in everyones home. the infrared remote control systems use infrared light-emitting diodes (leds) to send out an ir (infrared) signal when the button is pushed. a different pattern of pulses indicates the corresponding button being pushed. to allow the control of multiple appliances such as a tv, vcr, and cable box, without interference, systems generally have a preamble and an address to synchronize the receiver and identify the source and location of the infrared signal. to encode the data, systems generally vary the width of the pulses (pulse-width modulation) or the width of the spaces between the pulses (pulse space modulation). another popular system, bi-phase encoding, uses signal transitions to convey information. each pulse is actually a burst of ir at the carrier frequency. a high means a burst of ir energy at the carrier frequency and a low represents an absence of ir energy. there is no encoding standard. however, while a great many home entertainment devices use their own proprietary encoding schemes, some quasi-standards do exist. these include rc-5, rc-6, and rec-80. in addition, many manufacturers, such as nec, have also established their own standards. wireless sensor network (wsn) has become a hot research topic recently. great benefit can be gained through the deployment of the wsn over a wide range of applications, covering the domains of commercial, military as well as residential. in this project, we design a counting system which tracks people who pass through a detecting zone as well as the corresponding moving directions. such a system can be deployed in traffic control, resource management, and human flow control. our design is based on our self-made cost-effective infrared sensing module board which co-operates with a wsn. the design of our system includes infrared sensing module design, sensor clustering, node communication, system architecture and deployment. we conduct a series of experiments to evaluate the system performance which demonstrates the efficiency of our moving object counting system. 1.2 wireless sensor network wireless sensor network (wsn) is a wireless network which consists of a vast number of autonomous sensor nodes using sensors to monitor physical or environmental conditions, such as temperature, acoustics, vibration, pressure, motion or pollutants, at different locations. each node in a sensor network is typically equipped with a wireless communications device, a small microcontroller, one or more sensors, and an energy source, usually a battery. the size of a single sensor node can be as large as a shoebox and can be as small as the size of a grain of dust, depending on different applications. the cost of sensor nodes is similarly variable, ranging from hundreds of dollars to a few cents, depending on the size of the sensor network and the complexity requirement of the individual sensor nodes. the size and cost are constrained by sensor nodes, therefore, have result in corresponding limitations on available inputs such as energy, memory, computational speed and bandwidth. the development of wireless sensor networks (wsn) was originally motivated by military applications such as battlefield surveillance. due to the advancement in micro-electronic mechanical system technology (mems), embedded microprocessors, and wireless networking, the wsn can be benefited in many civilian application areas, including habitat monitoring, healthcare applications, and home automation. 1.3 types of wireless sensor networks wireless sensor network nodes are typically less complex than general-purpose operating systems both because of the special requirements of sensor network applications and the resource constraints in sensor network hardware platforms. the operating system does not need to include support for user interfaces. furthermore, the resource constraints in terms of memory and memory mapping hardware support make mechanisms such as virtual memory either unnecessary or impossible to implement. tinyos tinyos is possibly the first operating system specifically designed for wireless sensor networks. unlike most other operating systems, tinyos is based on an event-driven programming model instead of multithreading. tinyos programs are composed into event handlers and tasks with run to completion-semantics. when an external event occurs, such as an incoming data packet or a sensor reading, tinyos calls the appropriate event handler to handle the event. the tinyos system and programs are both written in a special programming language called nesc nesc which is an extension to the c programming language. nesc is designed to detect race conditions between tasks and event handlers. there are also operating systems that allow programming in c. examples of such operating systems include contiki contiki, and mantis. contiki is designed to support loading modules over the network and supports run-time loading of standard elf files. the contiki kernel is event-driven, like tinyos, but the system supports multithreading on a per-application basis. unlike the event-driven contiki kernel, the mantis kernel is based on preemptive multithreading. with preemptive multithreading, applications do not need to explicitly yield the microprocessor to other processes. 1.4 introduction to wireless sensor node a sensor node, also known as a mote, is a node in a wireless sensor network that is capable of performing processing, gathering sensory information and communicating with other connected nodes in the network. sensor node should be in small size, consuming extremely low energy, autonomous and operate unattended, and adaptive to the environment. as wireless sensor nodes are micro-electronic sensor device, they can only be equipped with a limited power source. the main components of a sensor node include sensors, microcontroller, transceiver, and power source. sensors are hardware devices that can produce measurable response to a change in a physical condition such as light density and sound density. the continuous analog signal collected by the sensors is digitized by analog-to-digital converter. the digitized signal is then passed to controllers for further processing. most of the theoretical work on wsns considers passive and omni directional sensors. passive and omni directional sensors sense the data without actually manipulating the environment with active probing, while no notion of “direction” involved in these measurements. commonly people deploy sensor for detecting heat (e.g. thermal sensor), light (e.g. infrared sensor), ultra sound (e.g. ultrasonic sensor), or electromagnetism (e.g. magnetic sensor). in practice, a sensor node can equip with more than one sensor. microcontroller performs tasks, processes data and controls the operations of other components in the sensor node. the sensor node is responsible for the signal processing upon the detection of the physical events as needed or on demand. it handles the interruption from the transceiver. in addition, it deals with the internal behavior, such as application-specific computation. the function of both transmitter and receiver are combined into a single device know as transceivers that are used in sensor nodes. transceivers allow a sensor node to exchange information between the neighboring sensors and the sink node (a central receiver). the operational states of a transceiver are transmit, receive, idle and sleep. power is stored either in the batteries or the capacitors. batteries are the main source of power supply for the sensor nodes. two types of batteries used are chargeable and non-rechargeable. they are also classified according to electrochemical material used for electrode such as nicd(nickel-cadmium), nizn(nickel-zinc), nimh(nickel metal hydride), and lithium-ion. current sensors are developed which are able to renew their energy from solar to vibration energy. two major power saving policies used are dynamic power management (dpm) and dynamic voltage scaling (dvs). dpm takes care of shutting down parts of sensor node which are not currently used or active. dvs scheme varies the power levels depending on the non-deterministic workload. by varying the voltage along with the frequency, it is possible to obtain quadratic reduction in power consumption. 1.5 challenges the major challenges in the design and implementation of the wireless sensor network are mainly the energy limitation, hardware limitation and the area of coverage. energy is the scarcest resource of wsn nodes, and it determines the lifetime of wsns. wsns are meant to be deployed in large numbers in various environments, including remote and hostile regions, with ad-hoc communications as key. for this reason, algorithms and protocols need to be lifetime maximization, robustness and fault tolerance and self-configuration. the challenge in hardware is to produce low cost and tiny sensor nodes. with respect to these objectives, current sensor nodes usually have limited computational capability and memory space. consequently, the application software and algorithms in wsn should be well-optimized and condensed. in order to maximize the coverage area with a high stability and robustness of each signal node, multi-hop communication with low power consumption is preferred. 1.6 research issues researchers are interested in various areas of wireless sensor network, which include the design, implementation, and operation. these include hardware, software and middleware, which means primitives between the software and the hardware. as the wsns are generally deployed in the resources-constrained environments with battery operated node, the researchers are mainly focus on the issues of energy optimization, coverage areas improvement, errors reduction, sensor network application, data security, sensor node mobility, and data packet routing algorithm among the sensors. in literature, a large group of researchers devoted a great amount of effort in the wsn. they focused in various areas, including physical property, sensor training, security through intelligent node cooperation, medium access, sensor coverage with random and deterministic placement, object locating and tracking, sensor location determination, addressing, energy efficient broadcasting and active scheduling, energy conserved routing, connectivity, data dissemination and gathering, sensor centric quality of routing, topology control and maintenance, etc. 移动目标点数与红外传感器网络作者 ki, chi keung 摘要 无线传感器网络(wsn)已成为最近的一个研究热点。伟大的效益通过部署的无线传感器网络在大范围的应用的领域,覆盖了商业、军事以及住宅。在这个项目,我们设计了一个计数系统,以追踪那些经过检测区以及相应的移动方向。这样的一个系统部署在交通控制、资源管理和人力的流量控制。我们的设计是基于我们的自制划算的红外传感模块板用无线传感器网络的联系。我们的系统的设计包括红外传感模块设计、传感器节点通讯、系统聚类、建筑和部署。我们进行了一系列的实验来评估系统的性能论证了高效率的移动对象计数系统。关键词:红外辐射，无线传感器节点1.1介绍红外 红外辐射,是一个部分的电磁辐射与波长在撒谎可见光与无线电波之间。现在已经被广泛应用红外线包括数据通讯、夜视装置,物件追踪等等。人们通常使用红外数据通信中,由于它是容易产生和只有受电磁干扰少。把电视遥控器控制作为一种例子,可以发现在每个人的家里。红外遥控系统利用红外发光二极管(led)散发出红外(红外线)讯号按钮推后。不同模式显示相应的按钮的脉冲的存在推。允许控制多种电器比如电视机、录像机、有线电视盒,不受干扰,系统通常有序言和一个地址进行同步识别来源的接收机的位置和红外信号。编码的数据,系统通常不同脉冲的宽度(脉宽调制)或宽度之间的间隔空间调制脉冲(脉冲)。另一种受欢迎的系统、双相编码,利用信号转换来传递信息。每次脉冲是其实一阵红外在载波频率。“高”的含义是一阵红外能量载波频率和一个“低”体现了一种不在红外能量。没有编码标准。然而,当许多家庭娱乐设备使用他们自己的一些quasi-standards专有的编码系统确实存在。这些包括rc-5、rc -(六)、rec-80。此外,许多汽车制造商,如nec、也成立他们自己的标准。 无线传感器网络(wsn)已成为最近的一个研究热点。伟大的效益通过部署的无线传感器网络在大范围的应用的领域,覆盖了商业、军事以及住宅。在这个项目,我们设计了一个计数系统,以追踪那些经过检测区以及相应的移动方向。这样的一个系统部署在交通控制、资源管理和人力的流量控制。我们的设计是基于我们的自制划算的红外传感模块板用无线传感器网络的联系。我们的系统的设计包括红外传感模块设计、传感器节点通讯、系统聚类、建筑和部署。我们进行了一系列的实验来评估系统的性能论证了高效率的移动对象计数系统。1.2无线传感器网络无线传感器网络(wsn)是一种无线网络是由大量不同传感器节点的自主使用传感器监测物理或环境条件,如温度、音响、振动、压力、运动或污染物,其代价就是寿命不同的地点。在传感器网络中每个节点通常配备了无线通信设备,一个小的单片机,一个或多个传感器,和一种能源,通常是一个电池。大小的单一传感器节点可以一样大,可作为鞋盒小面积的一粒尘埃,这取决于不同的应用程序中。成本的传感器节点是同样的变量,从几百美元到几美分,根据无线传感器网络的大小和复杂性的要求单一传感器节点。大小和成本约束条件下的传感器节点,因此,结果在相应的限制有可用的输入,例如精力,记忆,算法的计算速度和带宽。无线传感器网络的发展(wsn)起初的目的军事应用,如战场上的监视。由于进步微-电子机械系统(mems)技术,嵌入式处理器、和无线网络技术、无线传感器网络的受益在许多平民的应用范围,包括生境监测、医疗应用,以及家庭自动化。 1.3类型的无线传感器网络 无线传感器网络节点通常不那么复杂比通用由于操作系统的特殊要求的传感器网络应用及在传感器网络资源约束条件下的硬件平台。这操作系统不需要包括支持用户界面。此外,在资源约束的内存方面和内存映射的硬件支持机制如虚拟内存或者不必要或无法实现的。tinyostinyos可能是第一个操作系统专门设计无线传感器网络。与大多数其它操作系统基础上,tinyos事件驱动编程模型代替多线程。tinyos节目都是合成事件处理器和任务以跑到completion-semantics。当一个外部事件发生时,例如一个到来的数据分组或阅读,tinyos传感器调用合适的事件处理程序来处理这个事件。这tinyos系统和节目都是写在一种特殊的编程语言nesc称为nesc是一种延伸到c程序设计语言。nesc是用来侦测的种族条件和任务间事件处理器。也有操作系统,允许这样的例子程序,使用c操作系统包括contiki,contiki螳螂。contiki是设计用来在网络上支持加载模块加载和支持运行时的标准精灵的文件。contiki事件驱动的,就像tinyos内核,但制度的支持多线程每个基础操作。不像其指导思想是将事件驱动的contiki内核,螳螂的核心是基于先发制人的多线程。与先发制人的多线程、应用程序不需要明确的微处理器能在其他产量