采用红外传感器网络对移动目标的计数1江西城市职业学院毕 业 论 文 （ 设 计 ）题 目： 红外线自动计数器的设计 分 院： 机电工程学院 班 级： 08 应用电子技术（1）班 学 号： 085902020139 学生姓名： 张 博 起讫日期： 2010 年 11 月 15 日 指导教师： 石怿 职称： 助教 教研室主任： 石怿 审核日期： 采用红外传感器网络对移动目标的计数2Moving Object Counting with an Infrared Sensor Network By Chi-Keung Ki采用红外传感器网络对移动目标的计数3ABSTRACTWireless 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 Wireless Sensor Network1.1 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 采用红外传感器网络对移动目标的计数4devices 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. 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.Tiny