远程视频监控系统大学毕业论文外文文献翻译及原文
外文参考文献翻译-中文
外⽂参考⽂献翻译-中⽂基于4G LTE技术的⾼速铁路移动通信系统KS Solanki教授,Kratika ChouhanUjjain⼯程学院,印度Madhya Pradesh的Ujjain摘要:随着时间发展,⾼速铁路(HSR)要求可靠的,安全的列车运⾏和乘客通信。
为了实现这个⽬标,HSR的系统需要更⾼的带宽和更短的响应时间,⽽且HSR的旧技术需要进⾏发展,开发新技术,改进现有的架构和控制成本。
为了满⾜这⼀要求,HSR采⽤了GSM的演进GSM-R技术,但它并不能满⾜客户的需求。
因此采⽤了新技术LTE-R,它提供了更⾼的带宽,并且在⾼速下提供了更⾼的客户满意度。
本⽂介绍了LTE-R,给出GSM-R与LTE-R之间的⽐较结果,并描述了在⾼速下哪种铁路移动通信系统更好。
关键词:⾼速铁路,LTE,GSM,通信和信令系统⼀介绍⾼速铁路需要提⾼对移动通信系统的要求。
随着这种改进,其⽹络架构和硬件设备必须适应⾼达500公⾥/⼩时的列车速度。
HSR还需要快速切换功能。
因此,为了解决这些问题,HSR 需要⼀种名为LTE-R的新技术,基于LTE-R的HSR提供⾼数据传输速率,更⾼带宽和低延迟。
LTE-R能够处理⽇益增长的业务量,确保乘客安全并提供实时多媒体信息。
随着列车速度的不断提⾼,可靠的宽带通信系统对于⾼铁移动通信⾄关重要。
HSR的应⽤服务质量(QOS)测量,包括如数据速率,误码率(BER)和传输延迟。
为了实现HSR的运营需求,需要⼀个能够与 LTE保持⼀致的能⼒的新系统,提供新的业务,但仍能够与GSM-R长时间共存。
HSR系统选择合适的⽆线通信系统时,需要考虑性能,服务,属性,频段和⼯业⽀持等问题。
4G LTE系统与第三代(3G)系统相⽐,它具有简单的扁平架构,⾼数据速率和低延迟。
在LTE的性能和成熟度⽔平上,LTE- railway(LTE-R)将可能成为下⼀代HSR通信系统。
⼆ LTE-R系统描述考虑LTE-R的频率和频谱使⽤,对为⾼速铁路(HSR)通信提供更⾼效的数据传输⾮常重要。
视频监控系统外文翻译译
视频监控系统外文翻译译中文3630字毕业设计外文翻译2014 届信息科学与工程学院通信工程专业题目:子题:外文文献Video surveillance system is safe guard system is an important part of a preventive ability strong comprehensive system. Video monitoring with its convenient, intuitive and information content rich and widely used in many occasions. In recent years, with the development of modern science and technology, in particular network bandwidth, computer processing power and storage capacity rapidly increase and various practical video information processing technology, video surveillance technology also appeared a considerable development, video monitoring entered the digital network age, increasingly attention by people and attention. The development of video surveillance system is mainly early analog closed-circuit television monitoring system combined to video monitoring system model of digital video monitor and now the evolution process, and the system of digital video monitor system now according to the technical development and divided into three stages: digital monitor multimedia stage, digital monitor DVR stage and digital monitor network stage.1, video monitoring system simulations simulate video monitoring system is divided into microprocessor-based video switch control plus PC multimedia management and pc-based realize the switch control of matrix host and system multimedia management two types. Analog closed-circuit television monitoring system is actually the combination of many simulation monitoring equipment, system mainly consists of "front-end device" and "terminal control device" and "signal transmission medium" three parts, including: front-end equipment is mainly a camera, haeundae, decoder, control equipment is mainly a switching matrix, image segmentation device, monitor and control the keyboard, video, etc. Transmission medium including cable, control, etc. As microprocessors, the function, performance of microcomputers and heighten, multimedia technology application, the system in functionality,performance, reliability, structure pattern, etc, great changes have happened to the video monitoring system, more convenient, thecomposition of the interface with other technical system tends to regulate, man-machine interface more friendly. But because video monitor and control system in the flow of information form does not change, the video signal is still simulation system, the network structure is mainly a ChanGongNeng, one-way, lumped way of information collection network,so system although has developed to a high level, has not much potential can dig, its limitations still exist, to meet the higher request,digital is the only way. Simulation monitoring system of main faults are: a, usually only suitable for small range of regional monitor videosignal transmission, simulation tools, and is mainly coaxial cable to transmit analog video signal coaxial cable, the distance is not more than the distance twisted-pair dump more short, this determines the analog monitor only suitable for single building, small neighborhood and other small range of places. B, the system of expansion ability difference for has already built good system, if want to add new monitory point, often is one change makes all change, new equipment is also hard to add to the original system in. C, unable to form effective alarm linkage, because each part between independent operation, the control protocol is difficult to each other, linkage in the limited scope only.2 video monitoring system, digital multimedia technology, video with compression technology, network communication technology of digital video surveillance system development, the rapid rise, on the market today there are two types of digital video monitor system type, one is the digital video equipment video monitoring system for the core, another kind is embedded video Web server video monitoring system for the core.Digital video compression technology matures, the computer based on PC universalization, create conditions multimedia monitor. This new video monitoring system of rapid rise, partially replaced with video matrix image segmentation device, video as the core, complementary with other transmitter simulation video monitor mode, its advantage mainly displays in: a, PC multimedia monitor video matrix, the host integratedimage segmentation device, many functions of video recorders, simplifies the structure of the system. B, because use the computer network technology, digital multimedia remote network monitor from distance limit. C, due to the large capacity disk array inventory device or CD storage, can save you a lot of tape medium, and it is helpful to the multimedia information system.But as the PC video surveillance video system development, in actual engineering in use process, also exposed some shortage, mainly system work instability. The video surveillance video based on PC for: the structure of system compatible/industrial PC + video capture card + ordinary/more reliable operation platform + application software. From the system composition structure to analysis: a, PC for 24 hour uninterrupted job, its performance is not very stable, g-kong PCrelative compatible PC's stability have a class enhancement, suitablefor complex working environment. B, operating system: with Windows 98for operation platform system, the industry insiders know, there are certain Win98 stability problem, if at the same time the application software is not very standardized, it'll be easier in use process appears work instability, freezes and other issues, and PC video surveillance video system realization of their software in Windows 95/98 / NT, Unix, Linux operating system, such as general while system files, application software and image files are stored in the disk, video processing must high-density input of large quantities of data, and to work hard drive, the average for the hard disk logic (such as Windows,already can't adapt to FAT32) so susceptible, causing instability crashed phenomenon. C,application software: the simple application software system is not can be used for security video monitoring system, fields of application software ability should support multitasking concurrent processing, such as monitoring, video, playback, backup, alarm, control, remote connection, etc. The ability to deal with more work D, video capture card: video surveillance video system for road input system are usually video capture card, can use multiple CARDS way, also can use single card mode. Say commonly, a single card way better integration high stability will more than all the way, many using card has a card way very easy to form hardware conflicts, its stability will have a major influence. Embedded system is used as the center, software and hardware can be cut, to adapt application system function, reliability and cost, volume etc comprehensive demanding special computer system for monitoring system, i.e. the special computer system tailored.Embedded system mainly consists of embedded processor, relevant support hardware, embedded operating system and application software system etc, it is the collection software and hardware in theintegration of can work independently "devices". Embedded operating system is a kind of real-time, supports embedded system application operating system software, it is embedded system extremely important constituent, usually includes and hardware related software drivers, system kernel bottom, device driver interface, communication protocol,graphic interface, standardization browsers, embedded real-time operating system in the related hardware and efficiency of dependence, software application and specificity solid state has more prominent characteristics. The advantages and disadvantages of embedded system, the system for a special system, so the system is small, instruction downsizing and processing speed. B, system data in ROM/FLASH with fast speed, call, not be altered, good stability. C, system treatment of good real-time performance, stable performance. D, document management system ismore suitable for large amounts of video data. E, in network function, audio and video sync issues may also difficult satisfactory. Embedded video Web server mode, a built-in video server embedded Web server, the embedded real-time multitasking operating system. The video signal digital camera sent by high compression chip after through internal bus to compress, built-in Web server, Internet users can use directly on the Web server browsers on camera images, subscribers can also control the camera lens, haeundae, the actions or operate on system configuration.Because the video compression and Web function centralism to a small size within the equipment can be directly connected lans, achieve namely that look, omited inserted range of complex cable, convenientinstallation (only set an IP address), the user does not need to install any hardware device, with the browser can only watch. Embedded video Web server monitoring system and other surveillance system has the followingcharacteristics: a comparison of embedded video area is vast, have been supervised Web server monitoring system of Web server directly connected network, no cable length and attenuation, and the limit of the conceptof network is no distance, completely abandoned regional concept, expand have been supervised areas. B, the system has almost unlimited seamless expansion ability all equipment is mark, with IP address increased equipment just means that IP address the expansion. C, can form a very complicated monitoring network based on embedded Web server is the core of the monitoring system in network mode, with traditional analogmonitor and based on PC platforms screening method has greatly different, because Web server output has completed analog to digital conversion and compression, adopt uniform agreement on the network transmission,support across the router across the gateway, remote video transmission. D, stable and reliable performance, without staff management embedded Web server based on embedded computertechnology, actually using embedded real-time multitasking operating system, and video compression and Web function due to focus on a small size, within the device directly concatenation LAN or wan, namely that look, system insert real-time, stability, reliability greatly improved, also need not specially assigned management, which is very suitable for unattended conditions. E, when the monitoring center needs to watch a video camera image, more network bandwidth will have certain requirements.The development of video monitoring system1, video monitoring system development directionVideo digitizing, front integration, network, system integration is monitoring the development of video monitoring system, and recognized the direction is the premise of digital network, network and system integration of video monitor based, so, the biggest two characteristics is the digital and network.2, digitalDigital is the 21st century features, is the information technology as the core, the necessity of the development of electronic technology, digital is toward growth pass, along with the time development, our environment will become more and more digital.Video surveillance system is the system of digital first should flow in video, audio, (including from analog state control, etc.) state, which to digital completely break "classic cable TV system based on camera imaging technology as the center" structure, fundamentally changing video monitoring system from information acquisition, data processing, transmission and system control of the mode and structural form. The flow of information digitization, coding compression, open video monitoring system, make agreements with the security system in other between each subsystem realize seamless connection, and theunified operation platform to realize the management and control system integration, this also is the meaning.3 and networkVideo monitoring system of the structure of the network will mean system by lumped type to distribution type system transition.Distribution type system USES the multi-layer hierarchical structureform and the real-time kernel technology with micro multitask, multi-user, distributed operating system to achieve beat task scheduling algorithm fast response. Distributing type monitoring system of the hardware and software using the standardization, the modularization and the serialization of design, system equipment configuration has the versatility, openness, system configuration flexible, control theperfect function, data processing convenient, friendly man-machine interface and system installation, commissioning and maintenancesimplify the operation of the system, are hot backup, fault-tolerant reliable, etc. System in some degree of networked broke on regional and equipment have been supervised extended geographical and quantity limits. System network will make the whole network system hardware and software resources sharing and mission and load of sharing, this also is an important concept of the system integration. From the above can seevideo technology, the development of video, roughly experienced analog video, network video PC in three phases, and depending on the technology of the network, communication and transmission platform.外文翻译视频监控系统是安全防范系统的重要组成部分,是一种防范能力较强的综合系统。
ZigBee外文文献加翻译
A Coal Mine Environmental Monitor System with LocalizationFunction Based on ZigBee-Compliant PlatformDongxuan YangCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, ChinaYan ChenCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, China*****************Kedong WangCollege of Computer and InformationEngineeringBeijing Technology and BusinessUniversityBeijing, ChinaAbstract—This paper describes and implements a new type of coal mine safety monitoring system, it is a kind of wireless sensor network system based on ZigBee technology. The system consists of two parts underground and surface. Wireless sensor networks are constituted by fixed nodes, mobile nodes and a gateway in underground. PC monitoring software is deployed in the surface. The system can not only gather real-time environmental data for mine, but also calculate the real-time location of mobile nodes worn by miners.Keywords:ZigBee; localization; wireless sensor networks; coal MineI.RESEARCH STATUSAs an important energy, coal plays a pivotal role in the economic development. Coal mine monitoring system, is the important guarantee for coal mine safety and high efficiency production [1]. In order to ensure the safe operation, the installation of environment monitoring node in tunnels to real-time detection is very important. However, commonly used traditional monitoring node wired connection to obtain communication with the control system, this node exist wiring difficulties, expensive and other shortcomings. In contrast, wireless sensor node can be easily with current mine monitoring network connection, and good compatibility, facilitate constituted mine gas monitoring network, to suit various size of mine applications. Since wireless nodes are battery powered, so completely out of the shackles of the cable, shorten the construction period can be arranged at any time where the need to use.The ZigBee wireless communication technology is used in this coal mine environmental monitor system. This is a new short-range, low complexity, low power,low data rate, low-cost two-way wireless communication technology [2]. Now, wireless sensor network product based on ZigBee technology are quantity and variety, but the real product can be applied in underground environments of special sensor node is very few[3]. The sensor node that we designed in the system is truly able to apply to in-well environment, it through the wireless sensor node security certification. At the same time, due to the special nature of the wireless network is that it can spread the wireless signal, we can easily locate staff for coal mine safety monitoring provides more protection [4].II. SYSTEM ARCHITECTUREThis system is a comprehensive monitoring system which is combined with software and hardware. Hardware part includes wireless mobile nodes and fixed nodes which were deployed in the underground tunnel, the main function of them is to collect coal mine environment data and require person’s location. Software part refers to the PC monitoring software which is designed in VC++ is used to summarize and display the data of each node. Monitoring node is divided into mobile nodes and fixed nodes; they are using ZigBee protocol for wireless transmission of data. Because the fixed node is also using wireless data transmission method, so it's deployed in the underground roadway becomes very convenient. As the mobile node is carried by the miner, it must be using wireless transmission method. This allows the mine to form a topology of ZigBee wireless sensor network. The fixed node in wireless sensor network is router device and the mobile node carried by miner is the end device. Normally, the router of ZigBee network has no sensor equipment; it is only responsible for data forwarding. But considering the practical application, we believe that add sensor devices on the router will be better on monitoring underground coal mine environment. So in our design, the router also has an environment monitoring function which is usually designed in end device.Fixed node will sent received data from mobile node to the gateway, then the gateway transmits data to monitor computer through RS232 or optical fiber. The PC monitor software in the computer will process all data and display them in a visualization window. The PC software also calculates each mobile node’s real-time location through the specific localization algorithm, according to the received signal strength (RSSI) obtained from mobile nodes.III. NODE DESIGNSince the ZigBee wireless network platform sold on present market was designed for the general environment, for special underground so they are not suitable for the environment. Therefore, we need to customize the system for underground environment whit a special hardware circuit. Node photo are shown in Fig. 1 Then wireless microcontroller CC2530 chip is the core processor of the node device, it can constitute a ZigBee network with very few peripheral circuits. TheCC2530 is an IEEE 802.15.4 compliant true System-on-Chip, supporting theproprietary 802.15.4 market as well as the ZigBee, ZigBee PRO, and ZigBee RF4CE standards. Unlike other wireless chip, CC2530 built-in 8051 monolithic integrated circuits kernel, therefore we no longer need to use a single MCU to control the circuit, and this save us a lot of cost [5].A.Mobile NodeThe mobile node is the end device of a ZigBee network that can be carried by miner; it should be a portable and low power consumption node. So the mobile node we designed is only as small as a mobile phone, and it is by built-in lithium ion battery power supply. In power loss, the core processor CC2530 is a low power consumption chip, when it is in the sleep mode, it only need to use less then 1uA work current. In order to reduce power consumption as much as possible on the display, a 100*32 pixel matrix with no backlighting LCD screen was used. The battery’s capacity of the mobile node is 1500mAh,so it is enough to meet the miner’s long hour works in the underground. The battery charge management chip is TP4057, the maximum charge current can up to 500Ma.Figure 1. Node photo.The mobile node circuit includes the gas concentration sensor MJ4.0 and temperature sensor PT-1000. As far as we know, many wireless sensor platforms use the digital type sensor. The communication between the digital sensor and the MCU need strict timing requirements. But considering the actual application, the wireless MCU usually has a real-time operating system in general, if we use the microcomputer to simulate the strict timing, it will affect the real-time of whole operating system. These two sensors output analog signals not digital signals. Only input this signal into a differential amplifier, can we get an appropriate signal that can be converted to a digital signal by an ADC mode within the CC2530 chip. In order to facilitate the carrying, external antenna was not used in our mobile node, instead ofusing a 2.4GHz patch antenna. And we customize a shell like a cell phone size; it is enough to put all PCBs, sensors and battery in it. Taking into account the small shell of the explosive performance is not very good, the design of PCBs and the selection of component are all carried out the safety assessment.B. Fixed NodeFixed node is installed in the wall of the underground tunnel. Because it is big than the mobile node, it is not appropriate to carry around. The circuit of the fixed node is almost same with the mobile node, it also use a CC2530 chip as core processor. Because of underground tunnels generally deploy with power cable, fixed nodes can use cable power-supply modes. At the same time, because we use wireless signal transmission, the deployment of new fixed nodes become very convenient, which also resolves the problem of the signal lines deployment.As a fixed node, the minor who is doing work may far from it, in order to facilitate the miners observed environmental data around the fixed nodes, it uses LED digital display. At the same time, the large current LED lights and buzzer are designed in the circuit; it makes the fixed node with the function of sound-light alarm. Considering that it may occur the emergency of without electricity, fixed node also built-in a lithium-ion battery. Under normal conditions, lithium-ion battery is in charging status, when external cable disconnect, fixed node is automatic switched to battery power, which can ensure the mobile node can deliver the information through fixed nodes in underground.Without regarding to fixed nodes’ portability, we have a customized shell that has excellent explosion properties, and the internal space is enough to hold down the 2.4 GHz antenna. To ensure safety, all cables and the location of sensors are placed with particular glue sealed, so that it has a good seal.IV.POSITIONING FUNCTIONOne of the important functions of the wireless sensor networks is localization, especially in the underground tunnel, it relates to the safe of the miner's life. Currently most widely used orientation method is GPS satellite positioning, it is a high precision, all-weather and global multifunctional system with the function of radio navigation, positioning and timing. But the GPS positioning method is not suitable for the underground work environment of coal mine, once you enter the underground, it cannot receive satellite signal, thus unable to achieve targeting [6]. We need to consider how to use wireless network to realize positioning function, means using wireless signal between the communications of devices for positioning. The existing distance measuring technology between the wireless-devices basically is the following kinds of methods: TOA, TDOA, AOA and RSSI.About the TOA method, the distance between the two devices is determined by the product of the speed of light and transmission time [7]. Although the precision of this method is accurate, but it require a precise time synchronization, so it demand hardware is higher.TDOA technology need ultrasonic signal,which is setting on a node with receive and transmit function. When measure the distance, it can sent ultrasonic wave and wireless signals together. By measuring the difference between two signals arrival time, we can calculate the distance between two devices [8]. Using this method can also obtain accurate result, but the method need to increase ultrasonic sending and receiving device on the node circuit, it will increase cost.AOA technology needs to install multiple antennas through the nodes so it canobtain adjacent nodes’ signals on deferent directions [9]. With this it can determine the location information from number of adjacent nodes and calculate its own position. This method not only need to add additional hardware, but also it's still very vulnerable to external disturbance, therefore it's not suitable for utilize.RSSI ranging is a cheap and easy technology. By using this method, we don't need to add additional hardware design. We also do not need very precise time requirements. This technique is about with measuring the wireless signals strength in the propagation of the loss, to measure the distance between two nodes. Because of this method requires hardware equipment is less, algorithm is simple, so it has been using in many wireless communication field. Comprehensive all conditions, positioning on the use of RSSI ranging technique.A. Hardware Location EngineThe CC2431 wireless microcontroller chip produced by TI Company has a hardware location engine. From the software's point of view, CC2431’s hardware location engine has a very simple API interface, as long as writing the necessary parameters and waiting for calculation, it can read the location results [10].The hardware location engine is also based on RSSI technology. The localization system includes reference nodes and blind nodes. The reference node is a fixed node that located in a known position, the node know their place and send a packet notifyto other nodes. The blind node receives packets from reference nodes, which can obtains reference nodes’ location and the corresponding RSSI value and put them into the hardware location engine, and then the blind node’s location can be read from the engine [11].On the surface, using the CC2431 hardware location engine targeting the program as a good choice, but considering the practical application, it will encounter the following problems. First of all, we have choose the CC2530 as the main chip of fixed nodes of the system, its internal programs is running in ZigBee2007 protocol, but CC2431 as a early chip, it applies only to ZigBee2006 protocol. In the communications between CC2431 and CC2530 that will have compatibility problems. Secondly, CC2431 hardware location engine use the distributed computing, all mobile nodes’ location are calculated by themselves, and then they upload information to the gateway node, this will not only occupy the mobile node processing time, still it can take up more network resources. For this reason, we have to shelve this approach, consider how to implement location by using CC2530 chip.B. Software Location EngineIf we want to use CC2530 to implement location function, that we must write software location engine by ourselves. Because that chip do not have a hardware location engine inside of it. This software location engine is still used RSSI technology; meanwhile mobile node position is calculated by the PC software, so asto reduce the burden of mobile node computing. To calculate the mobile node location, there must be at least three reference nodes. We will regard router nodes as reference nodes in network, and record the X, Y coordinates of every reference node. Then we let the mobile node send signal to each reference node, so that each reference node can obtain a RSSI values, with these parameters, we can use trilateral measurement method to calculate the specified location of the mobile node. The simpler way give the mobile node to broadcast way to send data, then around it every router node would receive the data from the mobile node, thus obtains RSSI values. Once the mobile node number increasing network, this method will make router nodes more burden, because the every radio message that the router node receives will transmit from the low layer to the top layer. Finally the application layer will analyze data packets. Infact, the mobile node need not to broadcast transmitted data, other routing node can also receive the mobile node packets. Only child mobile nodes of the router node will continue to transmit the packet forwarding upward, the other router nodes will shield out the packet in the bottom of the protocol.In order to let all router nodes can receive the packet which sending by mobile nodes, and send its RSSI values up to the gateway node, we need to modify the relevant function in Z- Stack protocol which is provided by TI. First we find the function named afIncomingData, it deals with the received data from the bottom of protocol, in which we add some code that can obtain packet’s RSSI value. Then through the osal_set_event function to add and send an eventMY_RSSI_REPORT_EVT of RSSI value task to OSAL polling system. This event’s corresponding function will be executed in the task of OSAL interrupt-driven function, thus the mobile node corresponding RSSI values will be sent to gateway node. Through this method, the packet will only be processed by bottom function of the protocol. According to this method we can obtain corresponding RSSI value and save the computation time of mobile nodes.In fact, this software location engine is not implementing with a single mobile node, but through the operation of the whole system to achieve. By which the mobile node is only responsible for sending unicast packets. The mobile node’s parent router node is responsible to forward the packet to the gateway. Other router nodes are not responsible for forwarding this packet, just clipping the mobile node of RSSI value, then forwarded to the gateway. Finally the gateway bring all RSSI values of the mobile node to PC monitoring software, the corresponding mobile node’s location is calculated. In order to reduce the error, monitoring software will collect 10 times of the RSSI value and take average on it, and then select the nearest value of the three fixed nodes. Finally the trilateral measurement method is used to calculate the location of mobile nodes.V.SYSTEM IMPLEMENTATIONAll software systems embedded in nodes are based on Z-Stack. BecauseZ-Stack is an open-source project, it is very beneficial to the secondary development. These nodes were tested in a real coal mine locate in Shanxi Province. We deployed the fixed node every 50 meters in the tunnel, and also set a fixed node in each entrance of the work area. Because the fixed node have large size digital LED displays, so the display content of the fixed node can be seen far from away the miner. Each miner carries a mobile node, the temperature and gas concentration is displayed on the LCD screen at real-time.The gateway node is placed at the entrance of the mine, through the RS232 cable connected to the monitoring computer in the control room. In this system all packets collected by the gateway node are transmitted to PC through a serial port, and it can save historical data backup to a SQL database. The main function of monitoring software is to display and store the data of every node, and calculates related mobile nodes’ location according to RSSI values. The monitoring software has two main dialog interfaces, one is used to display a two- dimensional profile of the coal mine, and user can see all the miners' working position. Another interface is data displaying interface, and environmental data were shown here. The picture of PC monitoring software is shown in Fig. 2.Figure 2. PC monitoring software.VI.SYSTEM EV ALUATIONThrough repeated testing of the system, we made the system an objective assessment. First is the power consumption assess for node hardware, fixed node’s working voltage is in 9V ~ 24V when the power supplied by cable. The maximum operating current for fixed node is 93mA; the average operating current is 92.2mA. When the power cable was disconnected, fixed node powered by lithium-ion battery. On battery power, the fixed node’s maximum working current is 147mA; average working current is 146.3mA. Fixed nodes can work 8 hours on battery power at least.Another quite important performance is the location function of the system performance. At four different locations of tunnel and working areas, mobile nodes were placed there. Two sets of different average error data were shown in From table 1. Because this system uses RSSI technology and it relies mainly on the signal strength, the signal quality will be affected by interferences. From different locations’ errors we can see that, the error in working areas was larger than it in tunnels, because the tunnel is generally straight, but the shape of the working areas are uncertainty.We gratefully acknowledge Texas Instruments for devices provided to us free of charge. And also thank staffs of XinNuoJin Company for giving us supports onsystem testing.REFERENCES[1] Xinyue Zhong Wancheng Xie. “Wireless sensor network in the coal mineenvironment monitoring“. Coal technology, 2009, Vol. 28, No. 9,pp.102-103. [2] Shouwei Gao. “ZigBee Technology Practice Guide”. Beijing: Beijing Universityof Aeronautics and Astronautics Press , 2009, pp. 27-28.[3] Yang Wang, Liusheng Huang, Wei Yang. “A Novel Real-Time CoalMinerLocalization and Tracking System Based on Self-Organized Sensor Networks”.EURASIP Journal onWireless Communications and Networking, Volume 2010, Article ID 142092.[4] Sang-il Ko, Jong-suk Choi, Byoung-hoon Kim. “Indoor Mobile LocalizationSystem and Stabilization of Localizaion Performance using Pre-filtering”.International Journal of Control, Automation and Systems, Vol. 6, No. 2, pp.204-213, April 2008.[5] .[6] Hawkins Warren, Daku Brian L. F, Prugger Arnfinn F. “Positioning inunderg round mines”. IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006, pp. 3159-3163.[7] Zhu, Shouhong, Ding, Zhiguo, Markarian Karina. “TOA based jointsynchronization and localization”. 2010 IEEE International Conference on Communications, ICC 2010, 2010, Article ID 5502036.[8] Ni Hao, Ren Guangliang, Chang Yilin. “A TDOA location scheme in OFDMbased WMANs”. IEEE Transactions on Consumer Electronics,2008, Vol. 54, No. 3, pp. 1017-1021.[9] Dogançay Kutluyil, Hmam Hatem. “Optimal angular sensor separation for AOAlocalization”. Signal Processing, 2008, Vol. 88, No. 5, pp. 1248-1260.[10] K. Aamodt. “CC2431 Location Engine”. Texas Instruments, Application NoteAN042, SWRA095.[11] Tennina Stefano, Di Renzo Marco, Graziosi Fabio, Santucci Fortunato.“Locating zigbee nodes using the tis cc2431 location engine: A testbed platform and new solutions for positioning estimation of wsns in dynamic indoor environments”. Proc Annu Int Conf Mobile Comput Networking, 2008, pp.37-42.摘要-本文介绍并设计了一个新类型的煤矿安全监控系统,它是一种基于ZigBee 技术的无线传感器网络系统。
网络视频会议系统详细英文文献
CONTENTSAbstract 2Abstract 21 Introduction 32, the basic principles of video conferencing systems 43 Video Conferencing System Design and Implementation of 53.1 Introduction 5 Development Environment3.1.1 Java language and development tools Introduction 53.1.2 System Hardware Environment 63.2 The concrete realization of the system 63.2.1 JavaGroups concrete realization of 63.2.2 extension of JavaGroups 9 for video conferencing system3.3 Video Conference System-related technologies 133.3.1 Java Media Framework 133.3.2 CSCW 134 Concluding Remarks 145 Xie resigned 146 References 14AbstractAlways need traditional scheduled meeting time, location, uniform personnel and arranged a meeting venue, record, host, etc., meeting the problems to be solved, or programs to be developed, decision-making is often delayed because a number of objective factors. Video Conferencing (VideoConference) system is a can sounds, images, text and other information sent from one place to another communication system, which solves the above problems, eliminating the many meetings expenditure, reduced problem-solving cycle, so that greatly reduced the influence of objective factors. Video conferencing system as computer technology and communication technology product of the combination, with the whole world is the rise of the information highway has developed rapidly. This paper introduces the basic concepts of video conferencing systems, and associated Java Media Framework (JMF: Java Media Framework) and computer supported cooperative work (CSCW: Computer Supported Cooperative Work) system, Java language and development environment, and in accordance with video conferencing the basic structure and some related technologies, shows a small toolkit based JavaGroups video conferencing system design and implementation. Keywords: video conferencing system; JavaGroups kit; Java Media Framework; Computer supported cooperative workAbstractTraditionally, holding a conference needs some complex procedures for a long time, such as pre-arranging the schedule, place, people, preparingthe hall, recorder, master and so on. The goal of a meeting, resolving problemsor making plans and decisions, will be usually delayed by suchobjective factors. The video conference system is a communication system that transmits many kinds of signals such as video, audio, text and so on from one place to another. It is created to save money and time because of meetings and helps reducing the influence of objective factors. Thevideo conference system is the combination of computer technology and communication technology, and it is now developing very fast with the National Information Infrastructure of the whole world. This article introduces the basic concepts of the video conference, JMF (Java Media Framework) and the CSCW (Computer Supported Coorperative Work) system and Java language . According to the basic structure of video conference and some other technology, it describes the design and implementation of a mini-video conference system based-on JavaGroups toolkit.Key words: video conference system; JavaGroups toolkit; JMF; CSCW1 IntroductionMeeting of human society an integral part of economic life, the study shows that approximately 55% of the effectiveness of communication depends on the face (face-to-face) of the visual effects, 38% rely on talking voice, audio-visual people The most important form of access to information, and face to face discussions (face-to-face) is the most abundant human expression of ideas way. Since the industrial revolution, the technological advancement made a breakthrough progress in communication technology, telephone and telegraph invention of the distant sound of people and documents can be sent immediately. However, in addition to verbal communication, the human beings pay more attention to facial expressions and body expression, only voice transmission has been unable to meet the needs of modern communication, real-time video and interactive delivery of information more real and natural. (1) video conferencing system is in this generation, driven by an urgent need for a new generation of communications products.Video Conferencing (VideoConference) system is a can sounds, images, text and other information sent from one place to another communication system. Effective transmission of video-based information on a remote sector and intersectoral cooperation, and also can be achieved, such as video conferencing and video applications such as video on demand technology. Video conference system is the computer technology and communication technology product of the combination, multimedia communication technology as an important part of being affected with the rise of the global information superhighway and has developed rapidly.Video conferencing has been thirty years from the emergence, from the beginning to reduce travel costs, improve efficiency, to 911 domestic and international collaboration to accelerate the time to protect the personal safety, to safeguard social stability during SARS and the minimum work operation, the advantages of video conferencing is increasingly widely displayed. (2) In viewof the video conference system in the military, economic and cultural fields, the enormous role of the human and economic, national research and development of competing video conferencing systems, especially in very large scale integrated circuits, compression algorithms and visual physiology research breakthrough has been made and on a series of international standards for video conferencing were introduced, and a variety of image processing chips have the introduction of real-time video conferencing systems have come a long way before the practical development. The main application at home and abroad are:Business CommunicationBusiness ConferenceEnterprise customer service and product developmentDistance learning and technical trainingMarket research and intelligence gatheringTelemedicine and consultationCooperation in scientific research and engineering designMultinational applicationStaff recruitmentFrom the current perspective of the development, research on a lot of video conferencing technology, the products are very rich, although very attractive video conferencing system has broad prospects, but in this area there are considerable technical issues to be resolved, video conferencing systems at this stage of practicality, versatility and friendliness of the relevant technologies and related issues: software technology, database technology, network technology, sharing of technology, resource control, security technology and technology conference model. (3)The main research topics is the way of software, with the necessary peripherals to achieve a small video conferencing system.2, the basic principles of video conferencing systemsVideo Conferencing (VideoConference) system is the basic definition: two or more individuals or groups of different geographic location, through the transmission line and multimedia equipment, the sound, image, video, interactive video and file transfer data, to instant and interactive communication in order to complete the purpose of the conference system. Be read from above, video conferencing is a typical multimedia communications, the next diagram is a diagram of a typical video conferencing system:Figure 1.1 A typical schematic of a video conferencing system From the above diagram we can basically tell, the video conferencing system has three main components, namely, communication networks, conferencing terminals and multipoint control unit. Video conferencing systems andcomputer technology is essentially the product of combining communication technology, so the communication network is based video conferencing system component of the terminal session is video, audio, data, signaling, and so a variety of digital signals, respectively after combined into the composite digital stream, and then transforms to a code with the user - Network compatible interface, in line with the provisions of the transmission network of the frame structure of the channel to send the channel signal format for transmission. Multipoint control unit is multi-point video conferencing system, audio-visual information for transmission and switching part, which is based on certain criteria for audio-visual signal processing, and on request allocation of each channel to be connected, but it is not necessary for video conferencing.(1)Communication network is a series of devices, institutions and processes, through them, attached to the end user devices on the network can be a meaningful exchange of information. It relates to the network transport protocol, network programming interfaces and so on. (4)Video conferencing system has undertaken a variety of media terminal device information input, output and processing, and the connection between the user and network, interact and control a number of tasks. It belongs to the user digital communication equipment, in the system at the user's audio, data input / output devices and networks. (1)Sometimes the need for video conferencing between multiple points of information transmission and exchange, then you can control unit by means of multi-point (MCU) to achieve. Multipoint control unit is actually a multimedia information exchange, multi-point call and connection, to achieve video broadcasting, video selection, audio mixing, data broadcasting and other functions, the completion signal of the terminal tandem with the switch. MCU signals sent by the various terminals to separate, extract audio, video, data and signaling, respectively, corresponding to the processing unit, or switch audio mixing, video switching, data broadcasting, routing, session control, timing, and call processing, the processed signal from the multiplexer in accordance with the H.221 format, framing, and then sent to the designated port by the network interface. (5)3 Video Conferencing System Design and ImplementationIntroduction 3.1 Development Environment3.1.1 Java language and development tools IntroductionJava language is an emerging network of today's popular programming language, its object-oriented, cross-platform, distributed applications and so on to the programmer to bring a new computing concept, the WWW from the initial development of simply providing static information to the present provide a variety of dynamic services, has undergone tremendous changes. The emergence of Java has led a revolution in the field of programming, it is known as the 20th century, the most important emerging technologies. Java applets can not only write to achieve the sound embedded in Web pages andanimation capabilities, but also can be used independently of the medium and large applications, its powerful networking capabilities to the entire Internet as a unified operating platform, greatly expanded the traditional stand-alone or Client / Server mode application extension and intension. Since its inception in 1995, officially, Java has gradually advanced from a simple computer programming language developed into a major Internet platform, and thus caused, led the Java industry's development and growth, become the power of the computer industry and can not be ignored important development trends and direction. (6)General said, Java is an excellent, simple, object-oriented, distributed, interpreted, robust, secure, structured, neutral, portable, multithreaded and dynamic language .Java development tools into three categories, namely:text editor.λ These tools only provide text editing functions, it is only a tool similar to Notepad. Such tools, the development of a variety of programming languages, such as C, C + +, Java and so on. There are other editors UltraEdit and EditPlus.Webλ development tools. Such tools provide a Web page editing features, Java is mainly specific to the development of JSP pages. There are HomeSite and so on.integrated developmentλ tools. Such tools provide a Java development environment, inheritance, for those who need to integrate Java and J2EE developers, Web application development team provides program, Servlets, JSPs, EJBs, data access and enterprise applications with strong support. Now many tools of this type, but also the development trend of Java development tools. There are Jbuilder, WebGain, WebSphere Studio and so on.JBuilder is one of the best Java development tool, in the collaborative management of J2EE and XML support, etc. were walking in front of other products.JBuilder's main features are:λ provides Tomcat (Tomcat is a Servlet container for JSP environment. Servlet container is replaced by the user management and call Servlet runtime shell) integration, making it easier for Web developers.λ provides enterprise application development features, you can integrate multiple application servers.λ provide a more simple procedure publishing, all applications can be packaged.λ provides team development capabilities, to integrate a variety of version control products.JBuilder J2EE standard is to follow the Sun, a visual integrated development tools. It is a market-leading cross-platform environment, mainly for building industrial-strength enterprise Java with due process. Borland JBuilder company inherited the excellent characteristics of the development tools, which makes used Delphi, C + + Builder programmers easily transition to theJBuilder development environment. (7)The system used in Java development tools JBuilder9.3.1.2 System Hardware EnvironmentCPU: P4 1.70G Memory: 256MB HDD: 40GBOperating System: Microsoft Windows2000 Professional3.2 The concrete realization of the system3.2.1 JavaGroups concrete realization ofThe system is based JavaGroups to analyze and design. JavaGroups Cornell University is developing a Java-based toolkit, which provides a reliable group communication. Its function includes all members of the group to send messages, and to ensure that each member receives the same sequence of messages. Its basic concept is similar to the one socket BDS Channel: Users can give their wish to join the group name and then connect, send and receive messages and find all the current members to join, and when members join or leave can be notified. All channels can be of the same name each "discovered", and messages sent through a channel can be the same group (with the same name) receive all the channels. (8)JavaGroups folder contains 12 folders and 31 java files and put them together to generate a project file JBuilder9. The file is 12 packets and 31 Java Java files. These packages are: blocks, conf, debug, demos, ensemble, log, persistence, protocols, service, stack, tests, and util. This article discusses the four main types of package main functions:service package:Abstract class AbstractService: all servers implement a superset of the class, each server has two communication channels: one is the internal server to the legitimate group members and communication, and the other group was used for client-server communication.Class ServiceRunner: to start the server in standalone mode.class: ServiceRunnerpublic static method:(1) main (String args []) and Resourcename under args.length to determine whether the boot server.(2) startService (ResourceBundle res) extracted from the specialization of the resource parameters, create a server instance and start it.Private static method: printUsage () prints the role of this class.Public static field:(1) CLIENT_CHANNEL_STACK customer communications channel protocol stack.(2) CLIENT_GROUP_NAME customer communications channel group name.(3) SERVICE_CHANNEL_STACK server communication channel protocol stack.(4) SERVICE_GROUP_NAME server communication channel of the group name.Interface lease: describes a lease manager by enabling the label to allow for a limited time access to some resources.Interface: leasePublic method:(1) getExpiration () to obtain lease expiration time, the lease expiration time is always an absolute value.(2) getDuration () Check whether the lease expires.(3) getLeaseTarget () to obtain loan on behalf of the object and returns a unique identifier loan source.(4) getTenant () for the lessee of the lease and return the entity to obtain a unique lease identifier.(5) getFactory () for creating an instance of the leased LeaseFactory Interface LeaseFactory: responsible for approving the new lease, update and delete does not require the existing lease rental.Class LeaseFactoryClient: an implementation of the interface LeaseFactory, it represents one or more instances of the group LeaseFactotyService the loan is approved.Class LeaseFactoryService: is the ability to lease resources for users of the server. Lease request by the user - server communication channel given by the message headers in the presence of LeaseRequestHeader identify. In each message may have only one loan request, which contains the lease period and the entity requesting the information rent, the information payload payload includes a unique identifier for loan resources.Class LeaseRequestHeader: Header subclass represents the loan request. Class LeaseResponseHeader: Header subclass represents the response from the server, the existence of this header in the message that a previous request was successful. header type determines what type of request to meet.stack package:Class AckMcastReceiverWindow: to create and maintain an information stack, accept different information sent by the sender. Answer each message received, check whether it has been rejected, if it is, then discard the message, or reject it. Information includes the need to delete old information, serial number, they are removed from the information table.Class AckMcastSenderWindow: for each piece of information to maintain a stack, saving the recipient sent ack.Class AckSenderWindow: a sender ack-based sliding window, when receiving a ack, the message will be filled according to the order of sequence number added to the window, also delete response message.Class Configurator: to set up and configure the protocol stack, not the one used to describe the hierarchical level and configuration to create and configure a string passed to the configuration of the stack, and then return to the top of a parameter.Class GossipServer: for each member of the address lease to maintain abuffer, it has two basic functions: access to the members of a given group and for a given set up a new member.Class GossipClient: is a local stub, a private-based TCP protocol to connect to GossipServer.Class GossipData: Package GossipServer and data sent between GossipClient.Class Interval: 管理resend interval.Class IpAddress: depends on the network address, the UDP protocol stack generated the lowest level, contains a network address and port.Abstract class Protocol: the protocol layer provides a set of public servers. Each layer must be a subclass of protocol and override some methods (such as the typical up, down and getname). The order of each layer to be stacked together to form a stack.Class MessageProtocol: Protocol of the sub-class, which is based on the agreement, but the merged RequestCorrelator and GroupRequest, which is used to send messages to all members and accept their response.Class ProtocolStack: Protocol subclass, ProtocolStack manage many agreements, it creates all the protocol classes, initialize them, and when ready, to the lowest level of agreement started them. It also received the from the stack of information for distribution to the registered objects, such as channel, GMP, and the information sent to these objects to send down the stack down. ProtocolStack use Configurator to create and initialize the stack, and when they are destroyed when no longer needed the stack.Class NakReceiverWindow: the serial number according to the information maintained stack. Information is not allowed in order to add,And the serial number of lines can be a gap.Interface ProtocolObserver: setting for the debugger interface to receive notification about a protocol layer. Defines a hook, a major event occurs when they are called by the protocol, for example, an event is received. Each ProtocolObserver must have a reference for its monitoring of the agreement. Class Retransmitter: maintenance of a need to re-send the message sequence number pool, the information is marked with time, resend the request based on time priority.Class StateTransferInfo: contains the state transition parameters between the channel and STATE_TRANSFER conversion.tests Package: usedλ to test each module.λ util package: Java.util package includes the Java language, the use of some low-level tool, the util package in its basis a number of improvements to make it more suitable for the actual system. If one class LinkedListQueue, is built on top of the java.util.Queue, if you want to use this class instead of the original class, it can rename Queue.java and compile,1 前言会议,是人类社会经济生活中不可或缺的一部分,有关的研究表明,通信的有效性约55%依赖于面对面(face-to-face)的视觉效果,38%依赖于说话语音,视听是人们获取信息的最重要形式,而面对面的讨论(face-to-face)是人类表达思想最丰富的一种方式。
测控专业 毕业论文 外文翻译 中英文对照
Oscillation, Instability and Control of Stepper Motors LIYU CAO and HOWARD M. SCHWARTZDepartment of Systems and Computer Engineering, Carleton University, 1125 Colonel By Drive,Ottawa, ON K1S 5B6, Canada(Received: 18 February 1998; accepted: 1 December 1998)AbstractA novel approach to analyzing instability in permanent-magnet stepper motors is presented. It is shown that there are two kinds of unstable phenomena in this kind of motor: mid-frequency oscillation and high-frequency instability. Nonlinear bifurcation theory is used to illustrate the relationship between local instability and mid frequency oscillatory motion. A novel analysis is presented to analyze the loss of synchronism phenomenon, which is identified as high-frequency instability. The concepts of separators and attractors in phase-space are used to derive a quantity to evaluate the high-frequency instability. By using this quantity one can easily estimate the stability for high supply frequencies. Furthermore, a stabilization method is presented. A generalized approach to analyze the stabilization problem based on feedback theory is given. It is shown that the mid-frequency stability and the high-frequency stability can be improved by state feedback.Keywords: Stepper motors, instability, nonlinearity, state feedback.1. IntroductionStepper motors are electromagnetic incremental-motion devices which convert digital pulse inputs to analog angle outputs. Their inherent stepping ability allows for accurate position control without feedback. That is, they can track any step position in open-loop mode, consequently no feedback is needed to implement position control. Stepper motors deliver higher peak torque per unit weight than DC motors; in addition, they are brushless machines and therefore require less maintenance. All of these properties have made stepper motors a very attractive selection in many position and speed control systems, such as in computer hard disk drivers and printers, XY-tables, robot manipulators, etc.Although stepper motors have many salient properties, they suffer from an oscillation or unstable phenomenon. This phenomenon severely restricts their open-loop dynamic performance and applicable area where high speed operation is needed. The oscillation usually occurs at stepping rates lower than 1000 pulse/s, and has been recognized as a mid-frequency instability or local instability , or a dynamic instability . In addition, there is another kind of unstable phenomenon in stepper motors, that is, the motors usually lose synchronism at higher stepping rates, even though load torque is less than their pull-out torque. This phenomenon is identified as high-frequency instability in this paper, because it appears at much higher frequencies than the frequencies at which the mid-frequency oscillation occurs. The high-frequency instability has not been recognized as widely as mid-frequency instability, and there is not yet a method to evaluate it.Mid-frequency oscillation has been recognized widely for a very long time, however, acomplete understanding of it has not been well established. This can be attributed to the nonlinearity that dominates the oscillation phenomenon and is quite difficult to deal with.Most researchers have analyzed it based on a linearized model . Although in many cases, this kind of treatments is valid or useful, a treatment based on nonlinear theory is needed in order to give a better description on this complex phenomenon. For example, based on a linearized model one can only see that the motors turn to be locally unstable at some supply frequencies, which does not give much insight into the observed oscillatory phenomenon. In fact, the oscillation cannot be assessed unless one uses nonlinear theory.Therefore, it is significant to use developed mathematical theory on nonlinear dynamics to handle the oscillation or instability. It is worth noting that Taft and Gauthier , and Taft and Harned used mathematical concepts such as limit cycles and separatrices in the analysis of oscillatory and unstable phenomena, and obtained some very instructive insights into the so-called loss of synchronous phenomenon. Nevertheless, there is still a lack of a comprehensive mathematical analysis in this kind of studies. In this paper a novel mathematical analysis is developed to analyze the oscillations and instability in stepper motors.The first part of this paper discusses the stability analysis of stepper motors. It is shown that the mid-frequency oscillation can be characterized as a bifurcation phenomenon (Hopf bifurcation) of nonlinear systems. One of contributions of this paper is to relate the mid-frequency oscillation to Hopf bifurcation, thereby, the existence of the oscillation is proved theoretically by Hopf theory. High-frequency instability is also discussed in detail, and a novel quantity is introduced to evaluate high-frequency stability. This quantity is very easy to calculate, and can be used as a criteria to predict the onset of the high-frequency instability. Experimental results on a real motor show the efficiency of this analytical tool.The second part of this paper discusses stabilizing control of stepper motors through feedback. Several authors have shown that by modulating the supply frequency , the mid-frequency instability can be improved. In particular, Pickup and Russell have presented a detailed analysis on the frequency modulation method. In their analysis, Jacobi series was used to solve a ordinary differential equation, and a set of nonlinear algebraic equations had to be solved numerically. In addition, their analysis is undertaken for a two-phase motor, and therefore, their conclusions cannot applied directly to our situation, where a three-phase motor will be considered. Here, we give a more elegant analysis for stabilizing stepper motors, where no complex mathematical manipulation is needed. In this analysis, a d–q model of stepper motors is used. Because two-phase motors and three-phase motors have the same q–d model and therefore, the analysis is valid for both two-phase and three-phase motors. Up to date, it is only recognized that the modulation method is needed to suppress the mid-frequency oscillation. In this paper, it is shown that this method is not only valid to improve mid-frequency stability, but also effective to improve high-frequency stability.2. Dynamic Model of Stepper MotorsThe stepper motor considered in this paper consists of a salient stator with two-phase or three-phase windings, and a permanent-magnet rotor. A simplified schematic of athree-phase motor with one pole-pair is shown in Figure 1. The stepper motor is usually fed by a voltage-source inverter, which is controlled by a sequence of pulses and produces square-wave voltages. This motor operates essentially on the same principle as that of synchronous motors. One of major operating manner for stepper motors is that supplying voltage is kept constant and frequency of pulses is changed at a very wide range. Under this operating condition, oscillation and instability problems usually arise.Figure 1. Schematic model of a three-phase stepper motor.A mathematical model for a three-phase stepper motor is established using q–d frame-reference transformation. The voltage equations for three-phase windings are given byva = Ria + L*dia /dt − M*dib/dt − M*dic/dt + dλpma/dt ,vb = Rib + L*dib/dt − M*dia/dt − M*dic/dt + dλpmb/dt ,vc = Ric + L*dic/dt − M*dia/dt − M*dib/dt + dλpmc/dt ,where R and L are the resistance and inductance of the phase windings, and M is the mutual inductance between the phase windings. _pma, _pmb and _pmc are the flux-linkages of the phases due to the permanent magnet, and can be assumed to be sinusoid functions of rotor position _ as followλpma = λ1 sin(Nθ),λpmb = λ1 sin(Nθ − 2 /3),λpmc = λ1 sin(Nθ - 2 /3),where N is number of rotor teeth. The nonlinearity emphasized in this paper is represented by the above equations, that is, the flux-linkages are nonlinear functions of the rotor position.By using the q; d transformation, the frame of reference is changed from the fixed phase axes to the axes moving with the rotor (refer to Figure 2). Transformation matrix from the a; b; c frame to the q; d frame is given byFor example, voltages in the q; d reference are given byIn the a; b; c reference, only two variables are independent (ia C ib C ic D 0); therefore, the above transformation from three variables to two variables is allowable. Applying the above transformation to the voltage equations (1), the transferred voltage equation in the q;d frame can be obtained asvq = Riq + L1*diq/dt + NL1idω + Nλ1ω,vd=Rid + L1*did/dt − NL1iqω,Figure 2. a, b, c and d, q reference frame.where L1 D L CM, and ! is the speed of the rotor.It can be shown that the motor’s t orque has the following formT = 3/2Nλ1iqThe equation of motion of the rotor is written asJ*dω/dt = 3/2*Nλ1iq − Bfω – Tl ,where Bf is the coefficient of viscous friction, and Tl represents load torque, which is assumed to be a constant in this paper.In order to constitute the complete state equation of the motor, we need another state variable that represents the position of the rotor. For this purpose the so called load angle _ [8] is usually used, which satisfies the following equationDδ/dt = ω−ω0 ,where !0 is steady-state speed of the motor. Equations (5), (7), and (8) constitute the statespace model of the motor, for which the input variables are the voltages vq and vd. As mentioned before, stepper motors are fed by an inverter, whose output voltages are not sinusoidal but instead are square waves. However, because the non-sinusoidal voltages do not change the oscillation feature and instability very much if compared to the sinusoidal case (as will be shown in Section 3, the oscillation is due to the nonlinearity of the motor), for the purposes of this paper we can assume the supply voltages are sinusoidal. Under this assumption, we can get vq and vd as followsvq = Vmcos(Nδ) ,vd = Vmsin(Nδ) ,where Vm is the maximum of the sine wave. With the above equation, we have changed the input voltages from a function of time to a function of state, and in this way we can represent the dynamics of the motor by a autonomous system, as shown below. This will simplify the mathematical analysis.From Equations (5), (7), and (8), the state-space model of the motor can be written in a matrix form as followsẊ = F(X,u) = AX + Fn(X) + Bu , (10) where X D Tiq id ! _UT , u D T!1 TlUT is defined as the input, and !1 D N!0 is the supply frequency. The input matrix B is defined byThe matrix A is the linear part of F._/, and is given byFn.X/ represents the nonlinear part of F._/, and is given byThe input term u is independent of time, and therefore Equation (10) is autonomous.There are three parameters in F.X;u/, they are the supply frequency !1, the supply voltage magnitude Vm and the load torque Tl . These parameters govern the behaviour of the stepper motor. In practice, stepper motors are usually driven in such a way that the supply frequency !1 is changed by the command pulse to control the motor’s spee d, while the supply voltage is kept constant. Therefore, we shall investigate the effect of parameter !1.3. Bifurcation and Mid-Frequency OscillationBy setting ! D !0, the equilibria of Equation (10) are given asand ' is its phase angle defined byφ= arctan(ω1L1/R) . (16) Equations (12) and (13) indicate that multiple equilibria exist, which means that these equilibria can never be globally stable. One can see that there are two groups of equilibria as shown in Equations (12) and (13). The first group represented by Equation (12) corresponds to the real operating conditions of the motor. The second group represented by Equation (13) is always unstable and does not relate to the real operating conditions. In the following, we will concentrate on the equilibria represented by Equation (12).翻译译文步进电机的振荡、不稳定以及控制摘要本文介绍了一种分析永磁步进电机不稳定性的新颖方法。
智能控制系统毕业论文中英文资料对照外文翻译文献
智能控制系统中英文资料对照外文翻译文献附录一:外文摘要The development and application of Intelligence controlsystemModern electronic products change rapidly is increasingly profound impact on people's lives, to people's life and working way to bring more convenience to our daily lives, all aspects of electronic products in the shadow, single chip as one of the most important applications, in many ways it has the inestimable role. Intelligent control is a single chip, intelligent control of applications and prospects are very broad, the use of modern technology tools to develop an intelligent, relatively complete functional software to achieve intelligent control system has become an imminent task. Especially in today with MCU based intelligent control technology in the era, to establish their own practical control system has a far-reaching significance so well on the subject later more fully understanding of SCM are of great help to.The so-called intelligent monitoring technology is that:" the automatic analysis and processing of the information of the monitored device". If the monitored object as one's field of vision, and intelligent monitoring equipment can be regarded as the human brain. Intelligent monitoring with the aid of computer data processing capacity of the powerful, to get information in the mass data to carry on the analysis, some filtering of irrelevant information, only provide some key information. Intelligent control to digital, intelligent basis, timely detection system in the abnormal condition, and can be the fastest and best way to sound the alarm and provide usefulinformation, which can more effectively assist the security personnel to deal with the crisis, and minimize the damage and loss, it has great practical significance, some risk homework, or artificial unable to complete the operation, can be used to realize intelligent device, which solves a lot of artificial can not solve the problem, I think, with the development of the society, intelligent load in all aspects of social life play an important reuse.Single chip microcomputer as the core of control and monitoring systems, the system structure, design thought, design method and the traditional control system has essential distinction. In the traditional control or monitoring system, control or monitoring parameters of circuit, through the mechanical device directly to the monitored parameters to regulate and control, in the single-chip microcomputer as the core of the control system, the control parameters and controlled parameters are not directly change, but the control parameter is transformed into a digital signal input to the microcontroller, the microcontroller according to its output signal to control the controlled object, as intelligent load monitoring test, is the use of single-chip I / O port output signal of relay control, then the load to control or monitor, thus similar to any one single chip control system structure, often simplified to input part, an output part and an electronic control unit ( ECU )Intelligent monitoring system design principle function as follows: the power supply module is 0~220V AC voltage into a0 ~ 5V DC low voltage, as each module to provide normal working voltage, another set of ADC module work limit voltage of 5V, if the input voltage is greater than 5V, it can not work normally ( but the design is provided for the load voltage in the 0~ 5V, so it will not be considered ), at the same time transformer on load current is sampled on the accused, the load current into a voltage signal, and then through the current - voltage conversion, and passes through the bridge rectification into stable voltage value, will realize the load the current value is converted to a single chip can handle0 ~ 5V voltage value, then the D2diode cutoff, power supply module only plays the role of power supply. Signal to the analog-to-digital conversion module, through quantization, coding, the analog voltage value into8bits of the digital voltage value, repeatedly to the analog voltage16AD conversion, and the16the digital voltage value and, to calculate the average value, the average value through a data bus to send AT89C51P0, accepted AT89C51 read, AT89C51will read the digital signal and software setting load normal working voltage reference range [VMIN, VMAX] compared with the reference voltage range, if not consistent, then the P1.0 output low level, close the relay, cut off the load on the fault source, to stop its sampling, while P1.1 output high level fault light, i.e., P1.3 output low level, namely normal lights. The relay is disconnected after about 2minutes, theAT89C51P1.0outputs high level ( software design), automatic closing relay, then to load the current regular sampling, AD conversion, to accept the AT89C51read, comparison, if consistent, then the P1.1 output low level, namely fault lights out, while P1.3 output high level, i.e. normal lamp ( software set ); if you are still inconsistent, then the need to manually switch S1toss to" repair" the slip, disconnect the relay control, load adjusting the resistance value is: the load detection and repair, and then close the S1repeatedly to the load current sampling, until the normal lamp bright, repeated this process, constantly on the load testing to ensure the load problems timely repair, make it work.In the intelligent load monitoring system, using the monolithic integrated circuit to the load ( voltage too high or too small ) intelligent detection and control, is achieved by controlling the relay and transformer sampling to achieve, in fact direct control of single-chip is the working state of the relay and the alarm circuit working state, the system should achieve technical features of this thesis are as follows (1) according to the load current changes to control relays, the control parameter is the load current, is the control parameter is the relay switch on-off and led the state; (2) the set current reference voltage range ( load normal working voltage range ), by AT89C51 chip the design of the software section, provide a basis for comparison; (3) the use of single-chip microcomputer to control the light-emitting diode to display the current state of change ( normal / fault / repair ); specific summary: Transformer on load current is sampled, a current / voltage converter, filter, regulator, through the analog-digital conversion, to accept the AT89C51chip to read, AT89C51 to read data is compared with the reference voltage, if normal, the normal light, the output port P.0high level, the relay is closed, is provided to the load voltage fault light; otherwise, P1.0 output low level, The disconnecting relay to disconnect the load, the voltage on the sampling, stop. Two minutes after closing relay, timing sampling.System through the expansion of improved, can be used for temperature alarm circuit, alarm circuit, traffic monitoring, can also be used to monitor a system works, in the intelligent high-speed development today, the use of modern technology tools, the development of an intelligent, function relatively complete software to realize intelligent control system, has become an imminent task, establish their own practical control system has a far-reaching significance. Micro controller in the industry design and application, no industry like intelligent automation and control field develop so fast. Since China and the Asian region the main manufacturing plant intelligence to improve the degree of automation, new technology to improve efficiency, have important influence on the product cost. Although the centralized control can be improved in any particular manufacturing process of the overall visual, but not for those response and processingdelay caused by fault of some key application.Intelligent control technology as computer technology is an important technology, widely used in industrial control, intelligent control, instrument, household appliances, electronic toys and other fields, it has small, multiple functions, low price, convenient use, the advantages of a flexible system design. Therefore, more and more engineering staff of all ages, so this graduate design is of great significance to the design of various things, I have great interest in design, this has brought me a lot of things, let me from unsuspectingly to have a clear train of thought, since both design something, I will be there a how to design thinking, this is very important, I think this job will give me a lot of valuable things.中文翻译:智能控制系统的开发应用现代社会电子产品日新月异正在越来越深远的影响着人们的生活,给人们的生活和工作方式带来越来越大的方便,我们的日常生活各个方面都有电子产品的影子,单片机作为其中一个最重要的应用,在很多方面都有着不可估量的作用。
视频监控系统外文文献翻译、中英文翻译
附录一外文译文视频监控系统是安全防范系统的重要组成部分,是一种防范能力较强的综合系统。
视频监控以其直观、方便、信息内容丰富而广泛应用于许多场合。
近年来,随着现代科学技术的不断发展特别是网络带宽、计算机处理能力和存储容量的迅速提高一级各种实用视频信息处理技术的出现,视频监控技术也有长足的发展,视频监控进入了全数字化的网络时代,日益受到人们的重视和关注。
视频监控系统的发展基本上是从早期的模拟闭路电视监控系统向数模结合的视频监控系统和现在的数字视频监控系统演变的过程,而现在的数字视频监控系统根据技术的发展又分为三个阶段:数字监控的多媒体阶段、数字监控的DVR阶段和数字监控的网络阶段。
1.模拟视频监控系统:模拟视频监控系统分为基于微处理器的视频切换控制加PC 机的多媒体管理和基于PC机实现对矩阵主机的切换控制及对系统的多媒体管理两种类型。
模拟闭路电视监控系统实际上就是许多模拟监控设备的组合,系统主要由“前端设备”和“终端控制设备”以及“信号传输介质”三个部分组成,其中:前端设备主要由摄像机、云台、解码器等,控制设备主要由切换矩阵、画面分割器、监视器、控制键盘、录像机等、传输介质包括电缆、控制线等。
随着微处理器、微机的功能、性能、可靠性、结构方式等方面都发生了很大的变化,视频监控系统的构成更加方便灵活、与其它技术系统的接口趋于规范,人机交互界面更为友好。
但由于视频监控系统中信息流的形态没有变,仍为模拟的视频信号,系统的网络结构主要是一种单功能、单向、集总方式的信息采集网络,因此系统尽管已发展到很高的水平,已无太多潜力可挖,其局限性依然存在,要满足更高的要求,数字化是必经之路。
模拟监控系统的主要缺点有:通常只适合于小范围的区域监控,模拟视频信号的传输工具主要是同轴电缆,而同轴电缆传输模拟信号的距离不大于1Km,双绞线的距离更短,这就决定了模拟监控只适合于单个大楼、小的居民区以及其他小范围的场所。
系统的扩展能力差。
外文文献和翻译
本科生毕业设计(论文)外文文献翻译译文题目:基于MCGS的交通灯控制系统的设计学生姓名:刘家兴学号: 201207013120院系:机械与控制工程学院专业年级: 2012级自动化专业指导教师:张晓玲2016年 4 月20 日Design of traffic light control system based on MCGS Abstract:One kind of traffic light control system using programmable logic controller (PLC), via software control traffic lights run automatically. In the system,the original line is the program instead of the relay, programmable logic controller (PLC) system hardware and software resources to be fair use. Normal operation and emergency transport for a detailed description and from the East and West emergencies can be mutually linked. Traffic signal systems and two seven-segment digital display in the countdown order;also discussed in detail the wiring of the hardware and PLC ladder. Traffic lights at the crossroads of the remote monitoring system design configuration software MCGS,real-time monitoring of traffic lights, greatly improving the reliability of data transmission. At the same time,we can configure the traffic lights to change the status of photographs。
毕业设计的论文中英翻译
Anti-Aircraft Fire Control and the Development of IntegratedSystems at SperryT he dawn of the electrical age brought new types of control systems. Able to transmit data between distributed components and effect action at a distance, these systems employed feedback devices as well as human beings to close control loops at every level. By the time theories of feedback and stability began to become practical for engineers in the 1930s a tradition of remote and automatic control engineering had developed that built distributed control systems with centralized information processors. These two strands of technology, control theory and control systems, came together to produce the large-scale integrated systems typical of World War II and after.Elmer Ambrose Sperry (I860-1930) and the company he founded, the Sperry Gyroscope Company, led the engineering of control systems between 1910 and 1940. Sperry and his engineers built distributed data transmission systems that laid the foundations of today‟s command and control systems. Sperry‟s fire control systems included more than governors or stabilizers; they consisted of distributed sensors, data transmitters, central processors, and outputs that drove machinery. This article tells the story of Sperry‟s involvement in anti-aircraft fire control between the world wars and shows how an industrial firm conceived of control systems before the common use of control theory. In the 1930s the task of fire control became progressively more automated, as Sperry engineers gradually replaced human operators with automatic devices. Feedback, human interface, and system integration posed challenging problems for fire control engineers during this period. By the end of the decade these problems would become critical as the country struggled to build up its technology to meet the demands of an impending war.Anti-Aircraft Artillery Fire ControlBefore World War I, developments in ship design, guns, and armor drove the need for improved fire control on Navy ships. By 1920, similar forces were at work in the air: wartime experiences and postwar developments in aerial bombing created the need for sophisticated fire control for anti-aircraft artillery. Shooting an airplane out of the sky is essentially a problem of “leading” the target. As aircraft developed rapidly in the twenties, their increased speed and altitude rapidly pushed the task of computing the lead out of the range of human reaction and calculation. Fire control equipment for anti-aircraft guns was a means of technologically aiding human operators to accomplish a task beyond their natural capabilities.During the first world war, anti-aircraft fire control had undergone some preliminary development. Elmer Sperry, as chairman of the Aviation Committee of the Naval Consulting Board, developed two instruments for this problem: a goniometer,a range-finder, and a pretelemeter, a fire director or calculator. Neither, however, was widely used in the field.When the war ended in I918 the Army undertook virtually no new development in anti-aircraft fire control for five to seven years. In the mid-1920s however, the Army began to develop individual components for anti-aircraft equipment including stereoscopic height-finders, searchlights, and sound location equipment. The Sperry Company was involved in the latter two efforts. About this time Maj. Thomas Wilson, at the Frankford Arsenal in Philadelphia, began developing a central computer for firecontrol data, loosely based on the system of “director firing” that had developed in naval gunn ery. Wilson‟s device resembled earlier fire control calculators, accepting data as input from sensing components, performing calculations to predict the future location of the target, and producing direction information to the guns.Integration and Data TransmissionStill, the components of an anti-aircraft battery remained independent, tied together only by telephone. As Preston R. Bassett, chief engineer and later president of the Sperry Company, recalled, “no sooner, however, did the components get to the point of functioning satisfactorily within themselves, than the problem of properly transmitting the information from one to the other came to be of prime importance.”Tactical and terrain considerations often required that different fire control elements be separated by up to several hundred feet. Observers telephoned their data to an officer, who manually entered it into the central computer, read off the results, and telephoned them to the gun installations. This communication system introduced both a time delay and the opportunity for error. The components needed tighter integration, and such a system required automatic data communications.In the 1920s the Sperry Gyroscope Company led the field in data communications. Its experience came from Elmer Spe rry‟s most successful invention, a true-north seeking gyro for ships. A significant feature of the Sperry Gyrocompass was its ability to transmit heading data from a single central gyro to repeaters located at a number of locations around the ship. The repeaters, essentially follow-up servos, connected to another follow-up, which tracked the motion of the gyro without interference. These data transmitters had attracted the interest of the Navy, which needed a stable heading reference and a system of data communication for its own fire control problems. In 1916, Sperry built a fire control system for the Navy which, although it placed minimal emphasis on automatic computing, was a sophisticated distributed data system. By 1920 Sperry had installed these systems on a number of US. battleships.Because of the Sperry Company‟s experience with fire control in the Navy, as well as Elmer Sperry‟s earlier work with the goniometer and the pretelemeter, the Army approached the company for help with data transmission for anti-aircraft fire control. To Elmer Sperry, it looked like an easy problem: the calculations resembled those in a naval application, but the physical platform, unlike a ship at sea, anchored to the ground. Sperry engineers visited Wilson at the Frankford Arsenal in 1925, and Elmer Sperry followed up with a letter expressing his interest in working on the problem. He stressed his company‟s experience with naval problems, as well as its recent developments in bombsights, “work from the other end of the pro position.” Bombsights had to incorporate numerous parameters of wind, groundspeed, airspeed, and ballistics, so an anti-aircraft gun director was in some ways a reciprocal bombsight . In fact, part of the reason anti-aircraft fire control equipment worked at all was that it assumed attacking bombers had to fly straight and level to line up their bombsights. Elmer Sperry‟s interests were warmly received, and in I925 and 1926 the Sperry Company built two data transmission systems for the Army‟s gun directors.The original director built at Frankford was designated T-1, or the “Wilson Director.” The Army had purchased a Vickers director manufactured in England, but encouraged Wilson to design one thatcould be manufactured in this country Sperry‟s two data tran smission projects were to add automatic communications between the elements of both the Wilson and the Vickers systems (Vickers would eventually incorporate the Sperry system into its product). Wilson died in 1927, and the Sperry Company took over the entire director development from the Frankford Arsenal with a contract to build and deliver a director incorporating the best features of both the Wilson and Vickers systems. From 1927 to 193.5, Sperry undertook a small but intensive development program in anti-aircraft systems. The company financed its engineering internally, selling directors in small quantities to the Army, mostly for evaluation, for only the actual cost of production [S]. Of the nearly 10 models Sperry developed during this period, it never sold more than 12 of any model; the average order was five. The Sperry Company offset some development costs by sales to foreign govemments, especially Russia, with the Army‟s approval 191.The T-6 DirectorSperry‟s modified version of Wilson‟s director was designated T-4 in development. This model incorporated corrections for air density, super-elevation, and wind. Assembled and tested at Frankford in the fall of 1928, it had problems with backlash and reliability in its predicting mechanisms. Still, the Army found the T-4 promising and after testing returned it to Sperry for modification. The company changed the design for simpler manufacture, eliminated two operators, and improved reliability. In 1930 Sperry returned with the T-6, which tested successfully. By the end of 1931, the Army had ordered 12 of the units. The T-6 was standardized by the Army as the M-2 director.Since the T-6 was the first anti-aircraft director to be put into production, as well as the first one the Army formally procured, it is instructive to examine its operation in detail. A technical memorandum dated 1930 explained the theory behind the T-6 calculations and how the equations were solved by the system. Although this publication lists no author, it probably was written by Earl W. Chafee, Sperry‟s director of fire control engineering. The director was a complex mechanical analog computer that connected four three-inch anti-aircraft guns and an altitude finder into an integratedsystem (see Fig. 1). Just as with Sperry‟s naval fire control system, the primary means of connection were “data transmitters,” similar to those that connected gyrocompasses to repeaters aboard ship.The director takes three primary inputs. Target altitude comes from a stereoscopic range finder. This device has two telescopes separated by a baseline of 12 feet; a single operator adjusts the angle between them to bring the two images into coincidence. Slant range, or the raw target distance, is then corrected to derive its altitude component. Two additional operators, each with a separate telescope, track the target, one for azimuth and one for elevation. Each sighting device has a data transmitter that measures angle or range and sends it to the computer. The computer receives these data and incorporates manual adjustments for wind velocity, wind direction, muzzle velocity, air density, and other factors. The computer calculates three variables: azimuth, elevation, and a setting for the fuze. The latter, manually set before loading, determines the time after firing at which the shell will explode. Shells are not intended to hit the target plane directly but rather to explode near it, scattering fragments to destroy it.The director performs two major calculations. First, pvediction models the motion of the target and extrapolates its position to some time in the future. Prediction corresponds to “leading” the target. Second, the ballistic calculation figures how to make the shell arrive at the desired point in space at the future time and explode, solving for the azimuth and elevation of the gun and the setting on the fuze. This calculation corresponds to the traditional artillery man‟s task of looking up data in a precalculated “firing table” and setting gun parameters accordingly. Ballistic calculation is simpler than prediction, so we will examine it first.The T-6 director solves the ballistic problem by directly mechanizing the traditional method, employing a “mechanical firing table.” Traditional firing tables printed on paper show solutions for a given angular height of the target, for a given horizontal range, and a number of other variables. The T-6 replaces the firing table with a Sperry ballistic cam.” A three-dimensionally machined cone shaped device, the ballistic cam or “pin follower” solves a pre-determined function. Two independent variables are input by the angular rotation of the cam and the longitudinal position of a pin that rests on top of the cam. As the pin moves up and down the length of the cam, and as the cam rotates, the height of the pin traces a function of two variables: the solution to the ballistics problem (or part of it). The T-6 director incorporates eight ballistic cams, each solving for a different component of the computation including superelevation, time of flight, wind correction, muzzle velocity. air density correction. Ballistic cams represented, in essence, the stored data of the mechanical computer. Later directors could be adapted to different guns simply by replacing the ballistic cams with a new set, machined according to different firing tables. The ballistic cams comprised a central component of Sperry‟s mechanical computing technology. The difficulty of their manufacture would prove a major limitation on the usefulness of Sperry directors.The T-6 director performed its other computational function, prediction, in an innovative way as well. Though the target came into the system in polar coordinates (azimuth, elevation, and range), targets usually flew a constant trajectory (it was assumed) in rectangular coordinates-i.e. straight andlevel. Thus, it was simpler to extrapolate to the future in rectangular coordinates than in the polar system. So the Sperry director projected the movement of the target onto a horizontal plane, derived the velocity from changes in position, added a fixed time multiplied by the velocity to determine a future position, and then converted the solution back into polar coordinates. This method became known as the “plan prediction method”because of the representation of the data on a flat “plan” as viewed from above; it was commonly used through World War II. In the plan prediction method, “the actual movement of the target is mechanically reproduced on a small scale within the Computer and the desired angles or speeds can be measured directly from the movements of these elements.”Together, the ballistic and prediction calculations form a feedback loop. Operators enter an estimated “time of flight” for the shell when they first begin tracking. The predictor uses this estimate to perform its initial calculation, which feeds into the ballistic stage. The output of the ballistics calculation then feeds back an updated time-of-flight estimate, which the predictor uses to refine the initial estimate. Thus “a cumulative cycle of correction brings the predicted future position of the target up to the point indicated by the actual future time of flight.”A square box about four feet on each side (see Fig. 2) the T-6 director was mounted on a pedestal on which it could rotate. Three crew would sit on seats and one or two would stand on a step mounted to the machine. The remainder of the crew stood on a fixed platform; they would have had to shuffle around as the unit rotated. This was probably not a problem, as the rotation angles were small. The direc tor‟s pedestal mounted on a trailer, on which data transmission cables and the range finder could be packed for transportation.We have seen that the T-6 computer took only three inputs, elevation, azimuth, and altitude (range), and yet it required nine operators. These nine did not include the operation of the range finder, which was considered a separate instrument, but only those operating the director itself. What did these nine men do?Human ServomechanismsTo the designers of the director, the operato rs functioned as “manual servomechanisms.”One specification for the machine required “minimum dependence on …human element.‟ The Sperry Company explained, “All operations must be made as mechanical and foolproof as possible; training requirements must visualize the conditions existent under rapid mobilization.” The lessons of World War I ring in this statement; even at the height of isolationism, with the country sliding into depression, design engineers understood the difficulty of raising large numbers of trained personnel in a national emergency. The designers not only thought the system should account for minimal training and high personnel turnover, they also considered the ability of operators to perform their duties under the stress of battle. Thus, nearly all the work for the crew was in a “follow-the-pointer”mode: each man concentrated on an instrument with two indicating dials, one the actual and one the desired value for a particular parameter. With a hand crank, he adjusted the parameter to match the two dials.Still, it seems curious that the T-6 director required so many men to perform this follow-the-pointer input. When the external rangefinder transmitted its data to the computer, it appeared on a dial and an operator had to follow the pointer to actually input the data into the computing mechanism. The machine did not explicitly calculate velocities. Rather, two operators (one for X and one for Y) adjusted variable-speed drives until their rate dials matched that of a constant-speed motor. When the prediction computation was complete, an operator had to feed the result into the ballistic calculation mechanism. Finally, when the entire calculation cycle was completed, another operator had to follow the pointer to transmit azimuth to the gun crew, who in turn had to match the train and elevation of the gun to the pointer indications.Human operators were the means of connecting “individual elements” into an integrated system. In one sense the men were impedance amplifiers, and hence quite similar to servomechanisms in other mechanical calculators of the time, especially Vannevar Bush‟s differential analyzer .The term “manual servomechanism”itself is an oxymoron: by the conventional definition, all servomechanisms are automatic. The very use of the term acknowledges the existence of an automatic technology that will eventually replace the manual method. With the T-6, this process was already underway. Though the director required nine operators, it had already eliminated two from the previous generation T-4. Servos replaced the operator who fed back superelevation data and the one who transmitted the fuze setting. Furthermore, in this early machine one man corresponded to one variable, and the machine‟s requirement for operators corresponded directly to the data flow of its computation. Thus the crew that operated the T-6 director was an exact reflection of the algorithm inside it.Why, then, were only two of the variables automated? This partial, almost hesitating automation indicates there was more to the human servo-motors than Sperry wanted to acknowledge. As much as the company touted “their duties are purely mechanical and little skill or judgment is required on the part of the operators,” men were still required to exercise some judgment, even if unconsciously. The data were noisy, and even an unskilled human eye could eliminate complications due to erroneous or corrupted data. The mechanisms themselves were rather delicate and erroneous input data, especially if it indicated conditions that were not physically possible, could lock up or damage the mechanisms. Theoperators performed as integrators in both senses of the term: they integrated different elements into a system.Later Sperry DirectorsWhen Elmer Sperry died in 1930, his engineers were at work on a newer generation director, the T-8. This machine was intended to be lighter and more portable than earlier models, as well as less expensive and “procurable in quantities in case of emergency.” The company still emphasized the need for unskilled men to operate the system in wartime, and their role as system integrators. The operators were “mechanical links in the apparatus, thereby making it possible to avoid mechanical complication which would be involved by the use of electrical or mechanical servo motors.” Still, army field experience with the T-6 had shown that servo-motors were a viable way to reduce the number of operators and improve reliability, so the requirements for the T-8 specified that wherever possible “electrical shall be used to reduce the number of operators to a minimum.” Thus the T-8 continued the process of automating fire control, and reduced the number of operators to four. Two men followed the target with telescopes, and only two were required for follow-the-pointer functions. The other follow-the-pointers had been replaced by follow-up servos fitted with magnetic brakes to eliminate hunting. Several experimental versions of the T-8 were built, and it was standardized by the Army as the M3 in 1934.Throughout the remain der of the …30s Sperry and the army fine-tuned the director system in the M3. Succeeding M3 models automated further, replacing the follow-the-pointers for target velocity with a velocity follow-up which employed a ball-and-disc integrator. The M4 series, standardized in 1939, was similar to the M3 but abandoned the constant altitude assumption and added an altitude predictor for gliding targets. The M7, standardized in 1941, was essentially similar to the M4 but added full power control to the guns for automatic pointing in elevation and azimuth. These later systems had eliminated errors. Automatic setters and loaders did not improve the situation because of reliability problems. At the start of World War II, the M7 was the primary anti-aircraft director available to the army.The M7 was a highly developed and integrated system, optimized for reliability and ease of operation and maintenance. As a mechanical computer, it was an elegant, if intricate, device, weighing 850 pounds and including about 11,000 parts. The design of the M7 capitalized on the strength of the Sperry Company: manufacturing of precision mechanisms, especially ballistic cams. By the time the U.S. entered the second world war, however, these capabilities were a scarce resource, especially for high volumes. Production of the M7 by Sperry and Ford Motor Company as subcontractor was a “real choke” and could not keep up with production of the 90mm guns, well into 1942. The army had also adopted an English system, known as the “Kerrison Director” or M5, which was less accurate than the M7 but easier to manufacture. Sperry redesigned the M5 for high-volume production in 1940, but passed in 1941.Conclusion: Human Beings as System IntegratorsThe Sperry directors we have examined here were transitional, experimental systems. Exactly for that reason, however, they allow us to peer inside the process of automation, to examine the displacement of human operators by servomechanisms while the process was still underway. Skilled asthe Sperry Company was at data transmission, it only gradually became comfortable with the automatic communication of data between subsystems. Sperry could brag about the low skill levels required of the operators of the machine, but in 1930 it was unwilling to remove them completely from the process. Men were the glue that held integrated systems together.As products, the Sperry Company‟s anti-aircraft gun directors were only partially successful. Still, we should judge a technological development program not only by the machines it produces but also by the knowledge it creates, and by how that knowledge contributes to future advances. Sperry‟s anti-aircraft directors of the 1930s were early examples of distributed control systems, technology that would assume critical importance in the following decades with the development of radar and digital computers. When building the more complex systems of later years, engineers at Bell Labs, MIT, and elsewhere would incorporate and build on the Sperry Company‟s experience,grappling with the engineering difficulties of feedback, control, and the augmentation of human capabilities by technological systems.在斯佩里防空炮火控和集成系统的发展电气时代的到来带来了新类型的控制系统。
视频监控系统外文文献翻译、中英文翻译
附录一外文译文视频监控系统是安全防范系统的重要组成部分,是一种防范能力较强的综合系统。
视频监控以其直观、方便、信息内容丰富而广泛应用于许多场合。
近年来,随着现代科学技术的不断发展特别是网络带宽、计算机处理能力和存储容量的迅速提高一级各种实用视频信息处理技术的出现,视频监控技术也有长足的发展,视频监控进入了全数字化的网络时代,日益受到人们的重视和关注。
视频监控系统的发展基本上是从早期的模拟闭路电视监控系统向数模结合的视频监控系统和现在的数字视频监控系统演变的过程,而现在的数字视频监控系统根据技术的发展又分为三个阶段:数字监控的多媒体阶段、数字监控的DVR阶段和数字监控的网络阶段。
1.模拟视频监控系统:模拟视频监控系统分为基于微处理器的视频切换控制加PC 机的多媒体管理和基于PC机实现对矩阵主机的切换控制及对系统的多媒体管理两种类型。
模拟闭路电视监控系统实际上就是许多模拟监控设备的组合,系统主要由“前端设备”和“终端控制设备”以及“信号传输介质”三个部分组成,其中:前端设备主要由摄像机、云台、解码器等,控制设备主要由切换矩阵、画面分割器、监视器、控制键盘、录像机等、传输介质包括电缆、控制线等。
随着微处理器、微机的功能、性能、可靠性、结构方式等方面都发生了很大的变化,视频监控系统的构成更加方便灵活、与其它技术系统的接口趋于规范,人机交互界面更为友好。
但由于视频监控系统中信息流的形态没有变,仍为模拟的视频信号,系统的网络结构主要是一种单功能、单向、集总方式的信息采集网络,因此系统尽管已发展到很高的水平,已无太多潜力可挖,其局限性依然存在,要满足更高的要求,数字化是必经之路。
模拟监控系统的主要缺点有:通常只适合于小范围的区域监控,模拟视频信号的传输工具主要是同轴电缆,而同轴电缆传输模拟信号的距离不大于1Km,双绞线的距离更短,这就决定了模拟监控只适合于单个大楼、小的居民区以及其他小范围的场所。
系统的扩展能力差。
赵亚威毕业设计(论文)外文翻译
宁波大红鹰学院毕业设计(论文)外文翻译所在学院:机电学院班级: 09机自6班姓名:赵亚威学号: 091280742指导教师:张育斌合作导师:2012年 11 月 15 日The realization of wireless sensor networks and applications inagriculture1 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 today's 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 communicationnetwork 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.①power 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 network's worklife.② 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.③communication 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 sa me 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 microcontrollerhardware 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 company's 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 China's 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.Today's 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.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。
外文翻译
在数字化变电站中视频系统联动控制与继电保护摘要远程视频监控系统的变电站(RVSS)可以在电力系统变电站中提供设备的实时图像,提高了变电站运行的可靠性和安全性。
RVSS已成为变电站建设的必要项目。
作为在数字化变电站中最重要的通信服务,GOOSE(通用的面向对象的变电站事件)是用于在主设备中的控制和其中次级装置的互锁和联动。
在本文中,一个方法被引入到实现RVSS 的联动控制与继电保护。
通过GOOSE报文的分析,得到变电站通信网络的保护动作的信息,然后视频系统被驱动。
信息安全和保护也被研究了。
联动控制的计划很快执行在中国江西省第一个数字化变电站。
关键词:电力系统;数字化变电站;视频监控系统;联动控制I 引言RVSS已逐渐成为电力系统变电站建设中必要的项目[1-4]。
实时视频在变电站中的所有设备的信息可以被RVSS收集并发送至远程控制中心。
它的可靠性和变电站运行的安全性可以通过RVSS得到改善。
它还可以记录事故和报警信息这将有助于进行事故分析。
变电站自动化系统的视频联动控制系统(SAS)是RVSS的重要用途之一。
为了实现联动控制,四遥功能(遥信、远程控制、远程测量和遥调)SAS必须由RAS S获得和分析。
事故发生时,如信号的变化或报警信息出现,该摄像机可以被驱动来记录与图像相应的主设备或辅助设备。
关键问题是如何取得四遥功能信息SAS和如何建立与SAS之间的关系信息和视频系统。
在过去,由于各个变电站系统的独立性,RVSS只能通过四遥功能监控主机信息。
这增加了复杂性,及原有的系统和更额外的工作负载,从而导致没有主动的SAS供应商合作。
在这种情况下,完整性和实时性由RVSS获得的SAS信息不能保证。
因此,联动控制的效果受限。
近日,电力系统数字化变电站的应用是越来越多。
大部分的自动化功能在数字化变电站中通过网络通信实现。
所以,新的便利已经出现在RVSS联动控制设计。
作为最重要的通信服务数字化变电站GOOSE用于在初级控制设备间和二次设备的联锁联动。
基于GSM的远程监控外文翻译模板(计算机学院)
外文翻译原文及译文学院计算机学院专业计算机科学与技术班级84010102学号20080401010xx 姓名指导教师张维君负责教师张维君沈阳航空航天大学2012年6月Smart Home TechnologyLink your home's lighting, entertainment and security systems with new automated home technology.Smart home is expected to offer various intelligent services by recognizing residents along with their life style and feelings. One of the key issues for realizing the smart home is how to detect the locations of residents. Currently, the research effort is focused on two approaches: terminal-based and non-terminal-based methods. The terminal -based method employs a type of device that should be carried by the resident while the non-terminal-based method requires no such device..There is a growing interest in smart home as a way to offer a convenient, comfortable, and safe residential environment . In general, the smart home aims to offer appropriate intelligent services to actively assist in the resident’s life such as housework, amusement, rest, a nd sleep. Hence, in order to enhance the resident’s convenience and safety, devices such as home appliances, multimedia appliances, and internet appliances should be connected via a home network system, as shown in Fig. 1, and they should be controlled or monitored remotely using a television (TV) or personal digital assistant (PDA) .Especially, attention has been focused on location-based services as a way to offer high-quality intelligent services, while considering human factors such as pattern of living, health, and feelings of a resident . That is, if the smart home can recognize the resident’s pattern of living or health, then home appliances should be able to anticipate the resident’s needs and offer appropriate intelligent service more actively. For example, in a passive service environment, the resident controls the operation of the HVAC (heating, ventilating, and air conditioning) system, while the smart home would control the temperature and humidity of a room according to the resident’s conditio n. Various indoor location-aware systems have been developed to recognize the resident’s location in the smart home orsmart office. In general, indoor location-aware systems have been classified into three types according to the measurement technology: triangulation, scene analysis, and proximity methods [8]. The triangulation method uses multiple distances from multiple known points. Examples include Active Badges , Active Bats , and Easy Living , which use infrared sensors, ultrasonic sensors, and vision sensors, respectively. The scene analysis method examines a view from a particular vantage point. Representative examples of the scene analysis method are MotionStar , which uses a DC magnetic tracker, and RADAR , which uses IEEE 802.11 wireless local area network (LAN). Finally, the proximity method measures nearness to a known set of points. An example of the proximity method is Smart Floor , which uses pressure sensors.Alternatively, indoor location-aware systems can be classified according to the need for a terminal that should be carried by the resident. Terminal-based methods, such as Active Bats, do not recognize the resident’s location directly, but perceive the location of a device carried by the resident, such as an infrared transceiver or radio frequency identification (RFID) tag. Therefore, it is impossible to recognize the resident’s location if he or she is not carrying the device. In contrast, non-terminal methods such as Easy Living and Smart Floor can find the resident’s location without s uch devices. However, Easy Living can be regarded to invade the resident’s privacy while the Smart Floor has difficulty with extendibility and maintenance.Home automation has come a long way from the manual timer hooked up to the living room light. Today's "smart" home automatically regulates heat, air and light, distributes audio and video around the house, controls access to your home and can even remind you to exercise!New technologies and product advances have made home technology systems more affordable than ever and have brought home systems integration into the mainstream. According to a study done in 2004 by the National Association of Home Builders Research Center and the Consumer Electronics Association, nearly half of all new homes being built in the U.S. are now using structured copper "smart" wiring to enable the installation of new home technology systems.How it WorksThere are four main types of networks you can install in your home to support the available new technology. Each has its advantages and disadvantages depending on whether you are wiring a new home or upgrading an existing home.∙Structured wiring involves running specialized high performance cabling throughout your home. It provides a highly reliable and secure network that distributes data signals for phones, computers, TVs and audio components. It's ideal for new construction but not always easy to install in an existing home. Also, networking is limited to the reach of cables, jacks and plugs.∙Wireless networks provide the advantages of flexibility and mobility and virtually eliminate the wiring dilemmas often faced by existing homeowners.However, wireless networks tend to be less reliable and subject to interference from other devices such as baby monitors and cordless phones.∙Power-line networks use a home's existing electrical lines to transmit data.They are relatively easy to set up and operate but carry the risk of power surges, and an unencrypted household network may be accessible to neighbors sharing the same transformer.∙Phone-line networks use a home's telephone lines to carry multiple services.Typically, each service is assigned a unique frequency spectrum so they don't interfere with one another. Smart home technology may also enable you to dial in via a phone line to control specific home operating systems and/or be pre-set to dial out to a monitoring service in the case of a fire or break-in.While the possibilities for home automation are only limited by your imagination, the choices facing the average homeowner may seem daunting. The good news is that you do not need to become a technological expert in order to enhance your home's capabilities. A home technology integrator can design, implement, and tie together your home's various electronic systems. These include:Entertainment: You may have been impressed by a friend's home theatre setup one night, when they popped a movie in their DVD player and gave you the large screen, surround sound experience. But why not take this experience further? Using fairly simpleautomation technology, you could push a "movie" button on a touch pad in your family room. The lights would dim, the blinds would close, the popcorn maker would spring into action, the fridge would check for adequate ice levels for your soda, and your calls would be automatically forwarded straight to your answering service. With a little creativity and planning, all these events can be achieved using a home network.It would be equally simple, using motion sensors and your stereo system, to play music every time you enter a room in your home -- something upbeat, perhaps, for the home gym, maybe classical music for your study -- the possibilities are endless. Or you could sit in your living room and select the music you want to listen to via on-screen menus that are displayed on your TV.You could even monitor your children's television and video-game habits, when you're not at home by programming the network to alert your cell phone if your children watch too much television or inappropriate programming. Or you can simply program the TV or gaming console to shut off after a certain amount of time.Security: Using smart home automation technology, you can program your lights to simulate normal in-home activity when you're away. For example, some time around your regular bedtime, your bedroom lights and TV will turn on while the rest of the house will be darkened. And this lighting routine can be set up to change on the weekend.To protect against break-ins, you can position web cams at home entrances and install an alarm system that uses heat and motion sensors to alert you and a remote security company in the case of an intruder.In the case of fire, your smoke detector can be wired to sound not just an alarm but also to send a signal to your air-conditioning system fans to shut down, alert you and specified contacts and illuminate an evacuation route throughout the house.Energy: Energy savings can be realized by automating thermostats, lights and other environmental systems such as garden sprinklers and fountains. Integrating all of these into one environmental system can help ensure a minimum waste of energy in your home. For example, on a hot, sunny day, weather sensors can activate blind and drapery controls to shade your home, and ensure that your garden receives adequate irrigation at the right time of day. Motion and occupancy sensors can activate heat and lighting controlsas you enter and exit rooms.Today’s new smart IR sensors represent a union of two rapidly evolving sciences that combine IR temperature measurement with high-speed digital technologies usually associated with the computer. These instruments are called smart sensors because they incorporate microprocessors programmed to act as transceivers for bidirectional, serial communications between sensors on the manufacturing floor and computers in the control room (see Photo 1). And because the circuitry is smaller, the sensors are smaller, simplifying installation in tight or awkward areas. Integrating smart sensors into new or existing process control systems offers an immediate advantage to process control engineers in terms of providing a new level of sophistication in temperature monitoring and control.When you leave for work in the morning, your house could "check" for and turn off unnecessary energy consumers such as radios, TVs, stoves and irons (a nice safety feature). On your way home, you could use your cell phone or computer to change the temperature in your home, turn on lights, turn on the radiant heat in your bathroom floor and fill the bathtub to just the right level for a nice long soak.Appliances: From toasters to fridges to picture frames, the possibilities for networking computerized household appliances are limited only by your imagination and budget. Your refrigerator can keep track of food expiration dates and act as a family message center via a built-in screen. Coffee makers and other small appliances (such as toasters) can be activated remotely or as part of a sequence of events. You can even imitate Bill Gates and install framed electronic artwork that changes depending on the preference of the person who enters a room, or purchase Internet-connected picture frames that retrieve images from a gallery supplied by your friends and family for a constantly updated family portrait wall.The key to making your home more comfortable, enjoyable and safe through home automation is to follow three essential steps:Plan: Discuss automation needs and wants with your family members so you can plan ahead. Take into consideration your home's layout in terms of traffic and furniture.∙Consult: Talk to as many people as possible to get ideas and learn about their experiences with home automation; what worked, what didn't, what do they wish they had done differently?∙Decide: What do you definitely want to be able to do? What is optional? Will you install the network yourself or leave it to a professional? What kind of network and what types of technology best suit your needs? Home automation, from security systems to intelligent appliances, is becoming an accessible reality. With some careful planning and a little help, you too can enjoy the benefits of a "smart"homeIntelligent Homes, Building Management Systems (BMS) encompasses an enormous variety of technologies, across commercial, industrial, institutional and domestic buildings, including energy management systems and building controls. The function of Building Management Systems is central to 'Intelligent Buildings' concepts; its purpose is to control, monitor and optimise building services, eg., lighting; heating; security, TV and alarm systems; access control; audio-visual and entertainment systems; ventilation, filtration and climate control, etc.; even time & attendance control and reporting (notably staff movement and availability). The potential within these concepts and the surrounding technology is vast, and our lives are changing from the effects of Intelligent Buildings developments on our living and working environments. The impact on facilities planning and facilities management is also potentially immense.Smart home exampleAt 7:30am and you awake to the sound of your favourite cd playing in the background; the lights in your bedroom switch on; 'fading up' to allow you to wake up in your own time. The downstairs intruder alarm system is de-activated. In the kitchen the coffee machine turns on to make a drink. The ground floor curtains and blinds open; the towel heater in the bathroom warms the towels. And you haven't even got up yet.智能家居技术链接您家的灯光,娱乐和安全系统的新的自动化家用技术。
远程视频监控系统大学毕业论文外文文献翻译及原文
毕业设计(论文)外文文献翻译文献、资料中文题目:远程视频监控系统文献、资料英文题目:文献、资料来源:文献、资料发表(出版)日期:院(部):专业:电子信息工程班级:姓名:学号:指导教师:翻译日期: 2017.02.14外文文献翻译A System for Remote Video Surveillanceand MonitoringThe thrust of CMU research under the DARPA Video Surveillance and Monitoring (VSAM) project is cooperative multi-sensor surveillance to support battlefield awareness. Under our VSAM Integrated Feasibility Demonstration (IFD) contract, we have developed automated video understanding technology that enables a single human operator to monitor activities over a complex area using a distributed network of active video sensors. The goal is to automatically collect and disseminate real-time information from the battlefield to improve the situational awareness of commanders and staff. Other military and federal law enforcement applications include providing perimeter security for troops, monitoring peace treaties or refugee movements from unmanned air vehicles, providing security for embassies or airports, and staking out suspected drug or terrorist hide-outs by collecting time-stamped pictures of everyone entering and exiting the building.Automated video surveillance is an important research area in the commercial sector as well. Technology has reached a stage where mounting cameras to capture video imagery is cheap, but finding available human resources to sit and watch that imagery is expensive. Surveillance cameras are already prevalent in commercial establishments, with camera output being recorded to tapes that are either rewrittenperiodically or stored in video archives. After a crime occurs – a store is robbed or a car is stolen – investigators can go back after the fact to see what happened, but of course by then it is too late. What is needed is continuous 24-hour monitoring and analysis of video surveillance data to alert security officers to a burglary in progress, or to a suspicious individual loitering in the parking lot, while options are still open for avoiding the crime.Keeping track of people, vehicles, and their interactions in an urban or battlefield environment is a difficult task. The role of VSAM video understanding technology in achieving this goal is to automatically “parse” people a nd vehicles from raw video, determine their geolocations, and insert them into dynamic scene visualization. We have developed robust routines for detecting and tracking moving objects. Detected objects are classified into semantic categories such as human, human group, car, and truck using shape and color analysis, and these labels are used to improve tracking using temporal consistency constraints. Further classification of human activity, such as walking and running, has also been achieved. Geolocations of labeled entities are determined from their image coordinates using either wide-baseline stereo from two or more overlapping camera views, or intersection of viewing rays with a terrain model from monocular views. These computed locations feed into a higher level tracking module that tasks multiple sensors with variable pan, tilt and zoom to cooperatively and continuously track an object through the scene. All resulting object hypotheses from all sensors are transmitted as symbolic data packets back to a central operator control unit, where they are displayed on a graphical user interface to give a broad overview of scene activities. These technologies have been demonstrated through a series of yearly demos, using a testbed system developed on the urban campus of CMU.Detection of moving objects in video streams is known to be a significant, and difficult, research problem. Aside from the intrinsic usefulness of being able to segment video streams into moving and background components, detecting moving blobs provides a focus of attention for recognition, classification, and activity analysis, making these later processes more efficient since only “moving” pixels need be considered.There are three conventional approaches to moving object detection: temporal differencing ; background subtraction; and optical flow. Temporal differencing is very adaptive to dynamic environments, but generally does a poor job of extracting allrelevant feature pixels. Background subtraction provides the most complete feature data, but is extremely sensitive to dynamic scene changes due to lighting and extraneous events. Optical flow can be used to detect independently moving objects in the presence of camera motion; however, most optical flow computation methods are computationally complex, and cannot be applied to full-frame video streams in real-time without specialized hardware.Under the VSAM program, CMU has developed and implemented three methods for moving object detection on the VSAM testbed. The first is a combination of adaptive background subtraction and three-frame differencing . This hybrid algorithm is very fast, and surprisingly effective – indeed, it is the primary algorithm used by the majority of the SPUs in the VSAM system. In addition, two new prototype algorithms have been developed to address shortcomings of this standard approach. First, a mechanism for maintaining temporal object layers is developed to allow greater disambiguation of moving objects that stop for a while, are occluded by other objects, and that then resume motion. One limitation that affects both this method and the standard algorithm is that they only work for static cameras, or in a ”stepand stare” mode for pan-tilt cameras. To overcome this limitation, a second extension has beendeveloped to allow background subtraction from a continuously panning and tilting camera . Through clever accumulation of image evidence, this algorithm can be implemented in real-time on a conventional PC platform. A fourth approach to moving object detection from a moving airborne platform has also been developed, under a subcontract to the Sarnoff Corporation. This approach is based on image stabilization using special video processing hardware.The current VSAM IFD testbed system and suite of video understanding technologies are the end result of a three-year, evolutionary process. Impetus for this evolution was provided by a series of yearly demonstrations. The following tables provide a succinct synopsis of the progress made during the last three years in the areas of video understanding technology, VSAM testbed architecture, sensor control algorithms, and degree of user interaction. Although the program is over now, the VSAM IFD testbed continues to provide a valuable resource for the development and testing of new video understanding capabilities. Future work will be directed towards achieving the following goals:1. better understanding of human motion, including segmentation and tracking ofarticulated body parts;2.improved data logging and retrieval mechanisms to support 24/7 systemoperations;3.bootstrapping functional site models through passive observation of sceneactivities;4.better detection and classification of multi-agent events and activities;5.better camera control to enable smooth object tracking at high zoom; and6.acquisition and selection of “best views” with the eventual goal of recognizingindividuals in the scene.远程视频监控系统在美国国防部高级研究计划局,视频监控系统项目下进行的一系列监控装置研究是一项合作性的多层传感监控,用以支持战场决策。
视频监控系统外文翻译译
中文3630字毕业设计外文翻译2014 届信息科学与工程学院通信工程专业题目:子题:外文文献Video surveillance system is safe guard system is an important part of a preventive ability strong comprehensive system. Video monitoring with its convenient, intuitive and information content rich and widely used in many occasions. In recent years, with the development of modern science and technology, in particular network bandwidth, computer processing power and storage capacity rapidly increase and various practical video information processing technology, video surveillance technology also appeared a considerable development, video monitoring entered the digital network age, increasingly attention by people and attention. The development of video surveillance system is mainly early analog closed-circuit television monitoring system combined to video monitoring system model of digital video monitor and now the evolution process, and the system of digital video monitor system now according to the technical development and divided into three stages: digital monitor multimedia stage, digital monitor DVR stage and digital monitor network stage.1, video monitoring system simulations simulate video monitoring system is divided into microprocessor-based video switch control plus PC multimedia management and pc-based realize the switch control of matrix host and system multimedia management two types. Analog closed-circuit television monitoring system is actually the combination of many simulation monitoring equipment, system mainly consists of "front-end device" and "terminal control device" and "signal transmission medium" three parts, including: front-end equipment is mainly a camera, haeundae, decoder, control equipment is mainly a switching matrix, image segmentation device, monitor and control the keyboard, video, etc. Transmission medium including cable, control, etc. As microprocessors, the function, performance of microcomputers and heighten, multimedia technology application, the system in functionality,performance, reliability, structure pattern, etc, great changes have happened to the video monitoring system, more convenient, the composition of the interface with other technical system tends to regulate, man-machine interface more friendly. But because video monitor and control system in the flow of information form does not change, the video signal is still simulation system, the network structure is mainly a ChanGongNeng, one-way, lumped way of information collection network, so system although has developed to a high level, has not much potential can dig, its limitations still exist, to meet the higher request, digital is the only way. Simulation monitoring system of main faults are: a, usually only suitable for small range of regional monitor video signal transmission, simulation tools, and is mainly coaxial cable to transmit analog video signal coaxial cable, the distance is not more than the distance twisted-pair dump more short, this determines the analog monitor only suitable for single building, small neighborhood and other small range of places. B, the system of expansion ability difference for has already built good system, if want to add new monitory point, often is one change makes all change, new equipment is also hard to add to the original system in. C, unable to form effective alarm linkage, because each part between independent operation, the control protocol is difficult to each other, linkage in the limited scope only.2 video monitoring system, digital multimedia technology, video with compression technology, network communication technology of digital video surveillance system development, the rapid rise, on the market today there are two types of digital video monitor system type, one is the digital video equipment video monitoring system for the core, another kind is embedded video Web server video monitoring system for the core.Digital video compression technology matures, the computer based onPC universalization, create conditions multimedia monitor. This new video monitoring system of rapid rise, partially replaced with video matrix image segmentation device, video as the core, complementary with other transmitter simulation video monitor mode, its advantage mainly displays in: a, PC multimedia monitor video matrix, the host integrated image segmentation device, many functions of video recorders, simplifies the structure of the system. B, because use the computer network technology, digital multimedia remote network monitor from distance limit. C, due to the large capacity disk array inventory device or CD storage, can save you a lot of tape medium, and it is helpful to the multimedia information system.But as the PC video surveillance video system development, in actual engineering in use process, also exposed some shortage, mainly system work instability. The video surveillance video based on PC for: the structure of system compatible/industrial PC + video capture card + ordinary/more reliable operation platform + application software. From the system composition structure to analysis: a, PC for 24 hour uninterrupted job, its performance is not very stable, g-kong PC relative compatible PC's stability have a class enhancement, suitable for complex working environment. B, operating system: with Windows 98 for operation platform system, the industry insiders know, there are certain Win98 stability problem, if at the same time the application software is not very standardized, it'll be easier in use process appears work instability, freezes and other issues, and PC video surveillance video system realization of their software in Windows 95/98 / NT, Unix, Linux operating system, such as general while system files, application software and image files are stored in the disk, video processing must high-density input of large quantities of data, and to work hard drive, the average for the hard disk logic (such as Windows, already can't adapt to FAT32) so susceptible, causing instability crashed phenomenon. C,application software: the simple application software system is not can be used for security video monitoring system, fields of application software ability should support multitasking concurrent processing, such as monitoring, video, playback, backup, alarm, control, remote connection, etc. The ability to deal with more work D, video capture card: video surveillance video system for road input system are usually video capture card, can use multiple CARDS way, also can use single card mode. Say commonly, a single card way better integration high stability will more than all the way, many using card has a card way very easy to form hardware conflicts, its stability will have a major influence. Embedded system is used as the center, software and hardware can be cut, to adapt application system function, reliability and cost, volume etc comprehensive demanding special computer system for monitoring system, i.e. the special computer system tailored.Embedded system mainly consists of embedded processor, relevant support hardware, embedded operating system and application software system etc, it is the collection software and hardware in the integration of can work independently "devices". Embedded operating system is a kind of real-time, supports embedded system application operating system software, it is embedded system extremely important constituent, usually includes and hardware related software drivers, system kernel bottom, device driver interface, communication protocol, graphic interface, standardization browsers, embedded real-time operating system in the related hardware and efficiency of dependence, software application and specificity solid state has more prominent characteristics. The advantages and disadvantages of embedded system, the system for a special system, so the system is small, instruction downsizing and processing speed. B, system data in ROM/FLASH with fast speed, call, not be altered, good stability. C, system treatment of good real-time performance, stable performance. D, document management system ismore suitable for large amounts of video data. E, in network function, audio and video sync issues may also difficult satisfactory.Embedded video Web server mode, a built-in video server embedded Web server, the embedded real-time multitasking operating system. The video signal digital camera sent by high compression chip after through internal bus to compress, built-in Web server, Internet users can use directly on the Web server browsers on camera images, subscribers can also control the camera lens, haeundae, the actions or operate on system configuration.Because the video compression and Web function centralism to a small size within the equipment can be directly connected lans, achieve namely that look, omited inserted range of complex cable, convenient installation (only set an IP address), the user does not need to install any hardware device, with the browser can only watch. Embedded video Web server monitoring system and other surveillance system has the following characteristics: a comparison of embedded video area is vast, have been supervised Web server monitoring system of Web server directly connected network, no cable length and attenuation, and the limit of the concept of network is no distance, completely abandoned regional concept, expand have been supervised areas. B, the system has almost unlimited seamless expansion ability all equipment is mark, with IP address increased equipment just means that IP address the expansion. C, can form a very complicated monitoring network based on embedded Web server is the core of the monitoring system in network mode, with traditional analog monitor and based on PC platforms screening method has greatly different, because Web server output has completed analog to digital conversion and compression, adopt uniform agreement on the network transmission, support across the router across the gateway, remote video transmission. D, stable and reliable performance, without staff management embedded Web server based on embedded computertechnology, actually using embedded real-time multitasking operating system, and video compression and Web function due to focus on a small size, within the device directly concatenation LAN or wan, namely that look, system insert real-time, stability, reliability greatly improved, also need not specially assigned management, which is very suitable for unattended conditions. E, when the monitoring center needs to watch a video camera image, more network bandwidth will have certain requirements.The development of video monitoring system1, video monitoring system development directionVideo digitizing, front integration, network, system integration is monitoring the development of video monitoring system, and recognized the direction is the premise of digital network, network and system integration of video monitor based, so, the biggest two characteristics is the digital and network.2, digitalDigital is the 21st century features, is the information technology as the core, the necessity of the development of electronic technology, digital is toward growth pass, along with the time development, our environment will become more and more digital.Video surveillance system is the system of digital first should flow in video, audio, (including from analog state control, etc.) state, which to digital completely break "classic cable TV system based on camera imaging technology as the center" structure, fundamentally changing video monitoring system from information acquisition, data processing, transmission and system control of the mode and structural form. The flow of information digitization, coding compression, open video monitoring system, make agreements with the security system in other between each subsystem realize seamless connection, and the unified operation platform to realize the management and control systemintegration, this also is the meaning.3 and networkVideo monitoring system of the structure of the network will mean system by lumped type to distribution type system transition. Distribution type system USES the multi-layer hierarchical structure form and the real-time kernel technology with micro multitask, multi-user, distributed operating system to achieve beat task scheduling algorithm fast response. Distributing type monitoring system of the hardware and software using the standardization, the modularization and the serialization of design, system equipment configuration has the versatility, openness, system configuration flexible, control the perfect function, data processing convenient, friendly man-machine interface and system installation, commissioning and maintenance simplify the operation of the system, are hot backup, fault-tolerant reliable, etc. System in some degree of networked broke on regional and equipment have been supervised extended geographical and quantity limits. System network will make the whole network system hardware and software resources sharing and mission and load of sharing, this also is an important concept of the system integration. From the above can see video technology, the development of video, roughly experienced analog video, network video PC in three phases, and depending on the technology of the network, communication and transmission platform.外文翻译视频监控系统是安全防范系统的重要组成部分,是一种防范能力较强的综合系统。
电子信息工程专业毕业论文外文翻译【最新范本模板】
本科毕业设计(论文)中英文对照翻译院(系部)电气工程与自动化专业名称电子信息工程年级班级 04级7班学生姓名指导老师Infrared Remote Control SystemAbstractRed outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique,drive numerous hardware and software platform support。
Red outside the transceiver product have cost low,small scaled turn,the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos etc。
characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission,at short distance wireless deliver aspect to own very obvious of advantage。
Along with red outside the data deliver a technique more and more mature,the cost descend,red outside the transceiver necessarily will get at the short distance communication realm more extensive of application。
基于GPRS远程监控系统数据终端的研究外文资料翻译(1)
88888毕业设计(论文)外文资料翻译系(院):电子信息工程系专业:电气工程及其自动化姓名:学号:外文出处:Mobile Networks and Application(用外文写)附件: 1.外文资料翻译译文;2.外文原文。
指导教师评语:签名:年月日注:请将该封面与附件装订成册。
附件1:外文资料翻译译文基于GPRS远程监控系统数据终端的研究引言随着计算机技术的发展,特别是Internet技术广泛应用到人们生活的各个方面,使人们的生活发生了巨大的变化,从工业控制领域来讲,由于需要监控的区域广、监控的对象种类多,因而需要花费大量的人力、物力和财力进行设备的维护,而且有许多环境恶劣、人们不易到达或不能时刻停留的地方不经常的采集一些现场数据,如果进行大量的拉线工作则是不经济、不合理的,这就推动了无线通信的技术在远程监控领域的发展。
GPRS(通用分组无线业务),作为当前的GSM网络向第三代移动通信技术转换的过渡技术(2.5G)具有接入快速、时刻在线、按流量计费等优点,在远程突发性数据及时传输中有不可比拟的优势。
2 GPRS技术GPRS(General Packet Radio Service)通用分组无线业务,是在GSM系统的基础上建立的移动网络系统,他使用分组交换技术,能兼容GSM,并且能在网络上传输高速数据,GPRS在传统的GSM网络中引入了3个新的器件:PCU(Packet Control Unit,分组控制单元)、SGSN(Serving GPRS Support Node,GPRS服务支持节点)和GGSN(Gateway GPRS Support Node,GPRS网关支持节点),GPRS通信具有以下特点:资源利用率高 GPRS引进了分组交换的传输模式,用户只有在发送或接收数据期间才占用资源,这就是说多个用户可高效率地共享同一无线通信,从而提高了资源的利用率,而GSM传输数据方式为电路交换模式,在整个连接时期内,用户无论是否传送数据都将独自占用无线信道。
毕业论文英文翻译GPS实时监测【范本模板】
GPS Real-Time Supervisory System and Application in the Construction of FaceRockfill DamHUANG Sheng xiang LIU Jingnan ZENG Huai'enABSTRACTAccording to the quality control needs of filling construction of the face rockfill dam, by means o f the global satellite positioning technology ,the wireless data communication technology, the computer technology and the data processing and analysis technology, and integrating with the roller compaction machine,the GPS real-time supervisory system is developed in this paper。
It can be used to real—timely supervise the construction quality of the roller compaction for filling engineering.The composition and applied characteristics of GPS system,and the key technique problem and solution of the design are discussed。
The height accuracy of GPS system is analyzed and the preliminary application is introduced.KEY WORDS :GPS; filling construction; quality control; integrated system;face rockfill dam IntroductionAt present , in the quality management of filling construction of the face rockfill dam,the quality control method of “dual controls”is mainly adopted, of which one is manually controling the parameters of roller compaction including thickness and roughness of filling layer and rolled times and rolled speed o f compaction machines,the other is inspecting the test hole sampling manually in the area. The method play a positive role in promoting domestic development of concrete faced rockfill dam。
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毕业设计(论文)外文文献翻译文献、资料中文题目:远程视频监控系统文献、资料英文题目:文献、资料来源:文献、资料发表(出版)日期:院(部):专业:电子信息工程班级:姓名:学号:指导教师:翻译日期: 2017.02.14外文文献翻译A System for Remote Video Surveillanceand MonitoringThe thrust of CMU research under the DARPA Video Surveillance and Monitoring (VSAM) project is cooperative multi-sensor surveillance to support battlefield awareness. Under our VSAM Integrated Feasibility Demonstration (IFD) contract, we have developed automated video understanding technology that enables a single human operator to monitor activities over a complex area using a distributed network of active video sensors. The goal is to automatically collect and disseminate real-time information from the battlefield to improve the situational awareness of commanders and staff. Other military and federal law enforcement applications include providing perimeter security for troops, monitoring peace treaties or refugee movements from unmanned air vehicles, providing security for embassies or airports, and staking out suspected drug or terrorist hide-outs by collecting time-stamped pictures of everyone entering and exiting the building.Automated video surveillance is an important research area in the commercial sector as well. Technology has reached a stage where mounting cameras to capture video imagery is cheap, but finding available human resources to sit and watch that imagery is expensive. Surveillance cameras are already prevalent in commercial establishments, with camera output being recorded to tapes that are either rewrittenperiodically or stored in video archives. After a crime occurs – a store is robbed or a car is stolen – investigators can go back after the fact to see what happened, but of course by then it is too late. What is needed is continuous 24-hour monitoring and analysis of video surveillance data to alert security officers to a burglary in progress, or to a suspicious individual loitering in the parking lot, while options are still open for avoiding the crime.Keeping track of people, vehicles, and their interactions in an urban or battlefield environment is a difficult task. The role of VSAM video understanding technology in achieving this goal is to automatically “parse” people a nd vehicles from raw video, determine their geolocations, and insert them into dynamic scene visualization. We have developed robust routines for detecting and tracking moving objects. Detected objects are classified into semantic categories such as human, human group, car, and truck using shape and color analysis, and these labels are used to improve tracking using temporal consistency constraints. Further classification of human activity, such as walking and running, has also been achieved. Geolocations of labeled entities are determined from their image coordinates using either wide-baseline stereo from two or more overlapping camera views, or intersection of viewing rays with a terrain model from monocular views. These computed locations feed into a higher level tracking module that tasks multiple sensors with variable pan, tilt and zoom to cooperatively and continuously track an object through the scene. All resulting object hypotheses from all sensors are transmitted as symbolic data packets back to a central operator control unit, where they are displayed on a graphical user interface to give a broad overview of scene activities. These technologies have been demonstrated through a series of yearly demos, using a testbed system developed on the urban campus of CMU.Detection of moving objects in video streams is known to be a significant, and difficult, research problem. Aside from the intrinsic usefulness of being able to segment video streams into moving and background components, detecting moving blobs provides a focus of attention for recognition, classification, and activity analysis, making these later processes more efficient since only “moving” pixels need be considered.There are three conventional approaches to moving object detection: temporal differencing ; background subtraction; and optical flow. Temporal differencing is very adaptive to dynamic environments, but generally does a poor job of extracting allrelevant feature pixels. Background subtraction provides the most complete feature data, but is extremely sensitive to dynamic scene changes due to lighting and extraneous events. Optical flow can be used to detect independently moving objects in the presence of camera motion; however, most optical flow computation methods are computationally complex, and cannot be applied to full-frame video streams in real-time without specialized hardware.Under the VSAM program, CMU has developed and implemented three methods for moving object detection on the VSAM testbed. The first is a combination of adaptive background subtraction and three-frame differencing . This hybrid algorithm is very fast, and surprisingly effective – indeed, it is the primary algorithm used by the majority of the SPUs in the VSAM system. In addition, two new prototype algorithms have been developed to address shortcomings of this standard approach. First, a mechanism for maintaining temporal object layers is developed to allow greater disambiguation of moving objects that stop for a while, are occluded by other objects, and that then resume motion. One limitation that affects both this method and the standard algorithm is that they only work for static cameras, or in a ”stepand stare” mode for pan-tilt cameras. To overcome this limitation, a second extension has beendeveloped to allow background subtraction from a continuously panning and tilting camera . Through clever accumulation of image evidence, this algorithm can be implemented in real-time on a conventional PC platform. A fourth approach to moving object detection from a moving airborne platform has also been developed, under a subcontract to the Sarnoff Corporation. This approach is based on image stabilization using special video processing hardware.The current VSAM IFD testbed system and suite of video understanding technologies are the end result of a three-year, evolutionary process. Impetus for this evolution was provided by a series of yearly demonstrations. The following tables provide a succinct synopsis of the progress made during the last three years in the areas of video understanding technology, VSAM testbed architecture, sensor control algorithms, and degree of user interaction. Although the program is over now, the VSAM IFD testbed continues to provide a valuable resource for the development and testing of new video understanding capabilities. Future work will be directed towards achieving the following goals:1. better understanding of human motion, including segmentation and tracking ofarticulated body parts;2.improved data logging and retrieval mechanisms to support 24/7 systemoperations;3.bootstrapping functional site models through passive observation of sceneactivities;4.better detection and classification of multi-agent events and activities;5.better camera control to enable smooth object tracking at high zoom; and6.acquisition and selection of “best views” with the eventual goal of recognizingindividuals in the scene.远程视频监控系统在美国国防部高级研究计划局,视频监控系统项目下进行的一系列监控装置研究是一项合作性的多层传感监控,用以支持战场决策。