基于802.11b标准及嵌入式视频监控系统及设计-毕业论文.doc

南京航空航天大学硕士学位论文 摘  要 目前的视频监控系统仍以数字控制的模拟监控为主，而随着多媒体技术的提高和 网络通讯的发展，嵌入式视频监控系统的需求大增。嵌入式视频监控系统对于提高监 控系统的数字化、网络化、减少成本等方面具有积极的意义。同时，无线局域网技术 在笔记本、PC机获得了广泛的应用，众多需要监控的场合都提供了无线接入点，带 有无线网络通信功能的监控设备已经成为一种必然趋势。 本论文提出了基于802.11b标准的嵌入式视频监控系统解决方案，以ARM芯片 S3C2410X为核心，通过前向单元采集视频信号并送至处理器进行处理，处理后的视 频信号通过802.11b网卡进行数据的发送。最后在ARM上实现了嵌入式Web服务器， 使得客户端可以通过浏览器进行视频监控。 在系统设计和开发过程中，研究了摄像头和网卡在LINUX上的驱动，并通过移植 嵌入式web服务器和编写java程序，实现了网络的远程访问，完成了视频的监控。 论文中重点讨论了无线网络速率的特点所带来的一些需要解决的关键问题，给出 了具体的解决方法，包括双帧采集、采用环形缓冲区、采用动态帧显示速率等，最终 消除了图像的闪烁。 最后论述了系统的设计开发工作，包括系统软硬件设计、开发调试环境，以实验 的结果验证和分析了基于802.11b标准的嵌入式视频监控系统的实用性。 关键词：ARM，嵌入式Linux，Web服务器，802.11b网卡，视频监控 i 基于 802.11b 标准的嵌入式视频监控系统的设计 ABSTRACT At present,most of video surveillance systems transmit analogue signal.Along with the development of techniques of multimedia and network,there are huge demand of embedded surveillance system,which is which is developing rapidly.It brings surveillance system many benefits,including digital and network surveillance.Besides,WLAN is popular in book-computer,PC and public place.So it’s the trend that surveillance system have the function of WLAN. Concerned of the metioned,this paper introduce a embedded surveillance system based on 802.11b.The hardware structure,software design and the development of the driver under linux system are presented.The CPU S3C2410X captures the video signal, then processes them.Usb wireless NIC is used to transfer the processed video signal through WLAN.Finally,a embedded web server is realized on the ARM.It makecustomer can view video through explorer. In the course of design of the system,drivers of Camera and 802.11b NIC on Linux are researched,besides,embedded web server and java program make user access video through internet. This dissertation is focused on the application of wireless network.This paper takes measures to avoid the flicker of pictures,such as grabing two frames once,storing in round buffer,painting with dynamic frequency. Finally, this dissertation introduced the course of sy