远程数字系统实验平台关键技术研究

发布时间：2018-04-17 06:30

本文选题：远程实验 + 任务调度　；参考：《四川师范大学》2017年硕士论文

【摘要】：随着网络技术和信息技术的发展,远程教育逐渐普及,尤其是近年来大规模推广的大型开放式网络课程(Massive Open Online Courses,MOOC)和小规模限制性在线课程(Small Private Online Course,SPOC),使远程教育中实践难的问题逐渐突显,远程实验系统也逐渐成为各高校和研究机构的研究热点。现有数字系统实验的远程平台主要采用计算机为载体的体系架构,存在成本高,体积大等缺陷,也不符合物联网的发展趋势。针对这一问题,本文继承性提出了一种基于嵌入式系统的远程实验体系架构,将Web服务器、实验服务器、视频服务器等全部集中设计到嵌入式系统中,以达到远程实验系统微型化、低成本的目标,也便于集成在实验设备中,实现实验设备的智能化。与计算机相比,嵌入式系统处理能力孱弱,要实现基于嵌入式系统的远程实验体系架构需要解决三个关键技术,即在嵌入式系统中实现优化的任务调度算法、实现视频的实时采集与传输以及基于嵌入式的FPGA(Field Programmable Gate Array)远程配置。针对实验系统的任务调度算法,本文研究了计算机网络中的基于集群技术的Web服务器系统的架构和理论模型,对比分析了几种Web服务器的常用任务调度算法。针对嵌入式系统的特殊性,利用排队论对远程实验系统中任务调度进行了数学建模,并对基于内容分发的多种类型任务轮转调度算法(Multi-Class Round Robin,MC-RR)进行了参数调优,使之能够满足嵌入式远程实验系统中负载均衡和实时性等要求。针对视频的实时采集与传输,本文详细研究了嵌入式系统中视频采集与传输的实现方案。采用了V4L2(Video 4 Linux 2)驱动框架控制符合UVC(USB Video Class)规范的摄像头进行视频图像的采集,利用TCP/IP的Socket编程方式,实现了视频的实时采集和传输,并可在浏览器上进行观看。针对基于嵌入式的FPGA远程配置,本文详细研究了利用ARM对FPGA的远程配置方案。利用Jam STAPL在嵌入式系统中成功移植了Jam Player,在嵌入式平台中实现了FPGA的JTAG(Joint Test Action Group)方式配置。几项关键技术的研究表明,基于嵌入式系统的远程实验体系架构可以很好地满足远程数字系统实验平台的需要,可有效实现设备的智能化,并降低远程实验系统的成本。
[Abstract]:With the development of network technology and information technology, distance education is becoming more and more popular.In particular, the large-scale open Open Online course (massive Open Online course) and the small Private Online course (small Private Online course), which have been widely popularized in recent years, have made the problem of practice difficult in distance education more and more obvious.Remote experiment system has gradually become the research hotspot of universities and research institutions.The existing remote platform of digital system experiment mainly adopts the architecture of computer as the carrier, which has the defects of high cost and large volume, and does not accord with the development trend of the Internet of things.In order to solve this problem, this paper presents a remote experiment architecture based on embedded system. The Web server, experimental server and video server are all designed into embedded system.In order to achieve the goal of miniaturization and low cost of remote experiment system, it is convenient to integrate in the experimental equipment and realize the intelligence of the experimental equipment.Compared with the computer, the embedded system is weak in processing ability. In order to realize the remote experiment architecture based on the embedded system, three key technologies need to be solved, that is, to realize the optimized task scheduling algorithm in the embedded system.Real-time video capture and transmission and remote configuration based on embedded FPGA(Field Programmable Gate are realized.Aiming at the task scheduling algorithm of experimental system, this paper studies the architecture and theoretical model of Web server system based on cluster technology in computer network, and compares and analyzes several common task scheduling algorithms of Web server.According to the particularity of embedded system, the task scheduling in remote experiment system is modeled by queuing theory, and the multi-class Round Robin MC-RRR algorithm based on content distribution is optimized.It can meet the requirements of load balance and real-time in embedded remote experiment system.Aiming at the real-time video acquisition and transmission, this paper studies the implementation of video capture and transmission in embedded system in detail.The frame of V4L2(Video 4 Linux 2) is used to control the capture of video image by the camera which conforms to the UVC(USB Video Class specification. The real-time acquisition and transmission of video are realized by using the Socket programming mode of TCP/IP, and the video can be viewed on the browser.Aiming at the remote configuration of FPGA based on embedded system, this paper studies the remote configuration scheme of FPGA using ARM in detail.Jam player is successfully transplanted into embedded system by using Jam STAPL, and JTAG(Joint Test Action Group of FPGA is implemented in embedded platform.The research of several key technologies shows that the remote experiment architecture based on embedded system can meet the needs of the remote digital system experiment platform, realize the intelligence of the equipment and reduce the cost of the remote experiment system.
【学位授予单位】：四川师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：G434

【参考文献】