SIA OpenIR  > 工业控制网络与系统研究室
面向硬实时工业无线网络的高精度时间同步方法研究与实现
其他题名Research and Implementation of High Precision Time Synchronization Method Oriented to Hard Real-time Industrial Wireless Network
杨雨沱1,2
导师梁炜
分类号TN926
关键词工业无线网络 工厂自动化无线网络 Ieee 802.1 Tdma 时间同步
索取号TN926/Y29/2013
页数65页
学位专业控制理论与控制工程
学位名称硕士
2013-05-28
学位授予单位中国科学院沈阳自动化研究所
学位授予地点沈阳
作者部门工业控制网络与系统研究室
摘要工业无线网络技术是一种面向工厂设备间信息交互的无线网络技术。工业无线网络以其低成本、易使用、易维护等特点,已成为降低工业测控系统成本、扩展应用范畴的革命性技术。然而,工业应用的特殊性对无线技术提出了高可靠、硬实时、低能耗等严格的性能需求。针对这一问题,自20世纪以来,先进工业国家投入巨资开展了该方面的研究,工业无线网络技术获得了突飞猛进的发展。但目前的工业无线技术的应用还仅局限于过程自动化领域监测等具有软实时特征的应用,还无法满足具有硬实时通信要求的离散制造业工厂自动化应用需求。时间同步是实现硬实时通信的基础技术。工厂自动化应用对时间同步提出了更高的要求,现有技术还无法应对这一挑战。本文针对面向工厂自动化的工业无线网络的硬实时通信要求,设计了一套高精度时间同步方法,并在网络原型系统实现了该方法,最终通过软硬件测试平台验证了其有效性,取得的具体成果如下:1.概述了工业无线网络的概念、挑战及其发展现状;阐述了时间同步技术及其在工业无线网络中的重要作用;详细介绍和分析了现有无线传感器网络的时间同步方法;并进一步归纳了面向离散制造业控制系统的工业无线网络的时间同步需求。2.针对网络节点间的时钟相位偏移以及网络特性,分别面向小规模和大规模网络提出了两种高精度、低开销的时间同步方法。所提基于TDMA的小规模网络高精度双向时间同步方法通过时戳信息聚合与解聚、过程数据捎带等低开销双向时戳获取机制,可精确测算时钟源与网络节点间的时钟偏差值,消除同步报文传输的不确定性时延,且具有低开销的优点。基于接收者的大规模网络低开销时间同步方法充分利用星型网络的结构特征,将原本是时钟源的接入设备作为接收者,并利用其广播它与其他接受者的时间偏差,消除了任意接受者间一对一的时间偏差获取过程,降低了时间同步开销,提高了时间同步方法的可扩展性。3.针对恶劣工厂环境下网络节点间时钟频率偏移的不确定性,提出了基于预测补偿的自适应鲁棒时间同步方法。该方法采用指数加权移动平均算法预测时钟偏差,通过所提权重参数的自适应选取机制,实现了节点时钟频率漂移的线性补偿,使时钟漂移率趋于0。实验表明该方法可在通信不可靠等不确定环境下仍可保证时间同步的精度,并通过与之前所提时间相位偏移校准算法的结合,时间同步精度最高可达7us,能够满足工厂自动化无线网络的要求。4.为验证本文提出的时间同步算法,搭建了面向工厂自动化的工业无线网络原型系统;在此基础上,设计并开发了时间同步测试验证平台。该平台分别用软、硬件两种方法,测试时间同步精度,验证了本文所提出的时间同步算法的有效性。
其他摘要Industrial wireless network technology which caters for information transfer between devices is emerging at the beginning of this century. Industrial wireless network technology is becoming an innovation technology for reducing the cost of industrial measurement and extending the scope of application because of its low-cost, usability and maintainability characteristics. However, because of the particularity of industrial application wireless technology need to be high reliability, hard real-time and low energy consumption. In order to solve these problems the advanced industrial countries invested a lot to carry out the research, so the industrial wireless technology has gained rapid development since the 20th century. But the current industrial technology is limited that can only apply in soft real-time application such as monitoring process automation. It cannot meet hard real-time communication requirements of discrete manufacturing factory automation applications. Time synchronization technology is the supporting technology for hard real-time communication. Factory automation applications raise higher requirements for time synchronization. The existing technology cannot meet this challenge. Orienting the hard real-time requirements of factory automation wireless network, this text designed a high precision time synchronization method. Then we implement this method in network prototype. Finally we verify the validity of the time synchronization method by hardware and software testing platform. The specific results achieved are as follows: 1. Introduced the concept of industrial wireless network, challenges, and its development status, then this text described the time synchronization technology and its important role in the industrial wireless network. Summarized existing wireless time synchronization method in wireless sensor network; and summed up the time synchronization requirements for wireless network of discrete manufacturing control system industrial. 2. According to high time synchronization precision requirements of the factory automation wireless network and the network characteristics, first we design the two-way time synchronization algorithm based on TDMA mechanism which can highly accurate measurement of the value of the clock skew between the clock source and network nodes and transmission delay. After added time stamp information polymerization and depolymerization and incidentally process data technology the two-way time synchronization algorithm based on TDMA mechanism reduce the overhead significantly. Then we reference the idea of RBS algorithm and designed time synchronization algorithm based on recipients for large scale wireless network. Time synchronization algorithm based on recipients make time source be one of the recipients, and compare it’s time stamp to another recipient’s time stamp when receiving a packet. Then the other recipient can get precision time skew value. This method need only two nodes sending time stamp data to achieve the whole network time synchronization. What’s more, this algorithm can also eliminate the time stamp data transmission delay so it achieves high synchronization accuracy and low overhead. 3. To further improve the time synchronization accuracy and enhance the robustness and adaptive of the time synchronization algorithm, this paper design the high precision time synchronization algorithm based on prediction and compensation. Put the time skew value from the two-way time synchronization algorithm based on TDMA mechanism and time synchronization algorithm based on recipients to prediction model for time skew prediction and calibrating local time. This algorithm maximizes the precision of time synchronization. After the two-way time synchronization method added this time synchronization algorithm based on prediction and compensation, the time synchronization precision can reach 7us which can fully support microsecond TDMA slot scheduling of factory automation wireless network. This algorithm also avoid the big time skew value caused by time synchronization packet delivery failing. This algorithm has high precision, high reliability, strong adaptability advantages and so on. 4. For verifying the time synchronization algorithms above, orienting factory automation this paper build a network prototype system and time synchronization precision test beds which constituted both hardware and software. Then the test beds verify the effectiveness of the proposed time synchronization algorithm.
语种中文
产权排序1
文献类型学位论文
条目标识符http://ir.sia.cn/handle/173321/10743
专题工业控制网络与系统研究室
作者单位1.中国科学院沈阳自动化研究所
2.中国科学院大学
推荐引用方式
GB/T 7714
杨雨沱. 面向硬实时工业无线网络的高精度时间同步方法研究与实现[D]. 沈阳. 中国科学院沈阳自动化研究所,2013.
条目包含的文件
文件名称/大小 文献类型 版本类型 开放类型 使用许可
面向硬实时工业无线网络的高精度时间同步方(2417KB) 开放获取CC BY-NC-SA请求全文
个性服务
推荐该条目
保存到收藏夹
查看访问统计
导出为Endnote文件
谷歌学术
谷歌学术中相似的文章
[杨雨沱]的文章
百度学术
百度学术中相似的文章
[杨雨沱]的文章
必应学术
必应学术中相似的文章
[杨雨沱]的文章
相关权益政策
暂无数据
收藏/分享
所有评论 (0)
暂无评论
 

除非特别说明,本系统中所有内容都受版权保护,并保留所有权利。