[1]叶玲,李太华,代学武.无线传感器网络环境下基于卡尔曼滤波的PTP协议[J].智能系统学报,2012,7(6):518-524.
YE Ling,LI Taihua,DAI Xuewu.Kalman filtering based precision time protocol (PTP) in wireless sensor networks[J].CAAI Transactions on Intelligent Systems,2012,7(6):518-524.
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《智能系统学报》[ISSN 1673-4785/CN 23-1538/TP] 卷:
7
期数:
2012年第6期
页码:
518-524
栏目:
学术论文—智能系统
出版日期:
2012-12-25
- Title:
-
Kalman filtering based precision time protocol (PTP) in wireless sensor networks
- 文章编号:
-
1673-4785(2012)06-0518-07
- 作者:
-
叶玲,李太华,代学武
-
西南大学 电子信息工程学院,重庆 400715
- Author(s):
-
YE Ling, LI Taihua, DAI Xuewu
-
School of Electronic and Information Engineering, Southwest University, Chongqing 400715, China
-
- 关键词:
-
精确时间同步协议; 卡尔曼滤波; 无线传感器网络; 自回归模型; 状态空间模型
- Keywords:
-
precision time synchronization; Kalman filter; wireless sensor networks; AR model; state space model
- 分类号:
-
TP393
- 文献标志码:
-
A
- 摘要:
-
作为分布式系统的重要组成部分,精确时间同步是对时间敏感的工业无线网络的核心技术.基于时间信息包交换的IEEE 1588精确时间同步协议(PTP)主要针对有线网络提出,其同步精度受制于时间戳的精度和传输延迟抖动.在无线传感网中,节点难以获取精确时钟戳,同时由于信道共享、包冲突和信道衰落,无线网络的传输延迟抖动非常明显. 研究了无线网络中PTP的性能与时间戳精度之间的关系,提出了一个自回归模型来描述时钟漂移,将PTP中的包交换过程抽象为一组状态空间方程,将延迟抖动等作为观测噪音,从而利用卡尔曼滤波器予以滤除.仿真结果表明,在不同时间戳精度和延迟抖动下,卡尔曼滤波能有效改善时钟误差和稳定性.
- Abstract:
-
As a key technique in any distributed system, precision time synchronization plays a core role in timesensitive industrial wireless networks. Based on the time package exchange techniques, the IEEE 1588 Precision time protocol (PTP) is developed for wired Ethernet and its performance is degraded by the precision of time stamping and jitters of transmission delay. However, in wireless sensor network, it is difficult for the lowcost node to acquire accurate time stamps. Due to the sharing of wireless channel, transmission collision and severe fading, the jitters in WSN are overwhelming. In this paper, the relationship between PTP performance and precision of time stamping in wireless network is investigated. The drifting clock is modeled by an autoregressive (AR) model and the package exchanging behavior of PTP is abstracted as a set of state space equations. This allows the uncertainties of time stamping and jitters are treated as observation noises, which can be removed by the mature Kalman filter. The simulation results show that the proposed Kalman filtering technique improves the time synchronization, in terms of clock estimation error and clock stability, under various conditions of time stamping uncertainties and jitters.
更新日期/Last Update:
2013-03-19