多跳无线传感器网络下基于KF优化的PTP协议  

Precision time protocol(PTP) on the basis of Kalman filtering in the multi-hop wireless sensor network

作　　者：杨玉景[1] 黄艺文[1] 李太华[1] 代学武[1] 

机构地区：[1]西南大学电子信息工程学院,重庆400715

出　　处：《智能系统学报》2014年第2期174-179,共6页CAAI Transactions on Intelligent Systems

基　　金：国家自然科学基金资助项目(61101135);西南大学基本科研业务费专项资金资助项目(XDJK2012C065)

摘　　要：保持各节点时间上的同步在分布式系统中具有十分关键的地位,是保证各节点间协同工作,处理数据正确和传输可靠的前提。无线传感器网络的时间同步,由于获取精确时钟戳难度大、传输延迟抖动明显等问题,导致精度不够。针对无线传感器网络低功耗的特点及对时钟同步算法精度的要求,提出了一种基于卡尔曼滤波器优化的IEEE 1588 PTP时间同步方法,研究了无线网络中PTP的性能与时间戳精度之间的关系,在单跳同步实验基础上,将同步网络拓展到多跳,以验证不同协议模式下的多跳同步性能。仿真结果表明,针对不同时钟标记的不确定性,基于卡尔曼滤波器优化的PTP协议能够较好地滤除同步噪声,抑制同步误差的传递,在保持同步精度的前提下适用于更大规模的无线传感器网络。Precise time synchronization plays a central role in the distributed system. It is vital to maintain time syn- chronization for collaborative work between nodes, process data correctly, and transmit information reliably. The low accuracy of time synchronization among wireless sensor nodes is caused by obvious transmission delay jitters, low timestamp accuracy, etc. In accordance with the high accuracy and low power consumption requirements, an 1EEE 1588 PTP solution for applying the Kalman filtering based precision time protocol （PTP） in multi-hop wire- less sensor network has been proposed for researching the relationship between the performances of PTP in wireless networks and the accuracy of timestamps. The synchronization network is expanded to the multi-hop network based on the single-hop synchronization experiment for the purpose of validating the multi-hop synchronization performance with different protocol modes. The simulation results show that while focusing on the uncertainty of the marker for different clocks, the PTP based on Kalman filter optimization can fiterout the synchronization noise and decrease the synchronization errors, and this method is suitable for larger-scale wireless sensor networks with the goal of ensuring synchronization precision.

关 键 词：无线传感器网络 PTP协议 卡尔曼滤波器 多跳 时间同步 同步噪声 

分 类 号：TP212.9[自动化与计算机技术—检测技术与自动化装置] TN929.5[自动化与计算机技术—控制科学与工程]