EPA网络控制系统时钟同步主时钟控制算法研究  

Research on Control Algorithm to Optimal Master Clock of Clock Synchronization in EPA Networked Control Systems

作　　者：王颋[1] 王平[1] 向敏[1] 

机构地区：[1]网络化控制与智能仪器仪表教育部重点实验室,重庆邮电大学,重庆400065

出　　处：《系统仿真学报》2009年第1期146-151,156,共7页Journal of System Simulation

基　　金：国家863/CIMS主题资助项目(2006AA040301);重庆市自然科学基金计划(CSTC,2007BB2455);国家863/CIMS主题资助项目(2007AA041301)

摘　　要：为满足EPA网络控制系统时间同步的高精度要求,由EPA子网通讯确定性调度机制构建虚拟链路,建立基于时钟精度差的多层次主时钟选择算法。引入IEEE1588时钟变量σPTP,动态调整时钟精度偏差(CPD:Clock Precision Difference)与时间值偏差(TVD:Time Value Difference)为权重的时钟优先级(CP),建立一种二维模糊控制器确定设备时钟性能优劣层次,而系统采用公平竞争的方法从众多现场设备中快速、准确地决策一个时钟性能最好的设备作为EPA系统的最佳主时钟,保证了系统运行的稳定性,降低了本地时钟的波动,使时钟同步精度提高到50微秒。To meet the high quality for clock synchronization in EPA （Ethernet for plant automation） networked control system, virtual link was built due to EPA confirmed scheduling mechanism from sub network communication, and multi-level choice algorithm of master clock was built based on clock precision difference. Clock variable σ PTP of IEEE 15888 was induced, and weight of clock priority of CPD（Clock Precision Difference）and TVD（Time Value Difference）were regulated dynamically. A two-dimension fuzzy controller was constructed to demonstrate the quality of every device, and then the optimal master clock of system was selected quickly and exactly from multi-field devices based on equitable competition. Based on the algorithm, the stability of EPA system was improved and the fluctuation of local clock was reduced, and the accuracy of field devices’ clock synchronization is up to 50us.

关 键 词：EPA 主时钟 精确时间同步 模糊控制 时钟精度差 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]