張帆人臺灣大學:電機工程學研究所趙逸群Chao, I-ChungI-ChungChao2010-07-012018-07-062010-07-012018-07-062009U0001-2707200915404100http://ntur.lib.ntu.edu.tw//handle/246246/188138網際網路的蓬勃發展，不僅方便了人們的日常生活，更影響分散式系統的重要性。本論文架構在嵌入式平台遵從IEEE 1588 標準規範，引用不同的控制法則，讓不同主從( Master – Slave )節點的振盪器頻率相同，其亦使主從兩端時間高精度地同步。 IEEE 1588是高精度時間同步協定( Precision Time Protocol, PTP )，適用於分散式網路系統各節點之即時時間同步。時間伺服器是PTP的核心。利用主時鐘( Master Clock )與從時鐘( Slave Clock )的時脈偏差值當作回饋信號，透過控制法則，讓從節點的振盪器頻率緊隨著主節點振盪器，不斷地微幅調整。嵌入式系統強大的客制化及網路能力，受到分散式系統的青睞。本論文分析了計算機與分散式網路之間的相關細節，並整合實作出於分散式嵌入式架構下的同步系統。 本論文使用精確時間協定常駐程式( Precise Time Protocol daemon, PTPd )開放性原始碼，並對其設計雙輸入單輸出之模糊控制器，採用主從端之間的時脈偏差值以及累積時脈偏差值作為其輸入，而輸出為調整Linux核心之系統時間的頻率參數。在分散式的嵌入式主從架構環境下，透過修正型亞倫方差( Modified Allen Deviation )進行模糊控制器與比例積分控制器運行下的頻率穩定度分析，以及時域暫態收斂時間的比較；最後提出交換式控制器( Switching Controller )的概念：整合模糊法則與比例積分法則成為模糊比例積分( Fuzzy Proportional Integral, FPI )交換式控制器。FPI交換式控制器改善了原來的PI控制器之暫態收斂時間過長的缺點，而保留了PI控制器頻率穩定的優點。As the progress of internet, not only people feel convenient but also the distributed systems become popular. The implementation of embedded platforms which are designed according to IEEE 1588 standard for high precision synchronizing systems is investigated in this thesis. Moreover, we improve the performance of system response, that is, the clock offsets from the master to the slaves, by different control schemes. IEEE 1588, i.e. Precision Time Protocol (PTP), is suitable for distributed network system. The time servo is the core of PTP, in which the clock offsets between the master and the slaves are used to adjust the slave clock so that their oscillators have the same frequency. The powerful embedded systems become more and more important due to their abilities of customizing and networking. The Precise Time Protocol daemon (PTPd) is used to maintain the synchronized real-time clock system among the nodes of a distributed network. The fuzzy controller in the daemon is proposed. Its two inputs are clock offsets from the master to the slaves and the summation of clock offsets. Its one output is the argument of the system call of Linux operating system for tuning the clock frequency. Within a distributed embedded system, Modified Allen Deviation is used to analyze the stability of clocks. The comparision of stability of clocks between fuzzy controller and PI controller is mentioned. Also, the time responses are discussed. Moreover, the concept of switching controller is proposed. The integrated fuzzy controller and the PI controller are named FPI (Fuzzy Propotional Integrate) controller. The long transient time is reduced in the FPI controller via the operations of fuzzy function. The steady state frequency stability of the FPI controller is reserved via the operations of the PI function.中文摘要 ibstract ii錄 iii目錄 v目錄 vii一章 序論 1.1 研究動機 1.2 研究方向 1.3 論文架構 2二章 背景知識 3.1 時頻概論 3.1.1 頻率性能之衡定 3.1.2 時間偏差信號之數學模型 4.1.3 頻率精確度之量測 6.1.4 頻率穩定度之量測 7.2 嵌入式系統與計算機網路 8.2.1 計算機網路系統之概貌 9.2.2 網路封包與網路卡之互動 11.3 IEEE 1588標準 13.3.1 高精度時間同步協定標準簡介 13.3.2 時戳產生器 16.3.3 精確時間協定常駐程式 18三章 針對時脈偏移量之控制器設計 22.1 模糊控制理論 22.2 模糊控制器設計 23.2.1 系統特性分析 23.2.2 模糊控制器 25.2.3 模糊控制器設計步驟 26四章 時脈同步實驗之結果與分析 31.1 實驗設備及系統環境 31.1.1 實驗與系統環境 31.1.2 實驗設備 33.2 實驗結果及討論分析 36.2.1 系統效能影響因素之分析 36.2.2 比例積分控制器與模糊控制器之比較 37.2.3 整合模糊比例積分之交換式控制器 41五章 結論及未來展望 47.1 結論 47.2 未來展望 47考文獻 492207365 bytesapplication/pdfen-US時間同步系統高精度時間同步協定模糊控制切換式控制器分散式嵌入式系統Time Synchronization SystemPrecision Time ProtocolFuzzy ControlSwitching ControllerDistributed Embedded Systemthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/188138/1/ntu-98-R96921048-1.pdf