臺灣博碩士論文加值系統

在無線感測網路（Wireless Sensor Network, WSN）中，感測器總是大量的分散在惡劣甚至危險的環境下，造成感測器的電池難以充電或是替換。如何有效地延長電池的壽命及減少感測器的消耗功率成為最近無線感測網路的熱門研究。一般來說，當感測器處於活動模式（active mode）時，大部分的時間都處於閒置狀態。由於目前市面上的感測器大多是使用單頻率來操作，也就是說CPU不論是處於工作模式或是閒置模式所操作的頻率都是一樣的，在閒置狀態，感測器設定成高頻率會造成不必要的能量浪費。本論文提出將動態電壓及頻率調整（Dynamic voltage frequency scaling, DVFS）的機制整合至感測器，並依電池所剩的能量作為動態電壓頻率調整的基準來調整處理器的工作頻率以達到節能的目的。經由本實驗結果得知，感測器利用電池剩餘能量作為動態電壓頻率調整方式來運作，電池的壽命比使用在單頻的感測器延長約86%，比只有導入DVFS方式的感測器延長約27%左右。

Sensors are often distributed in rather adverse and even dangerous environments in wireless sensor network (WSN). It is difficult to change batteries of sensor nodes manually. Therefore, maximizing the battery life and effective power consumption have become hot research fields of WSN. Generally speaking, sensors in active mode are idle most of the time. Since most available sensors are operating on a single frequency, which indicating that same CPU frequency is used whether in working or in idle mode. It will result in unnecessary waste of energy if CPU were operated in high operating frequency during idle mode. In this thesis, we integrate DVFS (Dynamic voltage frequency scaling) mechanism into sensor node, and use the battery remaining energy as a criterion by adjusting CPU frequency to achieve energy-efficiency. According to the experimental results, the battery’s lifetime can be prolonged approximately 86% compared to single-frequency sensor and 27% compared to DVFS mechanism.

誌謝 II
摘要 III
Abstract IV
目錄 V
表目錄 VII
圖目錄 VIII
第一章 緒論 1
1.1 問題描述 1
1.2 研究動機 3
1.3 論文架構 4
第二章 背景及相關研究 5
2.1 無線感測網路之現況 5
2.1.1 無線感測網路介紹 5
2.1.2 感測器硬體架構 7
2.1.3 無線感測器網路之運用 8
2.2 功率消耗來源 9
2.3 動態頻率調整(Dynamic Frequency Scaling) 11
2.4 動態電壓頻率調整（Dynamic Voltage Scaling) 12
2.5 動態電源管理（Dynamic Power Management） 13
2.6 電池基本介紹及特性 14
2.6.1 理想電池與實際電池的差異 14
2.6.2 電池放電特性 16
2.6.3 電池模式 18
第三章 研究方法 22
3.1 MSP430特色 22
3.1.1 MSP430架構 23
3.1.2 電源管理模組Power Management Module (PMM) 24
3.1.3 Unified Clock System (UCS) 27
3.2 模擬情境 30
第四章 實驗結果與討論 35
4.1 實驗環境 35
4.2 實驗結果 35
第五章 結論與未來展望 39
5.1 結論 39
5.2 未來展望 40
參考文獻 41
附錄一 44
附錄二 44
附錄三 45
附錄四 45
附錄五 46
附錄六 47

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