無線感測網路是未來國際發展趨勢，也是目前各國學術研究單位爭相投入的熱門題目。顧名思義，感測器網路就是由釵h感測器節點所構成，彼此之間以網路通訊來進行溝通，將所得到的資料整合起來。無線感測網路可涵括多元化的偵測應用，包括：醫療照護、軍事、環境監控、交通控制、工廠管理等等。無線感測器網路的特色包括高彈性、錯誤容忍、高感測精確度、低成本與快速佈植。利用分散式資料融合技術，可以提高資訊的正確性，刪除不正確、誇張的錯誤訊息。
　　節點有處理、傳輸、與接收資料的能力，其上配有感測元件監控環境，包括溫度、壓力、振動、音波、及化學氣體，能自主的監控與處理大範圍的環境變化。每個感測器節點須有省電、低成本而且小的特性。基於成本和節能的觀點，一般節點並沒有被賦予移動的弁遄A大大的限制了它的方便性。
　　本論文闡述移動式節點的好處，設計與實作出一個移動式感測器節點；並發展出一套路徑規劃的演算法，找出移動式節點移動時的最佳移動路徑，以期快速地暫時取代故障的靜態節點。此外，我們設計一個簡易充電站，在動態節點電池耗盡之前，回自動回到充電站充電，以保持感測器網路的正常運作。

Wireless sensor network is an emerging technology, and many academic units and research centers devote a lot to this issue. As the name, sensor network is composed of many sensor nodes. The sensor communicates with others through the network, and the data of each node would be integrated. It could be applied in medical care, military, environmental monitoring, traffic control, industry and so on. Here are some features of this technology: high flexibility, fault tolerance, high precision, low production costs, and scalability. By using distributed data fusion, the environmental information could be more correct.
Sensor nodes are capable of detecting, communication, and processing data. The sensing unit can detect the temperature, pressure, vibration, sound or chemical vapor autonomously. Each sensor node has the characteristics of few energy consumption, low cost, and small size. A common design of sensor nodes lacks of mobility due to the high cost and energy consumption, but it limits the applications drastically.
In this thesis, some advantages of mobile nodes are listed, and an implementation is demonstrated. When one static node is broken, the mobile node can go to the place to replace it temporarily. We propose two path planning method for the mobile node to repair the sensor network quickly when the static node is unworkable. Besides, we design a simply auto-recharging station for mobile node to recharge its power. And the mobile node can help the sensor network work well for a long time.

誌 謝 i
中 文 摘 要 ii
Abstract iii
Table of Contents iv
List of Figures vi
List of Tables viii
Chapter 1 Introduction 1
1.1 About Sensor Networks 1
1.1.1 Applications of Sensor Networks 5
1.1.2 Major Issues and Challenges 7
1.1.3 Applications of Mobile Nodes 10
1.2 Motivation and Objectives 12
1.3 Thesis Organization 13
Chapter 2 Literature Review 14
2.1 An Overview of Other Mobile Nodes 14
2.1.1 CotsBots 15
2.1.2 MICAbot 18
2.1.3 Robomote 21
2.2 Related Works about Path Planning and Navigation 24
2.3 Brief Reviews of Power Recharging Methods 25
Chapter 3 Design and Implementation of a Mobile Node 26
3.1 Introduction 26
3.2 Hardware Architecture 27
3.2.1 Top Layer 29
3.2.2 Middle Layer 31
3.2.3 Bottom Layer 32
3.2.4 Power Unit 33
3.3 Software Configuration 34
3.4 Comparison 36
Chapter 4 Path Planning System 38
4.1 Framework Statements 38
4.2 Path Planning System 39
4.2.1 Triangular Selection Path Planning 39
4.2.2 Segmental Selection Path Planning 45
4.2.3 The New Obstacles Determining 47
4.3 Dead Reckoning System 51
4.3.1 Vehicle Kinematics 51
4.3.2 Sensorial Dead Reckoning 52
4.4 Simulation Result and Analysis 54
4.5 Experiment Result 58
Chapter 5 Auto-Recharge System 59
5.1 Problem Statements 59
5.2 System Configuration 59
5.2.1 Policy of Auto-Recharging 59
5.2.2 Power Station and Mechanism of Mobile Node 62
5.2.3 Diagram of Auto-Recharging 64
5.3 Docking Control 65
5.4 Docking Result 67
Chapter 6 Conclusions and Future Works 69
Chapter 7 Contributions 71
7.1 Contributions 71
7.2 List of Publications 71
References 72

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