當電腦大量的出現在家中、辦公室與人們的生活領域時，扮演資訊交換所發展的網路也悄悄的來到我們身邊，隨著電腦的快速發展各式各樣網路隨處可見，不但掀起資訊交換的革命也改變了人們的交流方式，今天我們善加利用網路可以加速我們工作的效率，可以查詢所需要的資訊，可以學習新的知識，甚至可以運用網路來購買生活上的一切所需，相對的沒有網路的電腦，如同沒有節目的電視機，我們可以說是網路把電腦帶入新紀元，但是強大的網路系統僅止於此嗎？我們深深覺得，未來網路不僅止於搭配電腦系統，還可以延伸到我們生活上所有的事物上，讓未來生活更加便利，於是我們以更靈活的網路裝置作為我們的研究方向，IEEE802.15.4 / Zigbee是一個低功率省電硬體架構簡潔的通訊技術，很適合使用在感測器網路上，來實現靈活的網路裝置。
      
   在感測器網路中，每當感測器節點取得觀測數值後會將這些資料傳送給後方儲存與處理，所以需要龐大的感測器節點群與數個橋接器，才能將感測網路與區域或廣域網路連接，我們實作出一台具移動功能的巡察系統，來減少感測器節點群密度或取代部分固定式橋接器，在一般Zigbee感測器節點上，其運算和通訊與電源供給都很有限，為了彌補這些感測器節點的不足，巡察系統具備中距離的區域網路通訊能力和足夠的運算能力與影像攝取能力，可以移動到固定型節點旁擔任數據收集者和協同移動式感測器節點群組移動，提供橋接區域網路和擔任複雜演算工作，當感測器節點出現狀況時，還可以提供感測器節點周遭影像資訊。
      
   巡察系統主要由嵌入式系統平台，802.11g無線區域網路模組、影像攝取壓縮模組、電源模組、Zigbee 通訊控制模組與移動機構模組所組成，802.11g無線區域網路模組與Zigbee 通訊控制模組負責橋接感測器網路與無線區域網路，影像攝取壓縮模組負責將區域影像壓縮並透過無線區域網路傳輸到遠端，移動機構負責任意方向自由移位，電源供應模組負責提供穩定電源。

在通訊性能方面，Zigbee 通訊控制模組其發射功率為0dbm，接收靈敏度為 -92dbm搭配內置型微型天線，實際在室內環境中通訊距離約30公尺，另搭載的無線網路模組發射功率為18dbm＠54M，天線增益為5dbi，接收靈敏度為-93dbm＠1M，經由實驗在空曠的室內環境中可以通訊至550公尺，(超過360公尺時畫面開始間歇性消失)，所以我們可以得知移動式橋接器的有效通訊半徑約為550公尺，這與一般型感測器節點30公尺的通訊能力相比顯然有較佳的涵蓋範圍，感測器節點至少需要使用19個來達到相同的通訊效果，其移動能力更是建立靈活的感測器網路的好方法，未來需要更強的通訊能力時，可直接將無線區域網路模組更換為3G 或WiMAX模組，則通訊能力更加無限延伸。

When computer massive appearances in home, office and people's life, the network, which acts as the information exchange, arrives quietly as well. Along with the fast development of computer, all kinds of network reside in everywhere obviously. The network is not just causing the revolution of information exchange but also people’s exchange way. With the use of network, we can accelerate the work efficiency; inquire the information which needed; study new knowledge, and even purchase commodities.Compare to these computers without the network connected, were similar to those televisions without any program. We are allowed to say the network leads the computer into the new era, but the formidable network system only stops at this? We deeply believe the future network will not stop on matching the computer system, but also will be allowed to extend to all aspects of our lives. It will make our live more convenient in the future. Thereupon, we set our research direction to the more nimble network equipment. IEEE 802.15.4 / Zigbee is the communication technology of a low electric hardware of power province with succinct structure, very suitable for using it in the sensor network, to realize the flexible network device.                              .

    In the sensor network, whenever the sensor node receives the observation value, it transfers these materials to the backend for storage and processing, therefore, the sensor network requires a huge of sensor nodes and several bridges to connect to the local area network or wide area network. In this thesis, we physically make a mobile wireless sensor network bridge to decrease the density of senor nodes or to be the substitute for the certain stationary bridge. Generally, the sensor node of Zigbee is with very limited capability of operation, communication and power supply, in order to remedy these nodal deficiencies of sensor nodes, a mobile patrol System has the communication, operation and the image absorption capability that can be functional in middle distance local area network. The mobile patrol System can move to the side of stationary bridge to act as a data collector or to accompany with other sensor nodes to make up the lack of sensor nodes to provide the bridge function as well to support the complex calculation work. It can also offer the image information around a sensor node when this sensor node is failed.                                             .

    The mobile patrol System consists of the embedded system platform mainly, 802.11g wireless local area network module, image absorption/compression module, power module , Zigbee communication control module and move mechanism module. The 802.11g, wireless local area network module and Zigbee communication control module are responsible for bridging the sensor networks to wireless area network. The image absorption/compression module is responsible for compressing the local image and transmitting it to the far end through the wireless local area network. Move mechanism module is responsible for shifting freely in all directions and the power supply module is responsible for offering and stabilizing the power.                  .

    In communication aspect, Zigbee communication control module’s transmit output power is 0dbm while the receiver sensitivity is - 92dBm coupled with internal miniature antenna, conducting the test in 30 meters distance in indoor environment. The transmit output power of 802.11g wireless module is 18dBm@ 54m, the antenna gain is 5dBi, while the receiver sensitivity is -93dbm@ 1m. In an experiment, the transmitted is to 550 meters in the spacious outdoor environment. (The image disappear intermittently at the beginning when exceeding 360 meters), so that we can probably learn the mobile patrol System’s the effective radius of communication is about 550 meters. Compare the communication ability of the mobile patrol System with that of general sensor node, the later only has 30 meters of communication ability. It’s very obviously; one mobile patrol System has better range of coverage; equals to at least 18 sensor nodes’ coverage.Its movement ability is a good method to set up the flexible sensor network. We can replace the wireless module with 3G or WiMAX module while stronger communication ability is needed in the future, then communication ability could be extended limitlessly.   .

目 錄
第一章 緒論.......................................1
1.1前言...........................................1
1.2 研究動機......................................3
1.3 論文架構......................................4
第二章 網路架構與運用機會.........................5
2.1無線區域網路概述...............................5
2.2 感測網路架構概述..............................7
2.3 IEEE 802.15.4/ZIGBEE 概述.....................9
2.4 巡察系統與感測網路相互搭配上之運用機會.......11
2.4.1 感測網路搭配巡察系統.......................11
2.4.2 巡察系統搭配感測網路.......................12
2.5 巡察系統其他運用機會.........................14
第三章 系統架構................................ .15
3.1 系統規劃.....................................15
3.2 硬體模組研製.................................19
3.2.1 主系統平台.................................22
3.2.2 移動機構...................................26
3.2.3 IEEE 802.11g 無線通訊模組..................30
3.2.4 ZIGBEE 通訊控制模組........................31
3.2.6 電池模組與馬達驅動模組.....................37
3.3 軟體模組研製.................................39
3.3.1 Linux作業系統架構..........................40
3.3.2 驅動程式模組...............................44
4.1 系統電源規劃.................................45
4.2 模組整合.....................................47
第五章 功能驗證與測試............................51
5.1 功能驗證.....................................51
5.2 通訊能力驗證.................................54
5.3 電源消耗測試.................................56
第六章 結論與未來方向............................58
6.1 結論與未來方向...............................58
參考資料.........................................60

 
圖目錄
圖2.1  WLAN 標準架構..............................6
圖2.2  多重群組之感測網路.........................8
圖2.3  IEEE 802.15.4與ZIGBEE負責層別.............10
圖2.4  感測網路搭配巡察系統運用..................11
圖2.5  巡察系統之感測網路運用圖..................12
圖3.1  系統架構概念圖............................16
圖3.2  巡察系統架構圖............................18
圖3.3  巡察系統細部方塊圖........................18
圖3.4  硬體研製流程..............................21
圖3.5  主平台系統方塊圖..........................24
圖3.6  垂直狀分佈子輪之全向輪....................27
圖3.7  螺旋狀分佈子輪之全向輪....................27
圖3.8  移動承載機構設計圖........................29
圖3.9  Zigbee控制模組方塊圖......................32
圖3.10  微帶線結構圖.............................34
圖3.11  PCB 堆疊結構圖...........................35
圖3.12  網路分析儀量測圖.........................35
圖3.13  馬達驅動模組架構圖.......................38
圖3.14  作業系統架構圖...... ....................39
圖3.15  Linux主要架構...... .....................40
圖4.1  電源規劃與分配圖..........................46
圖4.2  各部位模組實體圖..........................47
圖4.3  系統連接圖................................49
圖5.1  巡察系統完成實體..........................53
圖5.2  遠端控制介面之畫面........................53
圖5.3  Zigbee/WLAN 使用頻道狀況..................54
圖5.4  電源消耗紀錄圖............................57
 
表目錄
表1  X86嵌入式平台比較...........................25

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