近年來，具有高機動性的移動機器人之相關領域被高度的重視並且探討研究。藉由提供導航資訊，移動機器人可以認知自身的位置進而自主性的移動。隨後，各個機器人被應用於負責不同的區域以達到更廣的空間分布性以及更高的工作效率，這也使得與多機器人系統有關之研究蓬勃發展，多機器人的排隊理論正是被最廣泛地討論的主題之一。
本論文中所建立的多機器人系統主要預期實現整個群體能夠維持特定的隊型和避開障礙物並前往目標地，同時以變換隊形的方式適應不同的環境。多個移動機器人以跟隨領導者的概念，將群體中的機器人組成階層式隊形以達成控制，然而，在實現多機器人隊型控制系統的過程中存在著相當多問題，例如:如何取得領導者與跟隨者之間的距離和角度、如何讓移動機器人可以立即地跟其他機器人交換資訊。以上都是本論文設法去解決的主要問題。
本論文結合燈塔式定位法(Lighthouse Location Method) 和基於WIFI RSSI (Received Signal Strength Indication) 的匹配定位法(WIFI RSSI fingerprinting positioning method) 使得移動機器人能在特定的室內環境中認知自身位置，並且利用無線通訊的技術建立多移動機器人之間的網路結構以達到溝通與協調的目的。
論文的最後會呈現隊型控制的模擬成果，除此之外，硬體的實現結果和多移動機器人在實際的室內環境下運動的軌跡圖也會被提出並討論。

In recent years, the research of mobile robot is highly valued and investigated due to its high mobility. By equipping navigation technology, the mobile robot is able to recognize the position and move freely. Afterwards, multi-robot system has flourished rapidly because of the high efficiency caused by extensive distribution. Each robot takes charge of a different region, so it takes less time to finish one job than relying on merely one robot. The multi-robot system has also become feasible to be utilized in specific tasks through the wireless technology.
The main purpose of the system which is built up in this thesis is to make multiple mobile robots maintain specific hierarchical formation to the destination and verify different formations to avoid obstacles. Therefore, this thesis follows the leader-following approach to achieve the desired formation. However, during implementing the leader-following controller, there are many problems such as how to attain the relationship among the robots and share information immediately. Thus, this thesis integrates Lighthouse Location Method, WIFI’s RSSI fingerprinting positioning method and wireless communication technology to design and implement the hierarchical formation control system for multiple mobile robots in indoor environment. Then, the simulation results and hardware implementation are provided to verify the effectiveness of our design.

[1]D. Niculescu, “Positioning in Ad Hoc Sensor Networks,” IEEE Network, vol. 18(4), pp.24-29, 2004.
[2]D.K.P. Tan, H. Sun, Y. Lu, M. Lesturgie and H.L. Chan, “Passive Radar Using Global System for Mobile Communication Signal,” IEE Proceedings of Radar, Sonar and Navigation, vol. 152(3), pp.116-123, 2005.
[3]D.M. Stipanović, P.F. Hokayem, M.W. Spong, D.D. Šiljak, “Cooperative Avoidance Control for Multiagent Systems,” Journal of Dynamic Systems, Measurement, and Control, vol. 129(5), pp.699-707, 2007.
[4]E. Rimon, D.E. Koditschek, “Exact Robot Navigation Using Artificial Potential Functions,” IEEE Transactions on Robotics and Automation, vol. 8(15), pp.501-518, 1992.
[5]J. Haartsen,“BLUETOOTH—The Universal Radio Interface for Ad Hoc, Wireless Connectivity,” Ericsson Review, No. 3, pp.110-117,1998.
[6]J.R.T. Lawton, R.W. Beard, B.J. Young, “A Decentralized Approach to Formation Maneuvers,” IEEE Transactions on Robotics and Automation, vol.19(6), pp.933-941, 2003.
[7]J.Y. Shao, G.M. Xie, J.Z. Yu, L. Wong, “Leader-following Formation Control of Multiple Mobile Robots,” 2005 IEEE International Symposium on Intelligent Control & 13th Mediterranean Conference on Control and Automation, pp.808-313, 2005.
[8]M.L. Lewis, K.H. Tan, “High Precision Formation Control of Mobile Robots Using Virtual Structures,” Autonomous Robots, vol. 4(4), pp.387-403, 1997.
[9]O. khatib, “Real-Time Obstacle Avoidance for Manipulators and Mobile Robots,” 1985 IEEE International Conference on Robotics and Automation, pp.500-505, 1985.
[10]P. Baronti, P. Pillai, V.W.C. Chook, S. Chessa, A. Gotta, Y.F. Hu, “Wireless Sensor Networks A Survey on The State of The Art and The 802.15.4 and Zigbee Standards,” Computer Communications, vol. 30, pp. 1655-1695, 2007.
[11]R. Simmon, “The Curvature-Velocity Method for Local Obstacle Avoidance,” 1996 IEEE International Conference on Robotics and Automation, vol.4, pp.3375-3382, 1996.
[12]R. Peng, M.L. Sichitiu, “Angle of Arrival Localization for Wireless Sensor Networks,” 3rd Annual IEEE Communications Society on Sensor and Ad Hoc Communications and Networks, pp.374-382, 2006.
[13]S. Mastellone, D.M. Stipanovi´c, C.R. Graunke, K.A. Intlekofer, M.W. Spong, “Formation Control and Collision Avoidance for Multiagent Non-holonomic System,” The International Journal of Robotics Research, vol. 27, pp.107-126, 2008.
[14]T. Balch, R.C. Arkin, “Behavior-Based Formation Control for Multirobot Teams,” IEEE Transactions on Robotics and Automation, vol. 14(6), pp.926-939, 1998.
[15]T.H. Huang, “Coordination and Fault Tolerance Control of Hierarchical Formation for Mobile Robots,” National Cheng Kung University Press, 2010.
[16]W. Lehr, L.W. McKnight, “Wireless Internet Access 3G vs. WiFi,” Telecommunications Policy, vol. 27, pp. 351-370, 2003.
[17]W.Z. Li, “Implementation of Real-Time Positioning and Optimal Path Planning for a Navigation System Based on IEEE 802.11 WLAN,” National Cheng Kung University Press, 2012.
[18]Z.Y. Wang, D.B. Gu, “Distributed Leader-follower flocking control,” Asian Journal of Control, vol. 11(4), pp.396-406, 2009.