近年來，無人機除了軍事用途外，亦廣泛應用於各種民生需求，如空拍影像等。由於無人機輕巧、機動性高且不易受地形限制之特性，開始有應用無人機於基礎設施（如電塔、老舊大樓）等檢修的案例。然而，無人機的操作大多缺乏自主運動規劃能力，進行檢修時仍是由使用者透過搖桿等介面進行人工操控，使用上繁瑣耗時外，也不易上手。除此之外，目前並無針對立體建築物巡檢為目的而設計的無人機路徑規劃系統。本論文以此作為研究動機，開發無人機於立體建物檢視之覆蓋路徑規劃系統。透過使用者介面，輸入網格模型與相機參數，系統便能自動計算出無人機檢視之視點，並經由視點產生無人機巡檢路徑。該路徑混合立面與平面路徑，且無碰撞。最後本論文於模擬環境中使用四軸飛行器模擬飛行，證明本論文提出方法之有效性。

In addition to military applications, unmanned aerial vehicles (UAVs) have also been widely used in various applications, such as aerial photography. With the characteristics of lightweight and space maneuverability, using UAVs to inspect buildings is becoming popular. However, the operation of most UAVs still relies on skilled human operators. Equipped UAVs with autonomous motion planning ability is highly desirable. We have not seen motion planners that can generate inspection paths for vertical as well as horizontal surfaces of a building. In this study, we propose a UAV coverage path planning method for building inspection. Users can input a mesh model and camera parameters, and then the system will generate a sequence of inspection viewpoints, and compute an inspection path through these viewpoints. The inspection path is composed of sub-paths for inspecting horizontal and vertical surfaces and is guaranteed to be collision-free. Finally, the study verified the effectiveness of the proposed planner with a quadcopter in a simulation environment.

[1] E. Bone and C. Bolkcom, "Unmanned aerial vehicles: Background and issues for congress," 2003: Library of Congress Washington DC Congressional Research Service.
[2] (19-Sep). 經緯航太 | GEOSAT. Available: https://www.geosat.com.tw/TW/index.aspx
[3] 張竣堯, "運用無人飛行載具搭載紅外線進行建築外牆磁磚檢測," 建築研究簡訊 vol. 99, ed: 中華民國內政部建築研究所, 2018.
[4] P. Cignoni, C. Montani, and R. Scopigno, "A comparison of mesh simplification algorithms," Computers & Graphics, vol. 22, no. 1, pp. 37-54, 1998.
[5] D. Bommes, B. Lévy, N. Pietroni, E. Puppo, C. Silva, M. Tarini, and D. Zorin, "Quad‐mesh generation and processing: A survey," Computer Graphics Forum, vol. 32, no. 6, pp. 51-76: Wiley Online Library, 2013.
[6] J. Daniels, C. T. Silva, J. Shepherd, and E. Cohen, "Quadrilateral mesh simplification," ACM transactions on graphics (TOG), vol. 27, no. 5, p. 148: ACM, 2008.
[7] M. Tarini, N. Pietroni, P. Cignoni, D. Panozzo, and E. Puppo, "Practical quad mesh simplification," Computer Graphics Forum, vol. 29, no. 2, pp. 407-418: Wiley Online Library, 2010.
[8] E. Galceran and M. Carreras, "A survey on coverage path planning for robotics," Robotics and Autonomous systems, vol. 61, no. 12, pp. 1258-1276, 2013.
[9] T. Cabreira, L. Brisolara, and P. R. Ferreira Jr, "Survey on Coverage Path Planning with Unmanned Aerial Vehicles," Drones, vol. 3, no. 1, p 4, 2019.
[10] Y. Li, H. Chen, M. Joo Er, and X. Wang, "Coverage path planning for UAVs based on enhanced exact cellular decomposition method," Mechatronics, vol. 21, no. 5, pp. 876-885, 2011.
[11] M. Torres, D. A. Pelta, J. L. Verdegay, and J. C. Torres, "Coverage path planning with unmanned aerial vehicles for 3D terrain reconstruction," Expert Systems with Applications, vol. 55, pp. 441-451, 2016.
[12] P. Cheng, J. Keller, and V. Kumar, "Time-optimal UAV trajectory planning for 3D urban structure coverage," in 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 2750-2757: IEEE, 2008.
[13] A. Bircher, K. Alexis, M. Burri, P. Oettershagen, S. Omari, T. Mantel, and R. Siegwart, "Structural inspection path planning via iterative viewpoint resampling with application to aerial robotics," in Proceedings of the 2015 IEEE International Conference on Robotics and Automation (ICRA), 2015.
[14] S. Jung, S. Song, P. Youn, and H. Myung, "Multi-Layer Coverage Path Planner for Autonomous Structural Inspection of High-Rise Structures," in Proceedings of the 2018 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2018.
[15] T. Luukkonen, “Modelling and control of quadcopter,” Independent research project in applied mathematics. Aalto University School of Science, 2011.
[16] K. Helsgaun, "An effective implementation of the Lin–Kernighan traveling salesman heuristic," European Journal of Operational Research, vol. 126, no. 1, pp. 106-130, 2000.
[17] (9-Aug). DJI Maviz 2 Zoom. Available: https://store.dji.com/zh-tw/product/mavic-2?vid=45321
[18] (9-Aug). DJI Matrice 200. Available: https://www.dji.com/tw/matrice-200-series-v2