臺灣博碩士論文加值系統

本論文為建構一多軸旋翼無人機之視覺導引輔助自動降落系統。系統以NI myRIO為管理核心，藉由OpenMV Cam辨識之AprilTag資料，計算無人機之預計飛行軌跡，並由NI myRIO將此資訊傳遞給APM飛控系統，使無人機能夠朝目標點前進並進行降落。
本文首先說明由OpenMV擷取的影像資料經轉換成實際數值，並利用此資訊以計算出無人機所需於偏航與滾轉…等之修正量；接著探討終端導引所使用之AprilTag圖樣限制及導引過程中此圖樣之擺放限制。再利用作者以LabVIEW程式設計之地面監控站，初始設定飛行過程的AprilTag導引點，並顯示無人機的飛行狀態及視覺導引狀況。最後進行系統整合測試，藉由視覺導引方式使多軸無人機到達目標點並進行自動降落，以證實本系統的可行性。

A vision-guided augmentation for an automatic landing system of a multirotor drone is developed in this thesis. The NI myRIO is served as the management core of this system to get AprilTag information from OpenMV Cam and to calculate the required flight path. Once above information is delivered to the APM flight control system from NI myRIO, it will command this drone to fly toward the target point and make a landing.
The calculation for the corresponding corrections of yaw and roll… etc. with the actual numerical data which are converted from the images acquired by OpenMV of this system is introduced in this paper. Followed by investigating the conditional restrictions of the AprilTag patterns for terminal and midcourse guidance, the initialization of the AprilTag waypoints on the ground control station which is designed by author with LabVIEW is also included. Finally, the integration and feasibility tests of the system are evaluated based on the vision-guided drone to reach the target position and land automatically.

誌　　謝 I
摘　　要 II
ABSTRACT III
目　　錄 IV
圖 目 錄 VI
表 目 錄 X
第一章 緒論 1
1.1 研究動機 1
1.2 研究目的 2
1.3 文獻回顧 3
1.4 各章簡述 3
第二章 系統架構和硬體介紹 5
2.1 系統流程與架構 6
2.2 OPENMV 7
2.3 NI MYRIO 8
2.4 六軸旋翼機 9
2.5 APM 9
2.6 RC伺服馬達訊號切換器 10
2.7 遙控器與接收器 11
2.8 XBEE無線傳輸模組 11
第三章 辨識APRILTAG次系統 12
3.1 APRILTAG介紹 12
3.2 OPENMV辨識APRILTAG測試結果 13
3.3 OPENMV與MYRIO系統建構與驗證 16
3.4 距離換算與實際距離驗證 20
3.5 兩APRILTAG位置擺放之最遠距離測試 25
3.6 兩種尺寸APRILTAG合併於一張圖測試 27
3.7 同時辨識兩尺寸之APRILTAG並換算距離之驗證 33
第四章 視覺導引次系統與地面站 36
4.1 地面與空中通訊建構與測試 36
4.2 馬達比例控制 38
4.3 中途導引流程 42
4.4 終端導引流程 46
4.5 影像失效處理 47
第五章 系統整合與驗證 49
5.1 系統整合測試 49
5.1.1 安全切換開關測試 49
5.1.2 PWM訊號輸出與馬達實際行為驗證 55
5.2 空中驗證 60
5.2.1 AprilTag對正實驗驗證 60
5.2.2 中途導引驗證結果 62
5.2.3 終端導引驗證結果 70
5.2.4 影像失效驗證結果 83
第六章 結論與未來展望 84
參考文獻 86
附錄一 OPENMV規格 88

【1】維基百科(Multirotor)
https://zh.wikipedia.org
【2】無人機宅配(Workhorse)
https://dronesplayer.com
【3】亞馬遜送貨無人機(Prime Air)
https://www.amazon.com
【4】A. Gautam, P. B. Sujit, S. Saripalli, "Autonomous Quadrotor Landing Using Vision and Pursuit Guidance", IFAC-PapersOnLine, vol. 50, pp. 10501-10506, 2017.
【5】吳宗錞，運用視覺輔助功能與無人機自動降落系統之建構，逢甲大學航太系，民國108年7月
【6】T. H. Nguyen, M. Cao, T. Nguyen and L. Xie, "Post-Mission Autonomous Return and Precision Landing of UAV," 2018 15th International Conference on Control, Automation, Robotics and Vision (ICARCV), Singapore, pp. 1747-1752, 2018.
【7】The APRIL Robotics Laboratory at the University of Michigan
https://april.eecs.umich.edu/software/apriltag
【8】E. Olson, "AprilTag: A robust and flexible visual fiducial system," 2011 IEEE International Conference on Robotics and Automation, Shanghai, pp. 3400-3407, 2011.
【9】J. Wang and E. Olson, "AprilTag 2: Efficient and robust fiducial detection," 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), Daejeon, pp. 4193-4198, 2016.
【10】J. Wang, C. Sadler, C. F. Montoya and J. C. L. Liu, "Optimizing Ground Vehicle Tracking Using Unmanned Aerial Vehicle and Embedded Apriltag Design," 2016 International Conference on Computational Science and Computational Intelligence (CSCI), Las Vegas, NV, pp. 739-744, 2016.
【11】OpenMV
https://openmv.io/collections/cams/products/openmv-cam-m7
【12】NI myRIO
https://www.ni.com/zh-tw/support/documentation/supple
mental/13/ni-myrio-hardware-at-a-glance.html
【13】RC Servo Multiplexer
https://www.pololu.com
【14】AprilTag模組
https://docs.openmv.io/library/omv.image.html#class-apriltag-
apriltag-object
【15】Mission Planner
https://ardupilot.org/planner/