由於近年來在小型電腦、相關周邊配備、電子感測元件與光學遙測等設備在技術的快速進展，再加上一般化價格水平，使得無人飛機（Unmanned Aerial Vehicle, UAV）已經漸具有長程視距外飛行的發展潛力，這項功能無疑將會大大的擴展無人飛機的應用範圍並使無人飛機的發展大為看好，因此，除了一般軍事研發單位之外，也吸引了許多國際間大學研究單位競相投入這個具有挑戰性的領域。
在視距外飛行的目標下，本篇論文將著重於發展一套低價位的導航系統作為一架五分之一大小的西斯納182模型載台進行自動飛行之用，並提供機上一光學遙測系統在進行拍照時需預先知道的導航資訊。
這套無人飛機導航次系統主要透過一個全球衛星定位接收機（GPS Receiver）與三顆微型角速率陀螺所組成，次系統的任務需求是提供無人飛機即時的空間位置、速度及姿態；低價位的目標將限制我們選用目前市面上已經發展成熟的任何慣性導航儀（Inertial Measurement Unit, IMU），因此姿態判定的部分將透過三顆微機電角速率陀螺來建構一套固裝式（strapdown）的姿態判定裝置，Garmin GPS-25衛星接收機則用來提供飛機的位置和速度，此外，導航系統並同時使用一個壓力式高度計與空速計來量取飛機飛行時的壓力高與空速以補償GPS在相關資訊擷取上的缺失。
這套導航系統目前已經經過幾次的地面測試及一次飛行測試，並針對飛行測試後，系統的缺失進行補強工作以達成即時提供無人飛機進行自動飛行時所需的導航資訊。就價格上而言，這套導航系統相較於市面上的的導航系統的確便宜許多。

Grasping recent developments in miniature-sized computer, its peripherals, electronic sensors, and optical sensing equipment at affordable cost, the Unmanned Aerial Vehicle (UAV) with functions of long endurance and flight autonomy beyond the visual range has gradually undertaken an attractive challenge in the university sectors. Based on these specific mission requirements and employing the existing commercial on-the-shelf products, this paper therefore focuses on the development of a low-cost simple navigation system for the model kit size UAV of Cessna 182 with a CCD optical payload system for acquiring and transmitting images.
Having the simplicity of construction in mind, the navigation system is designed through a Global Positioning System (GPS) receiver and the miniature home-designed 3-axis rate gyroscopes. The mission requirements of the navigation system deem it to detect the three dimensional position, velocity and attitude, including roll, pitch and yaw angles of UAV. The attitude measurement system, which is the strapdown type, is therefore developed using three miniature rate gyroscopes for the optical sensing system. The Garmin GPS-25 is adopted for position and velocity observations. In addition, the air data sensing system is composed of a pressure altitude sensor and airspeed sensor to detect the pressure altitude and airspeed.
The whole system has already been demonstrated in the flight tests to be capable of providing the desired navigation information in real-time. The low-cost objective has also been achieved.

[1] Office of Secretary of Defense, “Unmanned Aerial Vehicles Roadmap, 2001~2025”, April, 2001
[2] The UAV forum homepage, www.uavforum.com
[3] The Aerosonde homepage, www.aerosonde.com
[4] Hsiao, F.B. and Lee, M.T., “System Engineering and Practice in Aircraft Design for Aerospace Education,” UNESCO 4th Annual Conference on Engineering Education, Bangkok, Thailand, 7-10 February 2001.
[5] Stanford University DragonFly Project
http://sun-valley.stanford.edu/hybrid/UAV/index.html
[6] University of Maryland Autonomous Vehicle Laboratory, http://uav.umd.edu/
[7] University of Michigan, http://www.engin.umich.edu/
[8] Hsiao, F. B. and Lee, M.T., “The Development of Unmanned Aerial Vehicle in RMRL/NCKU,” 4th Pacific International Conference on Aerospace Science and Technology, Kaohsiung, Taiwan, May 21-23, 2001.
[9] Hsiao, F.B. and Lee, M.T., “System Engineering and Practice in Aircraft Design for Aerospace Education,” UNESCO 4th Annual Conference on Engineering Education, Bangkok, Thailand, 7-10 February 2001.
[10] Guan, W.L., Hsiao, F.B. and Ho, C.S., “The Development of a GPS Navigation System for Remotely Piloted Vehicle”, AIAA Guidance, Navigation and Control Conference, New Oleans, LA Aug. 11-13, 1997
[11] Guan, W.L., Hsiao, F.B., Ho, C.S. and Huang, J.M., 1999, “Estimation of Longitudinal Aerodynamic Parameters by Differential GPS/EKF Techniques,” AIAA-99-4177, AIAA Atmospheric Flight Mechanics Conference, Portland, Oregon, 9-11 August 1999, pp.512-522
[12] Juang, J. W., “Development of Navigation Payload System for Unmanned Aerial Vehicle”, Master thesis, National Cheng Kung University, June, 1999.
[13] Hsiao F.B., Fang K.J., “Real Time Attitude Determination of Remotely Piloted Vehicle Using GPS Doppler Velocity Measurements”, Transactions of Aerospace Science and Technology of ROC, Sep., 2000.
[14] Hsiao F.B, Lin K.W, Lee M.T, Chang W.Y, Chao C.T, Lin C.F, “The Design of Stability Control System and Constructing Simple Navigation System for Long Endurance Autonomous UAV”, AIAA 1st Technical and Conference Workshop on Unmanned Aerial Vehicles, Portsmouth Virginia, 20~23 May, 2002.
[15] Yong-Ren Lin, ”The Development of an On-Board Computer System for Unmanned Aerial Vehicle”，Institute of Aeronautics and Astronautics, National Cheng-Kung University, Master thesis, July 2000.
[16] Jay Farrell, Matthew Barth, “The Global Positioning System and Inertial Navigation”, 1998, MacGraw-Hill, ISBN 0-07-022045-X.
[17] 莊智清, 黃國興, “電子導航”, 2001, 全華科技圖書股份有限公司, ISBN 957-21-3154-0
[18] 黃國興, “慣性導航系統原理與應用”, 1991, 全華科技圖書股份有限公司, ISBN 957-21-0125-0
[19] Stephen A. Whitmore, Mike Fife, and Logan Brashear, , “NASA Technical Memorandum 4775---Development of a Closed-Loop Strap Down Attitude System for an Ultrahigh Altitude Flight Experiment”, Jan.,1997
[20] Anthony Lawrence, “Modern Inertial Technology---Navigation, Guidance and Control”, 1993, Springer-Verlag, ISBN 0-387-97868-2.
[21] John H. blakelock, “Automatic Control of Aircraft and Missiles”, 2nd edition, 1991, Wiley Interscience, ISBN 0-471-50651-6
[22] Crossbow Technology Inc., http://www.xbow.com/
[23] NEC TOKIN America, Inc., http://www.nec-tokinamerica.com/
[24] 趙春棠, “PIC單晶片學習秘笈---以PIC16F877為例”, 2001 全威圖書有限公司, ISBN 957-8955-97-9
[25] Garmin International Inc., http://www.garmin.com
[26] Murata Electronics North America, Inc. http://www.murata.com/
[27] Microchip Technology Inc., http://www.microchip.com/