摘要或動機

無尾翼飛行器(Tailless Aircraft)在軍事上的價值極大，且對於目前正在起步的微飛行載具(Micro Air Vehicle)而言，亦是值得嘗試與投資的。然而，由於無尾翼飛行器缺乏用以平衡的水平尾翼，造成其靜態的不穩定，即使設法提高靜態穩定特性，但其氣動力阻尼低、穩定性仍舊不佳。操縱上更是困難，在飛行穩定性與控制系統設計上極其挑戰性。本研究目的在探討無尾翼飛行器之穩定性與控制技術，改善其先天之不穩定特性，考慮之項目有縱向靜態穩定性、動態穩定性、控制面與組件配置等因素等進行詳細之探討。首先，找出了適用於無尾翼飛行器之Reflex翼形，接著建立無尾翼飛行器之非線性縱向動態模式，然後針對一翼展8Ocm之小型飛行器進行外型設計，並觀察分析其實際飛行狀態，再以理論與經驗公式估算無尾翼飛行器之氣動力導數，探討其飛行穩定與操控性能。此外，並運用古典控制PID控制法則，設計控制器進行非線性受控系統之動態響應模擬。由模擬結果可看出，經由翼剖面改變與控制系統的輔助下，大幅提高了其性能，使得無尾翼飛行器克服了先天的不穩定特性，更提高了其發展空間 The tailless aircraft has a great value on the military use. Meanwhile, it is worthwhile to try and to invest in it for the investigation of MAV(Micro Air Vehicle), which is being developed now. However, because of lacking horizontal tail which is used for balance, the tailless aircraft is static unstable. Even with the attempt to enhance its characteristics of static stability, the stability of the tailless aircraft is still poor for the sake of it's low damping in aerodynamics. Therefore, it is a challenge to flight stability and control system designing. The purposes of this research are to study the stability and the control technique of the tailless aircraft. To improve its congenital lacking of stability, thought over the longitudinal static stability, dynamic stability and control system. First, find the "Reflex" airfoil is suitable for the tailless aircraft. Second, set up a non-linear and longitudinal dynamic model of the tailless aircraft. Third, design an 80cm span small airplane. Hence, observe and analyze its flying condition. Finally, utilize the theoretical and experiential equations to estimate the aerodynamic derivatives and investigate its stability and controllability. Besides, use the PID controller to proceeded the time-response simulation of the non-linear system. The result of simulation shows that the performance is improved through the change of the airfoil and with the auxiliary of the control system. With this improvement, the tailless aircraft overcome the congenital lacking of stability to broaden its utilization potential.