| 摘要: | 近年來，無人機商業化及軍事化越趨普遍，尤其典型的四軸飛行器應用最為廣泛。其僅需四個致動器就能完成全姿態運動，雖然本身為不穩定（unstable）、耦合（coupled）、欠驅動（underactuated）系統，但得益於其低成本、相對容易控制的特性，使其經常成為驗證控制理論或是實現應用的工具。
由於系統有上述特性，一旦槳葉損壞或是馬達失效，便可能使飛行器因缺少自由度而無法控制部分姿態。主要應對方法為避免碰撞或以失效狀態進行控制，第一種通常在機身適當位置配有距離感測器，結合演算法進行避障，另一種則需先識別出失效模型，再以當前模型進行控制。
本研究探討單顆馬達部分失效情況，在飛行過程模擬馬達故障，僅依靠姿態資料及直覺的旋轉誤差正負號判斷方式進行失效辨識，並使用P-PID控制及四軸飛行器耦合特性進行故障補償及控制。目標使飛行器在一定高度且缺少偏轉（yaw）自由度下進行故障控制。在高度為4 m時，馬達剩餘效率為0.8、0.6及0.2的情況下，落地前可將傾角控制在0.2 (rad)以內，且接觸地面時之衝量皆在 3.2 (kg ‧ m/s)內，以保證機身以水平姿態較慢地落地，並讓衝擊分散到四個機臂。
實驗部分先透過假設來簡化系統，模擬從正常飛行到失效後的識別及控制情況，最後再以實際戶外飛行來驗證控制方法。
;In recent years, the commercialization and militarization of unmanned arial vehicles (UAVs) have become increaseingly common, with quadcopters being particularly prevalent in various applications. Despite being inherently unstable, coupled, and underactuated systems, quadcopters benefit from their low cost and relatively easy controllability, which often makes them a tool for validating control theories or implementing applications.
Due to the aforementioned characteristics of the system, if a propeller blade is damaged or a motor fails, the aircraft may lose certain degrees of freedom and become uncontrollable in certain attitudes. The main approaches to address this issue are collision avoidance and control under failure conditions. The first approach typically involves equipping the aircraft with distance sensors at appropriate locations on the fuselage, combined with algorithms for obstacle avoidance. The second approach requires identifying the failure model first and then implementing control based on the current model.
This study investigates the partial failure of a single motor in a quadcopter. Motor failure is simulated during flight, and failure identification is conducted using only attitude data and an intuitive method of determining the sign of the rotational error. P-PID control and the coupling characteristics of the quadcopter are employed for fault compensation and control. The goal is to achieve fault control while maintaining the aircraft at a certain altitude and without the yaw degree of freedom. At an altitude of 4 meters, with remaining motor efficiencies of 0.8, 0.6, and 0.2, the tilt angle can be controlled within 0.2 radians before landing, and the impulse upon ground contact is kept within 3.2 (kg ‧ m/s). This ensures that the fuselage lands slowly in a horizontal attitude, allowing the impact to be distributed across the four arms.
In the experimental phase, the system is initially simplified through assumptions to simulate the identification and control process from normal flight to failure. Subsequently, the control methods are verified through actual outdoor flights. |
