面向执行机构故障的四旋翼无人机主动容错飞行控制方法研究

Study on Active Fault Tolerant Flight Control Systems for Quadrotor UAV with Actuator Failures

四旋翼无人机在执行高负荷、长航时任务时,桨叶的疲劳断裂易导致无人机失控甚至坠毁。针对这一问题,提出了一种基于积分滑模控制的四旋翼无人机主动容错飞行控制方法。首先通过运动学和动力学分析建立了执行机构故障时无人机的非线性模型,再构造观测器对执行机构故障进行实时观测,并据此设计积分滑模控制律对无人机的位置和姿态控制回路进行补偿。数字仿真和飞行实验结果均表明所给出的方法具有较强的容错能力,在单只桨叶部分断裂的情况下,该方法可有效地实现无人机的位置和姿态稳定并具有良好的动、静态特性。

The rotor blades＇ fatigue fracture of Quadrotor UAV easily causes the instability or even crash of the UAV due to high-load and long-endurance flight missions. Under this circumstances, an active fault-tolerant flight controller of Quadrotor UAV based on integral sliding mode is proposed to strengthen the fault-tolerant capability of UAV＇s attitude and position. First of all, nonlinear mathematical model of quadrotor UAV with actuator failures is derived by kinematics and dynamics analysis. Secondly, a fault observer is constructed to determine when the actua- tor failure will occur, subsequently the UAV＇s attitude and position flight controllers are compensated using integral sliding mode control. The digital simulation and flight test shows that the controller has powerful fault-tolerant capacity and preferable dynamic and static characteristics which can stabilize the attitude and position responses of UAV when partial failure of single blade occurs.