四旋翼飞行器固定时间自适应轨迹跟踪控制

Fixed-time Adaptive Trajectory Tracking Control for a Quadrotor UAV

针对具有外部扰动和不确定性的四旋翼飞行器,提出了基于命令滤波反步法的固定时间自适应轨迹跟踪控制方案。首先,将四旋翼飞行器分解为姿态子系统和位置子系统,分别利用固定时间命令滤波技术、反步设计方法及分数次幂误差补偿机制设计姿态控制器及位置控制器。其次,结合固定时间Lyapunov稳定性理论,证明了闭环系统的所有信号是固定时间有界的,同时姿态和位置跟踪误差在固定时间内收敛到原点附近的充分小邻域内,且收敛时间的上界独立于四旋翼飞行器初始状态。最后,通过仿真算例验证了所提固定时间控制算法的有效性。

The fixed-time adaptive trajectory tracking control scheme is proposed for a quadrotor unmanned aerial vehicle(UAV) with external disturbances and uncertainties via the command filtered backstepping method. Firstly, the quadrotor UAV is decomposed into the attitude and position subsystems, and the attitude and position controllers are designed via the fixed-time command filter technique, backstepping design method and fractional-order error compensation mechanism. Secondly, by combining with the fixed-time Lyapunov stability theory, it is proved that all signals of the closed-loop system are fixed-time bounded, and the attitude and position tracking errors converge to a sufficiently small neighborhood of the origin in a fixed time, and the upper bound of convergence time is independent of the initial states of the quadrotor UAV. Finally, the effectiveness of the proposed fixed-time control algorithm is verified by a simulation example.