四旋翼无人机固定时间姿态输出反馈控制

Fixed Time Attitude Output Feedback Control for Quadrotor Unmanned Aerial Vehicle

为实现角度不可测的四旋翼无人机(unmanned aerial vehicle,UAV)姿态跟踪,提出一种新的输出反馈控制方案。首先,将外界干扰与系统模型中的不确定作为综合扰动整体估计,设计了固定时间扩张状态观测器来估计未知角速度和综合扰动,保证估计误差能够在固定时间内收敛到原点,且收敛时间不依赖于系统的初始条件。同时为了提升控制精度和速度,设计基于齐次性理论的固定时间控制器,能够保证系统的跟踪误差在固定时间内收敛至零,且收敛时间与四旋翼无人机的初始状态无关。最后,通过仿真研究,验证本文所提方案的有效性。

To solve the problem of attitude tracking with unmeasured angular velocity for quadrotor unmanned aerial vehicle(UAV),a novel output feedback control scheme was proposed.Firstly,external disturbance and uncertainty in system model were arranged as lumped disturbance,the fixed time extended state observer was designed to estimate unmeasured velocity and lumped disturbance.The estimation errors can converge to origin in fixed time,and convergence time is independent of system initial state.At the same time,to improve control accuracy and convergence speed,a fixed time controller was designed based on homogeneity property,which can guarantee tracking errors of system to converge to zero in fixed time,and the convergence time is independent of initial state.Finally,the effectiveness of proposed scheme was verified by simulation.