Abstract This paper investigates the problem of disturbance observer-based output feedback control for quadrotor unmanned aerial vehicles with external disturbances, uncertainties and input saturation. Different from the existing results, we propose a novel control algorithm towards attitude system and position system. First, considering that not all signals can be measured directly by sensors, we construct a full-order state observer to estimate the unmeasureable state variables. Second, a nonlinear disturbance observer is designed to estimate the unknown external disturbance encountered by quadrotor during flight. Then, novel second order sliding mode surfaces are proposed to design the attitude controller and position controller, which can effectively attenuate the chattering effect without sacrificing the robustness of the controller. In addition, an auxiliary system is developed to eliminate the influence caused by input saturation. Moreover, by using the Lyapunov stability theory, it is proved that the designed attitude and position controllers can ensure that all signals of the resulting closed-loop system are uniformly bounded. Finally, a simulation example is given to verify the effectiveness of proposed algorithm.

中文翻译：

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具有输入饱和度的不确定 QUAV 的基于干扰观测器的输出反馈控制

摘要 本文研究了具有外部干扰、不确定性和输入饱和的四旋翼无人机的基于干扰观测器的输出反馈控制问题。与现有结果不同，我们提出了一种新的姿态系统和位置系统控制算法。首先，考虑到并非所有信号都可以由传感器直接测量，我们构建了一个全阶状态观测器来估计不可测量的状态变量。其次，设计了一个非线性干扰观测器来估计四旋翼飞行器在飞行过程中遇到的未知外部干扰。然后，提出了新的二阶滑模面来设计姿态控制器和位置控制器，在不牺牲控制器鲁棒性的情况下，可以有效地减弱颤振效应。此外，还开发了辅助系统，以消除输入饱和带来的影响。此外，通过使用李雅普诺夫稳定性理论，证明了所设计的姿态和位置控制器可以确保所得到的闭环系统的所有信号都是一致有界的。最后，通过仿真实例验证了所提算法的有效性。