基于快速终端滑模面的两旋翼飞行器有限时间姿态控制

A Twin-Rotor Aircraft Attitude Control Based On Fast Terminal Sliding Mode

摘要:

针对带有模型不确定和外部干扰的两旋翼飞行器，提出一种基于快速终端滑模面的有限时间自适应姿态控制方法，保证两旋翼飞行器对期望姿态角度的有限时间跟踪。构造快速终端滑模面，并设计分段连续函数避免滑模变量求导产生的奇异值问题。在此基础上，设计有限时间姿态控制器，并设计系统不确定上界的自适应更新律，抵消模型不确定性和外部干扰的影响。经李雅普诺夫方法证明滑模变量、姿态角误差、角速度误差等闭环信号最终一致有界，且有限时间收敛至平衡点邻域，收敛时间与系统状态变量初始值有关。最后，采用了矩形波和 曲线作为设定信号，设计相应的跟踪实验，并在两旋翼飞行器平台上验证所提控制方法的有效性，且分析双曲正切函数对系统控制输入影响，经实验测试其可减少系统颤振现象。

Abstract:

In this paper, a finite-time adaptive attitude control scheme is proposed based on fast terminal sliding mode surface for twin-rotor aircrafts with model uncertainties and external disturbances. A fast terminal sliding mode surface is constructed, and a piecewise continuous function is developed to avoid the singularity problem caused by differentiating the sliding mode variable. Then, the finite-time attitude controller is designed and adaptive update laws of system uncertainties are developed, such that the effect of the model uncertainties and external disturbances can be compensated. The Lyapunov synthesis is provided to show that the sliding mode variable, attitude error and velocity error could be uniform ultimate boundedness and converge to the neighborhood of the equilibrium within the finite time, and the setting time is relevant to the system state variable initial values. Finally, by contrast experiments of rectangular wave and S curve tracking, the effectiveness of the proposed scheme is validated on the twin-rotor platform. And that experimental results by using hyperbolic tangent function show that it can reduce the system flutter phenomenon.