固定时间扩张状态观测器下的四旋翼飞行器滑模控制策略

Sliding-Mode Control Strategy of Quadrotor With Fixed-Time Extended State Observer

针对滑模控制中系统状态接近滑模面后存在的抖颤现象,提出一种基于固定时间扩张状态观测器(FTESO)的二阶滑模控制策略.首先,设计全驱动子系统及欠驱动子系统的控制结构中的二阶滑模控制器;然后,通过FTESO对内部的参数不确定及外部扰动进行观测,在一定时间上限内收敛到观测值,利用观测值对控制器进行补偿,从而减少甚至消除抖颤现象;最后,通过李亚普诺夫函数保证设计的四旋翼飞行器系统的闭环稳定性,并进行仿真实验.结果表明:文中提出的控制策略具有优越性.

Aiming at the chattering phenomenon after the system approaching the sliding-mode hyperplane in sliding-mode control,a second order sliding mode control strategy base on fixed-time extended state observer(FTESO)is proposed.Firstly,the second order sliding-mode controller is designed in the control structure of fully-actuated subsystem and under-actuated subsystem.Then,the internal parameter uncertainties and external disturbances are observed by FTESO,which converge to the observed values within a certain time limit,the observed values are used to compensate the controller,so as to reduce or even eliminate the chattering phenomenon.Finally,the closed-loop stability of the designed quadrotor system is guaranteed through Lyapunov function,and simulation experiments are carried out.The results show that the proposed control strategy in this paper has advantages.