Abstract: A novel super twisted decoupling nonsingular fast terminal sliding mode control (STDNFTSMC) method is proposed for the existence of singular phenomena and sliding mode jitter in a class of four order under actuated system decoupling terminal sliding mode control. The under actuated system is divided into two subsystems, and nonsingular fast terminal sliding mode surfaces are designed, respectively. The saturation function of sliding surface of one subsystem is used to construct an intermediate variable, and the variable is introduced into the sliding surface of another subsystem to construct the sliding surface of the whole system. Equivalent control method and super-twisted reaching law are used to solve the control law of the system. The chattering phenomenon is effectively eliminated and the robustness of the system is improved. The Lyapunov method is used to prove the asymptotic stability of the sliding surface of each system. The simulation results show the effectiveness of the method.

Key words: Under actuated system, super twisted algorithm, decoupled sliding mode, nonsingular fast terminal sliding mode

摘要： 针对一类四阶欠驱动系统解耦终端滑模控制存在的奇异现象和滑模抖动问题，提出了一种新型的超扭曲解耦非奇异快速终端滑模控制(Super Twisted Decoupled Nonsingular Fast Terminal Sliding Mode Control, STDNFTSMC)。将欠驱动系统分为两个子系统分别设计非奇异快速终端滑模面，利用其中一个子系统滑动面的饱和函数来构造一个中间变量，将该变量引入到另一个子系统的滑动面中，构造出整个系统的滑动面。采用等效控制法和超扭曲趋近律求解系统的控制律，有效的消除了抖振现象，提高了系统的鲁棒性。利用Lyapunov方法证明了各系统滑模面的渐近稳定性，仿真实验验证了该方法的有效性。

关键词: 欠驱动系统, 超扭曲算法, 解耦滑模, 非奇异快速终端滑模