方向未知的非仿射非线性系统的模糊滑模控制

为解决一类控制方向未知的非仿射非线性系统的控制问题, 提出一种新的自适应模糊滑模控制方法, 无需系统控制方向和不确定项的上界的先验知识。采用模糊逻辑系统直接逼近控制器中的未知部分, 在参数自适应律中引入Nussbaum函数处理控制方向未知问题。用一类光滑非线性饱和函数改进传统的积分滑模面, 能使控制器在保证传统积分滑模控制跟踪精度的同时获得更好的动态性能。利用李雅普诺夫方法证明了闭环系统的稳定性。数值仿真验证了算法的有效性。

Fuzzy Sliding Mode Control for a Class of Non-Affine Non-Linear Aystems with Unknown Control Direction

We proposed a novel adaptive fuzzy sliding control to deal with the control problem of a class of non-affine non-linear systems with unknown control direction,requiting no prior knowledge of the control direction and bound of uncertainty.Fuzzy logic system is used to directly approximate the unknown part of the controller.Nussbaum function is applied in parameter updating laws to deal with the problem of unknown control direction.A new nonlinear saturation function is introduced to promote the performance of the traditional integral sliding mode surface,therefore the proposed controller can maintain the tracking accuracy with better dynamic performance.The stability of the closed-loop system is performed by Lyapunov approach.Simulation results are provided to verify the effectiveness of the proposed design.