具有未知非线性死区的自适应模糊控制

Adaptive fuzzy control with unknown nonlinear dead-zone

基于滑模控制原理,利用模糊系统的逼近能力,提出一种自适应模糊控制方法.该方法提出一种简化非线性死区输入模型,取消了非线性死区输入模型的倾斜度相等以及死区边界对称的条件,还取消了非线性死区输入模型各种参数已知的条件.该方法通过引入逼近误差的自适应补偿项来消除建模误差和参数估计误差的影响.理论分析证明了闭环系统是半全局一致终结有界,跟踪误差收敛到零.仿真结果表明了该方案的有效性.

Based on the principle of sliding mode control, using the simplified nonlinear dead-zone model and the fuzzy systems with linear adjustable parameters which are used to approximate plant unknown functions, a design scheme of adaptive fuzzy controller is proposed. By using the approach, the conditions that the dead-zone slopes and the boundaries are equal and symmetrical, are removed, respectively. In addition, the assumptions which all nonlinear dead-zone model parameters are known constants are canceled. The adaptive compensation term of the approximation errors is adopted to minify the influence of modeling errors and parameter estimation errors. By theoretical analysis, the closed-loop control system is proved to be semi-globally uniformly ultimately bounded with tracking errors converging to zero. Simulation results show the effectiveness of the approach.