Analytical structure of a class of product & interval-type-2 fuzzy controllers

被引:0
作者
Long Z.-Q. [1 ,2 ]
Xu Y.-B. [1 ]
Li L. [1 ]
机构
[1] College of Physics and Electronic Engineering, Hengyang Normal University, Hengyang, 421002, Hunan
[2] Department of Computers and Electronic Engineering, Wayne State University, Detroit, 48202, MI
来源
Kongzhi Lilun Yu Yingyong/Control Theory and Applications | 2016年 / 33卷 / 07期
基金
中国国家自然科学基金;
关键词
Analytical structure; Fuzzy controllers; Fuzzy sets; Fuzzy systems; IT2 fuzzy logic; Membership functions;
D O I
10.7641/CTA.2016.50777
中图分类号
学科分类号
摘要
The difficulties in deriving the analytical structure of IT2 (interval type-2) fuzzy controllers chiefly come from the iterative computation in type-reduction algorithms. In this paper, we propose a novel technique for deriving the analytical structure of the IT2 fuzzy controllers based on product AND operators. The controllers are configured with triangle IT2 input fuzzy sets, T1 output fuzzy singletons, center-of-sets type reducer, centroid defuzzifier, and product AND operators in precedent parts of fuzzy rules. In comparison to the analytical structure of traditional PID controllers, it is proven that such IT2 fuzzy controllers are equivalent to the sum of two nonlinear PI (or PD) controllers. By means of the iteration-stopping conditions of KM algorithm, an IC-partitioning approach with six steps is presented, which guarantees that a fired subspace can be partitioned correctly. Superimposing all subspaces can produce an overall figure of IC partitions. To avoid solving the symbolic mathematical equations repeatedly, a direct method is given to determine IC boundaries, which facilitates the six-step approach of IC partitioning. Our approach sidesteps the iterative computation in type-reducing algorithm, and guarantees that the closed-loop analytical expression of the IT2 fuzzy controllers can be obtained. © 2016, Editorial Department of Control Theory & Applications South China University of Technology. All right reserved.
引用
收藏
页码:929 / 935
页数:6
相关论文
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