Output feedback controller design of Takagi–Sugeno fuzzy systems

Abstract

This paper presents new systematic design methods of two types of output feedback controllers for Takagi–Sugeno (T–S) fuzzy systems, one of which is constructed with a fuzzy regulator and a fuzzy observer, while the other is an output direct feedback controller. In order to use the structural information in the rule base to decrease the conservatism of the stability analysis, the standard fuzzy partition (SFP) is employed to the premise variables of fuzzy systems. New stability conditions are obtained by relaxing the stability conditions derived in previous papers. The concept of parallel distributed compensation (PDC) is employed to design fuzzy regulators and fuzzy observers from the T–S fuzzy models. New stability analysis and design methods of output direct feedback controllers are also presented. The output feedback controllers design and simulation results for a nonlinear mass-spring-damper mechanical system show that these methods are effective.

Keywords:

• Takagi–Sugeno fuzzy model
• Fuzzy control
• Feedback controller
• Systematic design

Acknowledgement

The author would like to thank the reviewers for their helpful comments. This work was partially supported by China Postdoctoral Science Foundation under grant 20030151005.