Robust fuzzy output feedback controller for affine nonlinear systems via T-S fuzzy bilinear model: CSTR benchmark

Area of Science:

• Control Engineering
• Fuzzy Systems
• Nonlinear Systems

Background:

• Affine nonlinear systems are prevalent in various engineering applications.
• Disturbances can significantly impact system performance and stability.
• Existing control methods may struggle with complex nonlinear dynamics and external disturbances.

Purpose of the Study:

• To design a robust H-infinity fuzzy output feedback controller for affine nonlinear systems.
• To ensure stability and disturbance attenuation for the closed-loop system.
• To validate the proposed controller's effectiveness using a benchmark nonlinear process control problem.

Main Methods:

• Utilizing Takagi-Sugeno (T-S) fuzzy bilinear models to represent nonlinear systems.
• Employing Parallel Distributed Compensation (PDC) for fuzzy controller design.
• Formulating stability conditions using Lyapunov functions and Linear Matrix Inequalities (LMIs).

Main Results:

• The proposed controller achieves robust stability in the presence of external disturbances.
• Controller gains are systematically obtained by solving a set of LMIs.
• The H-infinity approach effectively attenuates system disturbances.

Conclusions:

• The designed H-infinity fuzzy output feedback controller is effective for affine nonlinear systems.
• The LMI-based approach provides a systematic way to obtain controller parameters.
• The approach demonstrates superior performance on the Continuous Stirred Tank Reactor (CSTR) benchmark problem.