Adaptive interval type-2 fuzzy controller for nonlinear networked Wiener systems subject to packet dropout and...

Area of Science:

• Control Systems Engineering
• Fuzzy Logic Systems
• Networked Systems

Background:

• Networked systems often suffer from packet dropout and time-varying delays, degrading control performance.
• Nonlinear Wiener systems present significant challenges for traditional control methods due to their complex dynamics.
• Existing controllers struggle to robustly handle both uncertainties and communication imperfections simultaneously.

Purpose of the Study:

• To propose a novel adaptive interval type-2 fuzzy controller (AIT2FC) for nonlinear networked Wiener systems.
• To effectively compensate for packet dropout and time-varying delays in both forward and feedback loops.
• To ensure system stability and enhance control performance under adverse network conditions.

Main Methods:

• Developed an AIT2FC comprising an adaptive interval type-2 Takagi-Sugeno (IT2TS) fuzzy controller, an IT2TS fuzzy Wiener model (IT2TS-FWM), and a delay/dropout compensator.
• Utilized an adaptive Smith predictor (ASP) for time-varying delay compensation and a stochastic Bernoulli approach for packet dropout compensation.
• Employed Lyapunov stability (LS) functions for online parameter and learning rate updates to ensure stability and convergence.

Main Results:

• The proposed AIT2FC successfully compensated for packet dropout and time-varying delays.
• Online adaptation of controller parameters and learning rates guaranteed system stability and fast convergence.
• The IT2TS-FWM accurately identified the nonlinear Wiener system dynamics online.

Conclusions:

• The novel AIT2FC demonstrates superior performance over existing controllers for nonlinear networked Wiener systems.
• The controller's adaptive nature and compensation mechanisms provide robustness against network imperfections.
• This research offers a promising solution for reliable control in challenging networked environments.