Nonlinear adaptive control based on fuzzy sliding mode technique and fuzzy-based compensator

Area of Science:

• Control Systems Engineering
• Nonlinear Dynamics
• Fuzzy Logic Systems

Background:

• Controlling nonlinear systems with uncertainty and disturbance (UAD) is challenging due to unknown factors and system delays.
• Existing methods often struggle with real-time control accuracy under UAD.

Purpose of the Study:

• To propose a novel controller, the Compensator-Fuzzy Sliding Mode Controller (CO-FSMC), for nonlinear systems subjected to UAD.
• To enhance control accuracy and reduce vibrations in challenging dynamic environments.

Main Methods:

• Independent design of a fuzzy sliding mode controller (FSMC) and a fuzzy compensator (CO).
• Development of an adaptive fuzzy structure to integrate FSMC and CO.
• Formulation of a closed-loop adaptive control law using fuzzy sliding mode techniques, disturbance observers, and Lyapunov stability analysis.

Main Results:

• The CO-FSMC demonstrated robustness, making chassis mass vibration insensitive to UAD.
• Simulations and a real-world semi-active train-car suspension application validated the controller's performance.
• The proposed CO-FSMC outperformed other fuzzy sliding mode control strategies in reducing vibrations.

Conclusions:

• The CO-FSMC offers a superior solution for controlling nonlinear systems with UAD.
• The method effectively mitigates vibrations and enhances system stability.
• The adaptive fuzzy integration provides a computationally efficient and accurate control strategy.