• Introduces a novel MFAC-SA-PID controller that integrates fuzzy self-adjusting PID with model-free adaptive control to handle strong nonlinearity in pH neutralization.
• Provides rigorous proof of convergence and stability for the proposed MFAC-SA-PID method.
• Demonstrates superior control performance over traditional MFAC and improved MFAC (IMFAC) methods in simulations, especially under step disturbances.
• Offers a practical solution for pH process control with enhanced robustness and stability, addressing parameter tuning challenges in industrial applications.