Performance analysis of model reference adaptive control versus conventional and fuzzy PID for precise temperature regulation in heating system

This study investigates the effectiveness of Model Reference Adaptive Controller (MRAC) utilizing MIT and Lyapunov methods, alongside conventional PID, Fuzzy PID, and Fuzzy PID with Model Reference (FPID+MR) controllers for temperature regulation in the PT326 Process Trainer heating system. The controllers were implemented and tuned to evaluate their ability to achieve optimal temperature control under operational conditions. The study first focused on designing, implementing, and tuning each controller using the ARX223 model derived through system identification in MATLAB/Simulink, addressing the first objective. Performance evaluation was conducted based on rise time, settling time, overshoot and root mean square error (RMSE). To fulfil the second objective, the study assessed the enhancement provided by fuzzy logic and model reference integration. Results showed that FPID improved the PID rise time from 27.22 seconds to 20.12 seconds and settling time from 49.86 seconds to 38.29 seconds, while FPID+MR further reduces them to 12.33 seconds and 23.61 seconds, with RMSE decreasing from 10.72 (PID) to 8.508 (FPID+MR). The results, which addressed the third objective, validated through simulations indicate that MRAC methods, particularly MIT-based approach, outperform conventional PID, Fuzzy PID, and FPID+MR controllers across all key metrics. The MIT rule exhibited the fastest response, minimal steady-state error, reduced overshoot, more accurate temperature tracking through RMSE. MRAC MIT achieved a rise time of 3.12 seconds and settling time of 8.10 seconds. The Lyapunov-based MRAC also demonstrated strong performance, especially in robustness and stability with a rise time of 3.93 seconds, settling time of 8.00 seconds, and the lowest RMSE of 6.202, though it was slightly less efficient than the MIT method. The FPID+MR controller showed improved adaptability compared to conventional PID and standalone Fuzzy PID controllers. It offered better response times and robustness, yet it still fell short of the MRAC methods. While Fuzzy PID improved upon conventional PID controllers, it remained inferior to both MRAC and FPID+MR approaches. MRAC-based controllers demonstrated the most significant enhancements, with MRAC MIT achieving the fastest rise time and MRAC-Lyapunov delivering the best balance of speed, stability, and tracking accuracy. The findings suggest that MRAC-Lyapunov is the most suitable control method for achieving fast, stable, and accurate temperature regulation in the PT326 heating system.