Investigations on MIT and Lyapunov rule-based modified MRAC for noninteracting and interacting two-tank coupled systems

Abstract

The adaptive control method is a technique that measures the dynamic characteristics of the plant automatically and continuously to make a comparison with its required output. It utilizes the difference between plant output and reference output to compute adaptable system parameters to maintain optimal performance regardless of the system variations. The behavior of the adaptation rule is significantly affected by the adaptation gain value. This paper describes the design of MIT (Massachusetts Institute of Technology) and Lyapunov rule-based modified Model Reference Adaptative Controller (MRAC) to stabilize a non-interacting and interacting two-tank process system. Investigation of variation in adaptation gain has also been done. Initially, a traditional MIT and Lyapunov rule-based MRAC is designed to stabilize the non-interacting and interacting tow-tank coupled system and it is found that both the systems are stable only for a few values of adaptation gain. To overcome this problem the modified MRAC is planned to stabilize and improve the response of the system. The modified MRAC scheme is just the PD (Proportional Derivative) controller superimposed on the MRAC control method. Now with the modified MRAC, the systems have been stabilized and their response has been improved for the wide range of adaptation gains. The comparative analysis of traditional and modified MRAC has also been presented. The performance analysis in terms of rise time, settling time, and peak overshoot has been carried out by comparing the results obtained for all the mentioned rules with the variations in the adaptation gain, on the MATLAB/Simulink platform. The obtained results present encouraging outcomes.