MRAC with variable adaptation gain for first order systems

This paper presents analysis and design of MRAC to incorporate variable adaptation gains to enhance the systems performance as compared to conventional MRAC. MRAC is a popular adaptive scheme which ensures the aspect of high dynamic tracking and stability. These are often considered as mutually contradictory features in a control system. Selection of adaptive parameter in MRAC plays crucial role to achieve good transient response and accurate performance in the steady state. The aspects of adaptability and stability are simultaneously enhanced by variable adaptive parameters. To incorporate the features of the variable adaptive parameters, three level adaption gains are incorporated through error scheduling approach. The improved performance is demonstrated on first order system under parameters variations and perturbations.