Enhanced VRFT design of adaptive PID controller

In this paper, an enhanced virtual reference feedback tuning (EVRFT) design method with specific application to adaptive PID controller design is developed. The proposed EVRFT design is an extension of conventional VRFT design and adaptive VRFT (AVRFT) design previously developed in the literature. The EVRFT design makes use of a second-order reference model instead of the first-order reference model used by both VRFT and AVRFT designs. In addition, unlike the AVRFT design, the parameter of reference model in EVRFT design is updated at each sampling instant to further enhance the performance of resulting adaptive PID controller. Simulation results demonstrate that the adaptive PID controller using the proposed EVRFT design gives better response than those obtained by the VRFT and AVRFT designs.