Model Reference Adaptive Control of Time Delay Plant in 2-DoF Framework

Systems with time delay in various configurations are very common in the engineering systems and they pose various challenges during the control systems design. This paper presents the design of a control system for an inherently unstable plant with time delay component. Padè approximation of the time delay component exhibits right hand plane (RHP) zero leads to Non-Minimum Phase (NMP) characteristics, which obstruct the stabilization as well as perfect tracking of the time delay system. Here, the feed-forward Model Reference Adaptive Control (MRAC) technique for the inverse plant model and the State Feedback (SFB) Control scheme as feedback compensation for the non-inverse plant model are designed in a two degree of freedom (2-DoF) framework to obtain the stable and good tracking performance of the above-said unstable plant. The performance of the proposed control algorithm has been verified for 1
^st
order and 2
^nd
order plant with their time delay component in the MATLAB SIMULINK environment and compared their dynamic responses with the SFB control technique.