Design LQR Controller for Higher Order Systems Based on the Reduction Model

Abstract

This paper present a simple method for reducing the linear higher order systems. The coefficient of the reduction model is obtained by using the modified dominant pole technique, while the coefficients of the numerator are obtained by reduced order model. Linear Quadratic Regulator (LQR) is used to design a controller for the higher order system depended on the linear reducing equations. LQR without and with integral effect method are used and compared for controlling the higher order systems. The LQR controller are designed and simulated using MATLAB/Simulink. Simulation results show that both the controllers are capable of controlling the systems successfully. The LQR with integral gives the better performance, compared to when the system without it. the LQR controller scheme with smith predictor connection is suggested in order to maintain the stability of the higher order plant in addition to improve the performance of the controlled system. The simulation results for this scheme are tested with two higher order time delay systems to illustrate the efficient performance for the proposed control scheme.