Comparison of LQR and robust controllers for stabilizing inverted pendulum system

This paper presents comparison of the time specification performance between two controllers for an inverted pendulum system. The objective is to determine the control strategy that delivers better performance with respect to pendulum´s angle and cart´s position. The inverted pendulum represents a challenging control problem, which continually moves toward an uncontrolled state. The problem is to balance a pole on a mobile platform that can move in only two directions, to the left or to the right. A Linear-Quadratic-Regulator (LQR) and a robust control technique for controlling the linearized system of inverted pendulum model are presented and compared. Simulation studies conducted in MA TLAB environment show that both the controllers are capable of controlling the multi output inverted pendulum system successfully. The result shows that LQR produces better response compared to H∞ loop shaping control strategies.