Stabilization and Performance Analysis of Double Link-Rotary Inverted Pendulum Using LQR-I Controller

This paper presents an optimal LQR-Integral based controller (LQR-I) for balancing control of the Double Link Rotary Inverted Pendulum (DL-RIP) system. It is one of the challenging topics in control and robotics due to its nonlinearity and instability, also complex system due to 3 degree of freedom rotary system. This system uses a motor to control and balance two rigid links serially connected pendulums in a vertically upward direction. Pole-zero mapping is used to determine the stability of the system. In this paper, a performance analysis of the system is done with an LQR-I controller using three reference paths (Square, Sawtooth, and Sinusoidal wave), two of which are discontinuous and one continuous path. The system shows less overshoot and deflection to stabilize the pendulum vertically upwardly with a continuous sinusoidal reference path compared to a square and sawtooth wave.