Design, implementation and comparison of different controllers for a rotary Inverted Pendulum

Inverted pendulum is widely used in the study of control theory. There are different types of inverted pendulums available, out of which a rotary inverted pendulum (RIP) with an L-shaped arm is considered in this work. The aim of this work is to stabilize the pendulum at its vertical upright position with minimum oscillations in both the pendulum and L-shaped arm. Firstly, a two loop Proportional Integral Derivative (PID) control is designed using root locus method, which is quiet challenging as the system is highly non-linear and under actuated. Secondly, a Full State Feedback (FSF) control by pole placement technique, and an Linear Quadratic Regulator (LQR) technique have been used. Finally, MATLAB based simulations and experimental results are compared and discussed. All controllers have been implemented on Quanser QNET RIP trainer system using LabVIEW tool and found that the LQR based controller is performing well.