Indian Journal of Science and Technology

Abstract

Background/Objectives: Rotary inverted pendulum is a system that is often used in the domain of control theory to perform experiments. It is a complex yet interesting system that helps better understand concepts of control mechanism. It is an example of a non-linear oscillator. The pendulum is under actuated and extremely non-linear due to the gravitational forces and the coupling arising from centripetal forces.The experiment aims at swinging up the pendulum and balancing it in the upright position.Methods/Statistical Analysis: This paper describes the existing system of Furuta Inverted Pendulum manufactured by Quanser. The system consists of a motor-run rotary arm which in turn controls a pendulum. PID controller is a very commonly used controller to set the process parameters at the desired values. It can be easily tuned and also helps make use of trial and error mechanism. Cascade controller makes use of two PID controllers. Findings:The main aim of this work is to compare the performance of two controllers, namely PID controller and Cascade controller, in controlling the pendulum in the upright position and to detect their performance. The criteria of comparison would be factors including low settling time and a stable output which would make the control action more efficient and smooth. The simulation results obtained in Matlab Simulink for Conventional PID and Cascade PID controllers are included. From the simulation results the Rise time and settling time has improved by using cascade PID controller but comparatively PID has given less noise.Applications/Improvements:This work can be made use of in a number of scenarios like flight control, control of rocket propeller, unicycle, Segway transporters (which are self-balancing battery powered vehicles), two-wheel robots etc.
Keywords: Cascade PID Controller, Balance Control, PID Controller, Robust Control, Rotary Inverted Pendulum