Robust Nonlinear Control Design and Disturbance Estimation for Ball and beam System

Robust output tracking of uncertain systems requires nonlinear controllers due to approximate parameters and exogenous disturbances. However, the design of nonlinear control is often more complex for practical implementation. This article presents a simple nonlinear robust control for the ball and beam system based on integral sliding mode control. In addition to this a low pass filter is designed to estimate the disturbance and alleviate the chattering effect. A comparison of the proposed technique with the conventional sliding mode control is carried out using MATLAB/ SIMULINK. The simulation results validate the efficacy and improved performance of the proposed technique in the presence of exogenous disturbances and parametric uncertainties.

I. INTRODUCTION

There has been extensive on-going research on the control of underactuated electro-mechanical systems for the past two decades. Ball and beam system control is considered as one of the benchmark problems while dealing with underactuated systems. Ball and beam system dynamics are highly nonlinear and complex, which makes it a challenging control problem. Several research studies have been carried out proposing different nonlinear control techniques to achieve the desired control objectives i.e. Stabilization and regulation. The ball position on the beam is controlled using several linear control techniques including PD, PID, LQG and LQR [1], [2]. A research used adaptive state feedback control for position control of the system and compared its performance with a linearized backstepping controller [3]. In another article, the robust controller based on the error convergence was proposed which enhance control performance for the sensor noise [4]. The alternative research on the ball and beam stabilization includes fuzzy based controllers, supervisory controllers, and neural network algorithms based controllers [5]-[9].