Position control for ball and beam system based on active disturbance rejection control

Abstract

This paper proposes a new control strategy to the position control of the ball in the ball and beam system by adopting an active disturbance rejection control (ADRC). ADRC is composed of a tracking differentiator (TD), an extended state observer (ESO), a nonlinear state error feedback control law (NLSEF), and a disturbance compensation device (DCD). The ESO observes and tracks the position of the ball and the direct current (DC) servomotor in real time. The total disturbance of the system can be expanded and amplified, and can also be effectively compensated in real time to suppress interferences by the ESO. The procedures of research are as follows. First, the model of the ball and beam system, including the motion equation of the system and the DC servomotor, is established. Second, ADRC is designed and applied to the ball and beam system and the DC servomotor. Third, the control model of the ball and beam system is built on the basis of ADRC. Finally, the ball position of ADRC is simulated and verified. The results show that the ball and beam system based on ADRC exhibits better performance than the proportion integration differentiation controller.

Keywords

• Ball and beam system
• active disturbance rejection control
• DC servomotor
• position control