In control engineering, the control of an unstable system is very concerning. An example of an unstable system that uses control principles is a ball and beam balancer system. This system consists of a long beam attached to a motor at its midpoint. A steel ball moves on the top of the beam with an acceleration proportional to the beam angle. If the system is uncontrolled well, the steel ball may fall from the beam. This paper presents an approach to modeling and controlling the ball position for the ball and beam balancer system. Starting with a mathematical equation for the nonlinear system, the model of the system is produced. Then, it demonstrates the design of the PID cascade controller system to stabilize the system and regulate the ball to its reference position. The performance of the system was evaluated and tested for set-point tracking signal and disturbance rejection test. The simulation studies were done using Matlab Simulink and the results indicated that the proposed approach yields robust closed-loop performance.
Part of the book: PID Control for Linear and Nonlinear Industrial Processes