Visual servo control of a Steward platform using fractional-order PID controller

Mechatronic systems are usually described by integer-order state equations. Based on these integer-order models, conventional integer-order PID controllers are designed. In this paper, we use a Steward platform (ball and plate system) with different balls to investigate the robustness of the fractional-order controller against the mass changes of the ball. The closed-loop performances of the fractional-order controller are compared with integer-order controller using the same performance criteria and the same tuning algorithms. The experimental results show that the fractional-order PID controllers outperforms the conventional integer-order PID controllers.