Cascaded fractional order sliding mode control for trajectory control of a ball and plate system

This paper presents a comparative study between a sliding mode controller and a fractional order sliding mode controller applied to the problem of trajectory control of a ball in a ball and plate system. The ball and plate system is a well-known benchmark to test advanced control strategies because of its multivariable nonlinear coupled dynamics, open loop instability, parameter uncertainty, and under actuation. A cascaded sliding mode controller is initially designed to mitigate the problem. Furthermore, to improve the performance, a cascaded fractional order sliding mode controller is proposed. The proposed control strategies are experimentally validated on a ball and plate laboratory setup (Feedback Instruments Model No. 033-240). Simulation and experimental studies reveal that the fractional order sliding mode controller outperforms the sliding mode controller in terms of tracking accuracy, speed of response, chattering effect, and energy efficiency.