DISCRETE SLIDING CONTROL OF A COUPLED-DRIVES APPARATUS WITH OPTIMAL SLIDING SURFACE AND SWITCHING GAIN

The paper details the design and experimental implementation of a prac tical discrete-time version of a sliding-mode controller. The controll er is derived and proven robustly stable to bounded plant modelling er rors and exogenous disturbances. Sliding-surface design is treated as an energy minimisation problem where state energy during sliding on th e surface is minimised according to a linear quadratic measure. Analys is of the properties of the control system lead to static and dynamic optimal switching gains. Application of the controller to simulated an d experimental versions of a coupled-drives apparatus provide evidence of the robust performance and stability of the controller with classi cal linear quadratic optimal control. Also demonstrated is the compare d effectiveness of the dynamic optimal switching gain.