Discrete-time sliding mode regulator for nonminimum phase systems

This work presents an approach to solve the output regulation problem for a class of nonlinear discrete-time nonminimum phase perturbed systems. Based on feedback linearization block control technique and discrete-time sliding mode (SM) control, we propose a sliding manifold on which the zero dynamics are stabilized. To enforce the robust SM motion on the designed manifold, a discrete-time super-twisting SM algorithm is implemented. The effectiveness of the proposed methodology is verified via the design of a position tracking controller for an under-actuated robotic system, the Pendubot.