Nonlinear output tracking via dynamic sliding manifolds

Nonlinear output tracking problems in multi-input-multi-output (MIMO) systems with unmatched nonlinearities and disturbances are addressed by sliding mode control methods. The nonlinear transformation of the coordinates of the nonlinear system was developed to change the system to a form convenient for the sliding mode synthesis. The sliding manifold as a dynamic operator, representable as a matrix transfer function acting on some states of the original system and on the output tracking error, was designed in order to provide the systemʹs desired linear performance. A system with such a sliding mode controller obtained the combined features of the system with the conventional compensator (accommodation to unmatched disturbances) and the conventional sliding mode controller (insensitivity to matched disturbances).