Model Following Sliding Mode Control Based on Uncertainty and Disturbance Estimator

A new design of sliding mode control based on an uncertainty and disturbance estimator (UDE) is given. The control proposed does not require the knowledge of bounds of uncertainties and disturbances and is continuous. Thus, two main difficulties in the design of sliding mode control are overcome. Furthermore, the method of UDE is extended to plants having significant uncertainty in the control input matrix and subjected to disturbances that nonlinearly depend on states.