Sampled-data Tracking and Disturbance Compensation of Nonlinear Systems

This paper solves the tracking problem for feedback linearizable sampled data nonlinear systems. The conversion of a continuous system into its sampled data equivalent has been discussed and the proposed control law has been derived. In classical control theory, high gain observers based feedback control has been adopted for stabilizing a nonlinear system and state estimation to track a varying reference, but it compromises the main design purpose. The proposed scheme uses augmented state estimation technique to find the additional compensation to be applied at input channel to minimize the tracking error. The results are shown through an illustrative example of an inverted pendulum system that verifies the effectiveness of the proposed scheme.