Open-Closed-Loop Iterative Learning Control for Discrete-time Systems with Vector Relative Degree under Iterative Varying Duration

An open-closed-loop iterative learning control (ILC) scheme is presented for linear discrete-time multiple-input multiple-output (MIMO) systems with iterative varying duration in this article, where the vector relative degree of MIMO system is considered. To recompense the absent tracking information at former iterations caused by iterative varying duration, the feedback control strategy is adopted in modified tracking error based ILC law. It is proved that the convergent condition depends on the P-type control gain. By selecting the proper feedback control gain, the developed open-closed-loop ILC scheme can expedite the convergent speed. Finally, a numerical example is provided for validation.