On ILC design for MIMO-LTI systems

This paper deals with iterative learning control (ILC) design for multiple-input multiple-output (MIMO), linear time-invariant (LTI) systems. Two particular ILC schemes are considered and analyzed in both frequency and time domains. The first scheme uses only the tracking error from the current iteration, while the second scheme uses the tracking errors from the current and the previous iterations (or only from the previous iteration). Some remarks on the convergence, implementation, robustness with respect to reinitialization errors and disturbances, as well as positive realness issues related to both schemes are given