Open-Closed-Loop Iterative Learning Control for Non-linear Discrete-time Systems under Iterative Varying Duration

This article presents an open-closed-loop iterative learning control (ILC) scheme for non-linear discrete-time multiple-input multiple-output (MIMO) systems under iterative varying duration. The improved P-type ILC law with feedback control is presented to compensate the missing tracking information of the previous iterations due to the iterative varying duration. It is proved that when the initial state expectation is identical to the reference sate, ILC tracking error can be driven to zero in mathematical expectation sense. Finally, a numerical example of simulation is provided to verify the validity of the proposed ILC law.