Iterative learning control for a class of nonlinear discrete-time systems with multiple input delays

This article, addresses the robust iterative learning control (ILC) problem for nonlinear discrete time-delay systems. The derivation of convergence and robustness for the proposed ILC rule is based on two-dimensional (2D) linear inequalities. For a class of nonlinear discrete-time systems with multiple input delays, it is shown that the ILC tracking errors are bounded in the presence of state, output disturbances and initial state uncertainty. As these disturbances and uncertainty satisfy required conditions, the ILC tracking errors even can be driven to zero. Two numerical examples are used to validate the proposed ILC method.