Design of iterative learning controllers with finite-time dead-zone modification
有限时间死区修正迭代学习控制器的设计

Iterative learning control with finite-time dead-zone modification is presented for a class of higher order nonlinear time-varying systems in the presence of initial condition errors. The Lyapunov-like approach is applied to design the iterative learning controller for dealing with parametric time-varying uncertainties, while a robust method is given to cope with norm-bounded uncertainties. With the introduction of finite-time dead-zone, the developed controllers ensure the specified error function to approach to zero over a pre-specified time-interval. A Gramian-based initial rectifying action is used to realize the complete tracking over another pre-specified time-interval. It is shown in the theoretical analysis and numerical simulation that the system states completely follow the desired trajectories after a pre-specified time, and the error function is always confined to stay within the region defined by the finite-time dead-zone. All the signals in the closed-loop system are proved to be bounded.