Robust finite-iteration tracking of discrete-time systems in repetitive process setting via ILC scheme

In this work, based on the robust iterative learning control (ILC) scheme, the finite-iteration tracking control is investigated for discrete-time linear systems in repetitive process setting with external disturbances. First, the concept of finite-iteration tracking is defined. Then by utilizing the lifted-vector-matrix technique, the discrete-time linear system can be reformulated as an input-output transmission equation. Moreover, a P-type ILC scheme is employed, and then the finite-iteration tracking of the resultant system is guaranteed with the designed iterative learning controller. Meanwhile, the settling iteration can be explicitly obtained. Particularly, the case of data loss occurred during information transmission is also studied, and sufficient conditions are presented such that the finite-iteration tracking can be achieved in a finite interval. Lastly, the effectiveness and applicability of the presented method are validated via a numerical simulation.