Iterative Learning Controller with Causal Learning Function for a Class of Linear Mon-minimum Phase Systems

This paper presents a design strategy of an iterative learning controller (ILC) with a causal filter-based learning function for a class of non-minimum phase systems. The learning function is part of the ILC used to stabilize the ILC closed-loop system and determine the convergence rate of the system output. In this paper, we present the design of ILC’s learning function in the form of a stable and causal filter. An ILC’s stability condition in the frequency domain is employed to formulate the minimization problem. Then, an optimization tool is used to solve the minimization problem. Simulation on non-minimum phase plant with a relative degree one demonstrates the effectiveness of the proposed design.