State Estimators for Plants Implementing ILC Strategies through Delay Links

Abstract

Random delays in the communication links affect the precise tracking of the expected trajectory by a plant controlled by the iterative learning control (ILC) strategy. To tackle the link impact, this paper proposes a state estimator to derive accurate plant outputs that are necessary for controller learning. First, a data pre-processing method is designed to ensure that both the controller and actuator ends receive only one piece of data at any given moment. Subsequently, the data pre-processing method and the system information are used according to the theory of orthogonality to construct the state estimator. The simulation examples demonstrate that the developed estimators aid in the precise tracking of the desired trajectory by the plant implementing ILC strategies through delay links.