Robust Iterative Learning Control in Finite Frequency Ranges for Differential Spatially Interconnected Systems

For a class of uncertain differential spatially interconnected systems in the particular case of active electrical ladder circuits, the problem of iterative learning control with stability and robust performance specifications in finite frequency ranges is investigated in this paper. Firstly, the dynamics are converted to an equivalent differential linear repetitive process. Then, based on the Kalman–Yakubovich–Popov Lemma, a control law design algorithm is presented in the form of the corresponding linear matrix inequalities. Since the system parameters are norm-bounded uncertain, an extension to robust control law is also discussed. The resulting dynamics satisfy the robust performance specifications, and the error monotonically converges in finite frequency ranges with the robust iterative learning control law. Finally, a control simulation of an active electrical ladder circuit is presented to illustrate the advantages of the proposed algorithm.