Iterative learning control design for uncertain dynamic systems with delayed states

Most available results on iterative learning control address trajectory tra cking problem for systems without time delay. The effect of time delay on t racking performance is not yet fully understood. This paper is concerned wi th iterative learning control design for the systems with delayed states, w here the system class under consideration is confined by a defined relative degree. A learning control scheme is proposed to overcome the uncertaintie s in delay times and /or in system parameters. Robustness of the learning c ontrol is established in the presence of initial function errors. Furthermo re, uniform convergence of system outputs to the desired trajectory is ensu red if the initial function at each cycle is set to align with the desired initial function. Validity of the results is demonstrated through numerical simulations.