Iterative learning control in feedback systems (Q1890984)

A new iterative learning control scheme is presented to provide tracking control for a class of nonlinear systems. The scheme uses a standard feedback control configuration, but is augmented by a feedforward term that is updated via iterative learning control. A sufficient condition for convergence of the learning controller is given and it is noted that this condition is the same as for the open-loop learning control problem. However, the rate of convergence is shown to be improved in the closed- loop strategy. The performance of the scheme is illustrated via simulation of the tracking control of a two-link manipulator.