Abstract
This paper investigates the design problem of an infinite-time preview feedforward controller from the viewpoint of the model-matching problem based on the two-sided Laplace transform. It is shown that the so-called preview-based stable inversion for linear time-invariant systems is equivalent to the noncausal solution to the model-matching problem. The preview feedforward controller can be easily discussed in the frequency domain where the design method for the optimal feedback controller has already been established. Moreover, with the same approach as stable inversion, we derive a transfer-function representation for the algorithm of adjoint-based iterative learning control. This indicates that the algorithm can be applied to infinite-dimensional systems such as flexible structures. This is demonstrated through an experiment on the tip control of a flexible arm.
