A hard error bound approach for quantification of model uncertainty in transfer function estimation

In this paper we address the problem of deriving hard error bounds for estimated transfer functions in a form suitable for robust control design. Our approach is to consider the noise and effect of undermodeling as bounded disturbances and to apply a set membership description of uncertainty. The main assumptions are a priori information consisting of a time domain bound on the noise and information about the decay rate of the system impulse response. A procedure is presented to derive regions in the Nyquist plane which contain the true systems Nyquist plot