Precision preview-based stable-inversion for nonlinear nonminimum-phase systems: The VTOL example

Abstract

This article quantifies the importance of the future desired trajectory in determining the exact-output-tracking input for nonlinear, nonminimum-phase systems by using system inversion techniques. It is intuitive that the effect of the desired output's distant-future values, on the output-tracking input at the current time instant, should be small. Therefore, at a current time instant ( t c ) , preview information of the desired output in a finite-time window [ t c , t c + T p ] should be sufficient to compute the output-tracking input with an arbitrarily small prescribed error, if the preview time T p is sufficiently large. The contribution of this article is the quantification of the needed preview time T p by using the benchmark VTOL aircraft model as an example. Additionally, simulation results are presented to evaluate the efficacy of the finite-preview-based stable-inversion approach.