Mapping of Nyquist/Popov Theta-Stability Margins Into Parameter Space

Abstract

The application of the parameter space method has proven to be useful for robustness analysis of uncertain parametric systems and robust control synthesis for quite a number of applications. However, it has been restricted to linear systems and the consideration of eigenvalue criteria. This paper enhances the application of the parameter space method to include various locus criteria. This allows not only for incorporation of linear criteria (e. g. gain and phase margin) but for nonlinear criteria as well (e.g. Popov- or circle criterion and the dual locus method).