Plant Template Generation for Uncertain Plants in Quantitative Feedback Theory

Abstract

The creation of templates for uncertain plants is an essential first step in Quantitative Feedback Theory (QFT) and other frequency domain methods. For plants with structured parametric uncertainty it is shown that the boundaries of templates can only be generated by the edges of the uncertain parameter set and particular critical interior points. A method to identify these critical interior points is presented. With the help of symbolic computation, a computationally tractable procedure for generating the templates is developed. The procedure is illustrated with an example of a vehicle clutch system where the uncertain parameters perturb the plant nonlinearly.