The Local Rational Method for H-infinity Norm Estimation

Accurate uncertainty modeling is of key importance in high performance robust control design. This poster shows a new uncertainty modeling procedure that enhances the accuracy of the H-infinity norm. A frequency response based approach is adopted. The key novelty is a method to address the intergrid error using local parametric modeling methods by means of the Local Rational Method (LRM). These local rational models enhance the estimates at the discrete frequency grid. Moreover, the presented methods are shown to enhance the intergrid error estimate. Compared to the local polynomial models, local rational models are able to handle lightly-damped resonances using far fewer data points and a far shorter measurement time. This is illustrated using experiments on an industrial active vibration isolation system.