Robustness of sampled-data control systems with physical uncertainties in the continuous part

Jury and Pavlidis have shown that sampled-data systems have three critical stability boundaries. These boundaries are described here in a Poisson series form. For systems with uncertain physical parameters the exponential parameter dependency in the characteristic polynomial is thus avoided. For low passplants a simple approximation can be obtained from the first term of the series. The approach is applied to automatic steering of a bus with uncertain velocity and mass