RESUMEN
The primary goal of this study is the formulation of a soft sensor that predicts industrially relevant mechanical properties for freeform bending. This serves as the foundation of a closed-loop property control. It is hypothesized that by inline measurement of hardness, predictions regarding residual hoop stresses, local strength and strain level can be achieved. A novel hardness-based correlation scheme is introduced, which is implemented into an extended Kalman filter (EKF) and allows an inline prediction of local strength, residual hoop stresses and plasticity. Furthermore, the ultrasonic contact impedance (UCI) method is validated as a suitable inline measuring solution.
RESUMEN
This note addresses the problem of instability in frequency weighted controller reduction methods based on similarity transformations. The aim is to reduce the complexity of the controllers derived by modern controller design packages for practical applications. For a given controller a framework is proposed that parameterizes a set of reduced controllers that preserve the stability of the closed loop system. Then based on this result a complementary algorithm to obtain a stabilizing stable reduced controller based on the two sided frequency weighted reduction method is presented. In addition, a sufficient condition for the existence of such a framework is derived.