A System Identification and Implementation of a Soft Sensor for Freeform Bending
Sophie Charlotte Stebner,
Daniel Maier,
Ahmed Ismail,
Shubham Balyan,
Michael Dölz,
Boris Lohmann,
Wolfram Volk,
Sebastian Münstermann
Affiliations
Sophie Charlotte Stebner
Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany
Daniel Maier
Chair of Metal Forming and Casting, Department of Mechanical Engineering, Technical University of Munich, Walther-Meißner-Straße 4, 85748 Garching, Germany
Ahmed Ismail
Chair of Automatic Control, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany
Shubham Balyan
Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany
Michael Dölz
Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany
Boris Lohmann
Chair of Automatic Control, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany
Wolfram Volk
Chair of Metal Forming and Casting, Department of Mechanical Engineering, Technical University of Munich, Walther-Meißner-Straße 4, 85748 Garching, Germany
Sebastian Münstermann
Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany
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.
