A System Identification and Implementation of a Soft Sensor for Freeform Bending

Materials, vol. 14, pp. 4549

Abstract

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.

Authors 8

1. Sophie Stebner corresponding Aachen Integrity of Materials and Structures Department of Ferrous Metallurgy

   RWTH Aachen University

   Affiliation as printed

   Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

2. Daniel Maier

   Technical University of Munich

   Affiliation as printed

   Chair of Metal Forming and Casting, Department of Mechanical Engineering, Technical University of Munich, Walther-Meißner-Straße 4, 85748 Garching, Germany

3. Ahmed Ismail

   Technical University of Munich

   Affiliation as printed

   Chair of Automatic Control, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany

4. Shubham Balyan Aachen Integrity of Materials and Structures Department of Ferrous Metallurgy

   RWTH Aachen University

   Affiliation as printed

   Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

5. Michael Dölz Aachen Integrity of Materials and Structures Department of Ferrous Metallurgy

   RWTH Aachen University

   Affiliation as printed

   Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany

6. Boris Lohmann

   Technical University of Munich

   Affiliation as printed

   Chair of Automatic Control, Department of Mechanical Engineering, Technical University of Munich, Boltzmannstraße 15, 85748 Garching, Germany

7. Wolfram Volk

   Technical University of Munich

   Affiliation as printed

   Chair of Metal Forming and Casting, Department of Mechanical Engineering, Technical University of Munich, Walther-Meißner-Straße 4, 85748 Garching, Germany

8. Sebastian Münstermann Aachen Integrity of Materials and Structures Department of Ferrous Metallurgy

   RWTH Aachen University

   Affiliation as printed

   Integrity of Materials and Structures (IMS), Department of Ferrous Metallurgy (IEHK), RWTH Aachen University, Intzestraße 1, 52072 Aachen, Germany