Control System Design for a Semi-Finished Product Considering Over- and Underbending

Abstract

In the last decades, the application of automatic control techniques in freeform bending processes was limited to the motion control of the bending die, i.e., the workpiece itself was not considered inside the closed-loop control system. In a previous work, a simple preliminary model for the workpiece was used as a foundation for developing a closed-loop system for freeform bending that includes both the geometry and the mechanical properties of the semi-finished product. However, this approach did not consider the fact that the same geometry can be reached by either over- or underbending the tube. In this work, the previously developed system model is extended to include this physical property of the system.

Keywords

• freeform bending
• automatic control
• over- and underbending of tubes
• finite element method (FEM)
• modelling
• computerized numerically controlled machines (CNC-Machines)