Metal forming processes operate in conditions of uncertainty due to parameter variation and imperfect understanding. This uncertainty leads to a degradation of product properties from customer specifications, which can be reduced by the use of closed-loop control. A framework of analysis is presented for understanding closed-loop control in metal forming, allowing an assessment of current and future developments in actuators, sensors and models. This leads to a survey of current and emerging applications across a broad spectrum of metal forming processes, and a discussion of likely developments.

Closed-loop control of product properties in metal forming

Manufacturing of advanced smart tooling for metal forming

A novel feedback control system – Controlling the material flow in deep drawing using distributed blank-holder force

This study discusses the development and implementation of noncontact split detection method, for automotive stamping press lines. The system features a novel fusion routine that combines thermal and visible images in real-time, assisted with principle component analysis (PCA) subroutine. The thermal detector scans the temperature maps of the highly reflective steel sheets in the die cavity to locate abnormal temperature readings that might be indicative of high local wrinkling pressure, while the visible vision system offsets the blurring effect caused by heat diffusion across the surface and provide a spatial reference. The employed PCA uses a new singular value decomposition (SVD) that is more efficient than standard SVD computations, enabling the PCA to be applied in real-time acquisitions (∼30 Hz). The PCA affects the images by reducing the nonvalue data content (reduce redundancy, noise) while highlighting important features. The fusion is done using a pixel-level algorithm using different variation...

/pdf/principal-component-analysis-based-image-fusion-routine-with-6gxxp94pzw.pdf

Principal Component Analysis-Based Image Fusion Routine with Application to Automotive Stamping Split Detection

http://www.nt.ntnu.no/users/skoge/prost/proceedings/ifac2008/data/papers/1201.pdf

H.-J Seidel

Papers

Contactless on-line measurement of material flow for closed loop control of deep drawing