Rolling Mill Contour Control Using Discrete Shape Specifications

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Solution Overview

Problem

Existing rolling technologies struggle to accurately control the contour of flat rolling stock, leading to economic disadvantages due to insufficient or incorrect contours, which can result in scrap material or lower-value usage.

Innovation Solution

An operating method for a rolling train that allows for the selection of discrete characteristic variables such as profile, edge, bone, edge drop, and wedge values to define the contour, using a control device that adjusts manipulated variables based on actual and target values to optimize the rolling process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only the profile value is specified as target parameter, then the control system is simple, but the contour control is insufficient and leads to economic losses

Engineering Contradiction:
Improvecontrol system complexityVSAvoidcontour control precision
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The contour specification is segmented into multiple discrete parameters (profile value, edge value, bone value, edge drop value, wedge value) instead of using a single profile value. This segmentation allows independent control of different contour characteristics, improving manufacturing precision while maintaining systematic control structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system transitions from one-dimensional profile control to multi-dimensional contour control by introducing additional discrete parameters that describe different aspects of the contour. This dimensional expansion enables comprehensive contour specification without proportionally increasing system complexity

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Manufacturing precision

If multiple discrete contour parameters are controlled, then the contour control precision is improved, but the device complexity increases

Engineering Contradiction:
Improvecontour control precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The control device is designed with multi-functionality to handle multiple discrete contour parameters (profile, edge, bone, edge drop, wedge values) through a unified control architecture. This universal approach allows the same control system to manage diverse contour specifications without requiring separate control mechanisms for each parameter

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system controls contour by changing multiple discrete parameters simultaneously rather than relying on a single parameter. By coordinating adjustments across profile value, edge value, bone value, edge drop value, and wedge value, the system achieves precise contour control through parameter optimization

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If contour control is insufficient, then the control system is simple, but the flat rolled material becomes scrap or lower-value product

Engineering Contradiction:
Improvecontrol system complexityVSAvoidmaterial loss
Core Design Contradiction:
Device complexityVSLoss of substance

Solution Approach 1:

The control device receives actual values of the flat rolled material and compares them with target values, then determines setpoints for manipulated variables based on this feedback. This closed-loop feedback mechanism ensures accurate contour control, preventing material from becoming scrap or lower-value product

Inventive Principle:
Principle #23Feedback

4Loss of substance

If precise contour control is implemented, then material utilization is improved, but the control device complexity increases

Engineering Contradiction:
Improvematerial lossVSAvoidcontrol device complexity
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The control device determines setpoints for manipulated variables before the rolling process based on actual values and target values. This preliminary action allows the system to pre-calculate optimal control parameters, ensuring precise contour control and minimizing material loss while maintaining efficient operation

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3706929B1Selected adjustment of contour by setting specifications
Publication Date: 2023.04.12 PRIMETALS TECH GERMANY GMBH
  • EP3706929B1 patent drawingFigure 1
  • EP3706929B1 patent drawingFigure 2~3
  • EP3706929B1 patent drawingFigure 4~6

AI summary

A rolling line for rolling a flat rolling material (2) comprises a number of roll stands (1). Prior to the rolling of the flat rolling material (2), a control system (3) of the rolling line receives actual variables (I) of the flat rolling material (2) before the rolling of the flat rolling material (2), and said control system receives target variables (Z) of the flat rolling material (2) after the rolling of the flat rolling material (2). The control system (3) determines desired values (S*) for control variables (S) for the roll stands (1), based on the actual variables (I) and the target variables (Z), in combination with a description (B) of the rolling line, using a model (10) of the rolling line. The control system (3) determines the desired values (S*) in such a way that variables (E1) that are expected for the flat rolling material (2) after the rolling of the flat rolling material (2) in the rolling line are aligned as far as possible with the target variables (Z). The control system (3) transfers the desired values (S*) to the roll stands (1) such that the flat rolling material (2) is rolled in the rolling line according to the transfered desired values (S*). The target variables (Z) comprise at least one freely selectable, discrete characteristic variable (K1 to K5, K2' to K4', K2" to K4") defining the contour (K) of the flat rolling material (2).