Rolling Mill Contour Control Using Non-Symmetrical Actuation

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Solution Overview

Problem

Conventional rolling processes struggle to control asymmetrical contours in rolled products, which can lead to economic losses and inefficiencies due to reworking or scrap, often caused by asymmetrical contours, temperature distributions, and actuator wear.

Innovation Solution

A method and system for controlling rolling mills to influence asymmetrical contours by determining and applying non-symmetrical control values using a process model, combining mechanical and thermal adjustments, such as asymmetrical movements and temperature gradients, to achieve desired contours.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional symmetrical control mechanisms are used in rolling mills, then the rolling process is simple to operate, but asymmetrical contours cannot be controlled or corrected

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

Solution Approach 1:

The patent applies asymmetry by introducing asymmetrical control values for actuators that are specifically designed to counteract asymmetrical contour deviations. Instead of using only symmetrical control mechanisms, the system calculates and applies different control values to different actuators based on the detected asymmetry in the rolled stock contour, enabling precise control of asymmetrical features.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The control mechanism is made dynamic by continuously detecting the actual contour during the rolling process and adjusting the control values in real-time. The system dynamically calculates asymmetrical control values based on the difference between target and actual contours, allowing the control mechanism to adapt to changing conditions and correct asymmetries as they occur.

Inventive Principle:
Principle #15Dynamics

2Manufacturing precision

If asymmetrical control values are applied to correct contour deviations, then contour control precision is improved, but the control mechanism becomes more complex

Engineering Contradiction:
Improveasymmetrical contour controlVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system implements feedback by continuously detecting the actual contour of the rolled stock during the rolling process and using this information to calculate appropriate asymmetrical control values. The detection unit monitors the contour in real-time, and the control values are adjusted based on the feedback from the actual contour measurements, enabling closed-loop control of asymmetrical features.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces complex mechanical adjustment mechanisms with a computational approach. Instead of using complex mechanical systems to physically adjust rollers asymmetrical to the center, the system uses a control unit that calculates asymmetrical control values and applies them electronically to actuators, substituting mechanical complexity with computational processing.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Productivity

If conventional rolling processes are used, then the production process is efficient, but asymmetrical contours result in reworking or scrap

Engineering Contradiction:
Improveproduction efficiencyVSAvoidcontour symmetry
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system performs preliminary action by proactively counteracting asymmetrical contour deviations during the rolling process itself, rather than detecting and correcting them after rolling is complete. By continuously monitoring and applying asymmetrical control values during the process, the system prevents asymmetrical contours from developing, eliminating the need for subsequent reworking or scrap disposal.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach allows precise control over asymmetrical contours, reducing or creating desired asymmetries in rolled products, enhancing production efficiency and reducing scrap, by compensating for uncontrollable effects in conventional methods.

Implementation Method 1

The at least two control values are expediently determined using a process model that maps the rolling process in the rolling mill, on the basis of the target contour and the actual contour

Methodology Applied
Scientific EffectProcess modeling:

Implementation Method 2

the contour can also be influenced by controllable roll or rolling stock cooling, as well as an edge heater

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

combining mechanical and thermal adjustments, such as asymmetrical movements and temperature gradients, to achieve desired contours

Methodology Applied
Scientific EffectTemperature gradient: Temperature Gradient

Implementation Method 4

Typical control mechanisms include bending, pair-crossing, and swiveling of work rolls, which can be implemented by controlling appropriate actuators

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Data Source

PatentEP4574287A1Rolling method, computer program product and rolling plant
Publication Date: 2025.06.25 PRIMETALS TECH GERMANY GMBH
  • EP4574287A1 patent drawingFigure 1
  • EP4574287A1 patent drawingFigure 2
  • EP4574287A1 patent drawingFigure 3~4

AI summary

The present invention relates to a method for rolling flat rolled stock (1a), a computer program product, and a rolling mill (2) for rolling flat rolled stock (1a). A target contour (Z) of the flat rolled stock (1b) is specified after a rolling process in the rolling mill (2), and an actual contour (I) of the flat rolled stock (1a) is provided before the rolling process in the rolling mill (2). Furthermore, at least two control values ​​(S) are determined for an adjustment mechanism (7a, 7b) of the rolling mill (2), with which the contour (10) of the rolled stock (1a) can be influenced during the rolling process. The at least two control values ​​(S) are expediently determined using a process model that maps the rolling process in the rolling mill (2), on the basis of the target contour (Z) and the actual contour (I).The rolling mill (2) is then operated with the at least two control values ​​(S), wherein the control mechanism (7a, 7b) is controlled non-symmetrically with the at least two control values ​​(S).