Temper Rolling Load Control for Faster Elongation Convergence

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Solution Overview

Problem

Existing rolling control methods fail to accurately adjust the elongation rate of steel sheets in temper rolling due to discrepancies between estimated and actual plasticity coefficients, leading to prolonged convergence times to target values, especially in sheets with varying plasticity.

Innovation Solution

A rolling control device and method that dynamically updates the preset load value based on actual operation results, using evaluation indices to adjust the plasticity coefficient differences, ensuring precise elongation rate control through multiple load updates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If the plasticity coefficient is estimated before the rolling load becomes the preset value, then the correction amount of rolling load can be derived, but the estimated plasticity coefficient may differ from the actual plasticity coefficient, causing the elongation rate to deviate from the target value

Engineering Contradiction:

Improvetime required to converge elongation rate to target valueVSAvoidaccuracy of plasticity coefficient estimation

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The patent implements feedback control by measuring the actual elongation rate after rolling, comparing it with the target elongation rate, and using this information to calculate a correction amount for the preset rolling load value. This closed-loop feedback mechanism ensures that the plasticity coefficient estimation is continuously refined based on actual measurement results, resolving the contradiction between quick convergence and estimation accuracy.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent performs preliminary estimation of the plasticity coefficient before the rolling load reaches the preset value to derive an initial correction amount. This preliminary action allows the system to proactively adjust the rolling load before actual rolling begins, reducing the time needed for elongation rate convergence while maintaining accuracy through subsequent feedback refinement.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If the temper rolling mill reduces the steel sheet based on an excessively large estimated plasticity coefficient, then the rolling load correction can be applied, but the reduction amount becomes excessively large, causing the elongation rate to exceed the target value

Engineering Contradiction:

Improveelongation rate control precisionVSAvoidresponse to plasticity coefficient variations

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies partial correction by calculating the correction amount based on the deviation between actual and target elongation rates rather than making excessive adjustments. This partial action principle ensures that the rolling load is adjusted just enough to correct the elongation rate deviation without causing overshooting, thereby maintaining manufacturing precision while adapting to plasticity variations.

Inventive Principle:

Principle #16Partial or excessive action

Solution Approach 2:

The patent makes the preset rolling load value dynamic by continuously updating it based on measured elongation rates and calculated correction amounts. This dynamic adjustment mechanism allows the system to adapt to varying plasticity coefficients in real-time, preventing excessive reduction amounts while maintaining precise elongation rate control throughout the rolling process.

Inventive Principle:

Principle #15Dynamics

3Productivity

If a single correction amount is derived before rolling, then the control process is simple, but the elongation rate may not converge to the target value in a short time due to plasticity coefficient discrepancies

Engineering Contradiction:

Improveconvergence speed of elongation rateVSAvoidcomplexity of control process

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent implements periodic measurement and correction by measuring the elongation rate at specific intervals during and after rolling, calculating correction amounts at each measurement point, and updating the preset rolling load value accordingly. This periodic action accelerates convergence by multiple correction cycles while keeping each individual control step relatively simple, thus improving productivity without excessive complexity.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent segments the correction process into multiple stages: initial correction before rolling, mid-process correction during rolling, and final correction after rolling. Each segment addresses specific plasticity coefficient discrepancies at different stages, enabling faster overall convergence while maintaining manageable complexity within each segmentation phase.

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12447517B2Rolling control device, rolling control method, and program

Publication Date: 2025.10.21 NIPPON STEEL CORPORATION

AI summary

A rolling control device (10) updates a preset load value Pset based on operation actual results at timings ta to tb. The rolling control device (10) derives a plasticity coefficient Qchk based on operation actual results at timings tb to tc. When the determining that it is necessary to re-update the updated preset load value Pset based on the plasticity coefficient Qchk, the rolling control device (10) updates the preset load value Pset again based on the operation actual results at the timings tb to tc.