Rolling Mill Strip Position Control via Stand Tilt Adjustment
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Solution Overview
Problem
Existing methods for controlling strip misalignment in rolling mills are inaccurate and slow, often leading to increased misalignment and wedge defects, which can cause rolling incidents and impair strip quality.
Innovation Solution
A method that calculates and applies additional tilts to rolling mill stands based on real-time measurements of strip position, using a gain matrix to adjust the clamping forces and ensure precise alignment, with sensors and processing units determining and transmitting the necessary tilt values to maintain the strip within a predetermined threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If lateral guides are used to correct strip misalignment, then strip position control is improved, but strip edges are damaged and guides wear out
Solution Approach 1:
The patent replaces the mechanical lateral guide system with a control system that adjusts the tilt of rolling mill stands. Sensors detect strip position, and the control system calculates and applies appropriate tilt adjustments to the stands, eliminating the need for physical guides that contact and damage the strip edges.
Solution Approach 2:
The patent introduces tilt adjustment as an intermediary mechanism between the rolling mill stands and the strip. Instead of direct mechanical contact through lateral guides, the tilt adjustment serves as a mediator that indirectly controls strip position by modifying the rolling force distribution, thereby avoiding edge damage.
2Manufacturing precision
If clamping force is increased to correct misalignment, then strip position control is improved, but measurement accuracy deteriorates due to force difference sensitivity
Solution Approach 1:
The patent implements a feedback control system where sensors continuously monitor strip position, the control system calculates the required tilt adjustment based on detected deviations from the reference position, and the tilt is adjusted accordingly. This closed-loop feedback mechanism maintains measurement accuracy while achieving precise position control.
Solution Approach 2:
The patent calculates and applies tilt adjustments in advance based on predicted strip behavior and pre-determined gain matrices. By performing preliminary calculations of the required tilt corrections, the system avoids reactive force adjustments that would compromise measurement accuracy.
3Device complexity
If misalignment correction is delayed, then system complexity is reduced, but manufacturing precision deteriorates due to belated detection
Solution Approach 1:
The patent maintains continuous monitoring and adjustment of strip position throughout the rolling process. Sensors continuously detect strip position, and the control system continuously adjusts tilt as needed, ensuring real-time correction without delays while maintaining manageable system complexity through standardized control algorithms.
Data Source
AI summary
A method of rolling a strip is provided. The method includes determining a value representative of the lateral position of the strip along a line transverse to a run direction downstream of each stand and calculating algebraic differences between the lateral positions and a reference position. A value of additional tilt is calculated from the algebraic differences to bring the algebraic differences below a predetermined threshold. Calculating the additional tilt values includes multiplying the algebraic differences by a gain matrix K that is determined by modeling relationships linking the algebraic differences and the tilts of the stand rolls. The additional tilt value is transmitted to each of the stands. The steps are repeated at predetermined time intervals until the strip is no longer gripped in the nip of the last stand of the rolling mill. A device for adjusting the lateral position of a strip is also provided.