Rolling Mill Curvature Recognition for Strip Deflection Control
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Solution Overview
Problem
Conventional multistand rolling trains face challenges in detecting and preventing tension differences between strip edges due to wedges in the strip profile, which leads to unpredictable strip deflection and potential collisions with side guides, as they rely on lateral force measurements from loop lifters that do not provide differential force data.
Innovation Solution
An operating method for multistand rolling trains that uses position acquisition devices and mathematical-physical models to determine outlet side head pitch and curvature, enabling control interventions to counteract deflections by adjusting rolling stand positions and tensions in real-time, without requiring loop lifters with force sensors on both sides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If loop lifters with force transducers are used to measure tension differences, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent replaces the mechanical force measurement system (loop lifters with force transducers) with an optical measurement system (position acquisition devices such as cameras or laser scanners). This substitution eliminates the need for complex mechanical force sensors while achieving the goal of detecting tension distribution through positional measurements of the strip head and intermediate stand displacement.
2Reliability
If adjustment of rolling stand control elements is delayed, then device complexity is reduced, but reliability deteriorates
Solution Approach 1:
The patent implements preliminary action by determining control interventions for rolling stands based on measured positional data before the strip foot actually reaches the rolling stand. The control device calculates required adjustments to swivel values or other control elements in advance, allowing the rolling stand to be pre-positioned to prevent strip foot deflection and collision, rather than reacting after the problem occurs.
Solution Approach 2:
The patent establishes a feedback loop where position acquisition devices continuously measure the strip head position and intermediate stand displacement, the control device processes this data to determine outlet side head curvature and tension distribution, and control interventions are automatically adjusted in real-time. This closed-loop feedback system enables rapid, automated adjustments without manual intervention delays.
3Ease of operation
If visual tracking by controller is used to set rolling stand adjustments, then ease of operation improves, but manufacturing precision deteriorates
Solution Approach 1:
The patent replaces the subjective visual tracking method with an automated optical measurement and calculation system. Position acquisition devices objectively measure strip head position and intermediate stand displacement, and the control device automatically calculates control interventions based on these measurements and mathematical-physical models. This eliminates human subjectivity and impression-based adjustments, significantly improving manufacturing precision while maintaining ease of operation through automated control.
Solution Approach 2:
The control device performs self-service by automatically determining control interventions based on measured data without requiring manual visual assessment or operator intervention. The system independently processes positional measurements, calculates tension distribution and outlet side head curvature, and generates appropriate control commands for rolling stand adjustments, making the operation both precise and automated.
Data Source
AI summary
In a multi-stand rolling mill train, a strip successively runs through individual rolling stands. The strip—always as seen in relation to a rolling center line—is threaded into each of the rolling stands with known respective head offset and inlet-side head pitch, and therefore a strip head emerges with the respective head offset, a respective outlet-side head pitch and a respective outlet-side head curvature. The respective outlet-side head pitch is determined on the basis of respective inlet-side head pitch and pass reduction which takes place in the respective rolling stand. The respective outlet-side head curvature of the strip is determined based on respective measured and further data. The respective outlet-side head curvature is used to determine a respective control intervention for the respective rolling stand and/or the one arranged directly downstream and to drive the corresponding rolling stand in accordance with the respective determined control intervention.