Rolling Mill Thickness Control via Integrated Regulator
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Solution Overview
Problem
Current rolling control methods in cold rolling processes suffer from parasitic and contradictory corrections due to separate application of thickness measurements and flow rate predictions, leading to inadequate rejection of thickness disturbances and variations in the rolled strip.
Innovation Solution
A method that combines thickness measurements downstream of the stand with flow rate-based predictions to correct roll spacing or rotation, using a single regulator to immediately address disturbances and account for transfer time offsets, thereby reducing parasitic corrections and improving rolling mill performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If two separate regulations are applied in parallel (one based on thickness measurement at outlet, another on flow rate prediction), then thickness variations can be reduced, but parasitic and contradictory corrections occur leading to inadequate rejection of thickness disturbances
Solution Approach 1:
The patent merges the two separate regulations (thickness measurement-based regulation and flow rate prediction-based regulation) into a single integrated regulation system. The regulator simultaneously processes both the actual thickness measurement downstream and the predicted thickness from flow rate law, combining them into a unified control action that eliminates parasitic and contradictory corrections while maintaining thickness uniformity and improving disturbance rejection capability
2Manufacturing precision
If thickness measurement at outlet is used for regulation, then thickness control is achieved, but delay in reaction to thickness disturbances occurs due to transfer time
Solution Approach 1:
The patent applies preliminary action by using flow rate prediction to estimate the thickness at the outlet based on current operating conditions (entry thickness, entry speed, exit speed) before the actual measurement is available. This prediction provides advance information about expected thickness, allowing the regulator to take corrective action earlier and reduce the reaction delay caused by the transfer time of the strip from the stand to the measurement point
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 integrated approach enhances the rejection of thickness disturbances, reduces variations in the rolled strip, and improves the overall performance of the rolling mill by avoiding contradictory corrections and leveraging real-time measurements.
Implementation Method 1
the measurement of the thickness of the strip downstream of the stand with respect to the direction of travel
Implementation Method 2
the estimation of the thickness of the strip at the outlet of the stand according to the flow rate law... the thickness of the strip at the outlet of the stand is obtained by the relationship: E s = E e .V e /V s
Implementation Method 3
Rolling therefore consists of reducing the thickness of a strip of metal by plastic deformation
Data Source
Figure 1
Figure 2
AI summary
The method involves measuring thickness (Js) of metallic sheared strip (B) in downstream of roll housing (8) with respect to projection direction by using a gauge (16), and estimating thickness of the strip in an outlet of the roll housing according to flow path by using a gauge (18). Spacing or rotational speed of work rolls (10) is corrected based on thickness of the strip in downstream of the housing and thickness of the strip in the outlet of the housing by a single regulator (24). An independent claim is also included for a device for controlling rolling of sheared strip comprising roll housing.