Roll Eccentricity Suppression via Tensile Force Feedback
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Solution Overview
Problem
Existing methods for suppressing roll eccentricities in rolling stock are inadequate due to unreliable measurements of rolling force, which are often falsified by friction, and the high cost and complexity of accurate thickness sensors.
Innovation Solution
A method that uses a process model to identify roll eccentricities based on measured tensile force, feeding this data to a control device to generate a correction signal for the roll stand's actuator, thereby compensating for eccentricities and maintaining uniform outlet thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rolling force measurement is used to identify roll eccentricities, then the measurement system is simple and inexpensive, but the measurement precision is poor due to friction falsification
Solution Approach 1:
The patent introduces tensile force measurement as an intermediary parameter to indirectly identify roll eccentricities. Instead of directly measuring rolling force (which is corrupted by friction), the system measures tensile force in the rolling stock and uses a process model to derive eccentricity information. This intermediary measurement approach avoids the friction problem while maintaining system simplicity.
Solution Approach 2:
The patent replaces the mechanical rolling force measurement system with a tensile force measurement system. By measuring tensile force rather than rolling force, the system avoids direct contact friction at the roll-strip interface. The process model then substitutes the mechanical relationship to identify eccentricities from the tensile force data.
2Measurement precision
If accurate thickness sensors are used to measure outlet thickness, then the measurement precision is high, but the device complexity and cost increase significantly
Solution Approach 1:
The patent uses tensile force measurement as an intermediary to indirectly determine outlet thickness characteristics. Instead of installing expensive thickness sensors directly at the roll stand, the system measures tensile force and uses process modeling to infer thickness information, achieving accurate measurement without complex sensing hardware.
Solution Approach 2:
The patent replaces direct mechanical thickness measurement with a combination of tensile force measurement and process modeling. This substitution eliminates the need for expensive thickness sensors while maintaining measurement accuracy through the relationship between tensile force and thickness in the rolling process.
3Manufacturing precision
If roll eccentricities are not suppressed, then the system operation is simple, but the manufacturing precision of the rolled strip deteriorates
Solution Approach 1:
The patent implements a feedback control system where tensile force measurements are continuously fed into a process model to identify roll eccentricities in real-time. The identified eccentricities are then used to generate correction signals that are fed back to the actuator system, creating a closed-loop control that maintains manufacturing precision.
Solution Approach 2:
The patent dynamically adjusts actuator parameters based on identified roll eccentricities. By changing the actuator control parameters in response to detected eccentricity conditions, the system compensates for roll imperfections and maintains consistent rolled strip thickness without requiring physical modifications to the rolls themselves.
Data Source
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AI summary
The invention relates to a method for suppressing the influence of roll eccentricities on the run-out thickness (ha) of a rolled stock (10), which runs through a rolling stand (1), roll eccentricities being identified by using a process model (27) and taken into consideration in the determination of a correction signal for at least one final control element, preferably a final control element for the adjustment position, of the rolling stand (1), wherein the measured tensile force (Fz) upstream of the rolling stand (1) is fed to the process model (27) to identify the roll eccentricities. According to the invention, variations in tensile force are fed back in a targeted manner to reduce the effects of periodic roll eccentricities on the rolled stock (10), whereas all other sources of variation are eliminated. A process model (27) of the rolling nip and the rolls, preferably based on the observer principle, produces reliable data on the roll eccentricity. In this way, given dimensions of the rolled stock (10) are achieved more uniformly than previously.