Cold Roller Mass Flow Regulation via Speed and Thickness Feedback
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Solution Overview
Problem
Existing cold rolling mills with strip feed devices operating in tension-controlled mode struggle to actively adjust mass flow, making precise adjustment of mass flow challenging when the strip feed device cannot actively influence the mass flow.
Innovation Solution
A control method that compares actual speed with target speed to adjust the circumferential roll speed of the roll stand, and tracks the roll gap based on the product of actual speed and strip thickness to maintain a target mass flow, allowing for precise adjustment of mass flow even when the strip feed device cannot actively control it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the strip feed device operates in tension-controlled mode, then the device complexity is reduced and ease of operation is improved, but the ability to actively adjust mass flow is lost
Solution Approach 1:
The control device acts as an intermediary between the strip feed device and the roll stand. It receives actual speed and strip thickness measurements, calculates the required mass flow, and adjusts the roll stand's circumferential roll speed accordingly. This intermediary control mechanism enables mass flow adjustment without requiring the strip feed device itself to have active control capabilities.
Solution Approach 2:
The invention changes the control parameter from direct strip feed device control to roll stand circumferential speed control. By measuring actual speed and strip thickness downstream and adjusting the roll stand's circumferential speed, the system achieves mass flow regulation through parameter transformation rather than direct feed device manipulation.
2Adaptability or versatility
If the strip feed device is used to actively influence mass flow, then mass flow adjustment capability is improved, but device complexity increases
Solution Approach 1:
The control device serves as a computational intermediary that processes measurements of actual speed and strip thickness, calculates the target mass flow, and determines the appropriate circumferential roll speed adjustments. This centralized control approach avoids the need for complex modifications to the strip feed device itself.
Solution Approach 2:
The invention replaces potential mechanical complexity in the strip feed device with a computational control system. Instead of modifying the mechanical strip feed mechanism to actively control mass flow, the system uses measurements and computational algorithms to adjust the roll stand's circumferential speed, achieving the same control objective with simpler mechanical components.
3Manufacturing precision
If the control system actively adjusts mass flow through circumferential roll speed control, then manufacturing precision of strip thickness is improved, but device complexity increases
Solution Approach 1:
The control system implements feedback control by continuously measuring actual speed and strip thickness downstream of the roll stand, comparing these measurements to target values, and adjusting the circumferential roll speed accordingly. This closed-loop feedback mechanism enables precise strip thickness control while keeping the control logic centralized and manageable.
Solution Approach 2:
The system transforms the control approach by changing from direct strip feed device control to roll stand circumferential speed control. This parameter transformation allows for precise mass flow and strip thickness control while maintaining relatively simple device architecture, as the control is achieved through speed adjustment rather than mechanical modification.
Data Source
Figure 1
Figure 2~3
AI summary
A cold rolling train comprises multiple roll stands, through which a cold rolled strip (1) successively runs. An actual speed (v) at which the cold rolled strip (1) is discharged from one (2-1) of the roll stands (2) is measured. The measured actual speed (v) is compared to a corresponding desired speed (v*). A desired value (vU*) for a circumferential roll speed (vU) of the respective roll stand (2-1) is adjusted on the basis of the comparison such that the actual speed (v) matches the desired speed (v*). The respective roll stand (2-1) is controlled according to the adjusted desired value (vU*) for the circumferential roll speed (vU) of the respective roll stand (2-1). Furthermore, a thickness (d) at which the cold rolled strip (1) is discharged from the respective roll stand (2-1) is detected. A nip (s) of the respective roll stand (2-1) is adjusted on the basis of at least the detected thickness (d) of the strip in such a way that the product of the actual speed (v) of the cold rolled strip (1) and the thickness (d) of the strip (d) corresponds to a desired mass flow rate (M*).