Levelling Machine Drive Control for Balanced Roll Stress

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Solution Overview

Problem

Conventional leveling machines for sheet material often face inefficiencies in stress distribution and energy consumption due to the independent operation of drives, leading to uneven deformation and curvature correction processes.

Innovation Solution

A control method and leveling machine design where the first and second drives are independently controlled using torque setpoint signals based on error signals from speed differences, with an additional torque gain applied to the second drive to enhance stress distribution and energy efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If independent drives are used for first and second groups of rolls, then deformation control is improved, but stress distribution becomes uneven and energy consumption increases

Engineering Contradiction:
Improvedeformation controlVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The control method employs feedback mechanisms where the speeds of both drives are continuously measured and compared against the setpoint speed. Error signals are generated from the differences between setpoint and actual speeds, and torque setpoint signals are adjusted based on these errors to achieve equitable stress distribution and optimize energy consumption while maintaining precise deformation control.

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If independent drives operate without coordinated control, then deformation capability is maintained, but stress distribution across drives becomes unequal

Engineering Contradiction:
Improvedeformation capabilityVSAvoidstress distribution
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The control method uses feedback control where speed measurements from both drives are continuously monitored. Error signals derived from the difference between setpoint speed and actual drive speeds are used to generate torque setpoint signals that coordinate the operation of independent drives, ensuring equitable stress distribution while maintaining deformation capability.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control method dynamically adjusts operational parameters (torque setpoint signals) based on measured speed deviations. By changing torque parameters in response to speed errors, the system achieves coordinated stress distribution across independent drives while preserving their individual deformation capabilities.

Inventive Principle:
Principle #35Parameter changes

3Speed

If torque setpoint signals are based solely on speed error, then speed control is achieved, but energy optimization is insufficient

Engineering Contradiction:
Improvespeed controlVSAvoidenergy optimization
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The control method implements feedback control by continuously measuring drive speeds, comparing them to the setpoint speed, and generating error signals. These error signals form the basis for torque setpoint signals that not only maintain speed control but also optimize energy consumption by equitably distributing the workload between the first and second drives based on their actual operational states.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4049770B1Control method of a levelling machine and levelling machine
Publication Date: 2024.10.16 FAGOR ARRASATE SCOOP
  • EP4049770B1 patent drawingFigure 1
  • EP4049770B1 patent drawingFigure 2~3
  • EP4049770B1 patent drawing

AI summary

Control method of a leveling machine and leveling machine, wherein the method comprises moving a sheet material (1) between a first (11) and a second group of rolls (12) following a winding path according to a setpoint speed (V*), driving the first group (11) by means of a first drive (13), driving the second group (12) by means of a second drive (14) independent of the first drive (13), measuring the speed (V1) of the first drive (13), measuring the speed (V2) of the second drive (14), controlling the speed (V1) of the first drive (13) by means of a first torque setpoint signal (T1*) which is a function of a first error signal (e1) obtained from the difference between the setpoint speed (V*) and the speed (V1) of the first drive (13), and controlling the speed (V2) of the second drive (14) by means of a second torque setpoint signal (T2*) which is a function of a second error signal (e2) obtained from the difference between the setpoint speed (V*) and the speed (V2) of the second drive (14), and is also a function of an additional torque gain.