Flatness Measurement of Metal Products Without External Traction

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Solution Overview

Problem

Existing methods for measuring the flatness of metal products, especially thick plates and moving strips, face limitations due to external traction requirements, high costs, and difficulties in measuring minute traction and flatness defects, particularly in non-reflective or hot products, which can lead to inaccurate results and operational inefficiencies.

Innovation Solution

A method involving illuminating a metal product under uniform intensity, capturing light line images, and relative movement to detect local amplitude variations in light intensity, allowing for the measurement of flatness without external traction, using a device with a light source and linear camera in an optical triangulation configuration, enabling dynamic and cost-effective assessment of flatness across varying product thicknesses and dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If external traction is applied to maintain the product during measurement, then measurement stability is improved, but measurement accuracy deteriorates due to induced hazards on intrinsic real traction

Engineering Contradiction:
Improvemeasurement stabilityVSAvoidmeasurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces a support roller as an intermediary element that provides mechanical support and stability during measurement without applying significant traction forces. The roller system allows the product to be supported while minimizing interference with the intrinsic traction being measured, thus resolving the contradiction between measurement stability and accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If laser measurement devices are used for thick plates, then measurement capability is improved, but cost increases significantly

Engineering Contradiction:
Improvemeasurement capabilityVSAvoidcost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent uses a camera to capture optical images of the product surface instead of expensive laser measurement devices. By copying the visual information through photography, the system achieves measurement capability for thick plates and various product types without the high cost associated with laser-based systems.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces complex laser measurement systems with a simpler optical imaging system using a camera. This substitution maintains measurement capability while significantly reducing device complexity and cost, making the system economically viable for industrial applications.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If the product is stopped for measurement, then measurement accuracy is improved, but productivity deteriorates due to interruption of continuous movement

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidcontinuous operation
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent enables measurements to be taken while the product is in continuous motion through the support roller system. The dynamic measurement capability eliminates the need to stop the product, maintaining both measurement accuracy and productivity by allowing simultaneous operation and inspection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent ensures continuous operation by enabling measurements to be performed without interrupting the product flow. The support roller system and optical measurement approach allow the useful action of both production and inspection to continue simultaneously, maintaining productivity while achieving measurement goals.

Inventive Principle:
Principle #20Continuity of useful action

4Difficulty of detecting and measuring

If grazing light illumination is used to reveal flatness defects, then defect visibility is improved, but device complexity increases due to multiple optical components

Engineering Contradiction:
Improvedefect visibilityVSAvoidoptical system complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent uses a camera to capture the optical pattern created by grazing light illumination. By copying the visual information of flatness defects through photography, the system achieves high defect visibility while avoiding the complexity of multiple active optical components, relying instead on passive optical effects captured by the camera.

Inventive Principle:
Principle #26Copying

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 approach provides a universal, efficient, and cost-effective method for measuring flatness, capable of detecting defects from cm to several tens of cm in length, suitable for both thin strips and thick plates, applicable in metallurgical processing lines without the need for external traction, enhancing measurement dynamics and accuracy.

Implementation Method 1

using a device with a light source and linear camera in an optical triangulation configuration

Methodology Applied
Scientific EffectOptical triangulation: Reflection

Data Source

PatentEP2834594B1Method and device for measuring the flatness of a metal product
Publication Date: 2020.06.03 PRIMETALS TECH AUSTRIA GMBH
  • EP2834594B1 patent drawingFigure 1~3
  • EP2834594B1 patent drawingFigure 4~6
  • EP2834594B1 patent drawingFigure 7

AI summary

A method for measuring the flatness of a metal product and an associated device are presented. Said method applies to a metal product, in the form either of a strip or of a plate from a metallurgical processing line, said product to be measured being, by default, free of external traction, and mainly comprises the following steps: a) illuminating a portion of at least one face of said product under uniform intensity; b) capturing an image of a light line of the illuminated portion, c) relatively moving the illuminated portion and the light line in relation to the product in a defined direction; d) repeating steps a), b) and c); e) collecting the images of lines in a two-dimensional distribution of intensities and selecting a strand direction of the product in which, if at least one wave intensity is detected, a local amplitude variation of said wave delivers a local strand flatness defect value.