Dynamic Panel Stiffness Measurement Using Optical Grid Deformation

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Solution Overview

Problem

Conventional methods for measuring dynamic panel stiffness of automobile parts only evaluate load displacement at a specific site, failing to quantify the deformation behavior of outer panels under moving loads, which is crucial for evaluating buckling sounds and improving panel stiffness.

Innovation Solution

A method and apparatus that use grids arranged in a regular lattice form on the outer panel surface, combined with fiducial markers and multiple cameras to capture three-dimensional deformation data, allowing for the application of both static and moving loads to quantify deformation and acoustic data, enabling detailed evaluation of dynamic panel stiffness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional static load measurement methods are used, then measurement simplicity is maintained, but the ability to evaluate dynamic deformation behavior under moving loads is lost

Engineering Contradiction:
Improvedynamic panel stiffness measurementVSAvoidmeasurement system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical measurement systems (load cells, displacement meters) with optical measurement systems (multiple cameras capturing grid deformation). This substitution enables dynamic measurement of panel stiffness under moving loads while maintaining measurement precision, as the optical system can track deformation continuously without mechanical contact constraints

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

Solution Approach 2:

The patent uses grids transferred to the panel surface as a visual copy of the deformation pattern. By tracking the deformation of these grid patterns through multiple cameras, the system captures dynamic deformation behavior without requiring direct mechanical measurement devices on the panel, thus reducing device complexity while improving measurement capability

Inventive Principle:
Principle #26Copying

2Measurement precision

If only load displacement at a specific site is measured, then measurement simplicity is maintained, but quantitative evaluation of deformation behavior under moving loads becomes impossible

Engineering Contradiction:
Improvedeformation behavior quantificationVSAvoidmoving load deformation
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the measurement into multiple independent components: multiple cameras positioned at different locations, grids divided into measurable units, and separate tracking of individual grid points. This segmentation enables comprehensive measurement of deformation behavior across the entire panel under moving loads, transforming an unmeasurable continuous deformation into discrete, quantifiable data points

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from one-dimensional load-displacement measurement to three-dimensional deformation field measurement by using multiple cameras to capture grid patterns from different angles. This dimensional expansion enables quantitative evaluation of deformation behavior across the entire panel surface, making it possible to track and analyze complex deformation patterns under moving loads

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 allows for accurate, quantitative measurement of dynamic panel stiffness, identifying factors influencing buckling sounds and deformation behavior, thereby improving panel design and reducing unwanted noise during operations like car washing.

Implementation Method 1

the grids on the surface of the outer panel deformed by loading of the indenter are simultaneously shot from plural positions by means of plural cameras

Methodology Applied
Scientific EffectPhotography: Photography

Data Source

PatentEP2916122B1Method and apparatus for measuring dynamic panel stiffness of outer panel for automobile parts
Publication Date: 2019.10.02 JFE STEEL CORP
  • EP2916122B1 patent drawingFigure 1
  • EP2916122B1 patent drawingFigure 2~3
  • EP2916122B1 patent drawingFigure 4

AI summary

[Task] It is to provide a technique for measuring dynamic panel stiffness in a higher accuracy. [Solution for task] A method for measuring dynamic panel stiffness of an outer panel for automobile parts by pushing an indenter onto a surface of an outer panel to be measured in a given pushing direction intersecting to the surface under a given load to deform the outer panel and measuring a deformation state of the outer panel, characterized in that grids arranged in a regular lattice form are transferred to a surface of a measuring site of the outer panel to be measured; fiducial markers previously knowing three-dimensional position information are arranged on the periphery of the measuring site of the outer panel; the indenter is pushed onto the surface of the measuring site of the outer panel under the load and moved in a direction perpendicular to the pushing direction, during which the grids on the surface of the outer panel deformed by loading of the indenter are simultaneously and repeatedly shot from plural positions by means of plural cameras; three-dimensional position information of the grids is calculated corresponding to the fiducial markers based on the shot image data to measure a change in the deformation state of the outer panel associated with the movement of the indenter, which is output as panel deformation data.