Airbag Cover Scoring with 3D Optical Residual Thickness Checking

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Solution Overview

Problem

Existing methods for scoring weakening lines on airbag upholstery materials face challenges in precision due to thermal deformations and measurement errors, requiring complex installations and potentially leading to incorrect airbag deployment and safety issues.

Innovation Solution

A process and apparatus that uses optical marking devices and a vision system to detect the spatial position and orientation of key components, allowing for precise measurement of residual thickness and self-diagnosis to ensure accurate scoring, while accounting for thermal deformations and providing reliability and safety guarantees.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If inductive sensors are used to measure residual thickness, then measurement can be performed, but the fitting must be specially designed to be detectable and thermal dilations affect precision

Engineering Contradiction:
Improveresidual thickness measurement precisionVSAvoidinstallation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces mechanical contact-based inductive sensors with an optical measurement system using cameras and image processing. This substitution eliminates the need for special fitting designs and reduces sensitivity to thermal dilations, as optical fields are not affected by thermal expansion in the same way mechanical contact points are.

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

Solution Approach 2:

The patent creates a digital optical copy (image) of the physical setup including the cutting tool, fitting, and material. By working with these optical copies through image processing, the system avoids direct mechanical measurement issues while maintaining measurement capability.

Inventive Principle:
Principle #26Copying

2Measurement precision

If complex measurement installations are used to account for thermal deformations, then measurement accuracy improves, but device complexity increases

Engineering Contradiction:
Improvemeasurement accuracy under thermal conditionsVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements self-service through automatic image processing and computational correction of thermal effects. The system captures images and automatically processes them to compensate for thermal deformations without requiring additional complex hardware or manual calibration procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the measurement parameter from direct physical contact (inductive sensing) to optical field interaction (imaging). This parameter change allows the system to measure residual thickness while being inherently more resistant to thermal deformations and requiring simpler installations.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If residual thickness is too high, then airbag exit is delayed or incorrect, but if residual thickness is too low, then damage occurs and airbag deploys at wrong time

Engineering Contradiction:
Improveresidual thickness controlVSAvoidairbag deployment safety
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent implements feedback control by measuring the actual residual thickness after scoring and using this information to verify and adjust the scoring process. The optical measurement system provides real-time feedback on whether the residual thickness is within the safe range, allowing for immediate correction if deviations are detected.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary measurement and verification of residual thickness before airbag deployment. By checking the residual thickness in advance using the optical system, the process ensures that the material properties are correct before the critical deployment moment, preventing both delayed exit and excessive damage.

Inventive Principle:
Principle #10Preliminary action

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

Ensures consistent residual thickness and correct scoring, enhancing the reliability and safety of airbag deployment by providing precise measurements and self-diagnosis capabilities, thus overcoming the limitations of prior art.

Implementation Method 1

optical marking devices associated with the machine frame, the robotic arm, the cutting tool and the fitting or support, respectively... detecting the spatial position of said optical marking devices by means of at least one vision device

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3378615B1Process and apparatus for scoring weakening lines
Publication Date: 2022.05.25 AUTOMATIONSROBOTIC GMBH
  • EP3378615B1 patent drawingFigure 1
  • EP3378615B1 patent drawingFigure 2
  • EP3378615B1 patent drawingFigure 3

AI summary

A process for scoring weakening lines on flexible materials intended to form airbag covers is performed in a scoring apparatus (1), which comprises a machine frame (2), a robotic arm (3) carrying a cutting tool (4), and a fitting or support (5) for the flexible material. The process comprises a step of checking the residual thickness (S) not cut by a cutting tool. The checking step comprises a step of spatial detection of the three-dimensional positions and of the orientation of at least: the machine frame (2), the cutting tool (4) and the fitting or support (5) performed by a. detecting the spatial position of optical marking devices (21,41,51) associated with the machine frame, the cutting tool and the support or fitting, respectively, by means of at least one vision device (7) and b. reconstructing based on the spatial position detected in step a. the three-dimensional positions and the orientation of the machine frame (2), of the cutting tool (4) and of the fitting or support (5) during a scoring step. Further subject matter of the invention is a scoring apparatus for carrying out the process specified above.