OCT Weld Seam Monitoring for Curved Seam Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing OCT-based seam tracking systems face challenges in accurately monitoring curved weld seams due to limited accuracy in positioning and interpolation of geometric features, leading to incorrect positioning of post-measurement lines and insufficient information for evaluating geometric seam features.
Innovation Solution
The method involves positioning the post-measurement line or point relative to the pre-measurement line to align with the curved weld seam, either by offsetting or rotating it, ensuring the line center lies on the seam for optimal evaluation of the OCT distance measurement image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the post-measurement line is positioned parallel to the pre-measurement line without offset or rotation, then the positioning system is simple, but the measurement precision deteriorates for curved weld seams
Solution Approach 1:
The post-measurement line positioning is made dynamic by automatically calculating and applying offset and rotation based on the detected curvature of the weld seam. The system adapts the line orientation in real-time according to the local geometry, transforming a static positioning approach into a dynamic one that responds to the workpiece features.
Solution Approach 2:
The system changes the positional parameters (offset distance and rotation angle) of the post-measurement line based on the detected weld seam curvature. By adjusting these parameters dynamically, the system optimizes the measurement geometry for curved surfaces without requiring complex manual repositioning.
2Manufacturing precision
If the interpolation length alongside geometric features is too short, then the device complexity is reduced, but the manufacturing precision deteriorates
Solution Approach 1:
The system performs preliminary positioning of the post-measurement line using offset and rotation calculations based on pre-measurement data and detected curvature. This preliminary action ensures that the measurement line is correctly oriented before interpolation occurs, allowing shorter interpolation lengths to achieve the same precision that would otherwise require longer interpolations.
Solution Approach 2:
The patent replaces the mechanical approach of using long interpolation segments to achieve accuracy with a computational approach. By calculating the correct orientation and position of the measurement line through offset and rotation, the system substitutes geometric compensation for extended measurement paths, reducing the required interpolation length.
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 stabilizes and enhances the accuracy of post-measurement data, allowing for precise geometric measurement and monitoring of the solidified weld seam, even when the weld seam is curved.
Implementation Method 1
carrying out distance measurements during the welding by means of a measurement beam of an optical coherence tomograph (optical coherence tomography, OCT) both at one or more pre-measurement points situated upstream of a present welding position
Implementation Method 2
OCT-based systems employ an OCT (small field) scanner that moves the OCT measurement beam rapidly over the component
Data Source
AI summary
A method for monitoring a curved solidified weld seam during the welding of a workpiece includes carrying out distance measurements using a measurement beam of an optical coherence tomograph both at one or more pre-measurement points situated upstream of a present welding position, and at one or more post-measurement points situated downstream of the present welding position, and monitoring the curved, solidified weld seam on the basis of the distance measurements. In the case of a plurality of post-measurement points, a post-measurement line is formed from the plurality of post-measurement points and positioned to be offset relative to a pre-measurement line in the direction of the pre-measurement line toward the curved, solidified weld seam and/or is rotated relative to the pre-measurement line. In the case of a single post-measurement point, spacing the single post-measurement point from a line passing through the present welding position in the welding direction.