Galvanometric Scanning Calibration via Geometric Feature Validation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current calibration validation methods for galvanometric scanning systems in laser marking machines face challenges in accurately identifying the center of laser-drawn markings due to non-uniform line thickness and ill-defined edges, leading to ambiguity in determining the center of intersecting lines and potential undetection of offset errors.
Innovation Solution
The method involves commanding the laser system to draw geometric features such as polygons or ellipses of varying dimensions around a test point, using an imaging system to image these features with sufficient magnification and fitting parametrically defined shapes to identify the center, which is resistant to measurement errors and line thickness variability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If intersecting lines (X or + shaped marking features) are used for calibration validation, then the laser system can be tested for positioning accuracy, but the non-uniform line thickness and ill-defined edges cause ambiguity in determining the center of intersecting lines, leading to potential undetection of offset errors
Solution Approach 1:
The patent changes the geometric shape from linear markings to circular markings with distinct geometric features. The circular markings provide well-defined geometric properties (radius, circumference, center) that can be precisely measured and analyzed, eliminating the ambiguity of center identification present in linear intersecting markings.
Solution Approach 2:
The patent employs circular markings instead of straight line intersections. The curved geometry of circles provides mathematically well-defined centers that can be precisely determined through geometric analysis, overcoming the ill-defined edge centers of linear markings.
2Ease of manufacture
If traditional line-based marking features are used, then the validation process is simple to implement, but the measurement accuracy is limited by the thickness and uniformity of the laser-drawn lines
Solution Approach 1:
The patent changes the fundamental geometric parameter from linear dimensions (line thickness, intersection point) to circular dimensions (radius, circumference, center coordinates). This parameter transformation enables measurement accuracy that is not constrained by line thickness variability, as circular features can be measured with precision independent of their radial thickness.
3Productivity
If the laser system marks intersecting lines at a test point, then calibration validation can be performed, but offset errors may go undetected due to the ambiguity in determining the exact center of the intersecting lines
Solution Approach 1:
The patent replaces the mechanical/visual inspection method of determining line intersections with a geometric analysis system that calculates the centers of circular markings. This substitution uses mathematical geometry (fitting circles to marked points and calculating centers) instead of visual or manual measurement of line intersections, providing objective and precise center identification for reliable offset error detection.
Data Source
AI summary
Some embodiments may include a method of generating assessment data in a system including a galvanometric scanning system (GSS) having a laser device to generate a laser beam and an X-Y scan head module to position the laser beam on a work piece. The method may include selecting a dimension based on a desired accuracy for validation (and/or a characteristic of an imaging system in embodiments that utilize an imaging system). The method may include commanding the GSS to draw a mark based on a polygon or ellipse of the selected dimension around a predetermined target point associated with the work piece to generate assessment data, and following operation of the GSS based on said commanding, validating a calibration of the GSS using the assessment data (or an image thereof in embodiments that utilize an imaging system). Other embodiments may be disclosed and/or claimed.