Edge Feature Video Tool Robust Edge Discrimination

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Solution Overview

Problem

Existing machine vision inspection systems face challenges in reliably detecting edges in regions of interest with multiple closely spaced edges, as users find it difficult to adjust edge detection parameters, particularly for unskilled operators, due to the complexity of edge conditions and part-to-part variations.

Innovation Solution

A method and system that improve edge detection reliability by using a video tool with a region of interest (ROI) and edge detection parameters such as edge gradient threshold, profile scan direction, and gradient prominence-counting parameter, allowing automatic determination of these parameters to accurately locate edges within a robust extremum margin, thereby simplifying the detection process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If manual adjustment of edge detection parameters is used, then flexibility in handling different edge conditions is improved, but ease of operation deteriorates due to complexity for unskilled users

Engineering Contradiction:
Improveflexibility in handling different edge conditionsVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system performs self-adjustment of edge detection parameters by automatically analyzing the image data and setting appropriate threshold values and scan directions without requiring user intervention. The computer executes algorithms that adaptively determine optimal parameters based on the actual edge characteristics in the image, making the system serve itself rather than requiring expert operation.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system automatically changes detection parameters such as gradient thresholds and scan directions based on the analyzed image characteristics. By dynamically adjusting these parameters according to the specific edge conditions detected in the image, the system achieves adaptability to different edge types and orientations without manual parameter tuning.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If automatic determination of edge detection parameters is used, then ease of operation is improved, but measurement precision may deteriorate due to loss of manual control

Engineering Contradiction:
Improveease of operationVSAvoidedge location accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system uses feedback from the image analysis process to automatically adjust parameters. By analyzing the detected edges and their characteristics, the system feeds this information back to refine parameter selection, ensuring that automatic parameter determination achieves high measurement precision through iterative optimization rather than fixed preset values.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual mechanical adjustment of parameters with automated computational algorithms. The computer-based system substitutes human operator intervention with algorithmic parameter determination, using image processing and pattern recognition to automatically set optimal detection parameters, thereby maintaining precision while improving ease of operation.

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

3Measurement precision

If complex edge detection algorithms are used to handle multiple closely spaced edges, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improveedge location accuracyVSAvoidalgorithm complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system segments the edge detection process into distinct computational stages: gradient calculation, threshold determination, scan direction selection, and edge location refinement. By dividing the complex detection task into modular segments that can be processed sequentially, the system achieves high precision for closely spaced edges while managing algorithmic complexity through structured organization of detection operations.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system introduces additional computational dimensions by analyzing edges in multiple scan directions and using multi-parameter optimization. By extending the detection approach from simple thresholding to multi-dimensional gradient analysis and prominence counting, the system achieves superior precision for complex edge patterns while organizing the complexity across multiple analytical dimensions rather than increasing single-algorithm complexity.

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

Data Source

PatentUS8917940B2Edge measurement video tool with robust edge discrimination margin
Publication Date: 2014.12.23 MITUTOYO CORP
  • US8917940B2 patent drawing
  • US8917940B2 patent drawing
  • US8917940B2 patent drawing

AI summary

A reliable method for discriminating between a plurality of edges in a region of interest of an edge feature video tool in a machine vision system comprises determining a scan direction and an intensity gradient threshold value, and defining associated gradient prominences. The gradient threshold value may be required to fall within a maximum range that is based on certain characteristics of an intensity gradient profile derived from an image of the region of interest. Gradient prominences are defined by limits at sequential intersections between the intensity gradient profile and the edge gradient threshold. A single prominence is allowed to include gradient extrema corresponding to a plurality of respective edges. A gradient prominence-counting parameter is automatically determined that is indicative of the location of the selected edge in relation to the defined gradient prominences. The gradient prominence-counting parameter may correspond to the scan direction.