Vision System Stability Testing via Affine Contour Comparison
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Solution Overview
Problem
Conventional manual inspection of industrial parts using contact instruments leads to high labor costs, low accuracy, and low efficiency, while machine vision systems suffer from instability issues affecting measurement accuracy due to changes in camera position or illumination, necessitating a method to test stability.
Innovation Solution
A method involving affine transformation of a reference contour model to obtain a current contour model, comparing diameters and grayscale values of circles and regions in the models to determine camera position and illumination changes, ensuring timely fault reporting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual inspection using contact instruments is used, then labor costs are high and inspection accuracy is low, but the method is simple to implement
Solution Approach 1:
The patent replaces manual mechanical inspection with an automated machine vision system that uses optical imaging and computer processing to measure industrial parts. The vision system captures images of parts and automatically analyzes dimensions, replacing the need for manual contact measurement with mechanical instruments, thereby improving both accuracy and efficiency simultaneously
2Productivity
If machine vision system is used to replace manual inspection, then inspection accuracy and efficiency are improved, but system stability deteriorates due to camera position changes
Solution Approach 1:
The patent implements a feedback mechanism where the vision system continuously monitors its own stability by capturing images of a standard piece, calculating position deviations of feature points, and comparing them against threshold values. When deviations exceed thresholds, the system generates stability test results indicating potential faults, allowing for timely correction before actual inspection work begins
Solution Approach 2:
The patent performs stability testing as a preliminary action before the vision system begins its normal inspection function. By conducting stability tests in advance using a standard reference piece, the system identifies and addresses potential instability issues (such as camera position drift) before they affect actual measurement accuracy, ensuring reliable operation during production inspection
3Measurement precision
If machine vision system is used to replace manual inspection, then measurement accuracy is improved, but labor costs increase due to system complexity
Solution Approach 1:
The patent uses a standard reference piece with known geometric features as a copy or model for stability testing. By capturing images of this reference piece and comparing feature point positions against predetermined coordinates, the system creates a simplified test model that requires minimal processing complexity while effectively verifying system stability and measurement accuracy
Data Source
AI summary
Embodiments of this application provide a method and apparatus for testing stability of a vision system, which can test whether the vision system is stable, so as to report a fault in a timely manner when the vision system is unstable, thereby guaranteeing accuracy of a measurement result of the vision system. The method includes: obtaining first position information of a spot inspection piece in a current image under the vision system; performing affine transformation on a reference contour model of the spot inspection piece for a position of the spot inspection piece in the current image based on the first position information, and obtaining, through fitting, a current contour model of the spot inspection piece in the current image based on the reference contour model; and determining stability of the vision system based on the reference contour model and the current contour model.