Defect Measurement Correction Using Reference Targets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting defects in structural surfaces, such as cracks and depressions, face challenges in accuracy due to variations in measurement environments like lighting and distance, leading to inconsistencies in defect length and width calculations.
Innovation Solution
A defect calculation system that includes a survey instrument, a controller, and a server unit, which uses a correction target with reference objects of varying line widths and orientations to correct defect data by comparing first line width data with known second line width data, accounting for environmental factors and measurement distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If image analysis is performed on captured images to detect defects, then defect detection capability is improved, but measurement precision deteriorates due to environmental variations
Solution Approach 1:
A correction target with reference objects of known dimensions is introduced as an intermediary element. This correction target is captured simultaneously with the defect in the same image, providing a reference for scale and orientation. The system uses the known dimensions of reference objects to calculate correction factors that compensate for lens distortion, perspective effects, and environmental variations, thereby improving measurement precision without sacrificing defect detection capability
Solution Approach 2:
The system dynamically adjusts measurement parameters based on the captured image conditions. By analyzing the apparent dimensions of reference objects with known actual dimensions, the system calculates correction parameters specific to each image's lighting, distance, and angle conditions. These parameter adjustments allow accurate defect measurement despite varying environmental factors across different capture scenarios
2Area of stationary object
If survey instrument is used to capture external appearance images, then defect detection coverage is improved, but measurement accuracy deteriorates due to distance and angle variations
Solution Approach 1:
The correction target serves as a mediator that bridges the gap between varying capture conditions and accurate measurement. Placed within the same field of view as the defect, it provides real-time reference information about the imaging conditions. Even when captured from different distances and angles across large areas, the known geometry of reference objects enables calculation of perspective and distortion corrections specific to each capture scenario
Solution Approach 2:
The system transitions from two-dimensional image analysis to three-dimensional measurement by incorporating depth information through the correction target's known spatial relationships. By utilizing the known three-dimensional geometry of reference objects and their projected two-dimensional images, the system calculates perspective transformations and depth factors, enabling accurate defect dimension measurement across varying distances and angles
Data Source
Figure 1A~1B
Figure 2A~3
Figure 4A~5D
AI summary
A target including a reference object of a known size is prepared. The reference object from target image data, which is generated by photographing the target using a survey instrument, is detected through image processing to calculate first size data on dimensions of the reference object. A defect from external appearance image data, which is generated by photographing an external appearance of a structure using the survey instrument, is detected through image processing to calculate defect data on dimensions of the defect. The first size data is compared with second size data on actual dimensions of the reference object to calculate correction data, which is used to correct the defect data.