Uncertainty Evaluation in Vision-Based Techniques for the Surface Analysis of Composite Material Components
Giulio D'Emilia1, Antonella Gaspari2, Emanuela Natale1
1Department of Industrial and Information Engineering and of Economics, University of L'Aquila, 67100 L'Aquila, Italy.
Sensors (Basel, Switzerland)
|July 24, 2021
Summary
This study presents a vision system and image processing method for measuring the yarn angle in glass-reinforced polypropylene for automotive parts. The developed technique achieves satisfactory uncertainty for process optimization and simulation validation.
Area of Science:
- Materials Science
- Mechanical Engineering
- Automotive Engineering
Background:
- Glass-reinforced polypropylene (GRP) is crucial for automotive components.
- Accurate measurement of yarn angle in GRP is essential for process optimization and simulation validation.
- Existing measurement methods may lack the required precision for validation purposes.
Purpose of the Study:
- To develop and validate a methodology for measuring the yarn angle of glass-reinforced polypropylene materials.
- To evaluate the uncertainty associated with the proposed measurement technique.
- To identify key factors influencing measurement accuracy for process improvement.
Main Methods:
- Utilized a vision system and image processing techniques, specifically edge detection, for angle measurement.
- Investigated the influence of material optical characteristics and piece geometry (flat sheets vs. semi-spherical object) on accuracy.
- Performed uncertainty evaluation of the angle measurement process.
Main Results:
- Achieved complete uncertainty in the order of a few degrees, deemed satisfactory for simulation validation.
- Identified and evaluated the effects of critical aspects in image acquisition and processing on overall accuracy.
- Determined the most relevant sources of uncertainty through an uncertainty budget analysis.
Conclusions:
- The developed vision system and image processing methodology provide a reliable method for measuring yarn angles in GRP materials.
- The uncertainty evaluation is critical for validating simulation results and optimizing manufacturing processes for automotive components.
- The study offers insights into improving measurement accuracy by addressing identified sources of uncertainty.
Related Concept Videos
00:59Uncertainty: Overview
1.2K
In analytical chemistry, we often perform repetitive measurements to detect and minimize inaccuracies caused by both determinate and indeterminate errors. Despite the cares we take, the presence of random errors means that repeated measurements almost never have exactly the same magnitude. The collective difference between these measurements - observed values - and the estimated or expected value is called uncertainty. Uncertainty is conventionally written after the estimated or expected value.
1.2K
01:10Propagation of Uncertainty from Systematic Error
1.1K
The atomic mass of an element varies due to the relative ratio of its isotopes. A sample's relative proportion of oxygen isotopes influences its average atomic mass. For instance, if we were to measure the atomic mass of oxygen from a sample, the mass would be a weighted average of the isotopic masses of oxygen in that sample. Since a single sample is not likely to perfectly reflect the true atomic mass of oxygen for all the molecules of oxygen on Earth, the mass we obtain from this...
1.1K
00:59Propagation of Uncertainty from Random Error
1.3K
An experiment often consists of more than a single step. In this case, measurements at each step give rise to uncertainty. Because the measurements occur in successive steps, the uncertainty in one step necessarily contributes to that in the subsequent step. As we perform statistical analysis on these types of experiments, we must learn to account for the propagation of uncertainty from one step to the next. The propagation of uncertainty depends on the type of arithmetic operation performed on...
1.3K
01:20Moments of Inertia for Composite Areas
1.3K
Composite areas are structures with multiple basic shapes connected in some way. These shapes usually include rectangles, triangles, circles, and other basic shapes that are connected in such a way as to form a single structure. Calculating the second moment of area for a composite area is essential when trying to understand the structure's overall stiffness.
The second moment of area, also known as the moment of inertia, measures a structure's resistance to bending. It is calculated by...
The second moment of area, also known as the moment of inertia, measures a structure's resistance to bending. It is calculated by...
1.3K
03:37Uncertainty in Measurement: Accuracy and Precision
97.6K
Scientists typically make repeated measurements of a quantity to ensure the quality of their findings and to evaluate both the precision and the accuracy of their results. Measurements are said to be precise if they yield very similar results when repeated in the same manner. A measurement is considered accurate if it yields a result that is very close to the true or the accepted value. Precise values agree with each other; accurate values agree with a true value.
97.6K
00:54Uncertainty: Confidence Intervals
7.4K
The confidence interval is the range of values around the mean that contains the true mean. It is expressed as a probability percentage. The interpretation of a 95% confidence interval, for instance, is that the statistician is 95% confident that the true mean falls within the interval. The upper and lower limits of this range are known as confidence limits. The confidence limits for the true mean are estimated from the sample's mean, the standard deviation, and the statistical factor...
7.4K