Tire Interferometry Testing via Phase Difference Summation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interferometry-based tire testing methods face challenges due to whole-body deformations, local deformations, and vibrations, which can lead to decoherence and increased noise in phase difference images, making it difficult to accurately detect tire defects.
Innovation Solution
The method involves capturing phase images at different pressures and generating partial phase difference images between successive images, then summing them to form an overall phase difference image, with one measurement phase having a pressure increase and the other a decrease, and including partial phase difference images from both phases with opposite signs to cancel out interfering influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a sequence of phase images is recorded during tire deformation and partial phase difference images are summed to form an overall phase difference image, then whole-body deformations are eliminated and coherence between phase images is maintained, but vibrations are amplified and measurement noise increases
Solution Approach 1:
The measurement process is segmented into multiple discrete measurement phases, each capturing phase images at specific pressure points. Partial phase difference images are generated from successive phase images within each phase and then combined across phases. This segmentation allows differentiation between systematic deformations (eliminated through phase differencing) and random vibrations (reduced through selective combination), resolving the contradiction between eliminating whole-body deformations and avoiding vibration amplification.
2Measurement precision
If pressure changes are applied to generate tire deformation for defect detection, then defect visibility is improved, but whole-body deformations and local deformations increase causing decoherence and measurement errors
Solution Approach 1:
The method employs feedback by recording phase images at multiple discrete pressure points during pressure changes and using these images to generate partial phase difference images. These partial differences are then combined to form an overall phase difference image that represents true deformation. This feedback mechanism allows the system to distinguish between harmful whole-body deformations (which cancel out in the differencing process) and useful local deformations from defects, maintaining measurement precision while reducing decoherence.
3Measurement precision
If multiple phase images are captured and processed to eliminate whole-body deformations, then measurement accuracy improves, but measurement time increases
Solution Approach 1:
The method performs preliminary actions by capturing phase images at discrete pressure points before final processing. Partial phase difference images are generated from successive phase images during the pressure change process itself, rather than requiring complete deformation cycles to be finished and processed afterward. This preliminary generation of difference images during the pressure change process reduces the overall measurement time while maintaining the accuracy benefits of multi-phase processing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the quality of tire testing by reducing the impact of whole-body deformations, local deformations, and vibrations, allowing for clearer defect detection while reducing measurement time and the required pressure changes, thus improving the sensitivity and accuracy of the test.
Implementation Method 1
the deformation of the tire generated by the pressure change is measured by interferometry. Phase images of the surface of the tire to be tested are captured at at least two different pressure states
Implementation Method 2
The interferometric test can be a holographic test or a shearographic test. However, use is typically made of shearography as it has the decisive advantage over holography that it can also be used in industrial conditions
Data Source
AI summary
A method for testing a tire by interferometry in a pressure chamber of a tire testing device includes capturing phase images at different pressures in the pressure chamber, generating partial phase difference images between successive phase images, and summing the partial phase difference images to form an overall phase difference image. The pressure in the pressure chamber is changed in a first direction during a first measurement phase and the pressure is changed in the opposite direction during a second measurement phase, wherein at least one partial phase difference image from the first measurement phase and at least one partial phase difference image from the second measurement phase are included in the summation.