Tire Uniformity Machine Characterization via Waveform Subtraction
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Solution Overview
Problem
Current tire uniformity machines provide inconsistent test results due to inadequate characterization of spindle and chuck assemblies, leading to distorted force contributions that affect the accuracy of tire uniformity measurements.
Innovation Solution
A method for characterizing the load wheel and spindle assemblies using reference waveform data, which involves obtaining and applying characterization waveforms to adjust for the unique force characteristics of each machine component, ensuring accurate and consistent alignment of the upper and lower chuck assemblies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If characterization waveforms are applied to adjust for machine component force characteristics, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies preliminary action by pre-characterizing machine components (load wheel, spindles, chucks) before actual tire testing. Characterization waveforms are obtained and stored in advance, representing the force contributions of each component. During tire testing, these pre-obtained characterizations are subtracted from the measured waveforms to remove machine-induced errors, thereby improving measurement precision without adding complexity to the testing process itself.
2Measurement precision
If filtering is applied to test results to account for machine characteristics, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent eliminates time loss by performing the filtering action in advance. Machine characterizations are obtained and stored before production testing begins. During actual tire testing, the pre-computed characterizations are simply subtracted from measured waveforms in real-time, avoiding the need for post-test filtering operations and significantly reducing the overall test procedure time while maintaining measurement precision.
3Device complexity
If spindle and chuck assemblies are not adequately characterized, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent applies segmentation by dividing the tire uniformity measurement system into distinct components (load wheel, upper spindle, lower spindle, upper chuck, lower chuck) and obtaining separate characterization waveforms for each. This segmented approach allows precise identification and subtraction of individual component force contributions from the total measured waveform, thereby improving measurement precision while managing device complexity through systematic decomposition of the characterization process.
Data Source
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AI summary
A tire uniformity machine includes an apparatus for receiving and rotating a tire. The apparatus includes opposed spindles for receiving, inflating and rotating a tire, and a load wheel applied to the rotating tire to obtain tire test results. A spindle alignment assembly is associated with the opposed spindles to align the spindles with one another each time a tire is received. At least one characterizing device is associated with components of the apparatus to characterize forces of the opposed spindles and the characterized forces are used in adjusting tire test results.