Rotator Surface Irregularity Correction via Arc Length Interpolation
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Solution Overview
Problem
Existing methods for measuring surface irregularities on rotating bodies, such as tires, face challenges in accurately distinguishing between irregularities caused by defects and those caused by eccentricity, leading to incomplete correction and increased costs for hardware modifications.
Innovation Solution
A method that interpolates irregularity data at equal intervals to correct for eccentricity effects by computing surface lengths and dividing them into equal arcs, allowing for accurate measurement and automation of irregularity data without hardware modifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the body is rotated and irregularity data is measured at measurement points, then irregularity data can be obtained, but the data includes errors due to eccentricity causing measurement points to be unevenly spaced
Solution Approach 1:
The patent calculates the arc length from the starting point to each measurement point before performing interpolation. This preliminary calculation of cumulative arc lengths allows the subsequent interpolation to correctly map irregularity values to evenly spaced angular positions, eliminating the effect of uneven spacing caused by eccentricity.
Solution Approach 2:
The patent creates a corrected irregularity data set by interpolating values from the original measurement points. This copying process generates new data points at evenly spaced angular intervals that represent what the measurements would have been if the body had been perfectly centered, thus eliminating eccentricity effects.
2Measurement precision
If hardware modifications are made to correct eccentricity, then measurement accuracy can be improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces potential mechanical correction methods (such as adjusting the rotation axis or repositioning sensors) with a computational approach. By using mathematical interpolation based on calculated arc lengths, the system achieves the same correction effect without modifying the physical apparatus, thereby reducing device complexity and cost.
3Ease of manufacture
If irregularity data is measured without correcting for eccentricity, then measurement process is simple, but the data cannot distinguish between defects and eccentricity effects
Solution Approach 1:
The patent performs preliminary calculation of arc lengths from the starting point to each measurement point. This additional computational step enables the distinction between irregularities caused by defects and those caused by eccentricity, while maintaining relative simplicity through automated calculation.
Solution Approach 2:
The patent generates a corrected copy of the irregularity data that has been adjusted to remove eccentricity effects. This copied data set preserves the information needed to identify actual defects while eliminating the confounding information from eccentricity, thus preventing information loss.
Data Source
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Figure 3(a)~3(d)
AI summary
Providing a method for correcting a data of irregularity of a surface of a body of rotation with an eccentricity included to a data being not affected by eccentricity. The distance data Lk between the tire crown portion 10t of the tire 10t to be inspected and the distance sensor 14 is measured at each of measurement points Xk at every angular displacement Δ θ in a circumferential direction of the tire and also radius value rk are computed from the above distance data Lk and the distance L0 between the center of rotation of the tire and the distance sensor; and further the surface length Sk is computed by integrating the radius value rk with respect to Δ θ from the measurement starting point to a current measurement point k and the irregularity data is converted into the form of (Xk, rk) and then the radius values Rk at the irregularity computing points Xk dividing the one round surface length Sk of the tire into equal intervals are computed based on the radius values rk and rk+1 at the measurement points Xk and Xk+1 adj acent to the irregularity computing point Xk, serving as an irregularity data (Xk,Rk) at respective points dividing the surface of the tire crown portion into equal intervals circumferentially the tire.