Annular Surface Shape Data Correction for Eccentric Rotating Bodies
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Solution Overview
Problem
Conventional methods for inspecting annular rotating bodies like tires face challenges in accurately correcting three-dimensional surface shape data due to eccentricity, which assumes a perfect circle, leading to distorted measurements and the need for time-consuming alignment and high-precision centering mechanisms.
Innovation Solution
A method that converts measurement data into equidistantly divided data along a planar shape on the tire's surface, reallocating it onto a perfect circle without altering the circumferential length, allowing for accurate shape correction and inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the least square method is used to correct surface shape data assuming a perfect circle, then the correction process is simple, but the accuracy deteriorates when the object is not a perfect circle
Solution Approach 1:
The patent changes the fundamental parameter assumption from 'perfect circle' to 'eccentric annular shape with distorted contour'. The correction method adapts to the actual geometric parameters of the tire, including eccentricity and non-uniform circumference, thereby improving measurement accuracy without sacrificing process simplicity
Solution Approach 2:
The patent creates a corrected surface shape data model that copies the actual measured geometry of the eccentric annular object rather than forcing it into a perfect circle template. This preserves the true shape characteristics while eliminating distortion errors
2Measurement precision
If the tire is fitted on the rim and inflated to limit distortion, then the measurement accuracy improves, but the inspection time increases
Solution Approach 1:
The patent replaces the mechanical preparation system (rim fitting and inflation) with a computational correction system. The data processing method mathematically compensates for distortion caused by eccentricity and non-circular shapes, achieving accurate measurements without time-consuming mechanical preparation
Solution Approach 2:
The patent performs correction calculations on the raw measured data before final analysis, eliminating the need for preliminary mechanical preparation. The computational correction is applied directly to the collected surface shape data, streamlining the inspection process
3Measurement precision
If a high-precision centering mechanism is used to align the central axis with the rotational axis, then the measurement accuracy improves, but the device complexity increases
Solution Approach 1:
The patent replaces complex mechanical centering mechanisms with a computational approach. The data processing method identifies and corrects for axis misalignment and eccentricity through mathematical analysis of the measured surface shape data, achieving high precision without mechanical complexity
Solution Approach 2:
The measurement system performs self-correction by analyzing its own measured data to detect and compensate for eccentricity and axis misalignment. The correction algorithm automatically adapts to the actual object geometry without requiring external centering mechanisms or manual alignment procedures
4Productivity
If the object is rotated eccentrically, then the inspection process is faster, but the measurement accuracy deteriorates due to distortion
Solution Approach 1:
The patent converts the harmful effect of eccentric rotation and distortion into beneficial information. The correction method uses the measured distortion patterns to calculate and eliminate the eccentricity effects, transforming what was previously a source of error into a means of achieving accurate measurements without requiring precise mechanical alignment
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 enables precise surface shape data acquisition for annular rotating bodies without requiring them to be perfectly circular or aligned, reducing measurement time and eliminating the need for high-precision centering mechanisms, thus simplifying the inspection process and improving accuracy.
Implementation Method 1
the images of the portion illuminated by slit light of the surface of an object to be inspected while the object is being moved are captured, and the three-dimensional shape data of the surface of the object to be inspected are measured from the pixel data of the captured images
Data Source
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AI summary
In order to provide a method for accurately correcting surface shape data of an annular rotating body, in correcting three-dimensional shape data on a surface of the annular rotating body, a reference line is set along the surface to be detected of the annular rotating body, and then reference equiangular division points, which divide the reference line by equal angles, are set. Next the circumferential length of the reference line is calculated from the distance between adjacent reference equiangular division points, and a plurality of reference equidistant division points, which divide the reference line into equal lengths, are set on the reference line, using the circumferential length. Then interpolation points for correction of the data on the surface to be detected of the annular rotating body are set at positions a preset distance apart in the radial direction of the rotating body from the reference equidistant division points. Then three-dimensional shape data at the interpolation points are calculated using the three-dimensional data to be corrected. Finally the interpolation points are moved onto a perfect circle centered about the rotational center and having the same circumferential length as the aforementioned circumferential length, using the aforementioned circumferential length and the distance.