Knitted Product Grading via Interpolated Size Corrections
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Solution Overview
Problem
The existing methods for grading knitted products, such as shoe uppers, require repeated test knitting for each size due to the difficulty in simulating exact sizes considering the physical properties of knitting yarns and knitting machines, making it labor-intensive and inefficient.
Innovation Solution
A grading method and system that inputs pattern and gauge data, converts it into knitting data, corrects errors through test knitting, and uses interpolation or extrapolation of correction amounts for subsequent sizes, reducing the need for extensive test knitting by determining correction amounts for at least two sizes and applying them to other sizes through interpolation or extrapolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If test knitting is performed for each size to ensure accurate dimensions, then manufacturing precision is improved, but productivity deteriorates due to labor-consuming repeated testing
Solution Approach 1:
The patent performs test knitting and determines correction amounts in advance for only two representative sizes (smallest and largest). These correction amounts are then interpolated to obtain correction values for all intermediate sizes, eliminating the need to perform test knitting for each individual size and significantly improving productivity while maintaining size accuracy
Solution Approach 2:
The patent creates a mathematical model that copies the correction pattern observed in the two test sizes and applies it to all other sizes through interpolation. This allows the correction data from two samples to represent and guide the production of all sizes in the product line
2Productivity
If simulation is used to predict knitted sizes without test knitting, then productivity is improved, but manufacturing precision deteriorates due to inability to accurately simulate physical properties of yarns and machines
Solution Approach 1:
The patent uses actual measurement feedback from test knitting of two sizes to determine correction amounts. This empirical feedback replaces theoretical simulation, ensuring that the correction values accurately reflect the real physical behavior of the yarns and knitting machines. The feedback loop closes by comparing measured sizes with pattern data and applying corrective adjustments
Solution Approach 2:
The patent changes the approach from attempting to simulate complex physical parameters (yarn properties, machine mechanics) to directly measuring and using correction amounts as empirical parameters. By working with actual correction data from test knitting rather than simulated parameters, the system achieves both speed and accuracy
3Productivity
If correction amounts are determined for only two sizes, then productivity is improved by reducing test knitting, but manufacturing precision may deteriorate if interpolation is inaccurate
Solution Approach 1:
The patent applies local quality correction by determining specific correction amounts for different sizes based on their position in the size range. Smaller corrections are applied to intermediate sizes through linear interpolation, while the two extreme sizes receive full correction based on actual measurement, creating a graduated correction scheme that maintains accuracy across all sizes
Data Source
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AI summary
Initial pattern data (50) and gauge data are stored, the pattern data is converted into knitting data based on the gauge data, and a knitted product is test-knitted. Sizes of the test-knitted product are compared with sizes indicated by the initial pattern data (50), and the pattern data or the knitting data is corrected. The correction amounts for the pattern data or for knitting data for two sizes are stored, and interpolation or extrapolation is performed based on the stored correction amounts to correct pattern data or knitting data for other sizes.