Dynamic Load Model Estimation for Tire Uniformity Testing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The existing load model used in tire uniformity testing assumes a constant spring constant, leading to errors in calculating tire load, which affects the accuracy of uniformity measurements and reduces productivity due to the need for repeated recalculations and failure to account for air pressure variations.

Innovation Solution

A method for estimating a load model that weights tire load measurements based on the pressing position of the rotary drum, using weight characteristic functions to prioritize data near the target pressing load and account for non-linear relationships, thereby improving the accuracy of tire load calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a constant spring constant is used in the load model, then the calculation is simple, but the accuracy of tire load calculation deteriorates due to non-linear relationships and air pressure variations

Engineering Contradiction:
Improvecalculation simplicityVSAvoidtire load calculation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent transforms the static constant spring constant model into a dynamic estimation model that adapts to varying operating conditions. The load model is updated based on actual measurement data, allowing the system to account for non-linear relationships and air pressure variations while maintaining computational efficiency through iterative estimation algorithms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter representation from a fixed constant spring constant to a variable load model that incorporates multiple parameters including air pressure, pressing position, and measured tire load values. This allows the system to capture the non-linear behavior of the tire system under different operating conditions.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If repeated recalculations are performed to improve accuracy, then measurement precision improves, but productivity deteriorates due to increased measurement time

Engineering Contradiction:
Improveuniformity measurement accuracyVSAvoidmeasurement throughput
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent performs preliminary estimation of the load model parameters using initial measurement data, allowing subsequent measurements to be conducted with higher accuracy without requiring repeated full recalculations. The pre-established load model provides a foundation that reduces the need for iterative recalculations during actual testing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where measurement results are used to continuously refine and update the load model parameters. This allows the system to improve accuracy progressively with each measurement cycle rather than requiring multiple full recalculations, thereby maintaining productivity while enhancing precision.

Inventive Principle:
Principle #23Feedback

3Device complexity

If air pressure variations are not accounted for, then the measurement process is simpler, but the reliability of tire load estimation deteriorates

Engineering Contradiction:
Improvemeasurement process complexityVSAvoidtire load estimation reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent creates a multi-functional load model that simultaneously accounts for multiple factors including air pressure variations, pressing position effects, and non-linear tire behavior. This universal model improves reliability without significantly increasing process complexity by integrating multiple considerations into a unified estimation framework.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3205999B1Use of a method for estimating load model in a tyre uniformity tester
Publication Date: 2020.05.06 KOBE STEEL LTD
  • EP3205999B1 patent drawingFigure 1~2
  • EP3205999B1 patent drawingFigure 3
  • EP3205999B1 patent drawingFigure 4

AI summary

A tire uniformity testing apparatus (1) measures uniformity of a tire (T) by measuring a load generated on the tire (T) pressed against a rotating rotary drum (2). A load model used to control a pressing position of the rotary drum (2) and express a relation between the pressing position of the tire (T) against the rotary drum (2) and a tire load generated in the tire (T) is configured to successively measure the tire load, while changing the pressing position of the tire (T) against the rotary drum (2), and to estimate the tire load using the measured value of the measured tire load.