Tyre Defect Detection Using Self-Referential 3D Profile
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for checking tyres for defects, particularly 'weak sidewall' issues, are subjective and time-consuming due to reliance on manual checks or require lengthy automatic processes that lack precision and repeatability, with the need for accurate positioning and force application complicating the measurement process.
Innovation Solution
A method and apparatus that utilize a three-dimensional profile of the tyre to establish an absolute coordinate system for deformation, applying a constant force to detect defects, reducing subjectivity and cycle time by eliminating the need for precise external reference systems and allowing for flexible checking across various tyre models.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If manual visual checking is used to identify defects, then the checking process is simple to implement, but the accuracy and objectivity of defect detection deteriorates due to subjectivity
Solution Approach 1:
The patent replaces manual visual inspection with an automated mechanical system that applies controlled forces to the tyre sidewall and measures deformations using sensors. This substitution eliminates human subjectivity while maintaining ease of implementation through a straightforward force-application and measurement mechanism.
Solution Approach 2:
The tyre itself serves as the reference by using its own three-dimensional profile, detected through imaging, as the basis for determining where to apply forces and how to evaluate deformations. This self-referential approach simplifies the system by eliminating the need for external reference objects or complex calibration procedures.
2Measurement precision
If automated checking with multiple forces and movements is used, then the objectivity of checking is improved, but the cycle time increases due to repeated checking steps
Solution Approach 1:
The patent applies forces in only two directions (radially outward and axially toward the crown) rather than multiple directions, and performs the checking in a single rotation rather than multiple repetitions. This partial action approach maintains sufficient objectivity while significantly reducing cycle time compared to more comprehensive multi-directional forcing schemes.
Solution Approach 2:
The tyre is checked during a single continuous rotation on the support plane, with forces applied continuously throughout the rotation. This eliminates the need to stop and reposition the tyre between checking steps, maintaining continuous useful action and minimizing cycle time while preserving measurement objectivity.
3Measurement precision
If precise positioning systems are used to determine force application points, then the accuracy of deformation measurement is improved, but the device complexity increases
Solution Approach 1:
The tyre's own three-dimensional profile, detected by an imaging device, serves as the reference for determining force application points and evaluating deformations. This self-referential approach eliminates the need for complex external positioning systems, reference objects, or calibration procedures, significantly reducing device complexity while maintaining measurement accuracy.
Solution Approach 2:
The imaging device acts as an intermediary that captures the tyre's profile and provides data to the control unit, which then uses this information to automatically determine force application points and evaluate deformations. This intermediary approach simplifies the overall system by using information already available from the imaging process rather than requiring separate complex positioning systems.
4Ease of operation
If the checking apparatus uses a support plane reference system, then the positioning is simplified, but the repeatability deteriorates due to variations in tyre placement
Solution Approach 1:
The tyre itself serves as the reference by using its own detected three-dimensional profile as the basis for all measurements. This self-referential approach eliminates sensitivity to variations in tyre placement on the support plane, as the profile is detected and used in real-time for each tyre, ensuring high repeatability while maintaining simple positioning procedures.
Solution Approach 2:
The system adapts to each tyre by detecting its specific three-dimensional profile and using that profile to determine force application points and evaluation criteria. This parameter adaptation ensures that measurements are consistent and repeatable for each tyre regardless of minor variations in placement, as the system adjusts its reference frame to match each tyre's actual geometry.
Data Source
Figure 1
Figure 2~6
Figure 3~7
AI summary
The present invention relates to a method for checking tyres, comprising : i. providing a tyre having a rotation axis on a support plane defining a rested lateral portion and a free lateral portion; ii. detecting at least one three-dimensional profile of a ring-shaped surface of said tyre with centre in said rotation axis of said tyre, said three-dimensional profile including a height of a plurality of points of said ring-shaped surface; iii. translating a tool towards said tyre arranged on the support plane so as to rest on a measurement surface, said measurement surface being a portion of said ring-shaped surface; iv. pushing said measurement surface by means of said tool so as to apply a tool pressing force on said measurement surface towards the support plane; v. setting said tyre in relative rotation with respect to said tool so that said tool is in successive contact with a plurality of different measurement surface, portions of said ring-shaped surface, angularly spaced, keeping the tool pressing force exerted by said tool on said measurement surfaces substantially constant along at least one complete rotation about said rotation axis; vi. measuring a height of said measurement surfaces at a plurality of relative angular positions between said tyre and said tool along said complete rotation during said pushing action; and vii. comparing said height of said measurement surfaces at a plurality of relative angular positions between said tyre and said tool with a height of a plurality of points of said three-dimensional profile of said ring-shaped surface at the same angular positions; and viii. determining whether said tyre has a defect based on said comparison. The invention also concerns an apparatus for checking tyres.