Wheel Run-Out Compensation via Optical Radius Tracking

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Solution Overview

Problem

Current wheel alignment methods face challenges in accurately determining the angle of rotation for wheel run-out compensation without a measuring head or magnetic marking points, particularly when combining with contactless wheel alignment, which affects the precision and reliability of toe and camber measurements.

Innovation Solution

Calculating the angle of rotation using the rolling path and effective rolling radius, determined through sliding plate displacement measurements and camera image data, allowing for precise detection of wheel run-out without physical contact or marking points, and integrating this compensation into the wheel alignment program for automated execution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a measuring head mounted on the wheel is used to determine the angle of rotation, then the angle of rotation can be directly measured, but the device complexity increases and manual mounting is required

Engineering Contradiction:
Improveangle of rotation measurementVSAvoidmeasuring head and adapter system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical measuring head system with an optical measurement system using video cameras. The angle of rotation is determined optically by tracking the position of the wheel relative to the sliding plate, eliminating the need for mechanical contact and complex mounting procedures.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces an intermediary reference system consisting of the sliding plate with marked positions. Instead of measuring the wheel directly, the system uses the sliding plate as a reference frame to determine the wheel's angular position through optical tracking of the wheel's movement relative to the plate.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If magnetic marking points are used on the wheel, then the angle of rotation can be detected, but the device complexity increases and additional components are required

Engineering Contradiction:
Improveangle of rotation detectionVSAvoidmagnetic marking points and sensors
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces magnetic detection systems with optical detection using video cameras. The angle of rotation is determined by optically tracking the wheel's position and movement, eliminating the need for magnetic marking points, sensors, and associated electronic systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If the theoretical radius of the tire is used for calculation, then the calculation is simple, but the accuracy decreases due to tire deformation

Engineering Contradiction:
Improvecalculation simplicityVSAvoidangle of rotation calculation accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent changes the radius parameter from the theoretical tire radius to the effective rolling radius. This parameter change accounts for tire deformation under vehicle weight, significantly improving the accuracy of angle of rotation calculations while maintaining the simplicity of the circular motion formula.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If manual turning of the vehicle wheels is required, then the measurement can be performed, but the productivity decreases and operational complexity increases

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidwheel alignment speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent enables the wheel alignment system to perform its own wheel turning function through the motorized sliding plate. The sliding plate automatically rotates the wheel during the measurement process, eliminating the need for manual intervention and significantly improving productivity while maintaining measurement reliability.

Inventive Principle:
Principle #25Self-service

5Reliability

If the vehicle is moved by hand for pushing compensation, then the wheel run-out can be compensated, but the time consumption increases and operational complexity increases

Engineering Contradiction:
Improvewheel run-out compensation accuracyVSAvoidcompensation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent enables the system to automatically perform wheel run-out compensation through motorized movement of the sliding plate. The system self-adjusts the wheel position and performs the compensation process without requiring manual vehicle movement, significantly reducing time consumption while maintaining compensation accuracy.

Inventive Principle:
Principle #25Self-service

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 enhances the accuracy and operational reliability of wheel alignment and run-out compensation, reducing manual intervention and costs while ensuring precise correction of toe and camber values.

Implementation Method 1

The rolling path of the wheel is determined via the sliding path of the sliding plate, because simple path measuring instruments are available for this purpose.

Methodology Applied
Scientific EffectDisplacement measurement: Displacement

Implementation Method 2

The effective rolling radius of the wheel that is still required to calculate the angle of rotation is preferably determined contactlessly from camera image data of the wheel during its rotation.

Methodology Applied
Scientific EffectOptical detection: Photography

Data Source

PatentEP1857774B1Method and device for wheel run-out compensation in axis measurement
Publication Date: 2008.12.31 OTTO NUSSBAUM GMBH & CO
  • EP1857774B1 patent drawingFigure 1
  • EP1857774B1 patent drawingFigure 2
  • EP1857774B1 patent drawingFigure 3

AI summary

The method involves measuring rolling distance of a wheel from moving distance of slide plates (4a, 4b). An effective rolling radius of the wheel is determined by the determination of a wheel center point from a camera image data. An angle of rotation of the wheel is determined. A track and an overturn of the wheel are determined with the measurement of the rolling distance such that a strip pattern is produced on the wheel by a beamer. A change of position produced during the wheel rotation is detected by a camera and is evaluated by a computer. An independent claim is also included for a device for executing a method for compensating wheel runout in an axis alignment of a motor vehicle by the rotation of a wheel.