Wheel Geometry Measurement Using Millimeter-Wave Radar Scanning

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Solution Overview

Problem

Existing wheel dimension measurement technologies face limitations such as slow scanning due to sound wave speed, sensitivity to environmental conditions, and reduced sample acquisition per revolution, leading to inaccuracies and prolonged processing times.

Innovation Solution

A method and apparatus utilizing a millimeter-wave radar system operating between 30 GHz and 300 GHz, specifically between 76 GHz and 81 GHz, for scanning wheel surfaces along trajectories perpendicular to the central axis, combined with accelerometer measurements in orthogonal directions to determine geometrical dimensions accurately and quickly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If ultrasonic sensors are used to measure wheel dimensions, then the measurement can be performed, but the scanning speed is limited due to the speed of sound waves

Engineering Contradiction:
Improvescanning speedVSAvoidmeasurement accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent replaces ultrasonic sensors (acoustic field) with electromagnetic sensors such as laser sensors or radar systems. This substitution leverages the much higher speed of electromagnetic waves compared to sound waves, enabling significantly faster scanning speeds while maintaining measurement precision through the use of appropriate sensors and processing algorithms.

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

2Speed

If optical sensors are used for wheel scanning, then scanning speed improves, but the sensors become sensitive to environmental conditions

Engineering Contradiction:
Improvescanning speedVSAvoidenvironmental sensitivity
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The patent employs radar systems operating at microwave frequencies that are less sensitive to environmental conditions such as dust, humidity, and lighting variations compared to optical sensors. By changing the operating parameters (frequency range, wavelength) of the electromagnetic radiation used, the system achieves both fast scanning speed and reduced environmental sensitivity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the wheel protector is lowered quickly to scan the wheel, then productivity increases, but ultrasonic sensors cannot properly scan the wheel due to speed limitations

Engineering Contradiction:
Improvescanning efficiencyVSAvoidscan quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces ultrasonic sensing with electromagnetic sensing (laser or radar), which allows the wheel protector to be lowered quickly without compromising scan quality. The high speed of electromagnetic waves enables accurate distance measurement even during rapid motion, thereby maintaining both productivity and reliability.

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

4Measurement precision

If a high number of samples per revolution is required for accurate wheel runout determination, then measurement precision improves, but the scanning time increases

Engineering Contradiction:
Improverunout measurement accuracyVSAvoidscanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent uses electromagnetic sensors (laser or radar) that can acquire a high number of samples per wheel revolution due to their fast response time and high wave speed. This enables accurate determination of wheel runout and centering without increasing scanning time, as the sensors can process multiple measurement points rapidly during a single wheel rotation.

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

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

Enables rapid, accurate, and reliable scanning of wheel parts with a high sample rate, reducing exposure time and sensor sensitivity to environmental conditions, while maintaining robustness and affordability.

Implementation Method 1

at least one sensor device comprises a radar system

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

the position of the at least one sensor device with respect to a fixed reference, and in that the at least one sensor device comprises a radar system

Methodology Applied
Scientific EffectAccelerometer: Accelerometer

Data Source

PatentEP4119889B1Method and apparatus for determining the geometrical dimensions of a wheel
Publication Date: 2025.12.10 SNAP ON EQUIP SRL
  • EP4119889B1 patent drawingFigure 1~2
  • EP4119889B1 patent drawingFigure 3~4
  • EP4119889B1 patent drawing

AI summary

Method and related apparatus for determining the geometrical dimensions of a wheel, or at least one part of a wheel, with particular reference to vehicle wheels, in the context of a wheel maintenance process. This method uses contactless sensors which comprise a scanning radar system, preferably a millimeter-wave radar system, to scan the wheel, or at least one part of the wheel, quickly and accurately, moving said contactless sensors along a trajectory lying in at least one plane which is perpendicular to a central axis of the wheel.