Non-Contact Wheel Alignment Sensor Using Light Planes

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Solution Overview

Problem

Existing methods for measuring vehicle wheel alignment, such as direct and indirect methods, are cumbersome, time-consuming, and less accurate, particularly in determining the orientation of vehicle wheels with respect to the vehicle centerline for setting toe and camber angles.

Innovation Solution

A non-contact measurement system that projects multiple light planes onto a tire and wheel assembly, using photoelectric devices to receive reflected images and determine three-dimensional spatial coordinates, allowing for the calculation of the wheel's orientation and alignment characteristics like toe and camber angles with increased precision and redundancy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple light planes are projected onto the tire to increase measuring points, then measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvewheel alignment measurement precisionVSAvoidlight projector system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The illumination system is divided into multiple discrete light planes (e.g., 5-10 parallel planes) projected onto the tire sidewall. Each light plane creates a separate illumination line that can be independently detected and processed, increasing the number of measurement points without requiring a single complex projection system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a reference illumination line projected at a different angle as an intermediary element. This reference line serves as a baseline for calculating spatial coordinates and determining the tire's orientation, enabling the system to process multiple measurement planes systematically

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If light beams are projected at discrete locations on the tire, then the measurement system is simpler, but measurement precision is reduced

Engineering Contradiction:
Improveillumination system complexityVSAvoidtire orientation determination precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The system transitions from measuring at discrete points to measuring along continuous lines. By projecting light planes that create illumination lines across the tire sidewall, the measurement extends from zero-dimensional points to one-dimensional lines, significantly increasing the amount of spatial information available for precision calculations

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If more illumination lines are projected on the tire, then the working field and sensitivity are enhanced, but the system becomes more complex

Engineering Contradiction:
Improvemeasurement robustnessVSAvoidmulti-line projection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system pre-calculates the expected positions and orientations of multiple parallel light planes before projection. By establishing the geometric relationships and spatial coordinates in advance, the system can process the reflected images from multiple illumination lines more efficiently, reducing the computational complexity during actual measurement

Inventive Principle:
Principle #10Preliminary action

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

The system provides more accurate and robust measurement of wheel alignment by increasing the number of measuring points and the working field, enhancing sensitivity and enabling noise reduction, allowing for precise calculation of camber, toe angle, and wheel center position.

Implementation Method 1

projecting a plurality of light planes from a first light projector onto a tire and wheel assembly to form a plurality of generally parallel illumination lines on a tire... receiving a reflected image of at least some of the illumination lines with a photo electric device reflected from the tire

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

receiving a reflected image of at least some of the illumination lines with a photo electric device

Methodology Applied
Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentEP2515074B1Non contact wheel alignment sensor and method
Publication Date: 2015.12.30 PORTER BURKE E MACHINERY CO
  • EP2515074B1 patent drawingFigure 1
  • EP2515074B1 patent drawingFigure 2~3
  • EP2515074B1 patent drawingFigure 4

AI summary

A method of determining alignment characteristics of a tire and wheel assembly mounted on a vehicle comprises projecting a plurality of light planes onto a tire and wheel assembly to form a plurality of generally parallel illumination lines on a tire of the tire and wheel assembly including either an identifiable gap between a pair of the illumination lines or one of said illumination lines being thicker than the other illumination lines. A reflected image of at least some of the illumination lines is received with a photo electric device, the photo electric device receiving images of the illumination lines reflected from the tire including either the pair of the illumination lines forming the identifiable gap or the thicker illumination line. The identity and location of the illumination lines is resolved and a plane defined by spatial coordinates from the illumination lines imaged by said photo electric device is determined, the plane representing the orientation of the tire and wheel assembly.