Sensorized Wheel Hub for Real-Time Tire Force Detection

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Solution Overview

Problem

Current suspension assemblies in vehicles lack the capability to effectively detect the stresses and forces applied to the tire while in motion, as existing sensor systems are complex, costly, and inefficient in transmitting this information to improve stability control.

Innovation Solution

A sensorized suspension assembly with a wheel hub unit and suspension upright, featuring a rolling bearing with strategically positioned strain sensors on the radially outer ring, allowing real-time detection of forces and moments applied to the tire, integrated with an electrical circuit for data transmission to enhance stability control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If strain sensors are fitted to elastic deformation areas of the outer ring, then detection capability is improved, but device complexity and cost increase

Engineering Contradiction:

Improvedetection capabilityVSAvoiddevice complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential detection function by fitting strain sensors to specific elastic deformation areas on the outer ring, rather than implementing complex sensor modules. This selective approach captures the necessary stress information while avoiding unnecessary complexity in the wheel hub unit design.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies strain sensors locally to the elastic deformation areas of the outer ring where stress concentrations occur. This localized sensing approach provides accurate detection of tire forces and moments without requiring comprehensive sensor coverage throughout the entire wheel hub assembly, thereby reducing overall system complexity.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If complex sensor modules with multiple strain sensors are used, then measurement coverage is improved, but ease of manufacture deteriorates

Engineering Contradiction:

Improvemeasurement coverageVSAvoidease of manufacture

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs simple, inexpensive strain sensors rather than complex sensor modules. These basic strain sensors are easy to manufacture and install on the elastic deformation areas, providing sufficient measurement coverage for detecting tire forces and moments without requiring sophisticated sensor assemblies.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent divides the measurement task into segments by placing strain sensors at specific elastic deformation areas on the outer ring. This segmentation allows each sensor to measure specific stress components, and through strategic placement, achieves comprehensive measurement coverage while maintaining manufacturing simplicity.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If existing sensor systems are implemented, then some detection capability is provided, but reliability in detecting tire forces deteriorates

Engineering Contradiction:

Improvedetection capabilityVSAvoidreliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent incorporates strain sensors during the manufacturing process of the wheel hub unit, specifically fitting them to the elastic deformation areas of the outer ring before final assembly. This preliminary integration ensures that the sensors are properly positioned and protected, improving the reliability of tire force detection compared to post-manufacturing sensor installation.

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 solution enables reliable, economical, and effective real-time monitoring of tire forces and moments, improving vehicle stability, ESP performance, and enabling autonomous driving by providing critical load information not previously available.

Implementation Method 1

a rolling bearing (34) which in turn comprises a radially outer ring (5) and a radially inner ring (35)... four flats (12) formed to be angularly spaced from each other on a radially outer lateral cylindrical surface (13) of the radially outer ring (5)... four sensor modules (14), each fixed integrally on a respective flat (12), each sensor module comprising a pair of strain sensors (15)

Methodology Applied

Scientific EffectStrain sensor detection: Piezoresistive Effect

Data Source

PatentUS11731455B2Sensorized suspension assembly for vehicles, including a wheel hub unit and a suspension upright or knuckle, and an associated method and wheel hub unit

Publication Date: 2023.08.22 AB SKF SKF PATENT DEPARTMENT

AI summary

In a vehicle suspension assembly a sensorized system applied to a wheel hub unit, in which radially outer cylindrical surface of an outer ring of the wheel hub unit configured for coupling to a suspension upright or knuckle has four circumferential flats formed to be angularly spaced from each other on the radially outer lateral cylindrical surface, each flat delimiting a plane surface which extends axially over a pair of annular tracks for rolling bodies of the outer ring; each flat carries integrally a sensor module including a pair of extensometers positioned parallel to each other and each at the position of a respective annular track, orientated in a circumferential direction so as to extend along a circumferential development of the annular track; an electrical circuit picks up a signal from each sensor module and sends it to a data socket carried by the suspension upright or knuckle.