Motorcycle Handlebar Strain Gauges for Steering Torque Measurement

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Solution Overview

Problem

Existing methods for determining driver steering torque are not applicable to single-track vehicles like motorcycles, as they fail to account for significant factors such as driver weight ratio and body movement, and are often expensive and space-intensive.

Innovation Solution

A device comprising a handlebar, fork bridge, and coupling device with deformation measuring elements, particularly strain gauges, to measure minimal deformations caused by steering forces, ensuring accurate determination of steering torque without interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional physical models are used to determine steering torque, then the method is applicable to two-track vehicles, but it cannot accurately determine steering torque on single-track vehicles due to unaccounted factors like driver weight ratio and body movement

Engineering Contradiction:
Improveapplicability to single-track vehiclesVSAvoidsteering torque determination accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent replaces complex physical models with strain gauge-based direct measurement. Instead of using mechanical/physical models that fail to account for motorcycle-specific dynamics, the invention uses electrical strain sensors to directly measure handlebar deformation, providing accurate steering torque data for single-track vehicles without requiring complex modeling of driver weight ratio and body movement effects

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

Solution Approach 2:

The patent introduces a deformation measuring element (strain gauge) as an intermediary between the steering input and the measurement system. The strain gauge acts as a mediator that converts mechanical deformation of the handlebar into electrical signals, enabling accurate torque measurement while isolating the measurement system from the complex dynamics of motorcycle operation

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If known devices for determining steering torque are used, then they are optimized for two-track vehicles, but they are comparatively expensive and space-intensive

Engineering Contradiction:
Improvesteering torque measurement accuracyVSAvoidcost and space requirement
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs strain gauges, which are inexpensive, simple sensors compared to complex steering torque devices. These compact electrical sensors can be easily integrated into the handlebar structure without requiring expensive mechanical components or complex sensor assemblies, thereby reducing both cost and space requirements while maintaining measurement accuracy

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent extracts only the essential measurement function from complex existing devices. By using solely strain gauges mounted on the handlebar rather than entire complex torque measurement systems, the invention isolates and implements only the necessary sensing element, eliminating unnecessary complexity, cost, and space requirements

Inventive Principle:
Principle #2Taking out (Extraction)

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 cost-effective and precise measurement of steering torque in single-track vehicles by minimizing interference and distortion, using strain gauges to detect deformations directly correlated with rider input.

Implementation Method 1

a deformation measuring element is provided on the handlebar between the grip section and the fork bridge, which is designed to measure a deformation of the handlebar to determine the steering torque

Methodology Applied
Scientific EffectDeformation: Deformation

Implementation Method 2

A device comprising a handlebar, fork bridge, and coupling device with deformation measuring elements, particularly strain gauges, to measure minimal deformations caused by steering forces

Methodology Applied
Scientific EffectStrain gauge measurement: Piezoresistive Effect

Data Source

PatentEP3917821B1Device for determining the driver steering torque
Publication Date: 2025.07.16 BAYERISCHE MOTOREN WERKE AG
  • EP3917821B1 patent drawingFigure 1~3

AI summary

The invention relates to a device for determining the steering torque on a single-track motor vehicle comprising a handlebar (10) mounted rotatably about a steering axle (Z), a fork bridge (30) mounted rotatably about the steering axle (Z), and a coupling device (20) arranged between the handlebar and the fork bridge and connected to them, the coupling device (20) being designed to transmit a steering movement directed about the steering axle (Z) from the handlebar (10) to the fork bridge (30), a gripping portion (11) into which a steering force (F1, F2) that causes the steering movement can be introduced being provided on the handlebar (10), and a deformation measuring element (40), which is designed to measure a deformation of the handlebar (10) or the coupling device (20) for determining the steering torque, being provided on the handlebar (10) or the coupling device (20) between the gripping portion (11) of the handlebar (10) and the fork bridge (30).