Motorcycle Airbag Sensor Layout for Accurate Frontal Collision Detection

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Solution Overview

Problem

Existing straddled vehicles do not effectively absorb and reduce kinetic energy during frontal collisions to minimize impact on the rider, and existing collision detection systems are prone to inaccuracies due to interference from vehicle components and yawing or pitching movements.

Innovation Solution

A straddled vehicle equipped with a body frame, front and rear wheels, a seat, a first and second acceleration sensor, and an airbag system that deploys based on acceleration detection, with sensors positioned strategically relative to the vehicle's center of gravity to accurately detect and absorb collision forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If acceleration sensors are disposed near the center of gravity to accurately detect collision forces, then measurement precision is improved, but device complexity increases due to interference from vehicle components

Engineering Contradiction:
Improvecollision force detection accuracyVSAvoidsensor placement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent divides the sensor placement into multiple discrete locations (forward, rearward, leftward, rightward of the center of gravity) rather than using a single complex sensor array. This segmentation allows each sensor to be positioned in a relatively simple location that avoids interference from major vehicle components while still providing comprehensive collision detection capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses the center of gravity as an intermediary reference point to determine sensor positions. By defining sensor locations relative to this well-defined reference, the system achieves precise measurement without requiring complex absolute positioning mechanisms. The center of gravity acts as a mediator that simplifies the relationship between sensor placement and measurement accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple acceleration sensors are positioned at different locations to detect collision direction, then measurement precision is improved, but the vehicle structure becomes more complex

Engineering Contradiction:
Improvecollision direction detection accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by positioning sensors at specific locations (forward, rearward, leftward, rightward of the center of gravity) where they can detect particular collision characteristics. Each sensor location is optimized for detecting specific directional forces, allowing the system to achieve comprehensive collision detection through simple, location-specific sensor placement rather than a complex integrated system.

Inventive Principle:
Principle #3Local quality

3Reliability

If the airbag deployment system is activated to absorb collision energy, then safety is improved, but energy consumption increases

Engineering Contradiction:
Improverider safetyVSAvoidairbag deployment energy
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements preliminary action by pre-positioning the airbag and inflator system ready for immediate deployment upon collision detection. The airbag is pre-installed in the vehicle structure, and the inflator is pre-configured with the necessary energy storage mechanisms. When collision sensors detect an impact, the system can immediately activate the airbag without requiring energy-intensive assembly or positioning operations, thus reducing overall energy consumption while maintaining safety effectiveness.

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

Enhances safety by accurately detecting and absorbing collision forces, reducing impact on the rider through precise airbag deployment and minimizing interference from vehicle components.

Implementation Method 1

a first acceleration sensor to detect an acceleration; and an airbag that expands in accordance with the acceleration detected by the first acceleration sensor

Methodology Applied
Scientific EffectAcceleration detection: Accelerometer

Implementation Method 2

an airbag that expands in accordance with the acceleration detected by the first acceleration sensor

Methodology Applied
Scientific EffectAirbag expansion:

Implementation Method 3

Because the airbag absorbs an impact resulting from the frontal collision

Methodology Applied
Scientific EffectImpact absorption: Damping

Data Source

PatentEP4530170B1Straddled vehicle
Publication Date: 2026.01.21 YAMAHA MOTOR CO LTD
  • EP4530170B1 patent drawingFigure 1
  • EP4530170B1 patent drawingFigure 2
  • EP4530170B1 patent drawingFigure 3

AI summary

A motorcycle (1) includes: a body frame (5) including a head pipe (5A); a front wheel (3); a rear wheel (4); a seat (2) disposed behind the head pipe (5A); a first acceleration sensor (31) to detect an acceleration; and an airbag (21) that expands in accordance with the acceleration detected by the first acceleration sensor (31). The motorcycle (1) further includes a second acceleration sensor (32). The first acceleration sensor (31) is disposed forward of a center of gravity (CG). The second acceleration sensor (32) is disposed rearward of the center of gravity (CG).