Optical fiber system for detecting forces during a collision test
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Solution Overview
Problem
Existing collision testing systems for anthropomorphic test devices face challenges in accurately measuring forces, particularly on soft tissues and internal organs, due to interference from structural components and the need for precise repositioning, leading to inconsistent test results.
Innovation Solution
A multi-core optical fiber system is integrated into the anthropomorphic test device to measure stress, strain, and deformation of skeletal structures, organs, and flesh, providing real-time data through Fiber Bragg Gratings and remote sensing, allowing for precise positioning and repeatable tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional strain gauges are used to measure forces on soft tissues and internal organs, then measurement capability is provided, but measurement precision deteriorates due to difficulty in measuring strain of low Young modulus materials using high Young modulus sensing elements
Solution Approach 1:
The patent replaces traditional mechanical strain gauges with an optical fiber sensing system that uses light instead of mechanical elements to measure strain. The optical fiber system includes multiple optical fibers embedded in the ATD body parts, with sensors that detect strain through optical properties rather than mechanical contact, eliminating the mismatch between high Young modulus sensing elements and low Young modulus soft tissues.
Solution Approach 2:
The patent changes the measurement parameter from electrical resistance change (traditional strain gauges) to optical properties such as light absorption, scattering, or refractive index changes. This parameter change allows the sensing system to detect strain in soft tissues without requiring high Young modulus sensing elements, as optical measurements are not limited by mechanical property mismatches.
2Adaptability or versatility
If the ATD is made highly adjustable to allow for many different configurations, then adaptability is improved, but it becomes difficult to reposition the ATD into precisely the same position and orientation for subsequent tests
Solution Approach 1:
The patent uses optical fibers to create a digital copy or map of the ATD's position and orientation by measuring strain patterns throughout the body. This optical mapping system captures the precise spatial configuration, allowing the ATD to be repositioned and verified for exact replication between tests, solving the problem of maintaining positioning precision despite high adjustability.
3Loss of information
If high speed cameras are used to monitor ATD movement and distortions, then visual monitoring capability is provided, but measurement capability deteriorates for body parts that are obstructed or difficult to estimate
Solution Approach 1:
The patent replaces visual monitoring with optical fiber sensors embedded directly in the ATD body parts. This substitution of optical sensing elements within the structure itself provides direct measurement capability for all body parts including internal organs and obstructed regions, eliminating the line-of-sight limitations of external cameras.
4Reliability
If cables are used to transmit electrical signals from sensors, then data transmission capability is provided, but the system complexity increases and interference from structural components occurs
Solution Approach 1:
The patent replaces electrical cable transmission with optical fiber transmission. The optical fibers serve dual purposes as both sensors and data transmission media, eliminating the need for separate electrical cables. This reduces system complexity and eliminates electromagnetic interference issues that plague electrical signal transmission through vehicle structures during collision tests.
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 enhances biofidelity and accuracy by minimizing interference, ensuring consistent test results and enabling real-time measurement of forces, even in complex environments, thus improving vehicle restraint evaluations and injury prediction.
Implementation Method 1
A multi-core optical fiber system is integrated into the anthropomorphic test device to measure stress, strain, and deformation of skeletal structures, organs, and flesh, providing real-time data through Fiber Bragg Gratings
Implementation Method 2
A multi-core optical fiber system is integrated into the anthropomorphic test device to measure stress, strain, and deformation of skeletal structures, organs, and flesh, providing real-time data through Fiber Bragg Gratings and remote sensing
Data Source
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AI summary
An optical fiber system for a body part of an anthropomorphic test device is disclosed that includes at least one body part and at least one optical fiber that has a plurality of cores in a spaced and parallel relationship with one another that extend between ends of the optical fiber for sensing positions of the at least one body part. Each of the cores have a plurality of grating sensors disposed along a length thereof capable of determining a position and orientation of the body part.