Optical Seat Belt Wearing Detection Using Near-Infrared Imaging

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Solution Overview

Problem

Conventional wearing detection apparatuses for seat belts rely on mechanical schemes, leading to erroneous detection when a dummy tongue plate is used, as they detect engagement rather than actual strap wearing.

Innovation Solution

A non-mechanical wearing detection apparatus using an imaging device to capture images of the seat belt strap, with recognition members visible under near-infrared light, and a control unit to determine strap usage based on these images, eliminating the need for mechanical sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a mechanical detection scheme is used to detect buckle engagement, then the detection apparatus can determine seat belt usage, but erroneous detection occurs when a dummy tongue plate is used

Engineering Contradiction:
Improveseat belt usage detection accuracyVSAvoiddetection reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the mechanical detection scheme with an optical imaging system. Instead of detecting buckle engagement mechanically, the system uses an imaging device to capture images of the strap and recognize wearing status through image processing, thereby eliminating erroneous detection caused by dummy tongue plates

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

Solution Approach 2:

The patent creates a visual copy (image) of the strap and uses image recognition to determine wearing status. The imaging device captures an optical copy of the strap, and the control unit analyzes this copy to detect whether the strap is worn, replacing direct mechanical detection with indirect visual detection

Inventive Principle:
Principle #26Copying

2Measurement precision

If an imaging device is used to capture strap images, then detection accuracy improves, but the system becomes more complex

Engineering Contradiction:
Improvewearing detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The imaging device serves multiple functions: capturing images of the strap, providing illumination through the light emitting device, and the control unit performs both image processing and recognition. This multi-functionality reduces the need for separate components, thereby managing system complexity while maintaining detection accuracy

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent introduces a light emitting device as an intermediary to illuminate the strap, enabling the imaging device to capture clear images in various lighting conditions. This intermediary component facilitates accurate imaging without requiring complex adjustments to the imaging device itself

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Accurately detects seat belt usage without mechanical interference, reducing false positives and enhancing reliability in various lighting conditions, including nighttime or tunnels.

Implementation Method 1

at least one light emitting device 22B is provided to emit light of a specific wavelength outside the visible light spectrum

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

The imaging device captures an image of the restraint device including the strap... capable of capturing an image, using light of a specific wavelength outside the visible light spectrum

Methodology Applied
Scientific EffectNear-infrared imaging: Infrared Radiation

Data Source

PatentEP3508385B1Wearing detection apparatus, imaging apparatus, restraint device, and wearing detection program
Publication Date: 2021.07.14 TOSHIBA INFORMATION SYSTEMS (JAPAN) CORPORATION
  • EP3508385B1 patent drawingFigure 1
  • EP3508385B1 patent drawingFigure 2
  • EP3508385B1 patent drawingFigure 3

AI summary

According to embodiments, a wearing detection apparatus includes a restraint device (4), an imaging device (22), a control unit (20), and an output device (28). The restraint device (4) is to restrain a passenger seated in a seat, and includes a strap (40) an exposed area of which changes when the strap is being worn and not worn. The imaging device (22) captures an image of the restraint device (4) including the strap (40). The control unit (20) detects from the image captured by the imaging device (22), a recognition image (50,52) corresponding to a recognition member (40A,40B) provided in an area that is exposed when the strap is worn. The output device (28) outputs a result of detection of the recognition image.