Multi-Wavelength Road Surface Detection via Headlight Reflection

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Solution Overview

Problem

Existing road surface detection systems can differentiate between dry, wet, and frozen states based on infrared light reflections but struggle to identify road surface materials and colors, which are crucial for accurate road surface typing.

Innovation Solution

A road-surface-detection device utilizing a light source emitting visible light across multiple wavelengths to detect reflection intensities, allowing differentiation between road surface states and materials by comparing reflection intensities across different wavelengths, including short, middle, and long wavelength ranges, and using detectors within the headlight to determine the type of road surface without additional light sources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If infrared light detection is used to detect road surface state (dry, wet, frozen), then road surface state detection is improved, but road surface material and color detection capability is lost

Engineering Contradiction:
Improveroad surface state detectionVSAvoidroad surface material and color information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The detection system segments the spectrum into multiple wavelength bands (short, middle, long wavelengths in visible range) and uses separate detectors for each band. This segmentation allows the system to capture different spectral characteristics simultaneously, enabling both road surface state and material identification without information loss.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from single-wavelength infrared detection to multi-wavelength visible light detection, adding the dimension of wavelength variation. By detecting reflection intensities across multiple wavelengths, the system gains additional information dimensions that enable both state and material detection.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple detectors for multiple wavelengths are added to detect road surface material, then detection capability is improved, but device complexity increases

Engineering Contradiction:
Improveroad surface material detectionVSAvoiddetection device structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention merges the headlight's existing light source function with the road surface detection function. The headlight serves dual purposes: illuminating the road and providing the light source for spectral analysis. This integration reduces device complexity by utilizing existing vehicle components rather than adding separate detection systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The detection system is designed to perform multiple functions using the same hardware components. The same light source and detectors used for basic road surface state detection are also utilized for material and color identification, making the system universal and avoiding additional complexity.

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

3Loss of information

If visible light with multiple wavelengths is used to detect road surface material and color, then material detection capability is improved, but energy consumption increases

Engineering Contradiction:
Improveroad surface material informationVSAvoidlight source energy consumption
Core Design Contradiction:
Loss of informationVSUse of energy by moving object

Solution Approach 1:

The system uses the vehicle's existing headlight as the light source for detection, making the headlight serve itself for dual purposes. This self-service approach eliminates the need for additional energy-consuming detection-specific light sources, as the headlights already emit visible light across multiple wavelengths during normal operation.

Inventive Principle:
Principle #25Self-service

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 device accurately detects road surface types, including dry, wet, frozen, and compacted snow states, as well as materials, by analyzing reflection intensities across various wavelengths, enhancing safety by providing detailed road surface information.

Implementation Method 1

reflection intensities of reflected light that is emitted from the light source and reflected on the road surface

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3686576B1Road-surface-detection device and vehicle
Publication Date: 2022.12.28 YAMAHA MOTOR CO LTD
  • EP3686576B1 patent drawingFigure 1
  • EP3686576B1 patent drawingFigure 2
  • EP3686576B1 patent drawingFigure 3~4

AI summary

Provided is a road-surface-detection device capable of detecting not only a road surface in a dry state, a road surface in a wet state, and a road surface in a frozen state, but also the type of a road surface based on a constituent of the road surface. A road-surface-detection device 100 includes: a light source 80 that emits, to a road surface 300, light of a plurality of different wavelengths including at least one type of visible light in visible light to near-infrared wavelength ranges; detectors 81 and 82 that detect reflection intensities of reflected light having a plurality of different wavelengths including at least one visible light in reflected light emitted from the light source 80 and reflected on the road surface 300; and a road surface determiner 70 that determines a type of a road surface based on the reflection intensities of the reflected light having the plurality of different wavelengths and detected by the detectors 81 and 82.