Polarization Splitter Optical Detection for Road Surface State
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Solution Overview
Problem
Conventional detection devices struggle to accurately differentiate between states of objects, such as road surfaces, based on moisture and ice presence using polarized light, as they rely on relative light intensity among specific wavelengths, which is insufficient for distinguishing between dry, snow-accumulated, under-water, and frozen states effectively.
Innovation Solution
A detection device that emits random polarized light with a uniform ratio of S-polarized and P-polarized light across two wavelength bands, where one band is less absorbed by water, and uses a polarization splitter and photoreceptor to determine object states by analyzing polarization intensities, distinguishing between dry, snow-accumulated, under-water, and frozen states based on specific intensity ratios and threshold values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional detection devices use relative light intensity among specific wavelengths to detect object states, then the device structure is simple, but the measurement precision is insufficient for distinguishing between dry, snow-accumulated, under-water, and frozen states
Solution Approach 1:
The invention segments the detection process by separating S-polarized light and P-polarized light components using a polarization splitter, and further segments the analysis by comparing intensity ratios across two different wavelength bands. This segmentation enables precise differentiation between various object states (dry, snow-accumulated, under-water, frozen) that cannot be distinguished using single wavelength or unpolarized light detection.
Solution Approach 2:
The invention changes the detection parameters by using polarized light with specific wavelength bands instead of conventional unpolarized light. By measuring the intensity ratios of S-polarized and P-polarized light at two different wavelengths and comparing these ratios, the system achieves higher measurement precision for detecting subtle changes in object surface states.
2Measurement precision
If the device uses multiple wavelength bands with polarization analysis to accurately detect object states, then the measurement precision improves, but the use of energy increases
Solution Approach 1:
The invention uses partial action by selecting specific wavelength bands that are most effective for distinguishing between different object states. Instead of using the entire spectrum, the system focuses on two key wavelength bands with a polarization splitter, thereby reducing the total energy required from the light source while maintaining high detection accuracy for moisture and ice presence.
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 the state of objects by combining light of different wavelengths, enhancing the differentiation between dry, snow-accumulated, under-water, and frozen states, improving the accuracy of moisture and ice detection compared to conventional methods.
Implementation Method 1
a light source that is configured to emit, toward an object, light of a first wavelength band, and light of a second wavelength band that is less readily absorbed by water than the light of the first wavelength band
Implementation Method 2
a polarization splitter that is configured to split at least P-polarized light from light that includes S-polarized light and P-polarized light and that has been reflected or scattered at the object
Implementation Method 3
a photoreceptor that is configured to receive light reflected or scattered at the object via the polarization splitter
Implementation Method 4
light that includes S-polarized light and P-polarized light and that has been reflected or scattered at the object
Implementation Method 5
light that includes S-polarized light and P-polarized light and that has been reflected or scattered at the object
Data Source
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AI summary
A detection device includes: a light source that emits, toward an object, light of a first wavelength band, and light of a second wavelength band that is less readily absorbed by water than the light of the first wavelength band; a polarization splitter that splits at least one of S-polarized light and P-polarized light from light that has been reflected or scattered at the object; a photoreceptor that receives light reflected or scattered at the object via the polarization splitter; and a control unit that determines a state of the object from information based on light received by the photoreceptor. The light emitted by the light source is random polarized light where the ratio of P-polarized light and S-polarized light is generally uniform.