Active Vision Spectral Band Selection to Resist Sun Glare
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Solution Overview
Problem
Existing vision systems are susceptible to the negative effects of sun glare, particularly in spectral bands strongly affected by sunlight, leading to inaccurate detection of hazardous conditions such as water, snow, and ice on roads and in the airspace, which can cause accidents.
Innovation Solution
An active vision system utilizing specific spectral bands where solar radiation is strongly absorbed by atmospheric constituents, employing a detector pair with filters and a data processor to calculate the radiance ratio in these bands, thereby reducing the impact of sun glare and enabling accurate detection of road and airspace conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If vision systems operate in spectral bands strongly affected by sunlight (visible and near infrared), then they can detect scenes under normal lighting conditions, but they suffer from sun glare that causes detection failures and accidents
Solution Approach 1:
The patent changes the operating spectral band parameter from visible/near-infrared to short-wave infrared (SWIR) and long-wave infrared (LWIR) bands. This parameter change allows the vision system to operate in spectral regions where solar radiation is significantly reduced, thereby eliminating sun glare interference while maintaining detection capability through thermal radiation detection.
Solution Approach 2:
The patent transitions from detecting reflected solar radiation (zeroth-order approach) to detecting thermal radiation emitted by objects (first-order approach). This dimensional shift in the detection mechanism allows the system to operate independently of solar illumination conditions, as thermal radiation detection is not dependent on reflected sunlight.
2Loss of information
If multi-spectral imaging is used to combine information from various spectral portions, then more comprehensive scene information is obtained, but the system complexity and susceptibility to sun glare increase
Solution Approach 1:
The patent extracts and utilizes only the thermal radiation information from the infrared spectral bands (SWIR and LWIR), separating this useful information from the problematic visible and near-infrared solar-reflected bands. By focusing exclusively on thermal emission bands, the system achieves comprehensive scene information without the complexity and sun glare susceptibility of full multi-spectral systems.
3Reliability
If vision systems use cameras or lidars operating in visible and near infrared bands, then they provide adequate obstacle detection, but they fail under intense sunlight conditions leading to accidents
Solution Approach 1:
The patent changes the operating wavelength parameter to SWIR (1.5-3.0 μm) and LWIR (3.0-14.0 μm) bands where the solar irradiance is significantly lower. This parameter change fundamentally resolves the sunlight interference problem while maintaining reliable obstacle detection through thermal radiation detection, making the system immune to sun glare conditions.
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 provides reliable detection of water, snow, and ice on surfaces, even under sunlight, by using spectral bands that minimize solar interference, allowing for improved navigation and hazard avoidance.
Implementation Method 1
spectral bands in which solar radiation is strongly absorbed by atmospheric constituents
Implementation Method 2
measuring the radiance reflected by an area of interest
Data Source
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AI summary
A vision system for monitoring areas of interest having a system for receiving an optical input, outputting a signal, and processing the signal. The system is configured to measure the radiance in spectral bands in which solar radiation is reduced substantially due to absorption by atmospheric constituents. This mitigates the negative effects of solar radiation such as sun glare. The system is configured to output a resultant detection signal in response to the measurements in the spectral bands selected.