Windscreen Fine Particulate Sensor Using LED Diffraction
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Solution Overview
Problem
Existing fine particulate sensors require frequent maintenance due to residue buildup and lack a compact, economical design for measuring fine particulates near motor vehicles.
Innovation Solution
A method using LEDs to illuminate outside air regions through a vehicle's windscreen, combined with an optical receiving device that captures and analyzes diffraction patterns for particle size and wetness, eliminating the need for a housing and allowing dual functionality with rain-light sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a housing is used to define the sample space in existing fine particulate sensors, then the measurement structure is stable and maintainable, but the device becomes more complex and requires frequent maintenance due to residue buildup
Solution Approach 1:
The patent removes the housing structure that traditionally defines the sample space in particulate sensors. Instead of using a physical enclosure, the sample space is defined by the intersection of the LED illumination area and the optical receiving device's capture area. This extraction eliminates the housing complexity and maintenance requirements while maintaining measurement stability through optical field definition.
Solution Approach 2:
The optical receiving device serves dual functions: it captures diffraction patterns from fine particulates for size determination and simultaneously detects light reflected from the windscreen for wetting detection. This multi-functionality reduces device complexity by eliminating separate housings and sample spaces for different measurement functions.
2Measurement precision
If multiple LEDs with different wavelengths are used to improve measurement accuracy, then more data is generated for better analysis, but the device complexity and cost increase
Solution Approach 1:
The same optical receiving device that captures diffraction patterns from multiple LEDs is also used to detect windscreen wetting by receiving reflected light. This universal use of the receiving device across multiple measurement functions amortizes the complexity cost and enables multi-wavelength particle analysis without proportionally increasing device complexity.
Solution Approach 2:
The system can switch LEDs on and off in alternating time points, allowing sequential measurement with different wavelengths. This periodic activation reduces the need for all LEDs to be simultaneously active, managing complexity while still gathering multi-wavelength data for improved particle size determination accuracy.
3Adaptability or versatility
If the optical receiving device captures both diffraction patterns and reflected light, then the device is more versatile and compact, but the analysis becomes more complex
Solution Approach 1:
The system switches between measuring diffraction patterns from particulates and detecting windscreen wetting by activating the LED and receiving device at alternating time points. This temporal separation allows a single optical receiving device to perform both functions without requiring complex simultaneous analysis, maintaining versatility while managing analysis complexity through time-division multiplexing.
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
This approach enables a low-maintenance, compact, and cost-effective measurement of fine particulates, enhancing accuracy through multiple LED wavelengths and flexible analysis timing, while integrating with existing sensors for enhanced functionality.
Implementation Method 1
at least one LED arranged inside the motor vehicle lights up an outside air region
Implementation Method 2
takes an intensity measurement in an area lit by the LED, and that the intensities measured are analysed for diffraction patterns that depend on the size of the fine particulates
Implementation Method 3
at least some of the radiation emitted by the at least one LED is reflected on the windscreen, and the light reflected by the windscreen is received and analysed with regard to wetting the windscreen with drops of water
Data Source
AI summary
In a method for measuring fine particulates in the vicinity of a motor vehicle with an optical receiving device, at least one LED (2, 3) arranged inside the motor vehicle lights up an outside air region. The optical receiving device is designed to capture the area under examination in a spatially localized manner and takes an intensity measurement in an area that is lit by the LED. The intensities measured are analyzed for diffraction patterns that depend on the size of the fine particulates. Additionally, a portion of the light that is coupled into the windshield is also analyzed for the presence of water on the windshield.