Windowpane Liquid Detection Using Statistical Reflection Analysis
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Solution Overview
Problem
Existing methods for detecting liquid on a windowpane, such as a vehicle windshield, are unable to distinguish between even moisture and large drops and fail to rapidly detect changing states of wetness.
Innovation Solution
A method involving the capture of radiation reflections in single measurements, calculation of an average value as a reference, and statistical evaluation of differences between measurements to rapidly detect changes in moisture state, using multiple measuring sections and radiation emitters/receivers, with classification into difference classes to differentiate between even moisture and drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional radiation reflection methods are used to detect liquid on windowpanes, then liquid detection capability is provided, but the ability to rapidly detect changing states of wetness and distinguish between even moisture and large drops is insufficient
Solution Approach 1:
The patent divides the windowpane into multiple measuring sections (first measuring section and second measuring section) that are irradiated separately. This segmentation allows independent measurement of different regions, enabling the system to detect spatial distribution patterns of liquid (even coating vs. large drops) and rapid temporal changes by comparing measurements across sections and over time.
2Productivity
If single measurements are taken to rapidly detect moisture changes, then detection speed is improved, but measurement accuracy and reliability are reduced
Solution Approach 1:
The patent implements periodic measurement cycles where each cycle includes multiple single measurements at different time points. By repeatedly measuring the same measuring sections in succession and evaluating the temporal development of measurement values, the system achieves both rapid detection (through frequent periodic cycles) and reliable results (through multiple measurements per cycle that can be statistically evaluated).
Solution Approach 2:
The patent uses feedback by comparing current measurement values with previously determined average values from prior measurement cycles. This feedback mechanism allows the system to detect changes in moisture state by identifying deviations from baseline conditions, thereby improving reliability while maintaining rapid detection capability through efficient comparison rather than requiring exhaustive measurements.
3Measurement precision
If multiple measuring sections are used to improve detection accuracy, then ability to distinguish moisture patterns is enhanced, but device complexity increases
Solution Approach 1:
The patent makes the radiation emitter and receiver serve multiple functions by having them alternately irradiate and measure different measuring sections through temporal multiplexing. The same emitter can irradiate the first measuring section at one time and the second measuring section at another time within the same measurement cycle. This multi-functionality reduces the number of physical components needed while maintaining the capability to detect moisture distribution patterns across multiple sections.
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
Enables rapid detection of changes in moisture state, distinguishing between fine coatings and large drops, and allows for precise control of wiper operations based on moisture distribution.
Implementation Method 1
The radiation that is coupled into the windowpane may be totally reflected inside the windowpane at the boundary surfaces of the windowpane with the environment
Implementation Method 2
The radiation coupled out of the windowpane may be directed via a further optical element to a radiation receiver, by which it is detected
Data Source
AI summary
A method for detecting liquid on a windowpane in which radiation is emitted by at least one radiation emitter, the radiation is coupled into the windowpane via at least one optical element, and, after reflection in the windowpane, the radiation is coupled out of the windowpane. The radiation which is coupled out of the windowpane is captured in single measurements. A measurement cycle is formed from a multiplicity of single measurements. An average value is calculated from the measurement results of a measurement cycle. The average value is used a reference value for the single measurements of the subsequent measurement cycle currently in progress. The differences between the measured values of the single measurements of a measurement cycle currently in progress and the reference value are determined. The differences between the measured values of the single measurements of the measurement cycle currently in progress and the reference value are evaluated statistically. A conclusion is drawn regarding the state of coverage with liquid of the measuring section on the windowpane from the statistical evaluation.