Windshield Rain Sensor Using Dual-Beam Soiling Detection
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Solution Overview
Problem
Current rain sensors are unable to simultaneously detect contamination and wetting on a vehicle's windshield reliably.
Innovation Solution
A rain sensor system utilizing two modulated light beams and a control device to measure changes caused by raindrops and contaminants, with a photodetector array and a control unit to analyze these changes, enabling detection of rain intensity and windshield soiling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single measurement beam is used to detect rain, then the device complexity is low, but the ability to simultaneously detect contamination and wetting is insufficient
Solution Approach 1:
The patent divides the measurement system into two separate measurement beams (first and second measurement beams) that traverse different paths through the windshield. The first beam detects rain intensity while the second beam detects contamination. By segmenting the measurement function into separate beams, the system achieves reliable simultaneous detection of both rain and contamination without requiring a single overly complex sensor
Solution Approach 2:
Each measurement beam is assigned a specific function: the first beam is optimized for rain detection while the second beam is optimized for contamination detection. The beams traverse different locations and paths through the windshield, allowing each to specialize in detecting specific conditions at its particular location, thereby improving overall detection reliability
2Reliability
If multiple measurement beams are used to detect both rain and contamination, then the detection capability is improved, but the use of energy increases
Solution Approach 1:
The patent employs modulated light beams that are activated in periodic cycles rather than continuously. The control device alternates between activating the first measurement beam for rain detection and the second measurement beam for contamination detection. This periodic activation significantly reduces energy consumption compared to continuous operation while maintaining reliable detection capabilities through systematic sampling
Solution Approach 2:
The system dynamically switches between different measurement modes and beam activations based on detection needs. The control device adjusts which beam is active at any given moment, creating a dynamic measurement approach that reduces overall energy consumption while maintaining detection reliability through adaptive beam selection and modulation
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 reliable detection of both rain intensity and windshield contamination, supporting adaptive windshield wiper control and enhancing vehicle safety through precise measurements and energy-efficient operation.
Implementation Method 1
at least one photodetector and/or a photodetector array, such as a photodiode or a photodiode array, which receives the altered measurement radiation and converts it into one or more electrical signals
Data Source
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AI summary
The invention relates to a rain sensor for motor vehicles that precisely detects rain intensity and dirt accumulation on the windshield. The sensor uses modulated light beams emitted by LEDs or laser diodes and guided through the windshield. Changes caused by raindrops or dirt are detected by photodetectors and analyzed by a control unit consisting of a computer system with a CPU and memory. The control unit processes the signals and derives measured values for the probability of rain and the windshield's attenuation. Additionally, the sensor supports encrypted communication, software updates, and integration into modern networked vehicle systems. Its modular design allows for adaptation to various vehicle models and environmental conditions.The rain sensor is future-proof and ready for integration into intelligent and autonomous vehicle systems, thus ensuring high precision and reliability under various weather conditions.