Vehicle Window Humidity Sensing for Automatic Defogging Control
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Solution Overview
Problem
Conventional vehicle air conditioning systems fail to accurately measure humidity on windows, leading to incomplete defogging and temperature control issues, as they rely on estimated humidity values from window surface temperature and interior humidity sensors, and lack independent control of the defrost door, causing discomfort for occupants.
Innovation Solution
An automatic defogging system with a window humidity sensor that directly detects relative humidity and controls the air conditioning system using a specific logic to selectively operate the intake door, blower, air conditioner, mode door, and defrost door to remove humidity and maintain vehicle temperature, allowing for independent defrost door control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If humidity is estimated using window surface temperature and interior humidity sensor, then the system can operate with existing sensors, but the humidity measurement is inaccurate leading to incomplete defogging
Solution Approach 1:
The patent extracts the humidity sensing function from the interior humidity sensor and places it directly at the window surface through a dedicated window humidity sensor. This separates the humidity measurement function from temperature measurement, allowing accurate humidity detection specifically at the window where defogging is needed, without requiring complex integration of multiple sensor functions.
2Ease of operation
If the defrost door is controlled together with other air conditioning elements, then the control system is simplified, but the defrost door cannot be independently controlled causing temperature changes inside the vehicle
Solution Approach 1:
The patent segments the control of air conditioning elements by providing independent control signals for the defrost door separate from other air conditioning control elements. This allows the defrost door to be controlled independently based on window humidity levels, preventing unwanted temperature changes in the vehicle interior that would occur if it were controlled together with other elements.
3Extent of automation
If conventional control logic is used, then the air conditioning system operates automatically, but the driver feels alienation and cannot maintain room temperature
Solution Approach 1:
The patent implements feedback control by continuously monitoring window humidity levels with the window humidity sensor and automatically adjusting the defrost door control signal accordingly. When window humidity exceeds a threshold, the system automatically activates the defrost door; when humidity decreases, it deactivates the door. This closed-loop feedback maintains automatic operation while eliminating driver alienation through responsive, needs-based control.
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 effectively removes humidity and maintains comfortable temperatures by directly sensing window relative humidity and phasically controlling the air conditioning system, ensuring accurate defogging and temperature regulation, thereby enhancing occupant comfort.
Implementation Method 1
an automatic defogging system of a vehicle which includes a window humidity sensor installed on the inner surface of a window
Implementation Method 2
selectively operating an air conditioning system in a phased manner depending on a detected signal to remove humidity
Implementation Method 3
By operating an air cooling function or an air heating function according to the weather, the concentrated humidity on a window can be automatically removed
Data Source
AI summary
An automatic defogging system of a vehicle according to an exemplary embodiment of the present invention includes: an input unit used for receiving a directly sensed window relative humidity value from a defogging sensor so as to directly sense a humidity generation degree in a window; a controller which controls operations of an air conditioning system programmed as a type of a logic that is selectively and phasedly controllable depending on the sensed relative humidity and; an output unit that is a selection mode of the air conditioning system that can be controlled by the controller. Accordingly, an automatic defogging system of a vehicle and a control method thereof automatically removes fog or frost on an inner surface of a window while maintaining comfortable conditions inside a vehicle.