Wiper Controller Rainfall Adaptation Delay Time
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Solution Overview
Problem
Existing vehicle wiper controllers using optical raindrop sensors face instability in detection due to mount location and small detection area, leading to inconsistent output values and delayed feedback, making it difficult to immediately adjust wiper operation speed in response to changing rainfall conditions, which can cause unpleasant driver experiences, especially when transitioning from high to low speed or stopping the wiper during heavy rain.
Innovation Solution
A wiper controller that includes a wiper operation time counter, delay time calculation unit, and operation change determination unit to calculate and adjust wiper operation based on the difference between actual and reference operation times, allowing for immediate adjustments in wiper speed or operation mode in response to changes in rainfall, using a sensor with a light-emitting and light-receiving element to detect raindrops on the windshield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If raindrop detection is performed using a small-area optical sensor at a fixed mount location, then the sensor structure is simple, but the detection stability is poor and results vary in similar rainfall states
Solution Approach 1:
The detection area is divided into multiple regions (first detection area and second detection area) with different detection thresholds. This segmentation allows each region to specialize in detecting different rainfall intensities, improving overall detection stability while maintaining a relatively simple sensor structure.
Solution Approach 2:
Different detection thresholds are applied to different detection areas. The first detection area uses a first threshold while the second detection area uses a second threshold, allowing each local region to optimize its detection characteristics for specific rainfall conditions, thereby improving detection reliability.
2Measurement precision
If the detection result is monitored for a predetermined period before controlling wiper operation, then detection accuracy is improved, but the feedback time to wiper control is prolonged
Solution Approach 1:
The detection threshold is dynamically adjusted based on the detected rainfall state. When continuous detection confirms a stable rainfall pattern, the system can respond more quickly by adapting the threshold levels, thus reducing the effective feedback time while maintaining detection accuracy through dynamic adaptation rather than fixed prolonged monitoring.
Solution Approach 2:
The system implements continuous feedback monitoring where detection results are continuously evaluated against thresholds. When the rainfall state consistently meets threshold criteria over a short period, the wiper control is activated, providing accurate yet timely feedback without requiring excessively long monitoring periods.
3Productivity
If the wiper operates at high speeds under heavy rain, then the windshield is kept clear effectively, but the wiper cannot be immediately stopped or slowed when entering a tunnel or rainfall decreases
Solution Approach 1:
The system continuously monitors rainfall detection results and provides real-time feedback to the wiper control. When rainfall detection indicates a change in conditions (such as entering a tunnel or rainfall decreasing), the feedback mechanism immediately triggers a response to adjust wiper speed or stop operation, ensuring responsive and appropriate wiper control adaptation.
Solution Approach 2:
The wiper operation parameters (speed, mode) are dynamically adjusted based on real-time rainfall detection. The system can transition from high-speed operation during heavy rain to low-speed or stopped state when conditions change, providing adaptive and responsive wiper control that matches actual windshield 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
This solution enables accurate detection of rainfall state changes and immediate adjustment of wiper operation, preventing unpleasant driver experiences by ensuring smooth transitions in wiper speed and operation, even during rapid changes in rainfall conditions.
Implementation Method 1
light rays irradiated from a light-emitting element reflect on a detection surface, and the light-receiving element receives the reflecting light to detect raindrops
Data Source
AI summary
A wiper controller which detects the raindrops adhered onto the windshield glass G of the vehicle to control the wiper based on the detected result is provided with a wiped water measurement unit for calculating an amount of water wiped by the wiper, a wiper operation time counter for counting the actual wiper operation time based on the ON/OFF signal of the wiper motor for driving the wiper, a delay time calculation unit which obtains the wiper operation delay time by comparing the actual wiper operation time with the reference wiper operation time, and an operation change determination unit for determining with respect to the need for changing the wiper operation based on the wiper operation delay time and the amount of water wiped by the wiper. The change in the rainfall state is derived from the wiper operation delay time and the amount of water wiped by the wiper to appropriately control the wiper in response to the change in the rainfall state.