Adaptive Raindrop Detection Threshold for Vehicle Windscreen
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Solution Overview
Problem
Existing raindrop detection systems on vehicle windshields face challenges in accurately distinguishing raindrops from other objects due to similar image characteristics, leading to misinterpretation and false detections, especially when objects close to the camera are present.
Innovation Solution
A method and camera assembly that modify the confidence threshold value based on the presence of objects within the vehicle's path, adjusting it according to the distance between the camera and the object to reduce false positives by considering the object's proximity and characteristics such as contour, contrast, and intensity, and utilizing bifocal cameras or external detection means for accurate raindrop identification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed threshold value is used for raindrop detection, then the detection process is simple and fast, but false detections increase when objects close to the camera are present
Solution Approach 1:
The patent applies dynamics by making the threshold value adaptive rather than fixed. The threshold is dynamically adjusted based on the detected distance to objects in the vehicle path. When objects are detected at close distances, the threshold increases to prevent false positives, while maintaining a lower threshold when no nearby objects are present, thus optimizing detection accuracy across varying conditions.
Solution Approach 2:
The patent changes the parameter of the threshold value based on object distance. By modifying the threshold parameter in response to detected object proximity, the system adapts its detection sensitivity. This parameter change allows the system to maintain high reliability across different driving scenarios without requiring a complex multi-sensor setup.
2Adaptability or versatility
If objects close to the camera are present, then the vehicle path information becomes available for threshold adjustment, but confusion between objects and raindrops increases
Solution Approach 1:
The patent applies local quality by adjusting the detection threshold specifically for regions of the image where nearby objects are detected. Rather than uniformly changing the threshold across the entire image, the system locally adapts the threshold in areas affected by nearby objects, preserving raindrop detection accuracy in unaffected regions while preventing false positives near detected objects.
Data Source
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AI summary
The invention relates to a method for detecting raindrops (26) on a windscreen of a vehicle, in which at least one image (30, 32, 34) is captured by a camera. An object extracted from the at least one image (30, 32, 34) captured by the camera is identified as a raindrop (26), if a confidence value assigned (S20) to the extracted object is above a predetermined threshold value. The threshold value is modified (S22) in dependence of the presence of an item (16) within the vehicle path. Moreover the invention relates to a camera assembly for detecting raindrops (26) on a windscreen of a vehicle.