Vehicle Headlight Glare Control via Illuminance Threshold Comparison

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Solution Overview

Problem

Existing control units for vehicle headlights fail to selectively reduce glare only when necessary, leading to unnecessary reduction in illuminated areas and misidentification of objects that are weakly illuminated as requiring glare reduction.

Innovation Solution

A control device with a memory to store illuminance levels for main headlights, comparing these levels with a predetermined amount to adjust light distributions and vertical light-dark boundaries dynamically, reducing illuminance only when necessary and maintaining adjustments for low illuminance levels to avoid glare.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If the control unit reduces glare for every detected object, then glare protection is improved, but unnecessary illumination reduction occurs in areas where glare reduction is not needed

Engineering Contradiction:
Improveglare protectionVSAvoidillumination level
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The control unit applies glare reduction selectively to specific locations based on illuminance thresholds. Instead of uniformly reducing glare for all detected objects, the system adjusts illumination locally only in areas where the illuminance exceeds the predetermined threshold, preserving normal illumination in areas where glare reduction is unnecessary.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The control unit changes the illuminance parameter dynamically based on comparison with a predetermined threshold. When the illuminance at a detected object's location exceeds the threshold, the control unit adjusts the light distribution to reduce glare; otherwise, it maintains normal illumination, thereby avoiding unnecessary illumination reduction.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the control unit identifies more objects for glare reduction, then glare protection coverage is improved, but false identification of weakly illuminated objects as glare sources increases

Engineering Contradiction:
Improveglare protection coverageVSAvoidobject identification accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The control unit uses illuminance level comparison as a discriminative parameter to accurately identify objects requiring glare reduction. By comparing the measured illuminance at each object's location against a predetermined threshold, the system distinguishes between actual glare sources (high illuminance) and non-glare objects (low illuminance), preventing false identification.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces subjective or simplistic object detection methods with an objective illuminance-based identification system. Instead of relying on object detection alone, the control unit uses measured illuminance levels to determine whether glare reduction is necessary, substituting mechanical/object-based detection with photometric measurement for more accurate identification.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP2596990B1Method and controller for controlling main headlights with adjustable light/dark limit for preventing glare from objects
Publication Date: 2019.01.23 HELLA GMBH & CO KGAA
  • EP2596990B1 patent drawingFigure 1
  • EP2596990B1 patent drawingFigure 2

AI summary

The control device has a processing unit that sets parameters for adjusting light distribution and light-dark boundary at right or left headlight in dependence on the scanned information. An output unit outputs the set parameter for adjusting the light distribution and the light-dark boundary. A control unit controls light distribution of headlight to preset location, by comparing the set parameters with illuminance value stored in the memory. An independent claim is included for a method for controlling headlights of vehicle.