Adaptive Vehicle Lamp Control for Smooth Glare-Free Shading

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Solution Overview

Problem

ADB control systems face issues with vehicle ROI jiggling, erroneous detection, and pitching vibrations leading to glare and illumination errors, which bother drivers and cause discomfort.

Innovation Solution

A controller for a variable light distribution lamp that adjusts light distribution patterns using gradual change control and dynamic electronic optical axis correction, employing different control waveforms based on vehicle ROI shifts and tilt angles to minimize glare and illumination errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If high beam illumination is used to illuminate wide and far front area, then visibility for driver is improved, but glare is cast to oncoming car or preceding car

Engineering Contradiction:
ImprovevisibilityVSAvoidglare
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The headlamp is divided into multiple independently controllable light-emitting units (pixels), allowing selective illumination of different regions. By controlling individual pixels or groups of pixels, the system can illuminate areas that need light while keeping areas that would cause glare dark, thus segmenting the illumination function to simultaneously achieve high visibility and reduce glare to other vehicles

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the headlamp emit light with different characteristics. The ADB control creates a light distribution pattern where some pixels are turned on (illumination zones) and others are turned off (shading zones) based on the detected positions of other vehicles. This local differentiation allows the system to provide high illumination intensity where needed while preventing glare in directions where other vehicles are present

Inventive Principle:
Principle #3Local quality

2Object-affected harmful factors

If ADB control dynamically adjusts shading zone to reduce glare, then glare to other vehicles is reduced, but light distribution pattern becomes complex

Engineering Contradiction:
Improveglare reductionVSAvoidlight distribution control
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The light distribution pattern is made dynamic through ADB control, which continuously adjusts which pixels are turned on or off based on real-time detection of other vehicles' positions. This dynamic adjustment allows the system to adapt to changing traffic conditions, maintaining glare reduction effectiveness while managing the complexity through automated control algorithms

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The ADB control system uses feedback from sensors (such as cameras or LiDAR) that detect the positions of oncoming and preceding vehicles. This feedback information is processed to determine which pixels should be turned on or off, creating a closed-loop control system that automatically adjusts the light distribution pattern to reduce glare while managing system complexity through automated decision-making

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If pixel values change gradually from zero toward target value, then glare is reduced and comfort is improved, but illumination response time increases

Engineering Contradiction:
Improvedriver comfortVSAvoidillumination response time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The pixel values are changed periodically over multiple control cycles rather than instantaneously. The control unit adjusts pixel values in steps across successive periods, allowing the illumination to transition smoothly. This periodic adjustment reduces sudden changes that cause glare and improves driver comfort, while the cumulative effect over time still achieves the target illumination level

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs preliminary adjustments to pixel values before reaching the final target state. By gradually increasing pixel values from zero toward the target value across multiple control cycles, the system prepares the illumination transition in advance, reducing the shock to driver's eyes while still achieving timely illumination of the required areas

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4678474A1Control device for light-distribution-adjustable lamp, vehicle lamp, and software program
Publication Date: 2026.01.14 KOITO MFG CO LTD
  • EP4678474A1 patent drawingFigure 1
  • EP4678474A1 patent drawingFigure 2
  • EP4678474A1 patent drawingFigure 3

AI summary

The controller 300 generates a control image IMG1 for controlling a variable light distribution lamp 210. The controller 300 acquires shading information ROI that indicates a shading zone which is a region to be shaded. Among a plurality of first pixels PIX1 contained in the control image IMG1, a pixel value of a part that corresponds to the shading zone is zero. When the controller 300 gradually changes the pixel value of the first pixels PIX1 contained in the control image IMG1 from zero towards a target value, the rate of increase α of the pixel value in the first period T1 that follows the start of the gradual change control is relatively lower than the rate of increase β of the pixel value in the second period T2 subsequent to the first period T1.