Vehicle Headlamp Light Distribution Controller Glare Prevention

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Solution Overview

Problem

Existing adaptive driving beam (ADB) control systems for vehicle headlamps frequently switch light distribution patterns when encountering oncoming vehicles, causing distractions to the driver due to frequent changes in light distribution, especially during multiple vehicle passes.

Innovation Solution

A light distribution controller that differentiates between preceding and oncoming vehicles by setting distinct threshold positions and switching margins, allowing for controlled light distribution adjustments based on vehicle type, reducing frequent pattern changes and glare prevention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If light distribution is switched frequently to prevent glare for oncoming vehicles, then glare prevention is improved, but driver stability and comfort deteriorate

Engineering Contradiction:
Improveglare to oncoming vehicle driverVSAvoiddriver stability and comfort
Core Design Contradiction:
Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The patent applies local quality by differentiating the response characteristics based on vehicle type: for oncoming vehicles, the system uses a larger switching margin to prevent glare, while for preceding vehicles, it uses a smaller margin to maintain stability. This localized differentiation resolves the contradiction by applying appropriate sensitivity levels to different scenarios.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically changes the switching margin parameter based on vehicle type detection. When an oncoming vehicle is detected, a larger margin is applied to prevent glare; when a preceding vehicle is detected, a smaller margin maintains stable light distribution. This parameter adaptation resolves the contradiction between glare prevention and driver comfort.

Inventive Principle:
Principle #35Parameter changes

2Speed

If light distribution follows vehicle position closely, then glare prevention responsiveness is improved, but light distribution stability deteriorates

Engineering Contradiction:
Improveresponsiveness to vehicle positionVSAvoidlight distribution stability
Core Design Contradiction:
SpeedVSStability of the object's composition

Solution Approach 1:

The patent implements dynamics by making the switching margin adaptive rather than fixed. The system adjusts the margin size based on vehicle type, creating a dynamic response characteristic that balances responsiveness and stability. This resolves the contradiction by allowing the system to be responsive when needed while maintaining stability during normal operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from vehicle type detection to adjust the switching behavior. By detecting whether a vehicle is oncoming or preceding, the system feedback-adjusts the switching margin accordingly, preventing excessive responsiveness that would cause instability while maintaining appropriate responsiveness for glare prevention.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If switching margin is reduced for frequent vehicle detection, then detection accuracy is improved, but false switching increases

Engineering Contradiction:
Improvevehicle position detection accuracyVSAvoidswitching reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by setting different switching margins for different vehicle types. For oncoming vehicles where precise positioning is critical for glare prevention, a smaller margin could be used. For preceding vehicles where stability is paramount, a larger margin prevents false switching. This localized approach resolves the contradiction between detection precision and switching reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system uses partial action by applying different levels of switching sensitivity appropriate to each vehicle type. Rather than uniformly reducing the margin for all vehicles, it selectively applies smaller margins only where necessary (oncoming vehicles), preventing false switching while maintaining detection accuracy where needed.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP2487068B1Vehicle headlamp light distribution controller
Publication Date: 2020.05.06 KOITO MFG CO LTD
  • EP2487068B1 patent drawingFigure 1
  • EP2487068B1 patent drawingFigure 2
  • EP2487068B1 patent drawingFigure 3

AI summary

A vehicle head lamp light distribution controller (100) includes an ADB controller (104) configured to: detect a position of a vehicle present ahead (CAR) of a subject vehicle; determine whether the vehicle ahead (CAR) of the subject vehicle is a preceding vehicle or an oncoming vehicle; set a threshold vehicle position (THx) based on whether the vehicle ahead (CAR) of the subject vehicle is a preceding vehicle or an oncoming vehicle; compare the threshold vehicle position (THx) and the detected vehicle position; and switch light distribution of head lamps (RHL,LHL) of the subject vehicle based on the comparison between the threshold vehicle position (THx) and the detected vehicle position.