Headlamp Tilt Calibration Using Gravity Sensor Reference Vectors

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Solution Overview

Problem

Existing systems for adjusting the emission direction of light in vehicle headlamps struggle to easily and accurately set the orientation in the vertical direction, particularly when there are deviations in the installation of sensors.

Innovation Solution

A control device for an actuator that receives signals from a triaxial acceleration sensor attached to the lamp unit, allowing it to adjust the emission direction of light in the vertical direction by tilting the lamp unit, and a calibration method that accounts for sensor deviations by measuring inclination angles using reference vectors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a sensor is attached to the lamp unit to detect inclination angle, then the emission direction can be adjusted in the vertical direction, but measurement precision deteriorates due to sensor installation deviations

Engineering Contradiction:
Improveadjustment of emission directionVSAvoidinclination angle detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent performs preliminary calibration by detecting inclination angles at multiple predetermined positions (e.g., horizontal position and tilted positions) before actual operation. The relationship between sensor output and actual inclination angle is pre-established and stored as reference data, allowing the system to compensate for installation deviations during normal use without requiring precise initial sensor alignment.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the sensor is tilted together with the lamp unit to detect emission direction, then the system can adapt to lamp unit orientation changes, but device complexity increases

Engineering Contradiction:
Improvedetection of emission directionVSAvoidsensor mounting structure
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent merges the sensor with the lamp unit by attaching the sensor directly to the lamp unit body, ensuring they move together as a single integrated assembly. This eliminates the need for separate mounting structures and complex mechanical linkages, reducing device complexity while maintaining the ability to detect emission direction changes.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If calibration is performed at multiple predetermined positions to compensate for sensor deviations, then measurement precision is improved, but loss of time increases

Engineering Contradiction:
Improveinclination angle detection accuracyVSAvoidcalibration time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The calibration process is performed once during installation or setup as a preliminary action, and the resulting reference data is stored in memory. After calibration, the system can quickly determine actual inclination angles by comparing current sensor readings against the pre-stored reference data, eliminating the need for repeated calibration operations and minimizing time loss.

Inventive Principle:
Principle #10Preliminary action

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

Enables easy and accurate adjustment of the emission direction of light in the vertical direction, minimizing errors due to sensor installation deviations, and ensuring precise alignment with the vehicle's orientation.

Implementation Method 1

a triaxial acceleration sensor that is tilted together with the lamp unit and outputs a signal related to a vector indicating a gravity direction

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP4703205A1Control device for actuator, lamp, and calibration method for same
Publication Date: 2026.03.04 KOITO MFG CO LTD
  • EP4703205A1 patent drawingFigure 1
  • EP4703205A1 patent drawingFigure 2~3
  • EP4703205A1 patent drawingFigure 4~5

AI summary

A vehicle headlamp (1) includes: a lamp unit (15); an actuator (20) capable of tilting the lamp unit (15) such that an emission direction of light of the lamp unit (15) is inclined in a vertical direction; a sensor (71) that is tilted together with the lamp unit (15) and outputs a signal related to an inclination angle of the lamp unit (15); and a control device (72) that receives the signal from the sensor (71) and controls the actuator (20).