Headlamp Optical Axis Control Using MEMS Gyroscope Feedback
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Solution Overview
Problem
Current headlight systems, especially high-resolution matrix systems, are susceptible to changes in the angular position of the optical axis relative to the road due to vehicle dynamics, leading to disruptions in light distribution and glare issues.
Innovation Solution
The use of MEMS gyroscopes to determine angular velocities and adjust the optical axis of headlights, ensuring it remains constant relative to the road by integrating angular velocity signals and applying control variables through a control unit, allowing for precise compensation of high-frequency vibrations and uneven road influences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-resolution matrix headlight systems are used to provide precise light distribution and projected light elements, then illumination precision and driver assistance capability are improved, but susceptibility to changes in angular position of the optical axis due to vehicle dynamics increases
Solution Approach 1:
The patent implements a feedback control system where a MEMS gyroscope continuously measures angular velocity of the vehicle, the control unit integrates these measurements to determine angular position changes, and the system automatically adjusts the optical axis position to compensate for detected movements. This closed-loop feedback mechanism maintains optical axis stability despite vehicle dynamics, directly resolving the contradiction between high-resolution lighting and susceptibility to positional changes.
Solution Approach 2:
The patent replaces traditional mechanical suspension-based angular position sensing with a MEMS gyroscope-based inertial measurement system. This substitution provides more accurate and responsive detection of angular velocity and position changes, enabling better compensation for optical axis deviations caused by vehicle dynamics, thereby maintaining reliability while preserving the high-resolution lighting capability.
2Device complexity
If manual adjustment or predetermined adjustment methods are used for headlight optical axis, then device complexity is reduced, but adjustment precision and responsiveness to vehicle dynamics deteriorates
Solution Approach 1:
The patent implements a self-adjusting system where the headlight assembly automatically compensates for angular position deviations without requiring manual intervention. The MEMS gyroscope continuously monitors vehicle dynamics, and the control unit autonomously adjusts the optical axis position in real-time, providing precise adaptation to changing conditions while eliminating the need for complex manual adjustment mechanisms.
3Measurement precision
If axle height sensors are used to determine vehicle inclination, then measurement capability is provided, but response delay increases due to distance from headlights and vehicle bus system connectivity
Solution Approach 1:
The patent introduces a MEMS gyroscope as an intermediary sensing element positioned close to the headlight assembly. This intermediary device directly measures angular velocity at the location where compensation is needed, eliminating the time delay associated with transmitting data from distant axle height sensors through the vehicle bus system. The local measurement enables immediate compensation response.
Solution Approach 2:
The MEMS gyroscope continuously measures angular velocity and the control unit integrates these measurements in advance to predict and compensate for optical axis position changes before they significantly affect the light distribution. This preliminary action approach reduces the effective response delay by maintaining constant readiness to compensate.
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
This solution provides precise and rapid adjustment of the optical axis, minimizing disruptions in light distribution and maintaining clear projection of symbols or markings on the road, even during vehicle movements, thus enhancing the reliability of high-resolution headlight systems.
Implementation Method 1
determine an actual angular position of an optical axis of a headlight of the motor vehicle relative to a road surface by means of an at least single-axis MEMS gyroscope
Implementation Method 2
adjustment of a desired angular position of the optical axis of the light module by means of a control unit as a function of an angular velocity determined by the at least single-axis MEMS gyroscope
Data Source
Figure 1
Figure 2
Figure 3a~3d
AI summary
The invention relates to a method for adjusting an angular position (Θ) of the optical axis (12) of a headlamp (14) of a motor vehicle (1), wherein the optical axis (12) of the headlamp (14) is adjusted relative to the road (16) depending on an actual angular position (Θ) of the headlamp (14). The method is characterised in that the actual angular position (Θ) is determined depending on an angular velocity (ω) of the optical axis (12), wherein the angular velocity (ω) of the optical axis (12) is determined by means of an at least single-axis MEMS gyroscope (2) that is secured in relation to the headlamp (14).