Variable-Transmission Screen Glare Control for Driving Assistance
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Solution Overview
Problem
Existing driving aid devices for motor vehicles reduce the perception of non-dazzling external light sources and consume excessive electrical power due to inefficiencies in pulsed lighting, while also failing to adequately address glare issues both day and night.
Innovation Solution
A driving aid device with a screen of variable transmission, equipped with glare evaluation means, adjusts its transparency and lighting control using pulsed signals to optimize illumination and reduce power consumption, ensuring minimal dazzle and maintaining external brightness perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If pulsed lighting is used to reduce dazzle and synchronize with variable transmission screen, then dazzle to other vehicles is reduced, but driver's perception of non-dazzling external light sources is reduced and electrical power consumption increases
Solution Approach 1:
The system uses a glare sensor to detect actual glare conditions and provides feedback to the control unit, which adjusts the duty cycle of the pulsed lighting and screen transmission accordingly. This feedback mechanism allows the system to operate in continuous mode when glare is absent (reducing power consumption) and switch to pulsed mode when glare is detected (reducing dazzle to other vehicles).
Solution Approach 2:
The system dynamically adjusts the duty cycle of both the lighting device and variable transmission screen based on real-time glare measurements. The duty cycle varies from 0% to 100% depending on glare intensity, allowing optimal balance between reducing dazzle and maintaining efficient power consumption under different driving conditions.
2Object-affected harmful factors
If variable transmission screen is permanently set to reduce transparency, then dazzle from external light sources is reduced, but driver's perception of external brightness is reduced
Solution Approach 1:
The system uses periodic pulsed lighting synchronized with periodic adjustment of the variable transmission screen's transparency. The screen transitions between transparent and opaque states in sync with the lighting pulses, allowing full external brightness perception during illumination phases while blocking glare during non-illumination phases.
Solution Approach 2:
The glare sensor continuously monitors external light conditions and provides feedback to dynamically adjust the screen's transmission coefficient. The screen transparency is adjusted based on actual glare levels rather than being permanently reduced, maintaining external brightness perception when glare is absent while reducing dazzle when glare is present.
3Illumination intensity
If pulsed lighting operates at higher currents, then illumination intensity is increased, but light source efficiency decreases and power consumption increases
Solution Approach 1:
The system changes the duty cycle parameter of the pulsed lighting to optimize the balance between illumination intensity and power consumption. By adjusting the duty cycle based on glare conditions and ambient light levels, the system achieves required illumination while minimizing power consumption and avoiding the efficiency losses associated with high-current pulsed operation.
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
The solution effectively reduces dazzle from external light sources while maintaining optimal brightness perception and minimizing electrical power usage, ensuring improved driver comfort and safety under various luminosity conditions.
Implementation Method 1
a screen with variable transmission, intended to be placed between a road scene and a driver of the vehicle, said aid device being configured for, in an active phase, to control a coefficient of transmission of the screen with variable transmission
Implementation Method 2
the vehicle being equipped with at least one lighting device capable of emitting a beam for illuminating the road scene in front of the vehicle, said aid device is configured to, in the active phase, to drive switching on at least one light source of the lighting device and said transmission coefficient of the screen with variable transmission, in relation to one another, by a pulsed signal
Implementation Method 3
the said device comprises means for evaluating, in particular for measuring, glare and is furthermore configured to modify the coefficient of transmission of the screen with variable transmission as a function of the glare measured by the glare evaluation means
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a driving assistance device for a motor vehicle (20), including a variable-transmittance display (26; 28; F) arranged between a road scene (SR) and a driver (24) of the vehicle, said assistance device being configured to, in an active phase, control a transmission factor of the variable-transmittance display (26; 28; F). The device includes a means for evaluating glare and is furthermore configured to modify the transmission factor of the variable-transmittance display (26; 28; F) depending on the glare measured by the means for evaluating glare.