Vehicle Cabin IR Light Control Based on Occupant Proximity
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Solution Overview
Problem
Conventional vehicle cabin monitoring systems using infrared (IR) or near-IR light LEDs for illumination in low-light conditions pose a safety risk due to potential eye damage from direct exposure to high-intensity IR light, especially when occupants approach the LEDs.
Innovation Solution
A vehicular cabin monitoring system that includes a camera and an electronic control unit (ECU) with image processing capabilities, which captures and processes image data to determine the illuminance of nonvisible light within a region of interest. If the illuminance exceeds a threshold, the system reduces the intensity of the nonvisible light emitted by the LEDs to prevent eye damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high-intensity IR LEDs are used for illumination in low-light conditions, then illumination capability is improved, but eye safety deteriorates due to potential eye damage from direct exposure
Solution Approach 1:
The patent applies dynamics by making the LED illumination intensity adjustable rather than fixed. The system dynamically changes the illumination intensity based on real-time detection of occupant proximity to the camera, transitioning between high-intensity mode (when no occupant is present) and low-intensity mode (when an occupant approaches), thereby resolving the contradiction between maintaining strong illumination and preventing eye damage
Solution Approach 2:
The patent implements feedback control where the illuminance sensor continuously monitors the light level in the camera's field of view and feeds this information back to the control unit. The control unit processes this feedback and adjusts the LED drive current accordingly, creating a closed-loop system that automatically maintains safe illumination levels while preserving monitoring functionality
Solution Approach 3:
The patent changes the illumination parameter (intensity) based on detected conditions. By monitoring the illuminance level and occupant proximity, the system adjusts the LED output parameter dynamically, switching between different intensity levels to balance illumination requirements with eye safety concerns
2Object-affected harmful factors
If the intensity of nonvisible light is reduced to prevent eye damage, then eye safety is improved, but monitoring functionality deteriorates due to insufficient illumination
Solution Approach 1:
The system dynamically adjusts illumination intensity based on real-time conditions rather than using a fixed low intensity. When occupants are far from the camera, the system maintains high-intensity illumination for optimal monitoring. When occupants approach within the dangerous zone, the system dynamically reduces intensity only in those specific regions, preserving monitoring functionality while preventing eye damage
Solution Approach 2:
The patent applies local quality by selectively reducing illumination intensity only in regions where occupants are detected near the camera, while maintaining high-intensity illumination in other regions of the field of view. This localized adjustment preserves monitoring functionality in safe zones while protecting occupants in dangerous zones
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 system effectively mitigates the risk of eye damage by dynamically adjusting the intensity of the IR light based on the proximity of occupants to the LEDs, ensuring safe illumination levels while maintaining optimal monitoring functionality.
Implementation Method 1
The system includes a light emitter operable to emit nonvisible light
Implementation Method 2
The camera includes an imager, and the imager includes a CMOS imaging array having at least one million photosensors
Data Source
AI summary
A vehicular cabin monitoring system includes a camera disposed within a cabin of a vehicle. Image data captured by the camera is transferred to and is processed at an electronic control unit (ECU). A light emitter that, when electrically operated to emit nonvisible light, illuminates at least a portion of the interior cabin that is viewed by the camera with nonvisible light. The vehicular cabin monitoring system, via processing at the ECU of image data captured by the camera and transferred to the ECU, determines illuminance of nonvisible light at a region of interest within the illuminated portion of the interior cabin that is viewed by the camera. The vehicular cabin monitoring system, responsive to determining that the illuminance of nonvisible light at the region of interest is greater than a threshold illuminance, reduces intensity of nonvisible light emitted by the light emitter.