Windshield Optical Sensor Calibration Using In-Situ Attenuation Measurement
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Solution Overview
Problem
Calibrating optical sensors and cameras mounted behind vehicle windshields is technically complex and costly due to varying windshield thicknesses and designs, requiring individual calibration for each type, which is not efficiently addressed by existing methods.
Innovation Solution
A method and system for calibrating optical sensors and cameras that automatically determine light attenuation values through a reference disk without manual intervention, using existing rain sensors to measure attenuation values and adjust calibration based on these values, allowing for universal calibration across different windshield types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If individual calibration is performed for each windshield type, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The calibration system performs self-calibration by automatically measuring light attenuation through the windshield using an integrated light source and sensor. The control unit calculates attenuation values and adjusts sensor readings without requiring manual calibration procedures or external reference measurements, enabling the system to adapt to different windshield types autonomously.
Solution Approach 2:
The system dynamically determines light attenuation parameters by measuring the actual windshield properties in situ. Instead of using fixed calibration values for different windshield types, the system measures the actual attenuation coefficient through the installed windshield and uses this measured parameter to calibrate the optical sensor, adapting to variations in windshield thickness and material.
2Measurement precision
If manual calibration procedures are used, then calibration accuracy can be achieved, but ease of operation deteriorates
Solution Approach 1:
The calibration system performs self-calibration by automatically measuring light attenuation through the windshield using an integrated light source and sensor. The control unit calculates attenuation values and adjusts sensor readings without requiring manual calibration procedures or external reference measurements, enabling the system to adapt to different windshield types autonomously.
Solution Approach 2:
The system replaces manual mechanical calibration procedures with an automated optical measurement system. Instead of requiring physical adjustment of sensor components or manual input of calibration data, the system uses electronic control to automatically measure attenuation and adjust sensor readings through software algorithms in the control unit.
3Device complexity
If existing rain sensors are utilized for calibration, then device complexity is reduced, but measurement precision may be compromised
Solution Approach 1:
The rain sensor is designed to serve dual functions: its original function of detecting rain on the windshield and a calibration function for measuring light attenuation through the windshield. By utilizing the existing sensor's light detection capability for both purposes, the system eliminates the need for separate calibration sensors while maintaining measurement accuracy through proper calibration algorithms in the control unit.
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 simple, cost-effective, and reliable automatic calibration of optical sensors and cameras, eliminating the need for manual calibration and windshield-specific data, while ensuring accurate light detection regardless of windshield variations.
Implementation Method 1
a light emitting device for emitting a light beam (84) into the second disk (50); a light receiver for receiving the light beam (86) reflected at the second side (54)
Implementation Method 2
the windshields have varying thicknesses and designs (angles of inclination), and ambient light or light from outside is attenuated to varying degrees by the windshield
Data Source
Figure 1
Figure 2
AI summary
A method for calibrating an optical sensor and/or camera for a motor vehicle, wherein the optical sensor and/or camera detects ambient light through a first disk (10) for the motor vehicle, the method comprising the following steps: receiving a first attenuation value of a first reference light beam reflected in a second disk (50) for a motor vehicle; receiving a second attenuation value of a second reference light beam passing through the second disk (50); sending a measuring light beam from a first side (12) of the first disk (10) into the first disk (10); receiving the measuring light beam reflected in the first disk (10) on the first side (12) of the first disk (10); determining a third attenuation value of the measuring light beam in the first disk (10) based on the sent measuring light beam and the received measuring light beam;and calibrating the optical sensor and/or camera based on the first attenuation value of the second disk (50), the second attenuation value of the second disk (50) and the third attenuation value of the first disk (10).;