Dynamic Filter Wheel for Lidar Background Radiation
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Solution Overview
Problem
Current lidar systems face performance degradation and potential damage due to background photons from ambient light, especially in high solar irradiation conditions, leading to noise interference and reduced availability.
Innovation Solution
A lidar system equipped with a movable intensity filter, such as a static gray or reflection filter, positioned in front of the detector to selectively absorb background radiation, allowing for dynamic adjustment based on ambient light conditions and object distance, thereby reducing interfering background light and enhancing system performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a narrow-band static optical filter is used to filter background photons, then the filter structure is simple, but the filtering effectiveness is insufficient and background noise remains high
Solution Approach 1:
The patent introduces a dynamic filter wheel mechanism that can rotate to position different optical filters (including narrow-band and broad-band filters) in the optical path. This dynamic configuration allows the system to adapt filtering characteristics to different operating conditions, resolving the contradiction between simple structure and effective filtering by making the filter selection adaptive rather than fixed.
Solution Approach 2:
The patent divides the filtering function into multiple segments by providing several different filters (narrow-band filters with different central wavelengths, broad-band filters) on the filter wheel. Each filter segment addresses specific filtering needs, and the system can select the appropriate segment based on the laser wavelength and background light conditions, thereby achieving comprehensive filtering effectiveness.
2Device complexity
If no intensity filter is used, then the system structure is simple, but the detector is damaged by high solar irradiation and background photons
Solution Approach 1:
The patent introduces an intensity filter (such as a neutral density filter or reflection filter) as an intermediary element in the optical path. This filter acts as a mediator that attenuates intense background light and solar irradiation before the light reaches the detector, thereby protecting the detector from damage while allowing the detection of reflected laser signals. The filter wheel mechanism enables dynamic insertion or removal of this protective intermediary based on lighting conditions.
3Object-affected harmful factors
If an intensity filter is added to protect the detector, then the detector is protected from damage, but the system complexity increases
Solution Approach 1:
The patent merges the intensity filtering function with the existing narrow-band filtering function by integrating both types of filters onto the same filter wheel mechanism. This combined approach allows the system to achieve both detector protection (through intensity filtering) and wavelength selection (through narrow-band filtering) using a single integrated component, thereby minimizing the increase in system complexity while maximizing protective and filtering effectiveness.
4Adaptability or versatility
If a dynamic filter wheel with multiple filters is used, then the filtering adaptability is improved, but the device complexity and cost increase
Solution Approach 1:
The patent designs the filter wheel mechanism to serve multiple functions: it provides both narrow-band wavelength filtering and broad-band intensity filtering, and can be rotated to select different filters based on operating conditions. This multi-functional design allows a single mechanism to handle various filtering requirements (different laser wavelengths, different background light conditions), thereby achieving high adaptability without proportionally increasing system complexity.
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 significantly improves the lidar system's availability and accuracy by effectively filtering out background light, preventing damage from high solar irradiation and maintaining performance across varying light conditions, thus ensuring reliable object detection and range extension.
Implementation Method 1
the at least one first filter being designed as an intensity filter for specifically absorbing background radiation
Data Source
AI summary
A lidar system is described for a vehicle for scanning a surrounding area of the vehicle using laser beams, including a transmitting device having a laser beam source which is designed to emit laser beams into the surrounding area of the vehicle, a receiving device having at least one detector for detecting the laser beams reflected in the surrounding area and having at least one first filter that is connectible in front of the detector, whereinthe at least one first filter is designed as an intensity filter for specifically absorbing background radiation. A method for operating a lidar system and a computer program are also described.