Off-Axis LiDAR Receiver for External Light Interference Filtering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR devices face interference and potential damage from external light sources, leading to false data points and operational issues, as they are unable to differentiate between their own emitted light and external light, which can originate from other devices or sources.
Innovation Solution
Incorporating an offset light detector positioned outside the predefined optical path to detect external light with similar optical characteristics, allowing the controller to modify sensor data, adjust mechanical operations, or change the emitted light's modulation to differentiate it from external light, thereby protecting the LIDAR device's operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a LIDAR device uses a single optical path for both transmitting and receiving light, then the device structure is simple, but it cannot differentiate between emitted light and external light causing interference
Solution Approach 1:
The patent divides the optical detection system into two separate optical paths: a first optical path for receiving reflected emitted light, and a second optical path for detecting external light. This segmentation allows the system to independently process and differentiate between light from the LIDAR device and external light sources, resolving the contradiction between structural simplicity and light source differentiation capability.
Solution Approach 2:
The patent introduces an offset light detector as an intermediary component positioned outside the predefined optical path. This intermediary detector specifically monitors for external light without interfering with the primary LIDAR measurement path, enabling the system to identify and filter external light interference while maintaining the simplicity of the main optical path.
2Device complexity
If the LIDAR device receives all incoming light through a single receiver, then the receiver structure is simple, but it cannot identify external light sources causing false data points
Solution Approach 1:
The receiver is segmented into multiple detection channels: a first light detector for receiving reflected light along the first optical path, and a second light detector (offset light detector) for detecting external light along the second optical path. This segmentation enables the system to distinguish between valid LIDAR returns and external light interference, improving measurement precision without excessive structural complexity.
Solution Approach 2:
The offset light detector is positioned at a specific location outside the predefined optical path where it can selectively detect external light while remaining insensitive to the LIDAR's emitted light. This local positioning gives the detector specialized functionality for external light detection, enabling accurate identification of interference sources while maintaining overall receiver simplicity.
3Device complexity
If the LIDAR device operates without external light detection capability, then the operational complexity is low, but it cannot mitigate interference from external light sources
Solution Approach 1:
The system implements a feedback mechanism where the offset light detector continuously monitors for external light and provides information to the controller. When external light is detected, the controller adjusts the LIDAR operation accordingly, such as filtering affected data points or adjusting transmission timing. This feedback loop enables automatic mitigation of external light interference without requiring complex manual intervention.
Solution Approach 2:
The offset light detector performs preliminary detection of external light sources before they can significantly interfere with LIDAR measurements. By detecting external light in advance, the system can proactively adjust its operation or filter potential erroneous data points, preventing interference issues rather than reacting to them after they occur.
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
Effectively mitigates interference from external light sources by accurately distinguishing and filtering out erroneous data, ensuring reliable operation and preventing damage to the LIDAR device.
Implementation Method 1
a receive lens that receives light from the environment, and focuses at least a portion of the received light along a predefined optical path
Implementation Method 2
an offset light detector positioned outside the predefined optical path to intercept and detect light propagating toward the LIDAR device
Data Source
AI summary
In one example, a LIDAR device includes a light sources that emits light and a transmit lens that directs the emitted light to illuminate a region of an environment with a field-of-view defined by the transmit lens. The LIDAR device also includes a receive lens that focuses at least a portion of incoming light propagating from the illuminated region of the environment along a predefined optical path. The LIDAR device also includes an array of light detectors positioned along the predefined optical path. The LIDAR device also includes an offset light detector positioned outside the predefined optical path. The LIDAR device also includes a controller that determines whether collected sensor data from the array of light detectors includes data associated with another light source different than the light source of the device based on output from the offset light detector.