Off-Axis LiDAR Receiver Layout for External Light Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LIDAR devices are vulnerable to external light interference from sources other than their own, which can cause damage and generate false data points, compromising vehicle safety and autonomous operation.
Innovation Solution
Incorporating an off-axis receiver and controller to detect and mitigate external light interference by modifying sensor data, activating shutters, or adjusting emission parameters to differentiate between internal and external light sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a LIDAR device uses a standard on-axis receiver to detect reflected light, then it can accurately measure distances to environmental features, but it becomes vulnerable to external light interference from other sources which can damage the device and generate false data points
Solution Approach 1:
The receiver is segmented into two distinct detection paths: an on-axis receiver for detecting reflected LIDAR light and an off-axis receiver for detecting external light sources. This segmentation allows the system to separately monitor and differentiate between legitimate reflected light and harmful external light interference, resolving the contradiction by enabling accurate measurement while protecting against interference.
Solution Approach 2:
The off-axis receiver acts as an intermediary monitoring system that detects external light sources before they can interfere with or damage the main on-axis receiver. By providing advance warning of external light conditions, it enables the controller to take protective actions, thus mediating between the need for accurate detection and the need to prevent harmful interference.
2Reliability
If the LIDAR device activates protective measures against external light interference, then it can prevent damage and false readings, but it increases device complexity and may reduce productivity due to additional processing requirements
Solution Approach 1:
The receiver system is divided into specialized components: an on-axis receiver for primary detection and an off-axis receiver for interference monitoring. Each component has a specific function, simplifying the control logic despite the added hardware. The segmentation allows for modular design where each part handles a specific task, making the overall system manageable despite increased complexity.
Solution Approach 2:
The off-axis receiver provides self-monitoring capability that automatically detects external light conditions and triggers appropriate protective responses without requiring complex external control systems. This self-service approach reduces the burden on the main controller and simplifies the overall control architecture while maintaining high reliability.
3Reliability
If the LIDAR device continuously monitors for external light sources, then it can prevent damage and false data, but it increases energy consumption and processing overhead
Solution Approach 1:
The system employs periodic scanning with the off-axis receiver monitoring for external light sources at regular intervals rather than continuous monitoring. This periodic action reduces energy consumption while still providing effective protection, as external light sources are detected when they appear in the monitoring field of view during scan cycles.
Solution Approach 2:
The off-axis receiver performs preliminary detection of external light sources before they can affect the main detection system. By detecting potential interference early in the scanning sequence, the system can prepare protective measures in advance, reducing the need for continuous high-energy monitoring and allowing for more energy-efficient 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
Protects LIDAR devices from external light interference, ensuring accurate data collection and preventing false readings, thereby enhancing vehicle safety and autonomous operation.
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 focused light from the received lens
Implementation Method 3
a light source that emits light having a wavelength with a wavelength range
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.