LiDAR Optical Phased Array Distance Measurement
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Solution Overview
Problem
Existing LiDAR devices face challenges in accurately measuring the time of flight (ToF) of light in noisy environments or when the target signal is weak, which affects the precision of depth image processing.
Innovation Solution
A LiDAR device utilizing an optical phased array to modulate light, with a processor determining distance based on the cross-correlation between a reference signal and a target signal, and employing a waveguide and photodetectors to enhance signal detection and processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional LiDAR devices use simple light transmission and reception, then the device structure is simple, but the measurement precision deteriorates in noisy environments or when target signals are weak
Solution Approach 1:
The patent introduces a reference signal as an intermediary element that is correlated with the target signal. This reference signal serves as a mediator to enhance the detection of weak signals in noisy environments by providing a template for correlation analysis, thereby improving ToF measurement precision without requiring complex signal processing algorithms alone
Solution Approach 2:
The patent employs correlation analysis that uses the reference signal (which contains information about the transmitted light characteristics) to feedback and verify the target signal detection. This feedback mechanism allows the system to continuously adjust and improve measurement accuracy by comparing the received target signal against the expected reference pattern
2Measurement precision
If LiDAR devices increase signal detection sensitivity, then measurement precision improves, but the device complexity increases due to additional photodetectors and signal processing
Solution Approach 1:
The patent designs the optical phased array to serve multiple functions: it acts as both the light transmission element and the reference signal generator. The same array that transmits the target signal also generates the reference signal by receiving light back through the array, thereby improving distance measurement accuracy without requiring separate dedicated components for reference signal generation
Solution Approach 2:
The patent merges the transmission and reception functions into a single optical phased array system. The array transmits light to the target and simultaneously receives the reflected light to generate the reference signal, combining what would traditionally be separate transmitting and receiving systems into one integrated component, thus reducing overall device complexity while maintaining high measurement precision
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
Improves the accuracy of distance measurement even in noisy conditions by using cross-correlation analysis of reference and target signals, reducing errors and enhancing precision in determining the ToF of light.
Implementation Method 1
an optical phased array configured to modulate a phase of light incident on the optical phased array and emit the light
Implementation Method 2
a first photodetector configured to detect, as a reference light, the light emitted from the optical phased array and generate a reference signal based on the reference light
Implementation Method 3
a waveguide configured to receive the reference light from the optical phased array and output the reference light to the first photodetector
Implementation Method 4
A basic operation principle for LiDAR devices is a time of flight (ToF) of light
Implementation Method 5
a processor configured to determine a distance between the LiDAR device and the object based on a cross-correlation between the reference signal and the target signal
Data Source
AI summary
A light detection and ranging (LiDAR) device may include: an optical phased array configured to modulate a phase of light incident on the optical phased array and emit the light; a first photodetector configured to detect, as a reference light, the light emitted from the optical phased array in a first direction toward the first photodetector, and generate a reference signal based on the reference light; a second photodetector configured to detect, as a target light including information about an object, the light emitted from the optical phased array in a second direction toward the object, and generate a target signal based on the target light; and a processor configured to determine a distance between the LiDAR device and the object based on a cross-correlation between the reference signal and the target signal.