LiDAR Distance Measurement with Alternating Laser Sources
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Solution Overview
Problem
LiDAR apparatuses using multiple light sources face reduced frame rates when measuring distances, leading to decreased measurement quality due to interference and the need for separate time periods for each light source.
Innovation Solution
A LiDAR apparatus and method that alternates irradiation times of different light sources based on light quantity accumulation values to manage frame rates efficiently, using a plane light source for short-distance and a line light source for long-distance measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple light sources are used to measure distances, then measurement quality is improved, but frame rate is reduced
Solution Approach 1:
The patent applies periodic action by alternating between different light sources in a time-division multiplexing scheme. The controller sequentially activates the first light source for short-distance measurement and the second light source for long-distance measurement within each frame period, allowing both measurements to be performed without continuous simultaneous operation. This periodic switching resolves the contradiction by enabling multiple light sources to contribute to measurement quality while maintaining the frame rate through efficient time management.
2Loss of information
If multiple light sources are used to measure distances, then comprehensive distance information is acquired, but light interference occurs
Solution Approach 1:
The patent extracts the harmful light interference by separating the operation of multiple light sources in time. Instead of having multiple light sources operate simultaneously which causes interference, the controller extracts each light source's operation into distinct time slots within the frame period. The first light source operates during a first time period and the second light source operates during a second time period, ensuring that their light paths do not interfere with each other while still providing comprehensive distance information.
3Object-affected harmful factors
If separate time periods are allocated for each light source, then light interference is prevented, but frame rate is reduced
Solution Approach 1:
The patent applies dynamics by making the time period allocation adaptive rather than fixed. The controller dynamically adjusts the duration of the first time period and second time period based on the specific measurement requirements, object distances, and light source characteristics. This dynamic time management allows the system to prevent light interference through separate time periods while optimizing the total frame period duration to maintain high frame rates, resolving the contradiction between interference prevention and productivity.
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
Maintains frame rate efficiency by simultaneously acquiring short- and long-distance information within a single unit frame time period, preventing light interference and enhancing measurement quality.
Implementation Method 1
receiving a first reflected laser light of the first laser light reflected from a first object located around the LiDAR apparatus
Implementation Method 2
receiving a first reflected laser light of the first laser light reflected from a first object located around the LiDAR apparatus, by using an optical sensor of the LiDAR apparatus
Implementation Method 3
measuring a time taken for the irradiated laser light to be reflected from the object and then returned
Data Source
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AI summary
A method of acquiring distance information of an object by using a LiDAR apparatus includes: irradiating first laser light of a first type for a first time period; receiving first reflected laser light of the first laser light; irradiating second laser light of a second type for a second time period following the first time period; receiving second reflected laser light of the second laser light; and acquiring an image frame including distance information representing a distance between the LiDAR apparatus and a first object and distance information representing a distance between the LiDAR apparatus and a second object, based on the first reflected laser light and the second reflected laser light.