LiDAR Time-of-Flight Measurement with Temperature Delay Cancellation
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Solution Overview
Problem
Existing LiDAR systems suffer from inaccurate time-of-flight measurements due to environmental parameters such as temperature, humidity, and air pressure affecting temperature-sensitive devices, leading to significant measurement errors.
Innovation Solution
Implement a method that differentially processes transmission times through separate signal links, one with temperature-sensitive devices and one with non-temperature-sensitive devices, allowing for the elimination of temperature-induced delay time variations by using shared temperature-sensitive devices and pre-stored delay times of non-temperature-sensitive devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional single signal link is used for time-of-flight measurement, then device complexity is reduced, but measurement precision deteriorates due to temperature-sensitive device delays
Solution Approach 1:
The patent divides the measurement system into two separate signal links: a first signal link containing only temperature-sensitive devices (for reference signal transmission) and a second signal link containing both temperature-sensitive and non-temperature-sensitive devices (for measurement signal transmission). This segmentation allows independent characterization and compensation of temperature effects, resolving the contradiction by enabling high precision measurement through structured complexity.
Solution Approach 2:
The reference signal transmitted through the first signal link acts as an intermediary that carries information about temperature-induced delays. By comparing the reference signal's transmission time with the measurement signal's transmission time, the patent indirectly measures and compensates for temperature effects without directly measuring temperature, thus improving precision while managing device complexity.
2Measurement precision
If temperature compensation is implemented through differential measurement, then measurement precision improves, but device complexity increases due to additional signal links and processing
Solution Approach 1:
The patent performs preliminary measurement of the reference signal transmission time through the first signal link before conducting the actual time-of-flight measurement. This preliminary action characterizes the temperature-sensitive delays in advance, allowing their subtraction from the measurement signal's transmission time to isolate the target object's distance information, thereby improving precision through structured complexity.
Solution Approach 2:
The patent extracts the temperature-sensitive delay component by measuring the reference signal's transmission time through the first signal link. This extracted reference measurement is then subtracted from the measurement signal's transmission time through the second link, separating the temperature effect from the actual distance measurement and improving precision while managing processing 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
This approach enhances the accuracy of time-of-flight measurements by isolating and compensating for temperature-sensitive device delays, thereby improving measurement precision.
Implementation Method 1
emit a detection laser beam to the target object, then compare signals reflected from the target object
Implementation Method 2
The built-in photoelectric receiving device converts optical signals reflected by the target object into analog electrical signals
Data Source
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AI summary
A method and device for measuring time of flight and a LiDAR are disclosed. The method includes: S201, transmitting reference signals in a first signal link, and determining first transmission time of the reference signals in the first signal link; S202, transmitting measurement signals in a second signal link, and determining second transmission time of the measurement signals in the second signal link, wherein a shared device of the first signal link and the second signal link is a temperature-sensitive device, and a non-shared device of the first signal link and the second signal link is a non-temperature-sensitive device; S203, acquiring delay time of the non-shared device; and S204, determining time of flight corresponding to a target object according to the first transmission time, the second transmission time, and the delay time of the non-shared device. Because the shared device of the first transmission link and the second transmission link is a temperature-sensitive device, the delay time of the temperature-sensitive device can be eliminated through the differential processing of the first transmission time and second transmission time. Thus the measurement results of the time of flight are only related to the delay time of the non-temperature sensitive device, thereby reducing the problem of inaccurate measurement of time of flight of a target object caused by temperature change of a device for measuring, and improving accuracy of the measurement of the time of flight by the device for measuring.