LiDAR Angle Scanning Compensation for Rotating Mirror Mismatch
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Solution Overview
Problem
The existing light detection and ranging systems using rotating mirrors suffer from angle mismatch errors due to continuous rotation, affecting measurement accuracy and requiring two detection systems, which increase cost and size.
Innovation Solution
A light detection and ranging system that emits frequency-modulated lasers with different wavelengths in a time-division manner, using a dispersion device to compensate for angle deviations caused by the rotating mirror, allowing for accurate measurement with a single detection system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a rotating mirror is used to scan the laser beam, then the system can detect targets in different directions, but angle mismatch errors occur due to continuous rotation affecting measurement accuracy
Solution Approach 1:
The patent segments the laser beam transmission into two independent channels: a first laser transmission channel using a first rotating mirror and a second laser transmission channel using a second rotating mirror. Each channel operates independently with its own detection system, allowing the system to cover different angular ranges while maintaining measurement accuracy in each segment.
Solution Approach 2:
The patent introduces an intermediary compensation mechanism that detects and compensates for angle mismatch errors caused by the rotation of the mirrors. This intermediary system measures the actual angular deviation and adjusts the detection parameters accordingly, eliminating the measurement errors while preserving the rotating mirror's scanning capability.
2Measurement precision
If two detection systems are used to eliminate angle mismatch errors, then measurement accuracy improves, but system cost and size increase
Solution Approach 1:
The patent merges the detection functions into a single integrated detection system that can process signals from both the first and second laser transmission channels. This unified detection system eliminates the need for separate detection systems while maintaining the ability to compensate for angle mismatch errors in both channels simultaneously.
Solution Approach 2:
The single detection system is designed with multi-functionality to handle different types of laser signals and perform various measurement tasks. It can detect targets in different directions, compensate for angle mismatches, and provide accurate distance and speed measurements all through one system, reducing overall complexity.
3Measurement precision
If frequency-modulated lasers with different wavelengths are emitted in time-division manner, then angle mismatch compensation is achieved, but system complexity increases
Solution Approach 1:
The patent employs periodic time-division multiplexing to switch between the first and second laser transmission channels. The frequency-modulated lasers are emitted in alternating time periods, with each period dedicated to a specific channel. This periodic switching simplifies the control logic while enabling the system to transmit multiple laser signals without interference, facilitating accurate angle mismatch compensation.
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
The system achieves improved measurement accuracy by compensating for angle mismatches without increasing cost or size, using a single detection system.
Implementation Method 1
using a dispersion device to compensate for angle deviations caused by the rotating mirror
Implementation Method 2
a laser unit configured to emit a first signal laser and/or a second signal laser, the first signal laser and the second signal laser are frequency modulated lasers
Implementation Method 3
a light emitter configured to emit the first signal laser and/or the second signal laser
Implementation Method 4
obtain a first beat frequency signal of the first reflected laser and a second beat frequency signal of the second reflected laser
Data Source
AI summary
A light detection and ranging system is provided. The system includes: a laser unit configured to emit a first signal laser and/or a second signal laser which are frequency modulated lasers, the first signal laser has an ascending-frequency duration, the second signal laser has a descending-frequency duration, wherein wavelengths or polarization directions of the first signal laser and the second signal laser are different, and an angle scanning compensator configured to receive the first signal laser and the second signal laser in a time-division manner, and to emit the first signal laser and the second signal laser in a substantially same direction.