Single Laser FMCW LIDAR Multipath Mitigation
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Solution Overview
Problem
Existing LIDAR systems using multiple lasers face issues with range and velocity estimation due to multipath effects and interference, and are costly and difficult to maintain, necessitating a more efficient and cost-effective solution.
Innovation Solution
A single laser Frequency Modulated Continuous-Wave (FMCW) LIDAR system that employs improved processing techniques, including spectral analysis and optical amplification, to mitigate multipath effects and enhance Signal-to-Noise Ratio (SNR), allowing for accurate range and velocity estimates without the need for simultaneous counter-chirp measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple lasers are used in a LIDAR system, then range and velocity estimation capability is improved, but system cost and complexity increase
Solution Approach 1:
The patent combines multiple laser functions into a single laser source by using optical switching to alternate between different laser wavelengths. This merging approach maintains the capability to perform multi-wavelength LIDAR measurements while reducing system complexity and cost associated with operating multiple simultaneous laser sources.
Solution Approach 2:
The single laser source is designed to perform multiple functions by emitting at different wavelengths at different times. The laser system becomes universal, capable of performing measurements that traditionally required multiple specialized laser sources, thereby reducing overall system complexity while maintaining measurement precision.
2Measurement precision
If multiple lasers are used in a LIDAR system, then measurement capability is improved, but maintenance difficulty increases
Solution Approach 1:
By merging multiple laser functions into a single laser source with optical switching, the system reduces the number of laser components that require maintenance. This consolidation makes the system easier to maintain while preserving the measurement capabilities that would otherwise require multiple lasers.
3Reliability
If spectral analysis processing is used, then multipath effects are mitigated and SNR is improved, but processing complexity increases
Solution Approach 1:
The patent replaces complex hardware-based signal filtering mechanisms with software-based spectral analysis processing. This substitution allows for sophisticated signal processing to mitigate multipath effects and improve SNR while avoiding the need for additional complex physical components, thereby managing processing complexity through computational methods.
4Power
If optical amplification is used, then increased optical power is achieved, but system complexity increases
Solution Approach 1:
The patent introduces an optical amplifier as an intermediary component that boosts the optical signal power without requiring fundamental changes to the laser source or detector system. This mediator approach allows for increased optical power while maintaining relative system simplicity by adding a single functional component rather than redesigning the entire system.
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 higher measurement rates, increased optical power, and improved SNR, reducing the impact of acceleration on velocity measurements and providing accurate range and velocity estimates while maintaining safe operating limits, thus overcoming the limitations of multi-laser systems.
Implementation Method 1
producing emitted electromagnetic radiation based on a frequency pattern
Implementation Method 2
defining combined frequency data based on a frequency of the emitted electromagnetic radiation and a frequency of the reflected electromagnetic radiation
Implementation Method 3
defining a set of spectral bins, based on a Fourier transform, in a frequency domain based on the combined frequency data
Data Source
AI summary
In one general aspect, a non-transitory computer-readable storage medium storing instructions that when executed cause one or more processors to perform a process. The process can include producing emitted electromagnetic radiation based on a frequency pattern and receiving reflected electromagnetic radiation reflected from an object. The process can include defining combined frequency data based on a frequency of the emitted electromagnetic radiation and a frequency of the reflected electromagnetic radiation. The process can also include defining a set of spectral bins, based on a Fourier transform, in a frequency domain based on the combined frequency data, and can include identifying a subset of the set of spectral bins.