Lidar Signal-to-Noise Ratio via Polarization Filtering

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Solution Overview

Problem

LIDAR systems face noise issues in electrical signals due to misdirected light signals, which reduce the reliability of the data generated, as these systems struggle to effectively filter out noise from the LIDAR signals.

Innovation Solution

A LIDAR system design that includes a light source with a filter to separate and filter out misdirected signals from the LIDAR path, using a polarization splitter and rotator to differentiate between LIDAR and misdirected signals based on polarization states, thereby reducing noise in the electrical signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the LIDAR system collects all reflected light signals, then the signal strength is improved, but noise from misdirected signals increases

Engineering Contradiction:
Improvesignal strengthVSAvoidnoise from misdirected signals
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts and removes misdirected signals from the optical path using a filter component. The filter is configured to block misdirected light signals while allowing the desired LIDAR return signals to pass through, thereby separating the harmful noise from the useful signal before detection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a filter as an intermediary component between the optical path and the detector. This filter acts as a mediator that selectively transmits or blocks specific light signals based on their directional properties, enabling the system to distinguish between misdirected noise and valid LIDAR returns.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If filtering components are added to remove misdirected signals, then noise is reduced, but device complexity increases

Engineering Contradiction:
Improvedata reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent integrates the filter functionality into the existing LIDAR system architecture in a way that allows a single component to serve multiple purposes: filtering misdirected signals while maintaining the optical path for valid signals. This multi-functional approach reduces the need for additional separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The filter component is designed to automatically distinguish and block misdirected signals based on their inherent directional properties without requiring external control or additional processing. The filtering action is self-contained and does not add complex control logic to the system.

Inventive Principle:
Principle #25Self-service

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 filtering of misdirected signals improves the signal-to-noise ratio, enhancing the reliability and accuracy of the LIDAR data by isolating noise from the intended LIDAR signals, leading to more precise radial velocity and distance measurements.

Implementation Method 1

using a polarization splitter and rotator to differentiate between LIDAR and misdirected signals based on polarization states

Methodology Applied
Scientific EffectPolarization: Polarisation

Implementation Method 2

The processing unit is configured to convert optical signals that include the LIDAR signal to electrical signals

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12140712B2Increasing signal-to-noise ratios in lidar systems
Publication Date: 2024.11.12 SILC TECHNOLOGIES INC
  • US12140712B2 patent drawing
  • US12140712B2 patent drawing
  • US12140712B2 patent drawing

AI summary

A LIDAR system includes a light source configured to output light. A portion of the light is included in a LIDAR signal that travels a LIDAR path from the light source to an object located outside of the LIDAR system and from the object to a filter and from the filter to a processing unit. The processing unit is configured to convert optical signals that include the LIDAR signal to electrical signals. A portion of the light is also included in one or more misdirected signals. Each of the misdirected signals travels a different misdirected path from the light source to the filter. Each of the misdirected paths is a different path from the LIDAR path. The system also includes a filter being configured to filter out the LIDAR signal from the misdirected signals. The system also includes electronics that generate LIDAR data from the electrical signals.