Coherent Light Vibration Detection via Pixelated Detector

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Solution Overview

Problem

Current vibration sensing methods, such as speckle interferometry, require scanning the scene to detect vibrations, which is time-consuming and inefficient for capturing vibrations across an entire field of view.

Innovation Solution

A system utilizing coherent light to illuminate a scene, focusing scattered light onto a pixelated detector, and analyzing pixel intensity signals to derive a vibration spectrum across the entire field of view, eliminating the need for scanning through the use of a processing unit that applies Fourier transforms and wavelet analyses, and enhancing signal modulation with a spatially patterned mask.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If speckle interferometry is used to detect vibrations, then vibration detection capability is achieved, but scanning is required which makes the process time-consuming

Engineering Contradiction:
Improvevibration detection capabilityVSAvoidtime-consuming scanning
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the scene into multiple regions of interest (ROIs) and processes them simultaneously using a pixelated detector array. Each pixel or pixel group corresponds to a specific scene element, allowing parallel vibration analysis across the entire field of view without sequential scanning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from one-dimensional sequential scanning to two-dimensional simultaneous detection by mapping the scene onto a pixelated detector plane. This spatial dimensionality enables all ROIs to be monitored concurrently, eliminating the time loss associated with scanning through the scene.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If scanning is used to detect vibrations across the scene, then comprehensive vibration coverage is achieved, but detection efficiency is reduced

Engineering Contradiction:
Improvecoverage areaVSAvoiddetection efficiency
Core Design Contradiction:
Area of stationary objectVSProductivity

Solution Approach 1:

The scene is divided into multiple independent ROIs that can be processed simultaneously. Each ROI is assigned to specific detector pixels, enabling comprehensive area coverage while maintaining high detection efficiency through parallel processing of all regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges multiple ROI detections into a single simultaneous measurement process. By combining the detection capabilities across all detector pixels, the system achieves both comprehensive scene coverage and high productivity without requiring sequential scanning.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If coherent light is used to illuminate the scene, then vibration signal detection is enabled, but signal modulation is weak requiring enhancement

Engineering Contradiction:
Improvevibration signal detectionVSAvoidsignal enhancement requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a spatially patterned mask as an intermediary element between the coherent light source and the scene. This mask modulates the light field to enhance the vibration signal contrast, making vibration detection more sensitive without requiring complex signal processing or additional active enhancement components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables simultaneous quantitative measurements of vibrations across the entire scene, providing a map of vibration amplitudes and frequencies, and allowing for the identification of vibrating objects, while improving sensitivity and reducing the need for scanning, thus enhancing the efficiency of vibration detection.

Implementation Method 1

The scattering of different portions of the light beam from the rough surface results in a random shift of the phases of the portions of the corresponding light waves and a random distribution of the intensities thereof. Consequently, the beam portions scattered from different surface portions interfere with each other, resulting in a light distribution with varying intensity in space.

Methodology Applied
Scientific EffectInterference: Interference

Implementation Method 2

The incident laser beam diffusively reflects therefrom. The scattering of different portions of the light beam from the rough surface results in a random shift of the phases of the portions of the corresponding light waves and a random distribution of the intensities thereof.

Methodology Applied
Scientific EffectSpeckle pattern formation: Scattering

Implementation Method 3

an optical unit configured to focus scattered light from the scene onto a pixelated detector

Methodology Applied
Scientific EffectFocusing: Focusing

Data Source

PatentEP3504524B1Optical detection of vibrations
Publication Date: 2021.04.07 ELBIT SYST LAND & C4I LTD
  • EP3504524B1 patent drawingFigure 1A
  • EP3504524B1 patent drawingFigure 1B
  • EP3504524B1 patent drawingFigure 2A~2B

AI summary

Systems and methods are provided for vibrations detection in a scene. Systems comprise at least one coherent light source configured to illuminate the scene, an optical unit configured to focus scattered light from the scene onto a pixelated detector, the detector configured to provide pixel intensity signals, and a processing unit configured to analyze the pixel intensity signals over the pixels of the detector to derive a vibration spectrum of elements in the scene that correspond to the pixels. The signal modulation at each pixel may be used to indicate the vibrations of the scene element(s) that corresponds to the pixel(s). Vibration information concerning the scene may be used to direct other methods of vibration measurements, such as speckle interferometry, according to derived vibration images of the scene.