Dual-Mode Illuminator for Optical Tracking

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Optical tracking systems face challenges in accurately imaging fiducials under varying lighting conditions, particularly when direct sunlight interferes with image capture and nighttime conditions require additional illumination to detect passive targets.

Innovation Solution

A dual-mode illuminator that uses different wavelengths of light under different lighting conditions, with LEDs for daytime illumination and VCSELs or LEDs for nighttime illumination, ensuring compatibility with Night Vision Goggles (NVGs and adjusting exposure times to optimize image capture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single illuminator is used for both daytime and nighttime imaging, then device complexity is reduced, but imaging accuracy deteriorates under varying lighting conditions

Engineering Contradiction:
Improveilluminator structureVSAvoidtarget imaging accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The illuminator is segmented into two independent light sources: a visible light illuminator for daytime operation and an infrared illuminator for nighttime operation. Each illuminator is optimized for its specific lighting condition, allowing the system to maintain high imaging accuracy across different environments without requiring a complex multi-functional single illuminator.

Inventive Principle:
Principle #1Segmentation

2Illumination intensity

If visible light illuminator is used during nighttime, then illumination intensity is sufficient, but it interferes with Night Vision Goggle compatibility

Engineering Contradiction:
Improvenighttime illuminationVSAvoidNVG compatibility interference
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

The illumination quality is made local to the operating conditions: visible light illuminator operates only during daytime when NVGs are not used, while the infrared illuminator operates during nighttime when NVGs are used. This spatial and temporal separation of illumination types eliminates NVG compatibility interference while maintaining sufficient illumination intensity for each operating mode.

Inventive Principle:
Principle #3Local quality

3Object-affected harmful factors

If infrared illuminator is used during daytime, then NVG compatibility is maintained, but sunlight interference prevents accurate target imaging

Engineering Contradiction:
ImproveNVG compatibilityVSAvoidtarget detection accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The system dynamically switches between visible light and infrared illuminators based on ambient lighting conditions detected by a sensor. During daytime, the visible light illuminator is activated to provide sufficient illumination that overcomes sunlight interference. During nighttime, the infrared illuminator is activated to maintain NVG compatibility. This dynamic adaptation resolves the contradiction between NVG compatibility and target detection accuracy.

Inventive Principle:
Principle #15Dynamics

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 dual-mode illuminator provides sufficient and NVG-compatible illumination for passive fiducial markers, effectively rejecting sunlight interference and ensuring accurate image capture in both daylight and nighttime conditions, enhancing the reliability of optical tracking systems.

Implementation Method 1

an illuminator including a vertical-cavity surface-emitting laser (VCSEL) emitter

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

a plurality of light-emitting diodes (LEDs)

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 3

a sensor configured to image the at least one fiducial marker while the illuminator illuminates the fiducial marker

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP3786686B1Dual-mode illuminator for imaging under different lighting conditions
Publication Date: 2022.03.16 THALES DEFENSE & SECURITY INC
  • EP3786686B1 patent drawingFigure 1
  • EP3786686B1 patent drawingFigure 2
  • EP3786686B1 patent drawingFigure 3

AI summary

An apparatus, system, and method for dual mode imaging under different lighting conditions. A sensor is configured to image a target. A dual-mode illumination source is configured to illuminate the target while the sensor images the target. The dual-mode illumination source is configured to illuminate the target using a first wavelength of light under a first lighting condition and to illuminate the target using a second wavelength of light under a second lighting condition. The system may be used in an optical tracking system to track the motion of an object.