Active Blade Tracker Using Retroreflective Markers

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Solution Overview

Problem

Existing methods for detecting the track height of rotating helicopter blades are unreliable across a wide range of environmental conditions and blade characteristics, leading to increased maintenance time and potential operational disruptions.

Innovation Solution

An active tracking device with paired emitters and detectors that emit and detect specific electromagnetic radiation, minimizing interference and providing reliable blade track height detection independent of ambient lighting and contrast.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If passive optics (photodiodes) are used to detect blade track height by sensing ambient light changes, then the system is simple and passive, but detection reliability deteriorates under varying environmental conditions and blade characteristics

Engineering Contradiction:
Improvedetection system complexityVSAvoidblade detection reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a passive retroreflective marker as an intermediary element attached to the blade. This marker actively returns emitted light to the detector, creating a reliable optical path that works consistently across all environmental conditions. The marker serves as a mediator between the active emitter and passive detector, ensuring detectability regardless of blade surface properties or ambient lighting.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs a retroreflective marker with specific optical properties that enhance contrast and detectability. The marker's reflective characteristics are engineered to return light efficiently to the detector, creating a consistent visual signal that transcends variations in ambient lighting, blade color, or environmental conditions.

Inventive Principle:
Principle #32Color changes

2Reliability

If manually intensive methods with reflective material are used to detect track height, then detection can be performed, but time consumption increases and operator experience becomes critical

Engineering Contradiction:
Improvetrack height detection capabilityVSAvoidmaintenance time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The system enables self-service operation where the automated active optical system with retroreflective markers performs blade track detection without requiring skilled operators. The system self-calibrates and automatically measures track height, eliminating dependence on operator experience and significantly reducing maintenance time while maintaining high detection reliability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical measurement methods with an automated active optical detection system. The system uses emitted light and retroreflective markers to automatically determine blade track height, substituting time-consuming manual procedures with rapid automated optical measurement that requires minimal human intervention.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Use of energy by moving object

If passive detection methods are used, then no additional energy is required, but detection fails under certain environmental conditions and blade characteristics

Engineering Contradiction:
Improveenergy consumptionVSAvoidenvironmental condition adaptability
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent employs periodic pulsed emission of light toward the rotating blade. The active emitter sends out light pulses at specific intervals, and the retroreflective marker returns these pulses to the detector. This periodic active illumination ensures consistent detection across all environmental conditions while maintaining energy efficiency through pulsed rather than continuous operation.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The retroreflective marker is designed with specific optical properties that enhance its ability to return emitted light across various wavelengths and environmental conditions. The marker's reflective characteristics are engineered to provide consistent detectability regardless of ambient lighting, blade color, or weather conditions, greatly improving environmental adaptability.

Inventive Principle:
Principle #32Color changes

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 accurate and efficient detection of blade track heights in various conditions, reducing maintenance time and allowing for seamless rotorcraft operation regardless of environmental factors.

Implementation Method 1

paired or otherwise associated with corresponding detectors located proximate to the emitters to sense, measure, or otherwise detect electromagnetic radiation that was emitted by its paired emitter and reflected back towards the tracking device

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2975427B1Active blade tracker and related systems and methods
Publication Date: 2019.10.02 HONEYWELL INTERNATIONAL INC
  • EP2975427B1 patent drawingFigure 1
  • EP2975427B1 patent drawingFigure 2

AI summary

Devices, methods and systems are provided for monitoring movement of an object (120), such as rotation of a blade (120) or other airfoil. One exemplary tracking device (102) includes a first emitter (140) to emit first radiation along a first line of sight (105), a first detector (142) proximate the first emitter (140) to detect the first radiation, a second emitter (160) to emit second radiation along a second line of sight (107), and a second detector (162) proximate the second emitter (160) to detect the second radiation.