LiDAR Hazardous-Beam Indication with Coaxial Visible Warning

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Solution Overview

Problem

Airborne LIDAR systems using invisible near-infrared light beams pose an eye hazard to ground crews servicing aircraft, as the light is not visible and can cause eye damage without automatic blink reflexes or pupil constrictions.

Innovation Solution

The system incorporates a visible light generator to project a visible light indicating beam that surrounds and encompasses the invisible light beam, ensuring that ground crews are alerted to the presence of the hazardous invisible light beam.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If invisible near-infrared light is used for LIDAR measurements, then low observability and low-cost optical components are achieved, but eye hazard to ground crews increases

Engineering Contradiction:

Improvevisibility of transmitted lightVSAvoideye hazard to ground crews

Core Design Contradiction:

Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

A visible light indicating beam is introduced as an intermediary element that mediates between the invisible hazardous beam and ground crew safety. The visible beam serves as a warning signal without interfering with the measurement function of the invisible beam, thus resolving the contradiction between invisibility and eye safety.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light beam is given different local qualities along its path: the core remains invisible near-infrared for measurement, while a surrounding visible component is added for safety indication. This spatial differentiation of light properties allows simultaneous achievement of low observability and eye hazard prevention.

Inventive Principle:

Principle #3Local quality

2Reliability

If invisible light beam is used, then automatic blink reflex and pupil constriction cannot be triggered, but measurement function is maintained

Engineering Contradiction:

Improveautomatic eye protection reflexVSAvoidcloud metrics measurement capability

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The light beam is segmented into two functional components: an invisible near-infrared core for measurement and a visible surrounding beam for safety indication. This segmentation allows each component to fulfill its specific function independently - the invisible core maintains measurement precision while the visible component triggers automatic eye protection reflexes.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The visible light component acts as an intermediary that triggers protective reflexes without interfering with the measurement function. It provides the safety warning needed to prevent eye damage while allowing the invisible measurement beam to operate effectively.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If visible light is used to warn ground crews, then eye hazard is reduced, but light beam visibility interferes with low observability requirement

Engineering Contradiction:

Improveeye hazard levelVSAvoidvisibility of transmitted light

Core Design Contradiction:

Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

Different portions of the light beam are assigned different visibility qualities: the core remains invisible for low observability, while a surrounding visible component provides hazard warning. This local differentiation resolves the contradiction between maintaining invisibility and providing safety warnings.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The light beam is constructed as a composite of two wavelengths: invisible near-infrared for measurement and visible light for warning. This composite structure allows simultaneous achievement of low observability and eye hazard reduction by combining the properties of both light types in a single beam system.

Inventive Principle:

Principle #40Composite materials

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 solution effectively protects ground crews by ensuring they are aware of the invisible light beam's presence, thereby preventing eye damage through automatic blink reflexes and pupil constrictions triggered by the visible light indicating beam.

Implementation Method 1

a dichroic combiner aligned with each of the visible and invisible light generators to receive and combine the light invisible to the human eye and the light visible to the human eye into a combined beam

Methodology Applied

Scientific EffectDichroic filtering: Dichroic Filter

Implementation Method 2

a detector configured to detect a reflected portion of the light invisible to the human eye reflected by a cloud atmosphere

Methodology Applied

Scientific EffectLight reflection and backscatter: Reflection

Data Source

PatentUS20250291035A1Lidar systems with hazardous-beam indication

Publication Date: 2025.09.18 ROSEMOUNT AEROSPACE INC

AI summary

Apparatus and associated methods relate to protecting ground crews from hazardous invisible-light beams of an activated LIDAR system. To protect such crews the LIDAR system is equipped with a hazardous-beam indicating system. The hazardous-beam indicating system is configured to project a visible-light indicating beam when the hazardous invisible-light beam is projected, at least during ground operations. The visible-light indicating beam is transmitted along an axis of projection shared with the hazardous invisible-light beam. Such a visible-light indicating beam is perceivable to persons whose eyes receive such a visible-light indicating beam. Such persons are thereby alerted to the presence of the corresponding hazardous invisible-light beam transmitted concurrently with the visible-light indicating beam.