Laser Vibration Measuring Device for Outdoor Distance Compensation

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Solution Overview

Problem

Outdoor laser-induced vibration wave measurements face challenges in achieving high-speed and high-accuracy due to environmental noise and irregularities at the irradiation location, which affect the vibration spectrum and make appropriate laser irradiation difficult.

Innovation Solution

A laser-induced vibration wave measuring system that includes an excitation laser device, measurement laser device, galvano scanner unit, biaxial mirror unit, and processing unit to adjust laser light paths and reduce environmental noise, allowing for high-speed and accurate measurement of infrastructure structures like tunnels and bridges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If laser-induced vibration wave measurement is performed outdoors, then measurement speed can be improved, but measurement accuracy deteriorates due to environmental noise and irregularities at irradiation location

Engineering Contradiction:
Improvemeasurement speedVSAvoidmeasurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system measures the actual irradiation distance between the laser device and the inspection target, then feeds back this information to automatically adjust the laser output energy. This feedback mechanism compensates for distance variations caused by environmental factors, maintaining measurement accuracy while enabling outdoor high-speed inspection

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically changes the laser output energy parameter based on the measured irradiation distance. By adjusting the energy parameter in real-time, the system compensates for environmental variations and maintains consistent measurement quality across different outdoor conditions

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If environmental noise is reduced through shielding or isolation, then measurement accuracy is improved, but device complexity and measurement time increase

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system replaces physical noise shielding mechanisms with an electronic compensation approach. By using sensors to detect environmental noise levels and algorithmically compensating for their effects on the vibration wave measurements, the system achieves high accuracy without adding complex physical shielding structures

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

3Measurement precision

If environmental noise is reduced through repeated measurements and averaging, then measurement accuracy is improved, but measurement time increases

Engineering Contradiction:
Improvemeasurement accuracyVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system uses real-time noise level detection to identify and skip measurement cycles taken during high-noise periods. By rapidly identifying acceptable measurement windows and executing measurements only during low-noise intervals, the system achieves high accuracy without the time penalty of repeated averaging

Inventive Principle:
Principle #21Skipping (Rushing through)

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 system improves measurement accuracy by compensating for changes in laser irradiation distance and reducing environmental noise, enabling quick and detailed inspections of infrastructure structures.

Implementation Method 1

laser ablation is the most basic technique to impart vibration to a sample and the sample irradiated with laser light is diagnosed on the basis of vibration generated when the sample is irradiated with the laser light. The laser ablation is a spraying or transpiration phenomenon when there is rapid heating of a sample or formation of plasma by irradiation with a high-power laser pulse.

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

The vibration generated in the sample is measured by a device using laser measurement technology such as a laser Doppler vibrometer and a laser interferometer.

Methodology Applied
Scientific EffectLaser Doppler vibrometry: Laser Doppler Velocimetry

Implementation Method 3

The vibration generated in the sample is measured by a device using laser measurement technology such as a laser Doppler vibrometer and a laser interferometer.

Methodology Applied
Scientific EffectLaser interferometry: Interference

Data Source

PatentEP3779431B1Measuring device, measuring system, moving body, and measuring method
Publication Date: 2025.08.13 NAT INST FOR QUANTUM & RADIOLOGICAL SCI & TECH
  • EP3779431B1 patent drawingFigure 1
  • EP3779431B1 patent drawingFigure 2
  • EP3779431B1 patent drawingFigure 3A~3B

AI summary

A measuring device for measuring an inspection target on the basis of vibration generated when the inspection target has been irradiated with laser light includes a condensing position deriving portion configured to derive an amount of adjustment of a distance between condensing lenses of a laser condensing unit configured to condense the laser light on the basis of a distance between a laser device configured to radiate the laser light and an irradiation location of the laser light and a communicating portion configured to transmit control information including information representing the amount of adjustment to the laser condensing unit.