Exterior Wall Hollowing Detection Using Temperature Gradient Analysis

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Solution Overview

Problem

Current infrared thermal imaging methods for detecting hollowing in exterior wall finish layers are limited by susceptibility to meteorological conditions, high labor and time costs, and subjective manual adjustments, leading to inefficiencies and incorrect judgments due to factors like solar radiation, emissivity, and color temperature ranges.

Innovation Solution

Converting infrared temperature images into temperature gradient images, using laser irradiation for auxiliary heating in poor conditions, and analyzing temperature differences during heating and cooling cycles to identify hollowing defects, thereby filtering out surface texture effects and improving detection accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If infrared thermal imaging method is used to detect hollowing, then detection efficiency is improved, but detection accuracy deteriorates due to susceptibility to meteorological conditions and solar radiation

Engineering Contradiction:
Improvedetection efficiencyVSAvoiddetection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent changes the parameter being measured from absolute temperature to temperature gradient. By calculating the gradient of temperature distribution across the wall surface, the method eliminates the influence of ambient temperature and solar radiation, maintaining high detection accuracy under various meteorological conditions while preserving the high efficiency of infrared imaging

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces temperature gradient as an intermediary parameter between the raw infrared temperature data and the hollowing detection result. This intermediary effectively filters out the interference of environmental factors while preserving the characteristic temperature differences caused by hollowing defects

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If manual color identification of temperature images is used, then detection process is simple, but reliability deteriorates due to subjectivity and instability

Engineering Contradiction:
Improveoperation simplicityVSAvoiddetection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent replaces the manual visual inspection mechanism with an automated computer-based image processing system. The system automatically calculates temperature gradients, processes infrared images, and generates detection results, eliminating human subjectivity while maintaining operational simplicity through automated batch processing

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

Solution Approach 2:

The detection system performs self-analysis by automatically processing the infrared images and temperature data without requiring manual intervention. The computer-based system independently completes the entire detection and analysis process, ensuring consistent and reliable results

Inventive Principle:
Principle #25Self-service

3Measurement precision

If cooling method is used to reduce detection errors, then detection accuracy is improved, but device complexity and cost increase due to additional cooling equipment and procedures

Engineering Contradiction:
Improvedetection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the harmful influence of environmental factors through data processing rather than physical intervention. By removing the confounding effects of ambient temperature and solar radiation through gradient calculation, the method achieves accurate detection without requiring additional cooling equipment or complex procedures

Inventive Principle:
Principle #2Taking out (Extraction)

4Reliability

If bulb heating method is used to improve detection effect, then detection capability is improved, but device complexity increases due to power supply and distribution requirements

Engineering Contradiction:
Improvedetection capabilityVSAvoidheating system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent converts the harmful effect of solar radiation into a beneficial factor by using the existing temperature differences created by environmental conditions. Instead of fighting against environmental influences, the method utilizes them to create detectable temperature gradients, eliminating the need for artificial heating systems

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This method enhances detection efficiency and reliability by reducing subjective manual adjustments and avoiding high-altitude hazards, enabling real-time, batch processing, and accurate identification of hollowing defects with improved resistance to environmental factors.

Implementation Method 1

the surface temperature distribution information is obtained by using an infrared camera to shoot

Methodology Applied
Scientific EffectInfrared thermal imaging: Infrared Radiation

Implementation Method 2

the surface of the exterior wall is heated by a bulb

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentUS11367171B2Method for detecting hollowing of exterior wall finish layer
Publication Date: 2022.06.21 DALIAN UNIV OF TECH

AI summary

The present invention belongs to the technical field of constructional engineering safety detection, and provides a method for detecting hollowing of an exterior wall finish layer. The method for detecting a defect of a facade finish layer of a building proposed by the present invention can realize remote detection in the on-site detection operation and avoid high-altitude hazardous operation of personnel, and is simple and convenient in operation. In data analysis and processing, the method not only can overcome the subjectivity and the instability caused by manual color identification of a temperature image, but also can realize batch processing of image analysis through software or conduct real-time detection and analysis.