Pipe Thickness Measurement Using Dual Luminance Profiles

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for measuring pipe thickness using X-ray radiography face challenges such as measurement errors due to pipe material, the need for multiple X-ray irradiation times, and difficulty in accurately detecting the inner diameter point, as signal changes near the outer diameter point are more pronounced than at the inner diameter point.

Innovation Solution

A pipe thickness measuring device and method that utilize different luminance profiles to detect outer and inner diameter points, with inner diameter point detection based on a luminance profile within two outer diameter points and outer diameter point detection using a second-order differential profile approximated by a predetermined function to minimize detection errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single luminance profile is used for detecting both outer and inner diameter points, then the detection process is simplified, but the detection accuracy of inner diameter point deteriorates due to weak and moderate signal changes

Engineering Contradiction:

Improvedetection process complexityVSAvoidinner diameter point detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the detection process into two separate segments: one for outer diameter point detection and another for inner diameter point detection. Different luminance profiles are applied to each segment based on their specific characteristics. The outer diameter detection uses a standard luminance profile, while the inner diameter detection uses a modified luminance profile that accounts for weak and moderate signal changes, thereby resolving the contradiction between process simplicity and detection accuracy.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different quality characteristics to different parts of the detection process. Specifically, it uses a standard luminance profile for outer diameter detection and a specially designed luminance profile with enhanced sensitivity for inner diameter detection. This local differentiation allows each detection task to use the most appropriate profile for its specific requirements, improving overall measurement precision without unnecessary complexity.

Inventive Principle:

Principle #3Local quality

2Measurement precision

If X-ray irradiation time is increased to enhance signal strength for inner diameter detection, then signal quality improves, but measurement time increases

Engineering Contradiction:

Improvesignal quality for inner diameter detectionVSAvoidX-ray irradiation time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent changes the parameters of the luminance profile rather than increasing X-ray irradiation time. By modifying the luminance profile to be more sensitive to weak and moderate signal changes, the system achieves better signal quality for inner diameter detection without extending the irradiation time. This parameter change approach resolves the contradiction between measurement precision and time loss.

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If measurement is based on transmission radiation amount, then the measurement process is simple, but measurement accuracy deteriorates due to material-dependent errors

Engineering Contradiction:

Improvemeasurement process simplicityVSAvoidpipe thickness measurement accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the direct transmission radiation amount measurement with an image processing-based detection method. Instead of relying solely on radiation intensity measurements that are material-dependent, the system captures radiographic images and extracts luminance profiles to detect outer and inner diameter points. This substitution eliminates material-dependent errors while maintaining operational simplicity through automated image analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach allows for accurate detection of both outer and inner diameter points, enabling precise pipe thickness measurement by applying distinct methods for each diameter point, thereby improving measurement accuracy and reducing errors.

Implementation Method 1

an image obtained by short-time X-ray irradiation

Methodology Applied

Scientific EffectX-ray transmission: X-Ray

Implementation Method 2

X-ray absorption does not occur outside an outer diameter point of the pipe

Methodology Applied

Scientific EffectX-ray absorption: Absorption (EM radiation)

Data Source

PatentEP2600102B1Pipe thickness measurement device and method, and recording medium

Publication Date: 2015.04.15 FUJIFILM CORP

Figure 1
Figure 2
Figure 3

AI summary

A pipe thickness measuring device 10 is provided, including a luminance profile obtaining unit obtaining luminance profiles of radiographic images of a pipe to be measured in a direction crossing the pipe, an outer diameter point detecting unit detecting outer diameter points of the pipe based on the obtained luminance profiles, a region setting unit setting a predetermined region inside two of the outer diameter points of the pipe detected by the outer diameter point detecting unit, and an inner diameter point detecting unit detecting inner diameter points of the pipe based on a luminance profile corresponding to the set predetermined region from among the luminance profiles obtained by the luminance profile obtaining unit.