Planar Magnetic Flux Leakage Imaging for Pipeline Weld Crack Detection

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Solution Overview

Problem

Existing pipeline defect in-line inspectors face limitations in spatial resolution and are prone to lift-off disturbances, particularly in recognizing circumferential weld cracks, which pose significant safety risks due to their reliance on discrete magnetic sensors and mechanical scanning devices.

Innovation Solution

A pipeline defect in-line inspector utilizing planar magnetic flux leakage array imaging with a magnetization module, distributed magnetic flux leakage array imaging modules, and a three-level synchronization architecture for high-speed synchronous acquisition and location synchronization to generate ultra-high spatial resolution magnetic flux leakage images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If discrete magnetic sensors are arranged in a straight line to form detection probes, then the device complexity is reduced and ease of manufacture is improved, but the spatial resolution cannot exceed 1mm

Engineering Contradiction:
Improvespatial resolutionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from one-dimensional linear array sensors to two-dimensional planar array sensors. The planar magnetic flux leakage array includes multiple magnetic sensors arranged in a plane with different spatial coordinates, enabling ultra-high spatial resolution imaging by capturing magnetic flux leakage signals from multiple dimensions simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent divides the detection system into multiple independent magnetic sensors within the planar array, each sensor independently detecting magnetic flux leakage at its specific location. This segmentation allows the system to achieve high spatial resolution by combining signals from numerous distributed sensors rather than relying on a single probe.

Inventive Principle:
Principle #1Segmentation

2Productivity

If detection probes move along the pipeline axis during inspection, then productivity is improved, but lift-off disturbance occurs causing severe signal distortion

Engineering Contradiction:
Improveinspection speedVSAvoidsignal accuracy
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent employs a three-level synchronization architecture that provides real-time feedback control during the movement of the planar array. The synchronization control unit coordinates the movement position with signal acquisition timing, and the data processing unit compensates for movement-induced distortions through algorithmic correction, thereby maintaining signal accuracy during high-speed inspection.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary synchronization calibration before actual inspection begins. The system pre-establishes the relationship between sensor array positions and corresponding pipeline locations, and pre-configures the data processing algorithms to compensate for expected movement effects, enabling accurate defect detection during high-speed traversal.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If discrete magnetic sensors are used with mechanical scanning devices, then device complexity is reduced, but measurement precision is limited to 1mm spatial resolution

Engineering Contradiction:
Improvespatial resolutionVSAvoiddetection difficulty
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements a two-dimensional planar sensor array that captures magnetic flux leakage signals across multiple spatial dimensions simultaneously. This planar configuration with sensors at different (x, y, z) coordinates enables ultra-high spatial resolution imaging, transforming the detection capability from one-dimensional scanning to multi-dimensional parallel measurement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent merges multiple magnetic sensors into an integrated planar array system, combining their signals through data processing to form a comprehensive magnetic flux leakage image. This merging of multiple sensor outputs achieves super-resolution capability that exceeds the individual sensor resolution, enabling detection precision well below 1mm.

Inventive Principle:
Principle #5Merging (Combining)

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 enables continuous acquisition of high spatial resolution images in real-time, effectively overcoming lift-off disturbances and improving the detection of circumferential weld cracks, providing a robust data basis for quantitative evaluation and defect localization.

Implementation Method 1

magnetic induction lines generated by the permanent magnet are coupled into the wall of the pipeline through the magnetic conductive structure

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

each planar magnetic flux leakage array imaging module is a planar micro-element array magnetic sensing unit, which is composed of magnetic sensing micro-elements arranged in planar array that convert magnetic signals into electrical or optical signals

Methodology Applied
Scientific EffectMagnetic signal conversion: Hall Effect

Data Source

PatentEP4697018A1Pipeline defect in-line inspector based on planar magnetic flux leakage array imaging
Publication Date: 2026.02.18 CHENGDU YOUYIDA TECHNOLOGY CO LTD
  • EP4697018A1 patent drawingFigure 1
  • EP4697018A1 patent drawingFigure 2
  • EP4697018A1 patent drawingFigure 3~4

AI summary

The present invention provides a pipeline defect in-line inspector based on planar magnetic flux leakage array imaging. Based on the existing magnetization module and the existing plurality of planar magnetic flux leakage array imaging modules, a plurality of magnetic flux leakage image high-speed synchronous acquisition units are added into the present invention to realize high spatial resolution magnetic flux leakage imaging and obtain a plurality of magnetic flux leakage images under the movement state of the pipeline defect in-line inspector. A location and magnetic flux leakage image synchronization module is added into the present invention to synchronize the plurality of magnetic flux leakage images with an acquisition location. An image synchronization module registers each two adjacent pluralities of magnetic flux leakage images by acquisition locations, data characteristics and physical model to obtain a pipeline magnetic flux leakage field distribution map of ultra-high spatial resolution, providing a data basis for quantitative evaluation and locating of defects of the pipeline.