Pipe Navigation Posture Measurement Using 3D Depth Sensors

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Solution Overview

Problem

Existing navigation algorithms for intelligent PIGs in pipe integrity management suffer from errors due to misalignment between the central line of the pipe and the central line of the intelligent PIG, particularly in pitch and yaw directions, leading to inaccurate location calculations.

Innovation Solution

A method and device for measuring the posture of a moving body within a pipe using a 3D depth sensor to generate three-dimensional shape information, an extension vector, and direction vector, along with guide parts to calculate inclination angles, including pitch and yaw, to correct for misalignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the navigation algorithm assumes alignment between pipe central line and intelligent PIG central line, then the navigation calculation is simplified, but location accuracy deteriorates when inclination exists

Engineering Contradiction:
Improvenavigation algorithm complexityVSAvoidlocation accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical assumption of alignment with an optical measurement system. A 3D depth sensor captures the pipe's internal geometry, and through image processing and coordinate transformation, the system calculates the actual inclination angle between the pipe central line and the PIG central line, substituting the simplified mechanical model with precise optical measurement and computational geometry.

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

2Measurement precision

If inclination measurement is added to correct navigation errors, then location accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvelocation accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The 3D depth sensor serves multiple functions: it maps the pipe's internal geometry, measures the inclination angle, and provides spatial reference for navigation correction. By making the depth sensor multi-functional, the patent avoids adding separate inclination measurement devices, thereby improving location accuracy while minimizing the increase in device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system uses the depth sensor data to automatically calculate and correct its own navigation errors. The inclination measurement and correction process is performed autonomously by the system itself, eliminating the need for external calibration equipment or manual adjustment mechanisms, thus improving accuracy without proportionally increasing complexity.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4650715A1Method and apparatus for measuring posture
Publication Date: 2025.11.19 KOREA GAS CORPORATION
  • EP4650715A1 patent drawingFigure 1
  • EP4650715A1 patent drawingFigure 2
  • EP4650715A1 patent drawingFigure 3

AI summary

According to an embodiment of the present invention, a method of measuring a posture is provided. The method may include generating three-dimensional shape information of a pipe in which a moving body moves, generating an extension vector of the pipe from the three-dimensional shape information, generating a direction vector indicating a direction in which the moving body is oriented, and generating a first inclination angle of the moving body with respect to the pipe based on the extension vector and the direction vector.