Multi-Position Inertial Alignment Method for Underground Pipelines Using Data Backtracking Based on Single-Axis...

Area of Science:

• Geomatics Engineering
• Inertial Navigation Systems
• Geophysical Surveying

Background:

• Accurate 3D trajectory mapping of underground pipelines is crucial for infrastructure management.
• Traditional inertial measurement methods rely on initial attitude determination, often hindered by complex urban magnetic fields.
• Inaccurate initial attitude leads to significant errors in pipeline trajectory reconstruction.

Purpose of the Study:

• To develop a novel multi-position initial alignment method for enhancing the accuracy of underground pipeline inertial measurement.
• To overcome the limitations of traditional magnetometer-based initial attitude determination in challenging environments.
• To improve the precision of 3D trajectory data for underground pipelines.

Main Methods:

• Proposed a multi-position initial alignment method utilizing a single-axis Fiber Optic Gyroscope (FOG) and a three-axis Micro-Electro-Mechanical Inertial Measurement Unit (MIMU).
• Designed a three-position alignment scheme based on the pipeline measuring instrument's three-point support structure.
• Developed an initial alignment algorithm employing data backtracking for both rough (FOG) and fine (FOG/MIMU) alignment.

Main Results:

• Experimental validation demonstrated high accuracy with pitch and roll angle errors under 0.05°.
• Azimuth angle errors were found to be less than 0.2°.
• The proposed method significantly improved the precision of the 3D trajectory of underground pipelines.

Conclusions:

• The novel multi-position initial alignment method effectively addresses the inaccuracies associated with traditional methods in complex magnetic environments.
• The combined use of FOG and MIMU data with a data backtracking algorithm provides a robust solution for precise initial attitude determination.
• This advancement offers a more reliable approach for accurate 3D mapping and management of underground pipeline infrastructure.