Underground Line Locator With RTK GNSS for Precise Utility Mapping

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Solution Overview

Problem

Existing line locator systems lack the precision needed for accurate mapping of underground utilities, particularly due to inaccuracies in determining the position of buried lines using Global Navigation Satellite Systems (GNSS) without Real-Time Kinematic (RTK) enhancements.

Innovation Solution

A precise line locator system incorporating an array of low-frequency antennas and a Real-Time Kinematic (RTK) GNSS antenna, along with an inertial measurement unit (IMU), which allows for precise positioning by aligning the RTK GNSS antenna with the electromagnetic locate axis, correcting errors through magnetic declination adjustments and geometric calculations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If standard GNSS positioning is used in line locator systems, then the system can determine utility location, but the positioning accuracy is insufficient for precise mapping requirements

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmapping accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies parameter changes by transitioning from standard GNSS positioning to RTK (Real-Time Kinematic) GNSS positioning. This changes the measurement parameters from meter-level accuracy to centimeter-level accuracy (1-2 cm horizontal, 3-5 cm vertical), directly resolving the contradiction between positioning accuracy and mapping reliability for precise utility mapping.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If RTK GNSS antenna is added to achieve precise positioning, then positioning accuracy improves, but system complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the RTK GNSS antenna integration with the existing line locator system architecture. The RTK antenna is integrated into the housing and communicates with the processing circuit, which already handles antenna signals and utility location data. This combining approach achieves centimeter-level positioning accuracy while minimizing additional system complexity through unified processing.

Inventive Principle:
Principle #5Merging (Combining)

3Measurement precision

If multiple orientations are required for RTK antenna positioning, then positioning accuracy improves, but operation time increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidoperation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by providing user interface guidance that directs the user to position the RTK antenna in the correct orientation before taking measurements. The system prompts the user to orient the antenna vertically or at specific angles, and only after proper orientation is achieved does the system proceed with data collection. This preliminary orientation step prevents the need for repositioning and reorienting, thereby reducing total operation time despite the additional initial setup requirement.

Inventive Principle:
Principle #10Preliminary action

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

Achieves centimeter-level accuracy in mapping underground utilities by integrating RTK GNSS with low-frequency antenna arrays, reducing positional errors and enhancing geographic precision.

Implementation Method 1

Line locating instruments typically include an array of spaced antennas that receive time-varying magnetic field signals generated by the underground utility itself

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a real-time kinematic (RTK) Global Navigation Satellite (GNSS) antenna attached to the housing

Methodology Applied
Scientific EffectGlobal satellite positioning:

Data Source

PatentEP3973303B1Underground line locator system with real time kinematic global satellite positioning
Publication Date: 2025.10.01 BUSAN TRANSPORTATION CORPORATION
  • EP3973303B1 patent drawingFigure 1
  • EP3973303B1 patent drawingFigure 2
  • EP3973303B1 patent drawingFigure 3

AI summary

A precise line locator is presented that provides precise line location. The locator includes a housing; a wand attached to the housing, the wand including an array of low frequency antennas arranged along the wand, the array of low frequency antennas defining an electromagnetic locate axis of the line locator system; a real-time kinematic (RTK) Global Navigation Satellite (GNSS) antenna attached to the housing; a user interface positioned in the housing; and a processing circuit coupled to the array of low frequency antennas, the RTK GNSS antenna, and the user interface, wherein the underground line locator determines locate data of the underground line based on signals from the array of low frequency antennas and determines a precise position of the underground line locator from the RTK GNSS antenna.