Dual GPR Sensor Layout for Buried Object Direction Detection

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Solution Overview

Problem

Existing ground penetrating radar (GPR) systems face challenges in efficiently determining the lay direction of buried objects, requiring multiple scanning directions and relying on prior knowledge of duct depth, which is often unavailable, and struggle with detecting objects close to the surface or with varying depths.

Innovation Solution

A method using a single scanning step with two GPR sensors positioned orthogonally to detect presence signals and compute the lay direction in real-time, iteratively refining measurements to minimize errors, and displaying the direction on a map using a control unit and navigation device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple scanning directions are used to determine lay direction of buried objects, then measurement precision is improved, but productivity deteriorates due to multiple scanning travels required

Engineering Contradiction:
Improvelay direction determination accuracyVSAvoidinspection speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system divides the scanning task into two simultaneous measurements using two GPR sensors positioned at different orientations (first sensor in first direction, second sensor in second direction). This segmentation allows both directional measurements to be captured in a single scanning travel, eliminating the need for multiple sequential scans while maintaining the precision needed to determine lay direction through comparison of the two sensor readings.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If GPR sensors are positioned at an angle to overlap trajectories for following lay direction, then measurement precision is improved, but device complexity increases due to angle adjustment requirements

Engineering Contradiction:
Improveburied object direction detection accuracyVSAvoidsensor positioning complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses two GPR sensors mounted at fixed but different orientations relative to the scanning direction. Rather than requiring dynamic adjustment of sensor angles during scanning, the fixed differential orientations enable the system to capture signals from multiple directions simultaneously. The lay direction is then determined by comparing the measurements from the two sensors, simplifying the mechanical design while maintaining detection precision.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If prior knowledge of duct depth is required for proper sensor positioning, then measurement precision is improved, but adaptability deteriorates when depth information is unavailable

Engineering Contradiction:
Improvesignal overlap accuracyVSAvoiddetection capability without prior depth information
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The system performs preliminary measurements using both GPR sensors simultaneously before attempting to determine lay direction. By capturing data from two different sensor orientations in advance, the system accumulates sufficient information to calculate the lay direction without needing prior knowledge of duct depth. The depth information is derived as part of the measurement process rather than being a prerequisite.

Inventive Principle:
Principle #10Preliminary action

4Productivity

If a single scanning step is used to improve productivity, then productivity is improved, but measurement precision deteriorates for lay direction determination

Engineering Contradiction:
Improveinspection speedVSAvoidlay direction detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The system merges the functionality of multiple scanning operations into a single scanning travel by positioning two GPR sensors at different orientations on the same moving platform. Both sensors collect data simultaneously during one pass, and the lay direction is determined by combining and comparing the measurements from both sensors. This merging approach maintains inspection speed while achieving the measurement precision that would otherwise require multiple separate scans.

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

Enables automatic and precise determination of the lay direction of elongated buried objects in real-time with a single scanning step, reducing measurement errors and improving detection accuracy for objects near the surface or with varying depths.

Implementation Method 1

at least one antenna is provided for receiving/transmitting a radiofrequency (GPR sensor)... emitting an RF signal and analysing a return signal reflected by the objects hit by the emitted signal (echo)

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

a first GPR sensor (110) arranged to measure a first plurality of presence signals... a second GPR sensor (110') arranged to measure a second plurality of presence signals

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Data Source

PatentEP2994773B1Device and method for detecting position and orientation of underground elongated bodies
Publication Date: 2023.07.05 IDS GEORADAR SRL
  • EP2994773B1 patent drawingFigure 1
  • EP2994773B1 patent drawingFigure 2
  • EP2994773B1 patent drawingFigure 3

AI summary

A method for defining a lay direction δ of at least one elongated buried object (50), by means of GPR technique (Ground Penetrating Radar), comprises the steps of moving a first GPR sensor (110) along a first trajectory s consisting of a plurality of points P, and moving a second GPR sensor (110'), integral to the first GPR sensor (110), along a second trajectory s' consisting of a plurality of points P' and parallel to the first trajectory s. The method also comprises the steps of detecting a first and a second plurality of presence signals concerning possible buried objects by the first GPR sensor (110) and the second GPR sensor (120), acquisition of a first and a second set of spatial coordinates for each point P and P' at which a presence signal is detected, and receiving by a control unit (150) the presence signals and the set of spatial coordinates. The method provides then a step of computing the data concerning the presence of possible buried elongated objects (50) and the set of spatial coordinates, in order to determine, among all points P and P' at which a presence signal has been detected, points P1 and P1' at which the probability of presence of an elongated buried object (50) is higher. Then, a step of determining, at the end of said computing step, the lay direction δ of at least one elongated buried object (50) is carried out responsive to the set of spatial coordinates corresponding to points P1 and P1'.