Dominant Vibration Frequency Identification for Underground Pipe Location

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Solution Overview

Problem

Existing methods for locating underground pipes, particularly non-metallic ones, are inaccurate due to interference from soil and pipe characteristics, and lack of conductivity in non-metallic materials, making it difficult to determine the precise location during digging operations.

Innovation Solution

Induce controlled acoustic waves over a predetermined frequency range using an exciter, measure the vibration response with a sensor, and apply Fourier transform to identify a dominant frequency using a vibration signal analyzer, allowing for precise location of underground structures by detecting peak vibration responses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If ground excitation methods are used to locate underground pipes, then the method can detect pipe appurtenances, but the measurement accuracy deteriorates due to interference from soil and pipe characteristics at certain distances and frequencies

Engineering Contradiction:
Improvepipe location capabilityVSAvoidlocation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the excitation frequency based on measured vibration responses. The frequency is varied to identify the dominant vibration response frequency of the pipe, allowing the system to adapt to different soil conditions, pipe materials, and depths. This dynamic frequency adjustment enables accurate location measurements regardless of distance or environmental interference.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the frequency parameter of the excitation signal to match the dominant vibration frequency of the pipe. By sweeping through a frequency range and identifying the frequency that produces the maximum vibration response, the system optimizes the excitation parameters to overcome interference from soil characteristics and pipe appurtenance properties.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If electromagnetic locators are used to locate underground pipes, then metallic pipes can be detected, but the method fails for non-metallic pipes due to lack of conductivity

Engineering Contradiction:
Improvedetection capability for metallic pipesVSAvoidapplicability to non-metallic materials
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system replaces electromagnetic detection methods with acoustic vibration-based detection. Instead of relying on electrical conductivity, the system uses mechanical acoustic waves generated by the exciter to induce vibrations in the pipe. These vibrations are detected by sensors, enabling the system to locate both metallic and non-metallic pipes through their mechanical response to acoustic excitation.

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

Solution Approach 2:

The acoustic vibration-based detection system provides universal applicability to both metallic and non-metallic pipes. By detecting the mechanical vibration response rather than electrical properties, the system can locate pipes regardless of material composition, making it suitable for plastic, concrete, clay, and metallic pipes alike.

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

3Adaptability or versatility

If acoustic waves are used to induce vibration in underground structures, then non-metallic pipes can be located, but interference from soil layering and pipe characteristics can still cause inaccurate measurements

Engineering Contradiction:
Improvecapability to detect non-metallic pipesVSAvoidvibration response accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system dynamically identifies the dominant vibration frequency by sweeping through a frequency range and measuring the vibration response at each frequency. The frequency that produces the maximum response is identified as the dominant frequency, and excitation is optimized at this frequency to overcome interference from soil layering and pipe characteristics.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback from the measured vibration response to determine the dominant frequency. The sensors detect the vibration amplitude at different frequencies, and this information is used to identify the peak response frequency. The system then uses this feedback to optimize the excitation frequency for accurate pipe location, compensating for interfering factors.

Inventive Principle:
Principle #23Feedback

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

Accurately locates underground structures by identifying a dominant vibration response, overcoming interference issues and material composition limitations, enabling efficient and precise pipe location.

Implementation Method 1

Controlled acoustic waves are induced in the structure via ground using a vibration exciter

Methodology Applied
Scientific EffectAcoustic waves: Sound

Implementation Method 2

Vibration response associated with the structure in response to the controlled acoustic waves over the predetermined frequency range is measured, using a measurement device in vibrational communication with the structure

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

converting the vibration response from a time-domain vibration response to a frequency-domain vibration response by applying a Fourier transform

Methodology Applied
Scientific EffectFourier transform:

Data Source

PatentEP4632339A1Method for frequency identification
Publication Date: 2025.10.15 SOLINAS TECH INC
  • EP4632339A1 patent drawingFigure 1
  • EP4632339A1 patent drawingFigure 2
  • EP4632339A1 patent drawingFigure 3

AI summary

A method for identifying a frequency producing a dominant vibration response of an underground structure includes the steps of inducing controlled acoustic waves in the structure via ground, the acoustic waves varying over a predetermined frequency range, measuring vibration response associated with the structure in response to the controlled acoustic waves over the predetermined frequency range, using a measurement device in vibrational communication with the structure, detecting a dominant vibration response among measurements across all frequencies of the predetermined frequency range, and, identifying a frequency of the predetermined frequency range which produced the dominant vibration response.