Cable Soft Fault Detection via Zero-Crossing Signal Amplification

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Solution Overview

Problem

Existing reflectometry methods struggle to detect and locate soft faults in cables, as they generate low-amplitude signals that are difficult to distinguish from noise, particularly in superficial defects, which can evolve into more significant issues if not identified early.

Innovation Solution

A method that injects a reference signal into the cable, acquires and processes the reflected measurement signal to selectively amplify low-amplitude fault signatures without amplifying noise, using elementary operations like addition, subtraction, and multiplication, and identifies critical points corresponding to zero crossings to generate modified signals that enhance fault detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If classic time-domain reflectometry methods are used to detect faults in cables, then obvious faults such as short circuits and open circuits can be detected, but non-obvious faults with low-amplitude reflected signals are difficult to detect due to noise interference

Engineering Contradiction:
Improvefault detection sensitivityVSAvoidnoise interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The method performs preliminary identification of signal regions corresponding to potential fault signatures before applying the amplification function. By pre-selecting regions of interest based on zero-crossing points and signal characteristics, the system prepares the measurement signal for targeted processing, ensuring that only relevant portions are amplified while noise remains suppressed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The amplification function is applied locally to specific signal regions rather than uniformly across the entire signal. The function selectively amplifies low-amplitude fault signatures in identified regions while maintaining noise suppression in other areas. This localized approach allows the system to enhance fault detectability without proportionally amplifying noise across the entire measurement signal.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If time-frequency reflectometry methods are used to improve detection of low-amplitude reflected signals, then detection sensitivity increases, but the complexity of implementation in embedded systems increases significantly

Engineering Contradiction:
Improvelow-amplitude signal detectionVSAvoidimplementation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The method uses elementary mathematical operations (addition, subtraction, multiplication) that are computationally inexpensive and easily implementable in embedded systems. Rather than employing complex time-frequency transform algorithms, the invention employs simple arithmetic operations that can be executed efficiently on resource-constrained devices, making the system both affordable and practical for portable equipment.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention replaces complex signal processing mechanisms with simpler mathematical operations. Instead of using sophisticated time-frequency analysis algorithms that require significant computational resources, the method substitutes these with elementary arithmetic operations that achieve similar fault detection goals with much lower complexity, making the system suitable for embedded and portable applications.

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

3Measurement precision

If signal amplification is applied to enhance fault signatures, then low-amplitude faults become more detectable, but noise is also amplified making detection more difficult

Engineering Contradiction:
Improvefault signature amplitudeVSAvoidnoise amplitude
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The amplification function is applied selectively to specific signal regions that have been identified as containing potential fault signatures. By limiting the amplification to these localized regions rather than applying it uniformly across the entire signal, the system enhances fault detectability while minimizing the amplification of noise in regions without faults.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system performs preliminary identification and selection of signal regions corresponding to potential fault signatures before applying the amplification function. This preparatory step ensures that amplification is applied only where needed, preventing unnecessary noise amplification in regions without faults while still enhancing the visibility of low-amplitude fault signatures in the identified regions.

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

This approach allows for the accurate detection and localization of soft faults without noise amplification, making it suitable for use in portable equipment and improving the reliability of cable diagnostics by identifying faults at an early stage.

Implementation Method 1

an electrical signal, the probe signal, often high-frequency or broadband, is injected at one or more points in the cable being tested. This signal propagates through the cable or network and reflects some of its energy back when it encounters an electrical discontinuity.

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP3298419B1Method for analysing a cable, involving a processing operation amplifying the signature of a soft fault
Publication Date: 2022.03.23 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3298419B1 patent drawingFigure 1
  • EP3298419B1 patent drawingFigure 2
  • EP3298419B1 patent drawingFigure 3

AI summary

A method for analysing a cable into which a reference signal s(t) with bounded time support is injected, characterised in that it comprises the following steps: - acquiring a measurement signal r(t) characteristic of the measurement of the reflection of said reference signal s in the cable, - identifying and selecting (101) at least one point of said measurement signal r corresponding to a shift of the signal to a zero value, - generating (104), over a time interval (102) centred around said at least one abscissa point t o, a modified signal z(t) using the following equation z(t o+t) = r(t o+t)- r(t o-t), - identifying at least one possible fault on the cable from the analysis of said at least one modified signal z(t).