Railway Diagnostic Device Wheel Diameter Update

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Solution Overview

Problem

Existing diagnostic systems for railway vehicle rotating components fail to accurately detect mechanical failures due to deviations in wheel diameter caused by wear or repair, leading to incorrect calculation of rotation frequency and missed detection of characteristic frequencies.

Innovation Solution

A method and diagnostic system that regularly updates the wheel diameter measurement to accurately calculate rotation frequency, using sensors and frequency transformations like DFT or FFT to determine characteristic frequencies and detect component failures by comparing signal amplitudes with reference values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the wheel diameter is not updated to account for wear or repair, then the diagnostic system maintains simplicity, but the rotation frequency calculation becomes inaccurate leading to missed failure detection

Engineering Contradiction:
Improvefailure detection accuracyVSAvoidwheel diameter update mechanism
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary measurement of wheel diameter at regular intervals and updates the stored value before it affects rotation frequency calculations. This proactive approach ensures that the wheel diameter used in calculations always reflects the current actual diameter, preventing inaccurate failure detection while maintaining system simplicity through scheduled updates rather than continuous monitoring.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If the wheel diameter is regularly updated to maintain accurate rotation frequency calculation, then the characteristic frequency determination becomes precise, but the measurement and update process becomes more complex

Engineering Contradiction:
Improverotation frequency measurement precisionVSAvoiddiameter measurement and update system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The wheel diameter is measured and updated in advance at regular intervals before it impacts the rotation frequency calculations. This ensures that the most current and accurate wheel diameter is always available for calculating characteristic frequencies, thereby maintaining high measurement precision without requiring complex real-time adjustment mechanisms.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the wheel diameter is not adapted to wear or repair measures, then the system operation remains simple, but the characteristic frequencies for failure detection become inaccurate

Engineering Contradiction:
Improvecharacteristic frequency accuracyVSAvoidsystem operation simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The system performs preliminary updates of the wheel diameter value at scheduled intervals, ensuring that the stored diameter reflects current wear or repair conditions before being used in characteristic frequency calculations. This maintains operational simplicity through periodic updates rather than continuous complex adjustments, while ensuring reliable and accurate failure detection.

Inventive Principle:
Principle #10Preliminary action

4Measurement precision

If the wheel diameter is updated at regular intervals, then the characteristic frequencies can be accurately determined, but the time required for measurement and update increases

Engineering Contradiction:
Improvecharacteristic frequency determination accuracyVSAvoidtime for diameter measurement and update
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The wheel diameter is measured and updated in advance at predetermined time intervals before affecting rotation frequency calculations. This ensures accurate characteristic frequency determination while limiting the time impact to only the scheduled measurement periods, rather than requiring continuous or real-time updates that would cause greater time loss.

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

Ensures precise and reliable detection of mechanical failures in rotating components by correctly calculating characteristic frequencies, allowing for timely recognition of increasing signal amplitudes indicative of wear or damage.

Implementation Method 1

The at least one sensor (5a to 5d) is mounted on at least one of the plurality of rotating components (4a, 4b, 8a, 8b, 6) and is used for measuring vibrations of the rotating components (4a, 4b, 8a, 8b, 6)

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 2

The captured time-based signal is transformed into a frequency response

Methodology Applied
Scientific EffectFourier Transformation:

Data Source

PatentEP3988896B1Method and system for diagnosing a rotation machine
Publication Date: 2023.04.05 HITACHI LTD
  • EP3988896B1 patent drawingFigure 1
  • EP3988896B1 patent drawingFigure 2a~2b
  • EP3988896B1 patent drawingFigure 3

AI summary

The herein described subject matter relates to a method and a diagnostic device 10 for precisely and reliably diagnose mechanical failures of rotating components in a railway vehicle 1 by precise determination of the characteristic frequencies of the rotating components. To determine the characteristic frequencies of a rotating component, the rotation frequency of the respective component is required. This rotation frequency is calculated based on the vehicle speed and the diameter of the wheels 7, 7a, 7b of the rail vehicle 1. In order to improve the accuracy of said rotation frequency determination, the wheel diameter is measured regularly at predetermined intervals.