Articulated Rail Vehicle Derailment Detection by Joint Angle Deviation

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Solution Overview

Problem

Existing methods for detecting rail vehicle derailments are inadequate for reliable and early detection, particularly at low vehicle speeds, and there is a need for improved derailment detection systems, especially for autonomous or automated rail vehicles.

Innovation Solution

A method and device utilizing a pivot joint between car bodies to measure the angle between their longitudinal axes, combined with position information from GNSS, odometer, or infrastructure-based systems, to compare the current angle with expected angles for the vehicle's position, issuing a derailment signal if the deviation exceeds a threshold or persists for a predetermined period.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing derailment detection methods are used, then derailment can be detected, but detection reliability and timeliness are insufficient especially at low speeds

Engineering Contradiction:
Improvederailment detection reliabilityVSAvoidderailment detection timing
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

Instead of directly detecting derailment indicators, the invention detects the angular relationship between car bodies and compares it with the expected angle for the current position. This indirect approach through angle measurement provides more reliable and timely detection, especially at low speeds where direct derailment indicators may be insufficient.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The system continuously monitors the angular relationship between car bodies, compares it with expected values based on position, and provides feedback through derailment signals when deviations exceed thresholds. This continuous feedback mechanism ensures reliable and timely detection of derailment conditions.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If angular monitoring between car bodies is implemented, then detection accuracy improves, but device complexity increases

Engineering Contradiction:
Improvederailment detection accuracyVSAvoiddetection system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The angular relationship monitoring system serves multiple purposes: it detects derailment conditions, provides position verification, and monitors vehicle configuration status. This multi-functionality improves detection accuracy while avoiding the need for separate dedicated systems, thereby limiting the increase in device complexity.

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

3Reliability

If continuous angular monitoring is performed, then early derailment detection is enabled, but energy consumption increases

Engineering Contradiction:
Improveearly derailment detectionVSAvoidmonitoring system energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs angular measurements and comparisons at periodic intervals rather than continuously, evaluating the angular relationship at defined measurement points along the track. This periodic approach enables early derailment detection while significantly reducing energy consumption compared to continuous monitoring.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP4091899B1Rail vehicle and method for detecting the derailing of a rail vehicle
Publication Date: 2026.04.29 ALSTOM HOLDINGS SA
  • EP4091899B1 patent drawingFigure 1~4

AI summary

The invention relates to a method for detecting a derailment of a rail vehicle (1) having at least two car bodies (2a, 2b) connected to each other via a joint (8) such that the longitudinal axes (9a, 9b) of the car bodies (2a, 2b) are angled relative to each other during a curve travel of the rail vehicle (1), wherein a detection device (3) receives: - angular information about an instantaneous angle (MW) of the car bodies (2a, 2b) relative to each other, - positional information about an instantaneous position of the rail vehicle (1) in a rail network, - the instantaneous angle (MW) is compared with an expected angle (EW) for the instantaneous position, and - if the instantaneous angle (MW) deviates from the expected angle (EW), an output signal is issued indicating a derailment of the rail vehicle (1), or the output signal is terminated.so that the absence of the output signal indicates a derailment of the rail vehicle (1).