Railway Brake Control Using Test Wheelsets for Early Adhesion Detection

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Solution Overview

Problem

Existing railway vehicle braking systems fail to detect reduced adhesion on rails early enough, leading to delayed responses and reduced braking performance due to wheel slide, as they are limited by normative boundaries on brake rise time and jerk.

Innovation Solution

A method and brake system that detects adhesion levels by initially braking a subset of wheels or wheelsets with increasing force, allowing early detection without exceeding build-up times, followed by adjusting braking force for all wheels based on the detected adhesion, using a brake controller with integrated wheel slide protection and adhesion management systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If braking force is increased quickly to detect adhesion early, then detection speed is improved, but brake rise time and jerk exceed normative boundaries

Engineering Contradiction:
Improvedetection delayVSAvoidjerk and brake rise time violation
Core Design Contradiction:
Loss of timeVSObject-affected harmful factors

Solution Approach 1:

The braking system is divided into two independent subsystems: a test brake device for adhesion detection and a service brake device for normal braking. This segmentation allows the test brake to apply higher braking forces for rapid adhesion detection without violating the brake rise time and jerk limitations of the service brake, as they operate independently with separate control channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary adhesion detection by applying test braking forces before full service braking is initiated. The test brake device quickly determines adhesion characteristics, and this information is used to optimize the subsequent service braking process, enabling early detection without compromising comfort or regulatory compliance.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If braking force is limited to avoid jerk, then comfort is maintained, but adhesion detection is delayed until wheel slide occurs

Engineering Contradiction:
Improvecomfort levelVSAvoidadhesion detection timing
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The braking system is divided into two independent subsystems: a test brake device for adhesion detection and a service brake device for normal braking. This segmentation allows the test brake to apply higher braking forces for rapid adhesion detection without violating the brake rise time and jerk limitations of the service brake, as they operate independently with separate control channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system performs preliminary adhesion detection by applying test braking forces before full service braking is initiated. The test brake device quickly determines adhesion characteristics, and this information is used to optimize the subsequent service braking process, enabling early detection without compromising comfort or regulatory compliance.

Inventive Principle:
Principle #10Preliminary action

3Power

If all wheels are braked simultaneously, then total braking force is maximized, but adhesion detection becomes inaccurate due to vehicle deceleration effects

Engineering Contradiction:
Improvetotal braking forceVSAvoidadhesion measurement accuracy
Core Design Contradiction:
PowerVSMeasurement precision

Solution Approach 1:

The system extracts the adhesion detection function from the overall braking system by dedicating specific wheel pairs to serve as test brake devices. These selected wheel pairs perform the measurement function independently, while other wheel pairs provide the service braking function, allowing accurate local adhesion measurement without the interference of global vehicle deceleration effects.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The braking system is divided into two independent subsystems: a test brake device for adhesion detection and a service brake device for normal braking. This segmentation allows the test brake to apply higher braking forces for rapid adhesion detection without violating the brake rise time and jerk limitations of the service brake, as they operate independently with separate control channels.

Inventive Principle:
Principle #1Segmentation

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 early detection of adhesion levels, allowing optimized braking force application to prevent jerks and maintain legal build-up times, enhancing braking performance and responsiveness.

Implementation Method 1

a brake system of the railway vehicle comprises at least two brake devices configured to brake one of the wheel or wheelsets of the railway vehicle, respectively

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4279345B1A method for braking a railway vehicle, brake system of a railway vehicle, railway vehicle comprising the brake system, and train comprising the railway vehicle
Publication Date: 2025.07.09 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP4279345B1 patent drawingFigure 1~2

AI summary

A method for braking a railway vehicle (2, 2') comprises the following steps: first, detecting an adhesion level of preselected wheels or wheelsets (3) of the railway vehicle (2, 2') or of a train of several railway vehicles (2, 2'), a number of which being at least one but less than all wheels or wheelsets (3), by braking these preselected wheel(s) or wheelset(s) (3) with an increasing braking force, until the adhesion level is detected, without exceeding a predefined build-up time of a total braking force, and second, braking further wheels or wheelsets (3), in particular all other wheels or wheelsets (3), with a braking force determined by taking into account the detected adhesion level.