Rail Grip Measuring Wheel for Real-Time Adhesion Detection

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Solution Overview

Problem

Existing technologies have not adequately addressed the need for a reliable method to determine the grip (adhesion) of a track during travel in autonomous rail vehicles, particularly in automated environments, where the train driver or other personnel have less or no responsibility over the control of the train driver. The grip of the track can be influenced by various factors such as weather-related moisture or icing, slippery leaves on the tracks, the condition of the tracks or wheels, and also the weight of the rail vehicle. Therefore, it is important to monitor and consider the changing grip to ensure safe and efficient train operations.

Innovation Solution

A measuring device and a method of the device are equipped with a measuring device and a method of the device are equipped with a measuring device that determines the grip of the track directly on the rail vehicle, allowing for real-time updates and consideration of rapidly changing conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If trackside information sources (traffic management system or trackside ETCS equipment) are used to provide grip characteristic values, then the information can be transmitted to the rail vehicle, but the information is not up-to-date for rural regions or less frequently used lines where constant monitoring is not feasible

Engineering Contradiction:
Improvegrip characteristic value accuracyVSAvoidtrack monitoring infrastructure
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

A measuring device with a measuring wheel is introduced as an intermediary between the track and the rail vehicle's control system. This measuring wheel directly contacts the track to measure grip characteristics, serving as a mediator that obtains fresh local measurements without requiring extensive trackside monitoring infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The rail vehicle performs its own grip measurement using the measuring device mounted on it. Instead of relying on external trackside systems to provide grip information, the vehicle independently measures the grip characteristic value by contacting the track with its measuring wheel, enabling self-service in areas without monitoring infrastructure.

Inventive Principle:
Principle #25Self-service

2Extent of automation

If manual input of grip characteristic value by the driver is used, then the driver can provide adhesion information, but this is not possible with higher levels of automation where no personnel is on board

Engineering Contradiction:
Improveautomation levelVSAvoidgrip characteristic value input capability
Core Design Contradiction:
Extent of automationVSLoss of information

Solution Approach 1:

The automated rail vehicle performs grip measurement independently without human intervention. The measuring device automatically contacts the track, measures the grip characteristic value, and provides this information to the ATO system, enabling the vehicle to serve itself in obtaining critical adhesion data even when no personnel is on board.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The manual process of driver input is replaced by an automated mechanical measuring system. The measuring wheel with contact pressure application and rotation detection automatically generates grip characteristic values, substituting the mechanical action of manual input with an automated measurement mechanism.

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

3Productivity

If the ATO system uses a grip value higher than the actual grip level, then the vehicle can accelerate and brake more aggressively, but this results in energy losses and potential wheel spin or lock

Engineering Contradiction:
Improveacceleration and braking efficiencyVSAvoidenergy loss from wheel spin
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The measuring device provides real-time feedback on the actual grip characteristic value to the ATO system. This feedback loop enables the ATO to adjust acceleration and braking commands based on current track conditions, preventing energy waste from wheel spin or lock while maintaining optimal productivity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The ATO system dynamically adjusts driving parameters (acceleration and braking force) based on the measured grip characteristic value. When grip is low, the system reduces tractive force to prevent wheel spin; when grip is high, it can apply more force for better productivity, optimizing performance by changing parameters according to actual conditions.

Inventive Principle:
Principle #35Parameter changes

4Measurement precision

If a measuring wheel with articulated connection is used to measure grip, then real-time grip characteristic values can be determined, but the device complexity increases with pressure medium and braking device

Engineering Contradiction:
Improvegrip characteristic value measurementVSAvoidmeasuring device structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The measuring wheel acts as an intermediary measurement element that directly contacts the track. By using this simple contact interface with articulated connection, the system obtains precise grip measurements without requiring complex sensor arrays or measurement mechanisms, achieving measurement precision through a relatively simple intermediary component.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The measuring device allows for precise and immediate determination of the track's grip, enabling the ATO system to control the rail vehicle effectively, reducing energy losses and wear by adapting to current grip conditions.

Implementation Method 1

The grip of a track, also known as adhesion, refers to the friction between a rail on the track and the wheel of the rail vehicle

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4549282B1Measuring device for a rail vehicle and method for determining at least one characteristic value on the vehicle side
Publication Date: 2026.05.20 SIEMENS MOBILITY GMBH
  • EP4549282B1 patent drawingFigure 1~2
  • EP4549282B1 patent drawingFigure 3
  • EP4549282B1 patent drawing

AI summary

The invention relates to a measuring device (6) for a rail vehicle (1) for determining at least one characteristic value for the grip of a track (3) during travel, comprising at least one measuring wheel (7) designed to contact the track (3), at least one wheel suspension (8) connected to the measuring wheel (7) in its axis of rotation (12), designed for attachment to the rail vehicle (1) and for establishing an articulated connection between the rail vehicle (1) and the measuring wheel (7), at least one pressure means (10) designed to generate a substantially constant contact force of the measuring wheel (7) against the track (3) during the measurement, at least one braking device (11) designed to generate a substantially constant braking torque acting on the measuring wheel (7) during the measurement, and at least one sensor device (9).which is designed to capture at least one measured value representative of the rotation of the measuring wheel (7) relative to the wheel suspension (8). The measuring device (6) according to the invention has the advantage that it can automatically determine a current characteristic value for the rail vehicle (1). The invention also relates to a method for determining at least one characteristic value for the grip of a track (3) on the vehicle side.