Track-Guided Vehicle Positioning Using Repeating Track Profiles

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Solution Overview

Problem

Current methods for determining the position of track-guided vehicles, especially near railway stations, are costly and computationally intensive, and face challenges such as altered track conditions due to debris or obscured features, making them uneconomical and inaccurate for precise stopping at platforms with platform screen doors.

Innovation Solution

A vehicle-mounted sensor measures the distance to the track superstructure, generating a distance profile that recognizes repeating patterns of track elements to determine the vehicle's position autonomously, reducing the need for infrastructure-based data and computational power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If balises are installed in spatially defined windows in front of all stopping points to achieve high stopping accuracy, then stopping precision is improved, but the quantity of infrastructure components and project costs increase considerably

Engineering Contradiction:
Improvestopping accuracyVSAvoidnumber of balises
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent replaces the mechanical infrastructure-based balise system with an optical sensing system mounted on the vehicle. The sensor scans the track bed and compares images to reference images to determine vehicle position, eliminating the need for numerous physical balises while maintaining stopping accuracy requirements for platform screen doors.

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

2Quantity of substance

If track bed scanning with sensors is used to avoid balises, then infrastructure costs are reduced, but reliability deteriorates due to altered track conditions from debris or obscured features

Engineering Contradiction:
Improveinfrastructure componentsVSAvoidlocation tracking reliability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent creates and stores reference images of the track bed during installation or maintenance when the track is in its proper state. During operation, the sensor scans the current track bed and compares it against these reference images to determine vehicle position, allowing the system to tolerate temporary alterations like debris while maintaining reliable location tracking.

Inventive Principle:
Principle #26Copying

3Measurement precision

If current state-of-the-art sensor-based tracking methods are implemented for all vehicles, then measurement precision is improved, but device complexity and computing power requirements increase significantly

Engineering Contradiction:
Improvevehicle position accuracyVSAvoidhardware and computing requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a simplified image comparison approach that uses partial processing of track bed images. Rather than requiring full 3D mapping or complex computational algorithms, the system captures images, compares them against stored references, and extracts position information through straightforward image matching, reducing computational requirements while maintaining sufficient accuracy for platform screen door operations.

Inventive Principle:
Principle #16Partial or excessive 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 method significantly reduces the number of required balises, minimizes hardware and computing costs, and ensures precise vehicle alignment with platform screen doors by using onboard sensors to track the track's elevation profile.

Implementation Method 1

a) a vehicle-side sensor generates a measurement result during the vehicle's journey, which represents a track traversed by the vehicle

Methodology Applied
Scientific EffectDistance measurement:

Data Source

PatentEP4640515A1Method for determining the position of a track-guided vehicle
Publication Date: 2025.10.29 SIEMENS MOBILITY GMBH
  • EP4640515A1 patent drawingFigure 1
  • EP4640515A1 patent drawingFigure 2~3
  • EP4640515A1 patent drawingFigure 4

AI summary

The invention comprises a method for determining the position of a track-guided vehicle (FZ). A vehicle-side sensor (SN) generates a measurement result during the vehicle's (FZ) travel, representing a track (GL) traversed by the vehicle (FZ). Based on this measurement result, the vehicle's (FZ's) current position on the track (GL) is determined by a computer. The measurement result includes a distance profile (AP), which describes a change (a) in the distance (a) of the sensor (SN) from the track superstructure (OB) comprising the track (GL) and its ballast, dependent on the distance traveled by the vehicle (FZ). Starting from a known reference position (RPOS), a relative positioning of the vehicle (FZ) is performed by the computer. A repeating pattern (MT) in the distance profile (AP), corresponding to predefined path segments, is detected and counted by the computer.To determine the position, the respective length (L) of the path segments to the reference position (RPOS) is added for each detected pattern (MT).