CBTC Junction Route Reservation With Safety Distance Checks

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Solution Overview

Problem

Existing CBTC systems face challenges as rail vehicles can come to a standstill near junctions, leading to potential collisions and conflicts, particularly at intersections.

Innovation Solution

A computer-implemented method and system that utilize model data to maintain a safety distance at junctions, ensuring rail vehicles do not stop within the junction area by dimensioning routes to allow braking within the safety distance, and implementing a route conflict check to prevent collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If CBTC systems allow trains to operate at varying distances to enable efficient use of the rail network, then productivity is improved, but the risk of collision at junctions increases because rail vehicles can come to a standstill within the vicinity of a junction

Engineering Contradiction:
Improveefficient use of rail networkVSAvoidcollision risk at junctions
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system performs preliminary checks before allowing a route to be set. The CBTC track module checks whether the desired route would cause the rail vehicle to stop within the safety distance of a junction. By performing this check in advance, the system prevents potential collisions before they can occur, while still allowing efficient train operation throughout the network.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary safety distance zone around junctions that acts as a buffer. This virtual safety distance serves as an intermediary protection layer between moving trains and potential collision hazards at junctions. The CBTC track module uses this intermediary zone to determine whether a desired route is safe, allowing efficient network operation while preventing stops within critical junction areas.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If rail vehicles are allowed to stop anywhere on the network for operational flexibility, then ease of operation is improved, but safety is worsened due to potential conflicts at junctions

Engineering Contradiction:
Improveoperational flexibilityVSAvoidsafety at junctions
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system applies a local restriction only in the immediate vicinity of junctions by defining a safety distance around each junction. This local quality approach allows rail vehicles to stop flexibly anywhere on the network except within these localized safety zones. The CBTC track module checks the desired route against these local safety constraints, maintaining operational flexibility throughout the network while ensuring safety at critical junction areas.

Inventive Principle:
Principle #3Local quality

3Reliability

If the route dimension is increased to ensure trains can brake within the route length, then safety is improved, but the route availability and network efficiency may be reduced

Engineering Contradiction:
Improvebraking safetyVSAvoidroute availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs preliminary validation to ensure that before a route is set, the rail vehicle can safely brake within the route length. The CBTC track module checks whether the desired route provides sufficient distance for braking before allowing the route to be established. This preliminary safety verification ensures braking safety is maintained while routes are optimized for network efficiency.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The safety distance around junctions is dynamically determined based on the specific characteristics of each junction and the operational context. Rather than using a fixed, overly conservative route length for all situations, the system dynamically calculates appropriate safety margins. This allows routes to be as short as possible while still ensuring safe braking distances, thereby maintaining both safety and network efficiency.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4071028B1Preventing collision of a railway vehicle at a junction in a cbtc system
Publication Date: 2026.02.11 STADLER RAIL
  • EP4071028B1 patent drawingFigure 1~2
  • EP4071028B1 patent drawingFigure 3
  • EP4071028B1 patent drawingFigure 4

AI summary

The invention relates to a computer-implemented method for preventing a collision of a rail vehicle at a junction. The method comprises the following steps: providing model data of a railway network, wherein the model data of the railway network comprises the data of a first edge and a second edge as well as a junction and, in particular, a safety distance (5), wherein the first edge and the second edge are connected by the junction and the safety distance (5) is, in particular, located on an edge, wherein, in particular, the safety distance (5) is adjacent to or surrounds the junction; receiving a request for the reservation of a route for a rail vehicle on a CBTC control module (12); determining a desired route (10) for the rail vehicle, wherein the route is located on at least one edge.and wherein the route is located in front of the rail vehicle in the direction of travel and is dimensioned at least such that the rail vehicle can be braked within the length of the route, in particular braked substantially without jerking, sending the data of the desired route (10) to a CBTC track module (13) to check whether an end of the desired route (10) lies within a safety distance (5) of a junction.