LEU Signal Current Sampling for Energy-Efficient ETCS

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Solution Overview

Problem

Modern train protection systems require significant infrastructure changes and high energy consumption when upgrading to ETCS, particularly in energy management for self-sufficient mini-LEUs controlling signal balises, due to the need for frequent sampling of AC signal currents which is energy-intensive.

Innovation Solution

A method for determining signal aspects using an electronic control unit on the track side that samples signal currents with a burst of samplings, where the time interval between samples is a quarter of the signal current period, allowing for energy-efficient detection and transmission of signal aspects with minimal additional installation effort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If frequent sampling of AC signal current is performed to reliably detect signal aspects, then measurement precision is improved, but energy consumption increases

Engineering Contradiction:
Improvesignal current detection accuracyVSAvoidenergy consumption of mini-LEU
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent applies periodic action by sampling the AC signal current at specific intervals synchronized with the signal period. Instead of continuous sampling, the system performs discrete sampling bursts at predetermined times within each signal period, reducing energy consumption while maintaining detection accuracy. The sampling occurs at multiple phases within the AC cycle to capture sufficient information about the signal aspect.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent implements partial action by performing a limited number of samplings (e.g., 2-5 samples) within each signal period rather than exhaustive continuous sampling. This partial sampling approach provides sufficient information to determine signal aspects while significantly reducing the energy burden on the battery-powered mini-LEU device.

Inventive Principle:
Principle #16Partial or excessive action

2Device complexity

If self-sufficient mini-LEUs are deployed without electrical power supply infrastructure, then device complexity and installation effort are reduced, but energy management becomes more difficult

Engineering Contradiction:
Improveinstallation infrastructure requirementsVSAvoidenergy management complexity
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The mini-LEU employs periodic sampling bursts synchronized with the AC signal period, allowing the device to remain in low-power states between measurements. This periodic operation pattern enables battery-powered operation without continuous power supply infrastructure, as the device only activates briefly to sample signals and then returns to sleep mode.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system achieves self-service by using the existing AC signal current from the railway infrastructure to power and operate the mini-LEU during sampling periods. The device harvests energy from the signal environment itself, eliminating the need for separate power supply infrastructure while maintaining operational capability.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If AC signal current is sampled at twice the frequency to account for rectification and phase cutting, then measurement precision is improved, but energy consumption increases

Engineering Contradiction:
Improvesignal current sampling accuracyVSAvoidsampling energy cost
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic sampling within each AC signal period, taking multiple samples at different phases to account for rectification and phase-cutting effects. By concentrating sampling efforts into specific time windows rather than continuous sampling, the system achieves the necessary measurement precision while minimizing energy consumption during the sampling bursts.

Inventive Principle:
Principle #19Periodic action

Data Source

PatentEP3012173B1Method for determining a signal aspect issued by a signal box
Publication Date: 2017.07.19 SIEMENS SCHWEIZ AG
  • EP3012173B1 patent drawingFigure 1

AI summary

The present invention is based on the objective of providing a method for determining a signal aspect issued by a signal box using a LEU, which also performs the sampling process of the signal current in the lamp circuit in a particularly energy-saving manner.This problem is solved according to the invention by a method for determining a signal aspect issued by a signal box, which can be transmitted to a rail vehicle by means of a point-type data transmission device arranged on the trackside, wherein: a) the signal aspect is issued for a number of signal lamps and is provided in the form of a signal current of known frequency per lamp circuit in each of the lamp circuits required for displaying the signal aspect; b) the point-type data transmission device is operated by an electronic control unit arranged on the trackside; and c) the signal current in each of the lamp circuits is sampled by the electronic control unit by means of a sampling burst with a number of samples, wherein the time interval of two successive samples within a sampling burst corresponds to a predefinable fraction of the wavelength of the signal current.In this way, it is possible to determine the signal aspect present in the signal circuits with minimal additional installation effort using the electronic control unit (LEU) and to prepare a telegram corresponding to this signal aspect for transmission via the point-type data transmission unit. This method is also characterized by its robustness and low energy consumption.