PUPIL - Track Geometry Assessment Tool

PUPIL - Track Geometry Assessment Tool

PUPIL is an innovative track geometry assessment tool from Ricardo to help ensure safe and reliable track conditions are maintained on the world's railways.

By analysing geometric data captured by track measurement vehicles – including level, alignment, cant, twist, curve radius etc. – PUPIL can pinpoint locations on track sections where the track alignment is approaching, or is already exceeding, the safety limit.

PUPIL has been in use with the Dutch infrastructure manager, ProRail, since 2005 and plays a central role in upholding an outstanding safety record. For example, there has been no reports of derailments due to cyclic top on tracks that are assessed by PUPIL.

Furthermore, PUPIL ensures track accessibility by removing the need to impose avoidable speed restrictions.

Key benefits of PUPIL

  • Assessment of track geometric quality (level, alignment, cant, twist) by means of calculated vehicle reactions.
  • Enhanced safety performance across your network.
  • Reduced costs through preventive maintenance processes.
  • Increased track capacity by intelligence-informed advice on safe speeds limits.
  • Higher passenger satisfaction through improved ride comfort.
  • Compliance to EN 13848-1:2019.
  • Easy implementation.
PUPIL clearly points out the critical locations in the network, finding 70% more incidents than classic geometry evaluation. Sytse Bisschop, ProRail, February 2021
PUPIL clearly points out the critical locations in the network, finding 70% more incidents than classic geometry evaluation.

How PUPIL brings a new approach

The traditional method of analysing track geometry measurements is based on comparisons (for various cord lengths) of the maximum amplitude of each measuring signal with a speed dependent limit value.

The disadvantage is that it does not account for multiple defects on the same locations (and their accumulated impact), nor considers the influence of driving direction, or the effect of the shape of the defect on the dynamic loads of the track.

This makes it very dificult to preserve safety, plan efficient maintenance and avoid unnecessary speed restrictions.

PUPIL's data-driven model

PUPIL is a sophisticated software tool that simulates the dynamic interaction between the rolling stock and infrastructure (known as vehicle response analyses). It uses a digital twin of the vehicle types running on the network and the track condition data that was captured by measurement vehicles.

The tool examines a selection of vehicle types typical to the track section across a range of variables such as differing speeds and loading conditions. The track geometry is evaluated using calculated vehicle reactions and provides an assessment on track forces, Y/Q safety against derailment coefficient and car body accelerations.

The most critical configuration determines the safety factor relative to the limit values from euronorm EN14363.

The analyses are undertaken for speeds up to the local maximum speed. If a safety limit is exceeded, PUPIL provides the safe speed where all vehicle responses are still within the limits.

PUPIL can also provide analysis of the causes of exceedances to help plan corrective maintenance works. For example, its analysis can help establish if an exceedance on maximum lateral track force could have originated from an alignment defect 30 meters back.

PUPIL factoid

Left image (Safety): In this location, various defects exist on the same location. PUPIL includes the impact of these multiple defects on the vehicle reactions, highlighting occasions where safety limits have been exceeded.
Right image (Availability): In this location, the traditional track geometry assessment shows an exceeding of the safety limit value for the Level 15m parameter. However, PUPIL shows the vehicle reactions are within the safety limit value so no speed restriction is required.

Features of PUPIL

  • Assessment of track geometric quality (level, alignment, cant, twist) by means of calculated vehicle reactions.
  • Safety assessment based on EN14363 quantities: safety against derailment, track loading, car body accelerations.
  • Library of 20 vehicle types: passenger trains, locos, freight wagons.
  • Assessments include multiple defects on the same location and periodic defects (such as cyclic top).
  • Maintenance advice showing cause of safety exceedance.
  • Speed-dependant assessment. In cases of exceedance of safety limit it provides advice on safe speed (speed restriction).
  • Track specific assessment possible (e.g. freight high speed, local) thus reducing unnecessary maintenance actions.
  • Fast processing due to smart model reduction.
  • Compatible with standard output of measuring cars.

Contact us to find out if PUPIL can work for you

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