Principal Investigator/Researcher

Ni Attoh-Okine and Ahmed Lasisi (student)

Project Description

Rail geometry defects constitute a major cause of accidents in the United States. Geometry related accidents are often very severe and damaging. While rail geometry-caused derailments continue to increase according to Federal Railroad Administration (FRA) safety data, track quality analysis remains effectively unchanged. The use of TQI or track quality index takes a narrow view of track assessment by focusing on quality without considering safety. The bipartite analysis of track quality and safety results into two maintenance types: routine and corrective maintenance respectively. This report shows how to create a hybrid index that combines both element of safety and geometry quality to predict only one maintenance regime based on track condition. It is an initial step towards the big picture of creating indices that will be iterated based on maintenance savings and defect probability thresholds. This study employs a linear and nonlinear dimension reduction technique that expresses the probability distribution of observations based on the similarity or dissimilarity in their embedded space whilst also maximizing the variance in data. This study found application in principal component analysis (PCA) and T-Stochastic neighbor embedding (TSNE) for separating geometry defects from higher dimensional space to lower dimensions. Results show that while both techniques effectively reduces track geometry data, PCA yields a potential defect probability threshold in spite of TSNE being a better geometry defect predictor.

Implementation of Research Outcomes

This study employs a linear and nonlinear dimension reduction technique that expresses the probability distribution of observations based on the similarity or dissimilarity in their embedded space whilst also maximizing the variance in data.

Correlogram of Geometry Parameters

Impacts/Benefits of Implementation

This study will develop a technique to process the data effectively.

Final Report

Outputs:

1 journal publication and 1 dissertation

  • Ahmed Lasisi, Nii Attoh-Okine, Hybrid rail track quality analysis using nonlinear dimension reduction technique with machine learning, Canadian Journal of Civil Engineering, Volume 48, Issue 12, Pages 1713-1723, 2021
  • Ahmed Lasisi, Dimension Reduction Techniques in Track Geometry Quality Analysis and Safety, Dissertation in the Civil Engineering at the University of Delaware, 2019