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Power Rail Health Monitoring of Mass Rapid Transit (MRT) Lines Through Radio Frequency Induction Technology

Technology Overview

This technology offer is a patented radio frequency (RF) inductive coupling technology that measures the quality of electrical contact between moving parts. By integrating this technology with a MRT train, the moving train doubles up as an inspection vehicle that monitors the condition of the power rail of the MRT network in real-time. It detects early signs of power rail defects for preventive measures before the defects deteriorate further and lead to unexpected MRT service interruptions. The potential users are MRT line operators and train manufacturers. The hardware system has been developed and tested on MRT lines and we are looking for partners who are strong in data analytics to develop an efficient defect classification algorithm.

Technology Features, Specifications and Advantages

Modern MRT trains are powered by high voltage power rails that run in parallel with the railway tracks. Any power rail defects, if not detected early, can disrupt the power supply to the train and cause it to stall. Existing technologies for power rail inspection are based on laser, linear variable displacement transducer (LVDT) and computer vision. These technologies measure the relative geometrical parameters of the power rail as an indicator of the defective power rail, such as sagging, misalignment and missing parts.

The proposed technology measures the electrical contact quality of the power rail and the moving train, which is an “electrical parameter” that directly reflects the health of the power rail that feeds the electricity to the train. Using a related electrical parameter to reflects the condition of the power rail eliminates defects that cannot be easily detected by the existing technologies.

A prototype based on the proposed technology has been designed and tested for the stringent railway electromagnetic compatibility (EMC) and vibration standards. The prototype has been trialed on SMRT North-South and East West Lines for three months and has shown good correlation with the data collected from SMRT’s existing LVDT system.

Potential Applications

This primary application area is real-time condition monitoring of the power rail of the MRT network for preventive maintenance purpose. It can also be used to predict the life cycle of the power rail for assets management and planning.

The proposed technology can be further extended to condition monitoring of mission-critical electrical assets, such as high voltage transformers, switchgears and induction motors, to detect early signs of internal faults. If any early signs of defects of these assets are not detected early, they can lead to irreversible damages of the assets and hence costly replacement. The global condition monitoring systems market was reported as US$458.7 million in 2019 and it expects to grow at a rate of 5.3% yearly and will reach US$ 563.1 million by 2025.

Customer Benefit

This technology offer has the following benefits :

  • Prevention of major MRT service interruptions that have both direct economic, social, and political impacts.
  • Prevention of mission-critical high voltage (HV) electrical infrastructures from irreversible damages and avoid costly replacement.
  • Preventive maintenance to replace periodic manual inspection and maintenance for higher productivity and significant cost savings.
Contact Person

Wye Boon Loh


NTU - NTUitive >> ICT, AgriTech and FoodTech

Technology Category

  • Electronics
  • Sensors & Instrumentation
  • Infocomm
  • Big Data, Data Analytics, Data Mining & Data Visualisation, Data Processing

Technology Readiness Level


Power Rail Health Monitoring of Mass Rapid Transit (MRT) Lines Through Radio Frequency Induction Technology