What is railway monitoring?
Railway infrastructures and systems play a significant role in highly efficient transportation, which is needed to meet the increasing demand in transporting both cargo and passengers. These structures are extremely susceptible to degradation and failure, due to extreme environmental situations under severe loading and working conditions, caused by the traffic growth, heavier axles and vehicles and increase in speed. Innovative sensing technologies based on fiber optic sensors have been utilized for structural health monitoring (SHM), the real time measurement and long-term assessment of structural properties.
A fiber optic structural health monitoring system allows for early-stage damage detection and characterization, which leads to timely remediation and prevention of disastrous failure. The use of fiber optic sensors for structural health monitoring is in great demand due to their inherent distinctive advantages, such as small size, light weight, immunity to electromagnetic systems. Furthermore, the geometry and versatility of these sensors allow them to be integrated into these structures for real time monitoring for sensing critical components of both railways and trains over long distances (up to 20 km).
A fiber optic monitoring system can be used for operation monitoring (train speed and components) and structural health monitoring (rails, sleepers, ballast, bridges, tunnels, rail security etc.) of railway structures. Such a system is being widely used due to its ability to measure physical quantities (such as strains, temperature, displacements, cracks etc.) continuously distributed over the full length of the fiber.
Fiber optic accelerometers are used for track condition monitoring, identifying wheel defects, and detecting train presence and direction. When combining these applications with artificial intelligence potential railway accidents and catastrophic train derailments can be prevented.
For this project fiber optic accelerometers are fixed at the T-beam web of the railway and measure the acceleration(g). The results can be seen below.
When looking at the graph below, a high acceleration peak is seen at 323 sec. This indicates a possible wheel defection.
Some of the many advantages:
Fiber optics is immune to Electro-Magnetic Interference (EMI) and is therefore well suited to measure various parameters of a railroad track.
A robust fiber optic accelerometer can measure the impact shocks of the wheels on the track and detects potential damage from a defect wheel
Fiber optic sensors are easily installed on the track and have unprecedented reliability. Models predict maintenance free operation for years
The Somni fiber optic sensing design can be easily expanded to cover kilometres of track and additional sensors can easily be added to increase insight into specific parts of the track