Monitoring train wheels and bearings to improve operations
The wheels and bearings of trains have a lot to put up with, and can suffer many damages. What exactly are these and what are the consequences for the availability of the train wagons? Lithuanian company Viezo develops a solution based on sensors to get ahead of the problems occurring.
To ensure a smooth journey, good working train wheels are of the utmost importance. An important element of this are the axle bearings, which connect the train wheel to the non-rotating parts of the vehicle. They have to transmit the weight of the train wagon to the wheelsets to provide a smooth movement of the wheels.
As bearings are an essential part, it is important to know when there are faults. When a vehicle is scheduled for maintenance, or due for overhaul, knowledge of the damage and severity is beneficial. This can result in fewer operational problems, optimising the fleet availability, and reduce the overall losses and interruption expenses, explains Vytautas Jaskevicius, co-owner of Viezo.
One of the problems that can also occur with train wheels is a flat spot. This occurs when a rail vehicle’s wheelset is dragged along the rail after the wheel has stopped rotating. Flat spots are usually caused by use of the emergency brake, or slip and slide conditions that cause wheels to lock up while the train is still moving.
Solution with sensors
To help plan maintenance and avoid bigger failures of wheels, Viezo develops sensor-based solutions. This can prolong the life of wheels and bearings and save money, says Jaskevicius. The solution, called Powerail, consists of 8 sensors and one gateway. The sensors are attached one the closest point to the bearing, and monitor the axle bearing health, detect flat spots on the wheels, and locate the wagon via GPS. “The solution can eliminate check ups at a set intervals, because the solution allows to monitor those parts without any need of human interaction, which saves money in return”, says Jaskevicius.
The end goal is to do predictive maintenance, where the sensors can tell what is deteriorating and when an earlier maintenance check is needed. “The first installation will be done at the end of Q1 of 2022, and additional predictive maintenance functions follow as more data is gathered.”
The sensors work mainly by measuring vibrations. Each sensor shares a complete frequency spectrogram to the gateway. The gateway is an autonomous wireless device, powered by a solar panel. It collects all measurement data from the sensors via a Bluetooth low energy (BLE) network immediately after the measurement is taken. It locates the wagon using GPS (once per hour) and shares the complete data package to the cloud via widely available LTE connectivity.
The temperature is also measured as an additional data point. When the axle bearing is overheating, it usually means there has been a problem for a while, so the temperature data can confirm there is no overheating. For now, this type of sensor is specialised for freight wagons, and can be pre-ordered by wagon owners. Eventually, the solution will also be made fit for passenger trains.
Testing in Lithuania
At this moment, the sensors are moving around Lithuania, being attached to wheels of trains of Lithuanian Railways LTG. In this way, the connectivity and working of the sensors are tested, which have good results according to Jaskevicius. Also, large amounts of data are gathered to further develop the software and capabilities.
The core know-how of Viezo is a patent-pending vibration energy harvesting technology, which converts vibrations into electricity to power sensors and is embedded in the hardware of Powerail to make the solution maintenance-free for at least 10 years.
In about two years, the company plans to offer a broad solution for many purposes, including brake monitoring. It will be the full package, with the software to interpret the date provided when needed. Viezo is now accepting pre-orders for the Powerail solution, for which installation will also be offered. Vehicles do not need to go to the repair shop, as they can be easily installed even in the field.
Watch a video with more information about the Powerail solution below: