eRDM
rail diagnostic system
Dynamic wheel load measurement at operating speed, for safe rail traffic and for the prevention of derailment
>> eRDM
Sensor network on the open track
Installed by Navipro (developed by evopro Innovation), the eRDM system is a digital sensor network built into the railway track, recording a high-resolution load signal from every single wheel of the trains passing at operating speed. The measurement is carried out with strain-gauge sensors, each of which works with its own digital signal processor, so the measuring point remains immune to track vibrations and to electromagnetic noise.
-
01
Real-time detection of potential risks
Preventing failures and derailments: the system detects in real time wagons that are overloaded or loaded asymmetrically, axle breakage, bogie suspension faults and wheel defects, then alerts traffic control before the faulty vehicle can cause any damage.
-
02
Three uses at once
The operator can set several mutually independent threshold values for the warning signals, so the same measurement serves traffic safety supervision, the planning of predictive maintenance and billing based on the actual load carried.
-
03
Weighbridge alternative
(without stopping)The static mass of wagons can be determined with high accuracy from dynamic wheel load measurement, making the eRDM a cost-effective alternative to the conventional weighbridge, without stopping the train.
>> Focus areas
Four derailment risks
Asymmetric load condition of wagons
Uneven left-right, front-rear or within-bogie loading of the wagon, or a load that slipped - overloading in itself already poses a risk of derailment, while also damaging both the track and the vehicle itself.
Uneven load on the wheels
An extreme load difference within a single axle may indicate axle breakage. A train running with a broken axle is one of the most dangerous conditions in rail traffic, so its detection is of special importance.
Uneven load across the two bogies
Fatigue of the bogie springs causes uneven load distribution, which also poses a derailment risk. With continuous monitoring of vehicles, the fault becomes visible well before the alarm level is reached.
Wheel defects
An oval, eccentric, flat or polygon-worn wheel puts periodic extra load on the track and on the vehicle's running gear. The system records a high-resolution waveform from every wheel and analyses the geometry of the wheel from it.
>> System design
From measuring point to dispatcher
Measuring section
The measuring section comprises twelve pairs of load measuring modules and two pairs of train detection trigger modules, mounted on the rail web and linked by a high-speed digital cable. A section is 34.2 metres long and can be fitted to the existing track without a separate substructure. Measurement works in both directions.
On-site data acquisition
Signals from the measuring modules arrive at a data acquisition and communication unit by the track, which runs on a battery-backed uninterruptible power supply with a mobile network link. Its low consumption means it can even be powered from the signalling network. Maintenance staff access it on site via Ethernet or Wi-Fi.
Central diagnostics
Data from several measuring points arrives at a single redundant diagnostic server, which stores, processes and analyses the measurements, then sends alarms to traffic control workstations. The system has a web interface that can also be integrated into the infrastructure manager's own IT system.
The system runs regular self-checks and self-tests: it compares measurement results with the known technical data of vehicles stored in a database, so the measuring point's accuracy stays traceable without human intervention. (For certification, wagons weighed on a high-precision scale can be used.)
>> Technical data
Measurement specs
- Axle load
- 10-400 kN (approx. 1-40 t)
- Accuracy (per wagon)
- ±2% (with TÜV certificate)
- Speed range
- 5-160 km/h
- Speed measurement accuracy
- 1%
- Measuring section length
- 34.2 m (at 600 mm sleeper spacing)
- Rail type (UIC)
- 48, 49, 54, 60
- Wheel diameter
- 350-1250 mm
- Minimum axle spacing
- 700 mm
- Operating temperature
- -25 °C / +60 °C
- Protection
- IP67
- Power supply
- 230 (190-250) V, 50/75 Hz
- Power consumption
- max. 150 VA during measurement
- In a power cut
- 20 minutes runtime (12 Ah battery)
- Service life, MTBF
- min. 10 years, 10,000 hours
The system meets the European standard governing measurement of vertical forces on wheels and wheelsets. Traffic control handles measuring point alarms under the infrastructure manager's procedures.
>> Benefits
3 reasons to choose eRDM
The system detects and reports the load distribution of a passing train and automatically recognises vehicles posing an accident risk. Early diagnosis of damaged wheels and bogies can prevent derailments and serious technical accidents. According to the D-RAIL research supported by the European Union, at least 20% of derailments can be prevented with dynamic wheel load measurement.
Predictive maintenance based on the latest measurement data can reduce maintenance costs and increase the utilisation of the rail vehicles. The system has low power consumption, can even be powered from the overhead line, and also helps to protect the condition of the track by identifying in good time the vehicles that are in need of repair.
Early detection of various wheel defects (wheel flats - oval, eccentric, flat or polygon-worn wheels) can reduce the noise and vibration emissions of the vehicle fleet, which brings a noticeable improvement especially along railway lines passing through inhabited areas.
>> Awards and recognition
Award-winning
engineering
- Hungarian Product Prize (2014)
- 24th Hungarian Innovation Prize (2015)
- Special Prize of the Hungarian Electrotechnical Association
>> More rail solutions