Extensive technology for a complete Dynotrain measuring train
The vehicles under test within the scope of the Dynotrain project included a locomotive, three freight cars and one passenger car, complemented by the DB Netz AG Railab for
recording of the track geometry and by a measuring car accommodating the central measurement technology components and the measurement team. These cars were coupled with six additional cars to ensure correct braking behavior. This train configuration - complemented by a traction locomotive for the respective power networks in Switzerland, France and Italy - was
up to 400 m long.
Ten of the above described measuring wheelsets were used in the five measuring cars.
Over 300 physical channels needed to be recorded and, because of partly differing filter configurations, about
1,000 measurement channels needed to be saved together with all acceleration and displacement signals, track geometry signals and additional information about temperature, air pressure and humidity, GPS data and braking pressure. This places tremendous demands on the measurement system, taking into account the sampling rates of up to 1,200 Hz. In the process, part of the CPU load is already being swapped out. Each of the five measuring wheelset computers
computes the total of 48 strain gage full bridge signals provided by two measuring wheelsets
up to 1,000 times per second providing the wheel-rail forces that are
digitally transferred to the MGC amplifier. The complex
fiber-optic network of insularly installed MGC amplifiers and measuring wheelset computers as well as powerful mainframe computers and memories has been
specifically designed to withstand such loads. Measurement-data statistics are determined online and can be visualized and subsequently analyzed immediately upon completion of the measurement run. Online recorders visualize part of the raw data to enable the engineer on board to monitor limit values in critical situations. Far more than
3,000 GByte of measurement data have been acquired and saved over about four weeks of measurement runs. They are presently available to the project partners via a fast server connection.
A total of seven MGC amplifier systems was used; they are outstanding for their
high flexibility and ease of use. The MGCplus system is suited to many different measurement tasks thanks to its
modular structure. Corresponding modules are available from stock for virtually all common transducer types. The Transducer Electronic Data Sheet (TEDS) enables a measurement system to be
quickly and easily configured. The amplifiers
automatically identify the transducers that are connected; no complex manual configuration is required.
Another advantage of the MGCplus system was of importance to its use in the DB Systemtechnik measuring train:
All channels of a measurement system can be recorded absolutely synchronously. This is particularly important in this application, because all measured quantities need to be correlated in subsequent analyses. The stage of data analysis has now begun and will require ongoing commitment on the part of the project partners for two to three years. The data obtained from this project will form a
basis for vehicle development, design and approval as well as subsequent research projects for many years.