Our data acquisition systems test power efficiency in transportation environments such as railway equipment monitoring and railway vehicle wheel development and quality control. Continue reading to learn more.
RAILWAY EQUIPMENT MONITORING
Development and Testing of Railway Vehicles
“Shaking” during railway vehicle movement is measured with the goal of making a more comfortable ride experience. A&D’s instruments perform well in noisy environments.
ISO2631 “Evaluation of human exposure to whole-body vibration” was published in 1974. In 1980, the Research Committee for Ride Quality Management Standards proposed ride quality standards. After taking into consideration the special characteristics of railways added the following independent improvements:
- Expanded ISO2631 and set the frequency band to 0.5 to 80 Hz.
- The logarithm of frequency corrected values (dB) is displayed against the acceleration to evaluate ride comfort at that magnitude.
- An average evaluation time of 1-5 minutes used for a ride quality evaluation.
- This standard applies generally to vertical and horizontal vibration.
The RA2300MKII data recorder can measure and analyze vibration data for the development of railway cars.
The RA2300MKII is equipped with a strain amplifier and can also fit a pressure sensor and displacement sensor.
Bolsterless Bogies and Ride Quality
Modern trains use air springs instead of bolsters to support weight between the train car and bogie due to the structural simplicity and reduced weight.
Bolsterless bogies are mainly used on local train lines due to their reduced effect on train tracks and superior maintainability. Compared to the traditional wheel truck, it is thought that bolsterless bogies perform poorly negotiating curves and crossing railway switches for an overall poor ride quality. The limit for curve negotiation performance for standing passengers is 0.8 m/s² and for sitting passengers is 0.9 m/s². Performance evaluation is made possible by measuring the performance of curve negotiation at the most severe vibration range which people feel, 4 Hz-12 Hz.
Did You Know?
The RA Series simultaneously measures voltage, current, control timing, vibration, rotation, pressure and more directly from sensors. Recorded data can be converted to .csv data or used with FFT analysis software.
RAILWAY VEHICLE WHEEL DEVELOPMENT AND QUALITY CONTROL
Testing Degree of Wear on Wheel Bearings and Rails
Measuring vibration and noise proves helpful for maintenance of bearings and wheel flanges in railway vehicles.
Repeated braking of railway vehicles causes wear leading to vibration and noise, both sources of reduced ride quality. Noise and vibration from wheel bearings during forward and reverse motion is measured and put into a database to determine the normal range of noise and vibration.
By comparing the measured values of noise and vibration with the database, the degree of wear of the wheel can be estimated.
RA2000A series digital oscillographic recorders connect directly to piezoelectric acceleration sensors, sound level meters or microphones and automatically print and record data as needed.
Rail-wheel Contact, Vibration and Noise Measurement System
The Current State of Frictional Force Adjustment
Conventional trains can run at about 60 mph on straight track and track that curves at a radius of 200m or less. Sections connected to sharply curved track require speeds less than 25 mph. The frictional force between the wheel and rail is the largest external force affecting movement characteristics of a railway vehicle.
On straight track a large frictional force is required for the driving force and braking force. However, when the frictional force becomes too great it can be a source of wheel flange and rail wear as well as noise on curved tracks. The friction coefficient can have large fluctuations over the day due to temperature and humidity. Maintaining an appropriate friction coefficient is important for track and train maintenance.
| Item | Model | Specifications |
|---|---|---|
| 2CH High Resolution Amp | AP11-101 | ±100mV ~ ±500V, A/D res 16bit 10ìs |
| 2CH High Speed Amp | AP11-103 | ±100mV ~ ±500V, A/D res 12bit 1ìs |
| Event Amp | AP11-105 | Input: 8 logic (Voltge/Contact) |
| 2CH TC-DC Amp | AP11-106A | Input: R • T • J • K • W (±100mV ~ ±50V) |
| 2CH AC Strain Amp | AP11-104A | Response Frequency: 2KHz |
| 2CH DC Strain Amp | AP11-110 | Response Frequency: 50KHz |
| 2CH Vibration/RMS Amp | AP11-109 | ±100mV ~ ±500V |
| F/V Converter | AP11-108 | Input: 1KHz ~ 10KHz |
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