Chromasonic® Applied to the Rail Industry
Introduction
Chromasonic® provides an innovative way to monitor, in real time, the condition of running track and rolling stock wheels. It has the potential to offer total track condition monitoring and for rolling stock wheel, brake, wheel-bearing and suspension along with pantograph, on EMU systems, condition monitoring..
What does it do?
Chromasonic® monitors the sound signature that, for example, a wheel generates when in contact with the track. The analysis of the sound signature is carried out using specialized algorithms that have been developed specifically for this task. Normal methods of analysis, such as Fourier Transforms, are not suitable, as they are incapable of extracting the required data. Initial work was carried out on road vehicles where the tyre/road interface was monitored and proof of concept established. The potential for Chromasonic® in the Rail Industry was quickly recognized and a trial analysis on the acoustics generated at the wheel track interface has been conducted. This is looked at in detail below.
The Running Track
The graph below shows the analysis of acoustics taken over approximately 45 metres of track. The locomotive was traveling at approximately 160kph. The track was known to have a 'squats' and 'wheel-burns' along with other unidentified defects.
Items 1, 2 and 3 stand out. Item 2 is clearly audible to the human ear. Item 3 is not so distinct but it is clearly generating more data and covering several metres. Item 4 and 5 are identified to within ½ metre. Item 6 is very similar to item 3 and could be the earlier stages of item 3 while 7 and 8, the earlier stages of item 1. It can be seen that these defects are given to a resolution of under a metre. The graph below shows two of the Chromasonic parameters plotted together in the form of a polar diagram.
What is Chromasonic®?
Chromasonic® is the application of chromatic processing techniques (normally used for optical analysis) to acoustic signals. By processing the data in this manner it unlocks a wealth of previously hidden information. The diagram below shows a typical Fourier analysis (standard tool used to carry out acoustic analysis) of an acoustic signal.
It gives a lot of information on the signal content, power and dominance but it is difficult to extract meaning full information from this mass of data. Apply Chromasonic® processing, to the same data, and look at what is revealed
Items 1 (red square), 2 (blue diamond) and 3 (blue triangle) are shown. Notice that normal running is in the first quadrant. Items 1, 2 and 3 are outside this quadrant with the most complex, item 3, appearing in all four quadrants.
It is believed that the application of the Chromasonic® technology to the inspection of track will detect the following defects at normal running speed.
- Broken Rails
- Squats & Wheel burns
- False Flange Damage
- Spalling
- Severe Head checking etc
Rolling Stock
In a similar manner Chromasonic® can be applied to rolling stock to monitor wheels, wheel bearings and even the operation of the vehicle suspension system. Chromasonic® has the potential to offer a real time running wheel and bogie condition monitoring system
Static monitoring systems
So far we have discussed systems that are fitted to moving vehicles but it is possible to set up a static system that monitors passing traffic for running wheel defects.
Pantograph monitoring
Chromasonic® also has the potential to monitor pantograph wear and integrity and as this data is generated by the pantograph, being in contact with the overhead line, it enables Chromasonics to be used to monitor the condition of the power line.
A typical system
Unlike Fourier, Chromasonic® does not require a high performance computer. Once the parameters that are to be monitored are known the system can be run by a small microprocessor. So a simple system would consist of an acoustic sensor and a microprocessor. If such a system was to monitor bogies for wheel defects a number of such units would be used to supply data to a central microprocessor for evaluation, storage and alarm generation as required. A track evaluation unit would use more powerful computers to allow real time parameter changes and manipulation along with high density data storage.
Patents and Licenses
Chromasonic® is a registered trade mark. Chromasonic® is protected by world patents and licenses.
For further information please contact mailto:info@chromasonicsystems.comat Tekgenuity Ltd.
Top of Page
This document maintained bywebmaster@chromasonicsystems.com.
Material Copyright © 2003 - 2006
Tekgenuity Limited