 Joined: 12/01/2002(UTC) Posts: 2,578 Location: Sweden
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In the "Braking digitally" article under "Operation related", Lars Westerlind writes, as one (rejected) possibility:
"Using a computer which keeps track of every loco on the layout, and/or expensive train recognition equipment;"
My question is now: Does this "expensive train recognition equipment" exist as a commercial product, or is it just a hypothetical idea ?
I'm trying to build train recognition equipment (i.e. equipment that can identify which train that passes over a sensor). If commercial such systems exist, I would be interested in information about them, to be able to compare with my own system.
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Joined: 25/07/2001(UTC)
Posts: 11,165
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It is also known as "transponding", and eg the Helmo system can be seen at http://www.helmo.de . Digitrax also has similar stuff. You could also implement train recognition by eg bar codes under the loks/cars and scanners to read them... An example of commercial train control software that supports Helmo and Digitrax is the Railroad & Co by Juergen Freiwald - http://www.railroadandco.com . |
Juhan - "Webmaster", at your service...
He who asks a question is a fool for five minutes. He who does not ask a question remains a fool forever. [Old Chinese Proverb] |
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Joined: 12/01/2002(UTC) Posts: 2,578 Location: Sweden
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Thanks !
The Helmo system uses RFID (Radio Frequency IDentification) technology. This system is capable of detecting that a certain vehicle passes over the sensor. I have thought of using RFID, but I found it too difficult to build as a hobby project, and the commercial equipment I found was far too expensive. Very interesting to see that there is actually a commercial system based on RFID for model railroads!
The Digitrax system is not so interesting. It sends back the information via the track, and can therefore not give the exact position of the vehicle.
Barcodes could be used of cause, but they have a lot of drawbacks. Barcode readers are rather expensive, and probably not so reliable.
I have decided to go with IR communication, with transmitters in the locos and receivers in the track. The investigations so far indicate that this will be very reliable, and not very expensive. There is one big drawback with IR compared to the Helmo system, and that is that the transmitter requires power. With the Helmo system you can easily put one transponder on every vehicle.
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Joined: 12/01/2002(UTC) Posts: 2,578 Location: Sweden
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Does anyone know approximate prices for the Helmo stuff, and where you can buy it ? I have searched the web for shops that sell it but I haven't found any. The only possibility seems to be directly from Helmo.
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Joined: 30/08/2002(UTC) Posts: 1,288
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Initially, I also had the idea of using a train recognition equipment. However, by using software like Railroad & Co http://www.railroadandco.com etc. that keeps track of the train location, at least I see no reason for investing in such equipment. <img src=icon_smile_cool.gif border=0 align=middle> Peter |
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 Joined: 13/05/2002(UTC) Posts: 676
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Hi Perz, Do you happen to have an update on the Helmo transponders? Did you order the catalog and price list? I found their web site http://www.helmo.de/ extremely interesting. They appear to be in a transition phase, with many types of products announced, which makes it difficult to understand what would be the best equipment to select. |
*Bart |
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Joined: 12/01/2002(UTC) Posts: 2,578 Location: Sweden
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Hello Bart,
No, I didn't follow up on this. I'm working on my own system based on infrared transmission, and I was just interested in comparing. I have some general knowledge of the RFID technology ( the technology used by Helmo). I have thought of using that technology myself, but I don't think it is possible to make the readers cheap enough to be a good alternative for train traffic control, at least not without a lot of engineering investments. The tags in the locos/waggons can be made very cheap however. I therefore think the main application for the Helmo system is automated switching operations, not train control.
With my own IR based system, it is the opposite. The detectors are cheap, and you can have a lot of them, but the transmitters have a limited number of codes, need power and are complicated to install in the rolling stock.
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Joined: 13/05/2002(UTC) Posts: 676
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Perz, You're right. I all depends on the purpose of the system. I would like to use it for automatic shunting -- distributing freight cars using a hump. For that, one detector will do, but it requires many unpowered tags in the waggons. Back in the 1960s, I have experimented with a light source next to a photo cell in the track, and an array of reflecting pads under each waggon. The number of pads generated a sequence of pulses, identifying the waggon. (Too bad I was not smart enough to go on and invent [and patent] what would become the barcode <img src=icon_smile_big.gif border=0 align=middle>). Therefore, I still have a soft spot for barcode detection, but I agree with your earlier remark that it has a lot of drawbacks. There appears to be a barcode train ID supplier, www.holtermann-modellbahntechnik.de , but I'm pessimistic about the technical drawbacks. BTW, Holtermann have also announced an IR system! |
*Bart |
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Joined: 12/01/2002(UTC) Posts: 2,578 Location: Sweden
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For automatic shunting, I think a system based on RFID, like the Helmo system, is the best. It is interesting to see the Holtermann description of their IR based system. It seems to be very close to what I have built myself. It's a pity they don't give more information about it, but maybe it is too early yet.
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