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Non-contact, non-powered RFID ... at 30 MPH covered in snow. — Parallax Forums

Non-contact, non-powered RFID ... at 30 MPH covered in snow.

stamptrolstamptrol Posts: 1,731
edited 2014-04-25 12:50 in General Discussion
Looking for ideas for our highway department.

On our highways, there are sections of guard-rail in various places which also have energy dissipating end units to increase survivability when a motorist hits them at speed. They work well and cost about $5K to replace after being hit.

We also get huge amounts of snow which can completely cover the guard rail ends for months at a time. Traditionally, the end of the guard rail is marked by a stake or other marker to warn the plow driver to either lift the wing plow or veer away in guarded sections. The stakes are easily damaged or otherwise obscured thus increasing the likelihood of the plow hitting the end of the guard rail. Hitting the ends can damage the wing plow or the plow truck or can force it into the other lane of traffic. It can also cause the driver to have to change his shorts!

The ideal solution is to put some kind of static RFID tag down the road ahead of the guard rail end so the driver is warned well in advance. The RFID detector would be on the truck. Realistically, the RFID tag has to be read as the truck goes by about 10 feet away at 30 - 40 MPH.(50 - 70 KPH). So far the RFID systems we've seen operate at much shorter distances. The tag would be down the road about 100 feet to give 2 or 3 secs to get the wing plow up.

Any thoughts on novel approaches or perhaps an RFID system that has long range?

Thanks,

Tom

Comments

  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2014-04-24 08:29
    Long Range RFID might have to not be passive to get the kind of results you want.

    Here is a UHF device which claims to read 1 to 25 meters, but through a snow bank is is getting a bit too much. Can you listen to a radio station while scuba diving?

    http://www.robotshop.com/en/long-range-adjustable-1m-25m-uhf-rfid-reader.html
  • stamptrolstamptrol Posts: 1,731
    edited 2014-04-24 09:14
    Thanks, Loopy

    That reader looks interesting. Haven't quite sorted out their reference to 902-928 MHz when the tags operate at 125Khz.

    Cheers,
  • PublisonPublison Posts: 12,366
    edited 2014-04-24 09:28
    I think he was looking at a system like what we have in the US called EZ-Pass

    Technology details/B][/URL][B][URL="http://en.wikipedia.org/w/index.php?title=E-ZPass&action=edit&section=3"]edit[/URL

    The E‑ZPass transponder works by listening for a signal broadcast by the reader stationed at the toll booth. This 915 MHz signal is sent at 500 kbit/s using the TDM (formerly IAG) protocol in 256‑bit packets. Transponders use active Type II read/write technology. In April 2013, Kapsch (purchasers of Mark IV Industries) made the protocol available to all interested parties royalty free in perpetuity and is also granting the right to sublicense the protocol.[8]

    This system looks like the receiving transponder needs to be powered, which would not work in your case.
  • PublisonPublison Posts: 12,366
    edited 2014-04-24 09:37
    Another thread that was talking about long range:

    http://forums.parallax.com/showthread.php/155199-Active-RFID-tag-small-light-and-long-range

    You'll have to supply the bee and battery. :)

    Jim
  • stamptrolstamptrol Posts: 1,731
    edited 2014-04-24 09:37
    Hi Publison,

    Yes we have the EZ-Pass here as well for toll control on bridges and hiways.

    But, you're quite right that both ends are powered.

    Cheers,
  • vanmunchvanmunch Posts: 568
    edited 2014-04-24 10:48
    What about marking the GPS locations for each one and have them loaded into the GPS unit that I'm guessing they're using already? If they don't have a GPS unit you could probably make an app that runs on a smart phone. Just have it play a tone when they get close so that the driver has time to raise/move the blade.
  • kwinnkwinn Posts: 8,697
    edited 2014-04-24 11:59
    The GPS approach sounds like the most practical approach as long as the accuracy is adequate. The only RFID approach that I can see being practical is a large coil (~4-6' Diam.) and circuitry embedded in the road and a read coil on the plow. Sort of an oversized RFID system where the tag is in the roadway and the RFID reader is on the bottom of the plow.
  • stamptrolstamptrol Posts: 1,731
    edited 2014-04-24 12:02
    GPS might be a viable option. The resolution might overlap for guard rails on either side of the roadway, but that might be better than the present situation.

    Cheers,
  • SRLMSRLM Posts: 5,045
    edited 2014-04-24 13:12
    stamptrol wrote: »
    GPS might be a viable option. The resolution might overlap for guard rails on either side of the roadway, but that might be better than the present situation.

    Cheers,

    You could use your GPS based heading to determine the side of the road that you're on. Guard would have 3 values: lat, long, and heading. You have to be +- for each of those before it warns you.

    Edit: I get it. You're talking about a divided highway, where rails may be on either my left or my right side. Correct? In which case the heading option wouldn't work. But you could just add an extra value to each point: left side of road, right side of road.
  • FranklinFranklin Posts: 4,747
    edited 2014-04-24 13:37
    There is this. https://www.youtube.com/watch?v=xCMlbOUVdPA not sure it is still a viable option though.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2014-04-24 14:55
    The nice thing about the GPS approach is that it won't require any onsite tag maintenance and its associated costs.

    -Phil
  • W9GFOW9GFO Posts: 4,010
    edited 2014-04-24 16:11
    stamptrol wrote: »
    Hi Publison,

    Yes we have the EZ-Pass here as well for toll control on bridges and hiways.

    But, you're quite right that both ends are powered.

    Cheers,

    The RFID tags that we use in WA (Good to Go) for toll collection are not powered.
  • stamptrolstamptrol Posts: 1,731
    edited 2014-04-25 12:50
    W9GFO wrote: »
    The RFID tags that we use in WA (Good to Go) for toll collection are not powered.

    You don't happen to know the manufacturer of the Washington system, do you?

    Thanks,
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