RFID Positioning 1

[jpolson]

I am looking for a way to position trucks under loadout spouts without guidance from the control room.

Each truck can have different loading location along its length relative to the ends of the truck, as well as a different height.

I am looking for a RFID system/sensor that can do linear positioning at a distance of about 10' and either give me analog or discrete outputs for position. There are few enough trucks moving through that I should be able to put a RFID tag on each truck without an issue. My goal would be to put in a simple stoplight for the drivers to be able to position themselves.

Does anyone know of a sensor?

Thanks,
Joel

Joel Olson

 

[jraef]

I have worked on possibly this exact application, mine was for asphalt trucks taking on loads from silos. On occasion the asphalt plant operator would not be able to see the exact truck position and would dump hot asphalt mix on the cab, almost killing a driver once. It was fraught with pitfalls however and I was forced to abandon the project. The major stumbling block was that the original concept was predicated on inexpensive "passive" tags that could be embedded in a bolt head on each trailer, since the leading edge of each trailer would be the only consistent position marker. Passive RFID systems, i.e. those that used tags that are powered and activated by a transceiver, have too limited of a range to work on a truck trailer. The tags needed to be what are called "active" tags, meaning they carry their own power source in the form of a battery (like toll transponders used on bridges and highways). My end user was unwilling to deal with the possibility of making the truck drivers have to worry about a dead battery in the tag. The trailers didn't always go with the same tractors, so who was going to keep track of battery replacement? The cost was too prohibitive as well, Active tags are a quantum leap more expensive and in that application, highly susceptible to damage.

If those are not insurmountable issues in your case, it should work fine.

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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[jpolson]

I actually just switched from the Asphalt/Aggregate/Concrete industry to Lime (CaO) production.

I think I can get the haulers to install the tags and maintain them since it is in their best interest to load quickly. Since we have a pretty limited group of haulers I can probably get it on each truck also.

I can not seem to find any active tags that have enough distance (10' ish) in them. Do you know of a manufacturer?

I can do it with laser transmitters and plc logic due to the opening in the truck being so small (about 1.5' dia hole), but i don't think the system will be as robust due to the dust in the environment and the reliance on multiple analog signals.

Thanks.

Joel Olson

 

[jraef]

Siemens RFID group has some smallish active tags that can go 15 feet (3m). I was originally using Balluff passive tags since they are the one's who came to me with the project but they don't have active tag options. We switched to proposing Siemens but the project died before we got very far with it.

Siemens Moby U series active tags.

The RF600 Series can go up to 30m, but they are very large and even more expensive.

"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
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